Refactor code

Merge branch 'master' into Managed-Client-V2
Merge master
2026-10-15 17:00:03 +08:00 · 2023-01-19 20:53:57 +01:00 · 2023-01-19 20:50:34 +01:00 · 2022-12-28 14:15:27 +01:00 · 2022-12-28 14:15:21 +01:00 · 2022-11-13 18:41:28 +01:00
160 changed files with 3082 additions and 4093 deletions
@@ -1,3 +1,8 @@
-* [Server] Fixed not working _UpdateRetainedMessageAsync_ public api (#1858, thanks to @kimdiego2098).
-* [Client] Added support for custom CA chain validation (#1851, thanks to @rido-min).
-* [Client] Fixed handling of unobserved tasks exceptions (#1871).
+* [Core] Added net7.0 builds (#1635, thanks to @YAJeff).
+* [Client] Added support for passing MQTT v5 options (User properties etc.) for disconnects.
+* [Client] An internal exception is no longer caught silently when calling _DisconnectAsync_ to indicate that the disconnect is not clean (BREAKING CHANGE).
+* [Client] MQTTv5 features are now checked and an exception is thrown if they are used when using protocol version 3.1.1 and lower. These checks can be disabled in client options. (BREAKING CHANGE!).
+* [Server] Exposed MQTT v5 sent properties from the affected client in _ClientDisconnectedAsync_ event.
+* [Server] Fixed wrong client ID passed to _InterceptingUnsubscriptionEventArgs_ (#1631, thanks to @ghord). 
+* [Server] Exposed socket settings for TCP keep alive in TCP options (#1544).
+* [Server] Exposed server session items at server level and allow custom session items for injected application messages (#1638).
@@ -3,7 +3,7 @@ name: CI
 on: [push, pull_request]

 env:
-  VERSION: "4.3.2.${{github.run_number}}"
+  VERSION: "4.2.0.${{github.run_number}}"

 jobs:
  build:
@@ -54,7 +54,7 @@ jobs:
        uses: darenm/Setup-VSTest@v1

      - name: Core Tests
-        run: vstest.console.exe Source\MQTTnet.Tests\bin\Release\net7.0\MQTTnet.Tests.dll
+        run: vstest.console.exe Source\MQTTnet.Tests\bin\Release\net6.0\MQTTnet.Tests.dll

      - name: ASP.NET Tests
        run: vstest.console.exe Source\MQTTnet.AspNetCore.Tests\bin\Release\netcoreapp3.1\MQTTnet.AspNetCore.Tests.dll
@@ -1,4 +1,67 @@
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+	<s:String x:Key="/Default/CodeStyle/CodeCleanup/Profiles/=MQTTnet/@EntryIndexedValue">&lt;?xml version="1.0" encoding="utf-16"?&gt;&lt;Profile name="MQTTnet"&gt;&lt;CppReformatCode&gt;True&lt;/CppReformatCode&gt;&lt;ShaderLabReformatCode&gt;True&lt;/ShaderLabReformatCode&gt;&lt;XMLReformatCode&gt;True&lt;/XMLReformatCode&gt;&lt;HtmlReformatCode&gt;True&lt;/HtmlReformatCode&gt;&lt;VBReformatCode&gt;True&lt;/VBReformatCode&gt;&lt;CSReformatCode&gt;True&lt;/CSReformatCode&gt;&lt;CSCodeStyleAttributes ArrangeVarStyle="True" ArrangeTypeAccessModifier="True" ArrangeTypeMemberAccessModifier="True" SortModifiers="True" ArrangeArgumentsStyle="True" RemoveRedundantParentheses="True" AddMissingParentheses="True" ArrangeBraces="True" ArrangeAttributes="True" ArrangeCodeBodyStyle="True" ArrangeTrailingCommas="True" ArrangeObjectCreation="True" ArrangeDefaultValue="True" ArrangeNamespaces="True" /&gt;&lt;CSArrangeQualifiers&gt;True&lt;/CSArrangeQualifiers&gt;&lt;CSFixBuiltinTypeReferences&gt;True&lt;/CSFixBuiltinTypeReferences&gt;&lt;CppCodeStyleCleanupDescriptor ArrangeBraces="True" ArrangeAuto="True" ArrangeFunctionDeclarations="True" ArrangeNestedNamespaces="True" ArrangeTypeAliases="True" ArrangeCVQualifiers="True" ArrangeSlashesInIncludeDirectives="True" ArrangeOverridingFunctions="True" SortIncludeDirectives="True" SortMemberInitializers="True" /&gt;&lt;FormatAttributeQuoteDescriptor&gt;True&lt;/FormatAttributeQuoteDescriptor&gt;&lt;CSUpdateFileHeader&gt;True&lt;/CSUpdateFileHeader&gt;&lt;CppUpdateFileHeader&gt;True&lt;/CppUpdateFileHeader&gt;&lt;IDEA_SETTINGS&gt;&amp;lt;profile version="1.0"&amp;gt;&#xD;
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+  &amp;lt;inspection_tool class="TypeScriptExplicitMemberType" enabled="true" level="WARNING" enabled_by_default="true" /&amp;gt;&#xD;
+  &amp;lt;inspection_tool class="UnterminatedStatementJS" enabled="true" level="WARNING" enabled_by_default="true" /&amp;gt;&#xD;
+  &amp;lt;inspection_tool class="WrongPropertyKeyValueDelimiter" enabled="true" level="WARNING" enabled_by_default="true" /&amp;gt;&#xD;
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+  &amp;lt;Language id="CSS"&amp;gt;&#xD;
+    &amp;lt;Reformat&amp;gt;true&amp;lt;/Reformat&amp;gt;&#xD;
+    &amp;lt;Rearrange&amp;gt;true&amp;lt;/Rearrange&amp;gt;&#xD;
+  &amp;lt;/Language&amp;gt;&#xD;
+  &amp;lt;Language id="EditorConfig"&amp;gt;&#xD;
+    &amp;lt;Reformat&amp;gt;true&amp;lt;/Reformat&amp;gt;&#xD;
+  &amp;lt;/Language&amp;gt;&#xD;
+  &amp;lt;Language id="HTML"&amp;gt;&#xD;
+    &amp;lt;Reformat&amp;gt;true&amp;lt;/Reformat&amp;gt;&#xD;
+    &amp;lt;Rearrange&amp;gt;true&amp;lt;/Rearrange&amp;gt;&#xD;
+    &amp;lt;OptimizeImports&amp;gt;true&amp;lt;/OptimizeImports&amp;gt;&#xD;
+  &amp;lt;/Language&amp;gt;&#xD;
+  &amp;lt;Language id="HTTP Request"&amp;gt;&#xD;
+    &amp;lt;Reformat&amp;gt;true&amp;lt;/Reformat&amp;gt;&#xD;
+  &amp;lt;/Language&amp;gt;&#xD;
+  &amp;lt;Language id="Handlebars"&amp;gt;&#xD;
+    &amp;lt;Reformat&amp;gt;true&amp;lt;/Reformat&amp;gt;&#xD;
+  &amp;lt;/Language&amp;gt;&#xD;
+  &amp;lt;Language id="Ini"&amp;gt;&#xD;
+    &amp;lt;Reformat&amp;gt;true&amp;lt;/Reformat&amp;gt;&#xD;
+  &amp;lt;/Language&amp;gt;&#xD;
+  &amp;lt;Language id="JSON"&amp;gt;&#xD;
+    &amp;lt;Reformat&amp;gt;true&amp;lt;/Reformat&amp;gt;&#xD;
+  &amp;lt;/Language&amp;gt;&#xD;
+  &amp;lt;Language id="Jade"&amp;gt;&#xD;
+    &amp;lt;Reformat&amp;gt;true&amp;lt;/Reformat&amp;gt;&#xD;
+  &amp;lt;/Language&amp;gt;&#xD;
+  &amp;lt;Language id="JavaScript"&amp;gt;&#xD;
+    &amp;lt;Reformat&amp;gt;true&amp;lt;/Reformat&amp;gt;&#xD;
+    &amp;lt;Rearrange&amp;gt;true&amp;lt;/Rearrange&amp;gt;&#xD;
+    &amp;lt;OptimizeImports&amp;gt;true&amp;lt;/OptimizeImports&amp;gt;&#xD;
+  &amp;lt;/Language&amp;gt;&#xD;
+  &amp;lt;Language id="Markdown"&amp;gt;&#xD;
+    &amp;lt;Reformat&amp;gt;true&amp;lt;/Reformat&amp;gt;&#xD;
+  &amp;lt;/Language&amp;gt;&#xD;
+  &amp;lt;Language id="Properties"&amp;gt;&#xD;
+    &amp;lt;Reformat&amp;gt;true&amp;lt;/Reformat&amp;gt;&#xD;
+  &amp;lt;/Language&amp;gt;&#xD;
+  &amp;lt;Language id="RELAX-NG"&amp;gt;&#xD;
+    &amp;lt;Reformat&amp;gt;true&amp;lt;/Reformat&amp;gt;&#xD;
+  &amp;lt;/Language&amp;gt;&#xD;
+  &amp;lt;Language id="SQL"&amp;gt;&#xD;
+    &amp;lt;Reformat&amp;gt;true&amp;lt;/Reformat&amp;gt;&#xD;
+  &amp;lt;/Language&amp;gt;&#xD;
+  &amp;lt;Language id="XML"&amp;gt;&#xD;
+    &amp;lt;Reformat&amp;gt;true&amp;lt;/Reformat&amp;gt;&#xD;
+    &amp;lt;Rearrange&amp;gt;true&amp;lt;/Rearrange&amp;gt;&#xD;
+    &amp;lt;OptimizeImports&amp;gt;true&amp;lt;/OptimizeImports&amp;gt;&#xD;
+  &amp;lt;/Language&amp;gt;&#xD;
+  &amp;lt;Language id="yaml"&amp;gt;&#xD;
+    &amp;lt;Reformat&amp;gt;true&amp;lt;/Reformat&amp;gt;&#xD;
+  &amp;lt;/Language&amp;gt;&#xD;
+&amp;lt;/profile&amp;gt;&lt;/RIDER_SETTINGS&gt;&lt;CSOptimizeUsings&gt;&lt;OptimizeUsings&gt;True&lt;/OptimizeUsings&gt;&lt;/CSOptimizeUsings&gt;&lt;CSShortenReferences&gt;True&lt;/CSShortenReferences&gt;&lt;VBOptimizeImports&gt;True&lt;/VBOptimizeImports&gt;&lt;VBShortenReferences&gt;True&lt;/VBShortenReferences&gt;&lt;Xaml.RemoveRedundantNamespaceAlias&gt;True&lt;/Xaml.RemoveRedundantNamespaceAlias&gt;&lt;AspOptimizeRegisterDirectives&gt;True&lt;/AspOptimizeRegisterDirectives&gt;&lt;CSReorderTypeMembers&gt;True&lt;/CSReorderTypeMembers&gt;&lt;RemoveCodeRedundancies&gt;True&lt;/RemoveCodeRedundancies&gt;&lt;CSUseAutoProperty&gt;True&lt;/CSUseAutoProperty&gt;&lt;CSMakeFieldReadonly&gt;True&lt;/CSMakeFieldReadonly&gt;&lt;CSMakeAutoPropertyGetOnly&gt;True&lt;/CSMakeAutoPropertyGetOnly&gt;&lt;CppAddTypenameTemplateKeywords&gt;True&lt;/CppAddTypenameTemplateKeywords&gt;&lt;CppJoinDeclarationAndAssignmentDescriptor&gt;True&lt;/CppJoinDeclarationAndAssignmentDescriptor&gt;&lt;CppMakeLocalVarConstDescriptor&gt;True&lt;/CppMakeLocalVarConstDescriptor&gt;&lt;CppMakeMethodConst&gt;True&lt;/CppMakeMethodConst&gt;&lt;CppMakeMethodStatic&gt;True&lt;/CppMakeMethodStatic&gt;&lt;CppRemoveCastDescriptor&gt;True&lt;/CppRemoveCastDescriptor&gt;&lt;CppRemoveElseKeyword&gt;True&lt;/CppRemoveElseKeyword&gt;&lt;CppRemoveElaboratedTypeSpecifierDescriptor&gt;True&lt;/CppRemoveElaboratedTypeSpecifierDescriptor&gt;&lt;CppRemoveRedundantLambdaParameterListDescriptor&gt;True&lt;/CppRemoveRedundantLambdaParameterListDescriptor&gt;&lt;CppRemoveRedundantMemberInitializerDescriptor&gt;True&lt;/CppRemoveRedundantMemberInitializerDescriptor&gt;&lt;CppRemoveRedundantParentheses&gt;True&lt;/CppRemoveRedundantParentheses&gt;&lt;CppShortenQualifiedName&gt;True&lt;/CppShortenQualifiedName&gt;&lt;CppDeleteRedundantSpecifier&gt;True&lt;/CppDeleteRedundantSpecifier&gt;&lt;CppRemoveStatement&gt;True&lt;/CppRemoveStatement&gt;&lt;CppRemoveTemplateArgumentsDescriptor&gt;True&lt;/CppRemoveTemplateArgumentsDescriptor&gt;&lt;CppDeleteRedundantTypenameTemplateKeywords&gt;True&lt;/CppDeleteRedundantTypenameTemplateKeywords&gt;&lt;CppRemoveUnreachableCode&gt;True&lt;/CppRemoveUnreachableCode&gt;&lt;CppRemoveUnusedIncludes&gt;True&lt;/CppRemoveUnusedIncludes&gt;&lt;CppRemoveUnusedLambdaCaptures&gt;True&lt;/CppRemoveUnusedLambdaCaptures&gt;&lt;CppCStyleToStaticCastDescriptor&gt;True&lt;/CppCStyleToStaticCastDescriptor&gt;&lt;CppReplaceExpressionWithBooleanConst&gt;True&lt;/CppReplaceExpressionWithBooleanConst&gt;&lt;CppMakeIfConstexpr&gt;True&lt;/CppMakeIfConstexpr&gt;&lt;CppMakePostfixOperatorPrefix&gt;True&lt;/CppMakePostfixOperatorPrefix&gt;&lt;CppChangeSmartPointerToMakeFunction&gt;True&lt;/CppChangeSmartPointerToMakeFunction&gt;&lt;CppReplaceThrowWithRethrowFix&gt;True&lt;/CppReplaceThrowWithRethrowFix&gt;&lt;CppTypeTraitAliasDescriptor&gt;True&lt;/CppTypeTraitAliasDescriptor&gt;&lt;CppReplaceExpressionWithNullptr&gt;True&lt;/CppReplaceExpressionWithNullptr&gt;&lt;CppReplaceTieWithStructuredBindingDescriptor&gt;True&lt;/CppReplaceTieWithStructuredBindingDescriptor&gt;&lt;CppUseAssociativeContainsDescriptor&gt;True&lt;/CppUseAssociativeContainsDescriptor&gt;&lt;CppUseEraseAlgorithmDescriptor&gt;True&lt;/CppUseEraseAlgorithmDescriptor&gt;&lt;RemoveCodeRedundanciesVB&gt;True&lt;/RemoveCodeRedundanciesVB&gt;&lt;Xaml.RedundantFreezeAttribute&gt;True&lt;/Xaml.RedundantFreezeAttribute&gt;&lt;Xaml.RemoveRedundantModifiersAttribute&gt;True&lt;/Xaml.RemoveRedundantModifiersAttribute&gt;&lt;Xaml.RemoveRedundantNameAttribute&gt;True&lt;/Xaml.RemoveRedundantNameAttribute&gt;&lt;Xaml.RemoveRedundantResource&gt;True&lt;/Xaml.RemoveRedundantResource&gt;&lt;Xaml.RemoveRedundantCollectionProperty&gt;True&lt;/Xaml.RemoveRedundantCollectionProperty&gt;&lt;Xaml.RemoveRedundantAttachedPropertySetter&gt;True&lt;/Xaml.RemoveRedundantAttachedPropertySetter&gt;&lt;Xaml.RemoveRedundantStyledValue&gt;True&lt;/Xaml.RemoveRedundantStyledValue&gt;&lt;Xaml.RemoveForbiddenResourceName&gt;True&lt;/Xaml.RemoveForbiddenResourceName&gt;&lt;Xaml.RemoveRedundantGridDefinitionsAttribute&gt;True&lt;/Xaml.RemoveRedundantGridDefinitionsAttribute&gt;&lt;Xaml.RemoveRedundantUpdateSourceTriggerAttribute&gt;True&lt;/Xaml.RemoveRedundantUpdateSourceTriggerAttribute&gt;&lt;Xaml.RemoveRedundantBindingModeAttribute&gt;True&lt;/Xaml.RemoveRedundantBindingModeAttribute&gt;&lt;Xaml.RemoveRedundantGridSpanAttribut&gt;True&lt;/Xaml.RemoveRedundantGridSpanAttribut&gt;&lt;CSharpFormatDocComments&gt;True&lt;/CSharpFormatDocComments&gt;&lt;VBFormatDocComments&gt;True&lt;/VBFormatDocComments&gt;&lt;/Profile&gt;</s:String>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpCodeStyle/BRACES_FOR_FOR/@EntryValue">Required</s:String>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpCodeStyle/BRACES_FOR_FOREACH/@EntryValue">Required</s:String>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpCodeStyle/BRACES_FOR_IFELSE/@EntryValue">Required</s:String>
@@ -8,23 +71,28 @@
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/KEEP_EXISTING_INITIALIZER_ARRANGEMENT/@EntryValue">False</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/KEEP_EXISTING_INVOCATION_PARENS_ARRANGEMENT/@EntryValue">False</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/KEEP_EXISTING_PROPERTY_PATTERNS_ARRANGEMENT/@EntryValue">False</s:Boolean>
+	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/KEEP_EXISTING_SWITCH_EXPRESSION_ARRANGEMENT/@EntryValue">False</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/KEEP_USER_LINEBREAKS/@EntryValue">False</s:Boolean>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_ACCESSORHOLDER_ATTRIBUTE_ON_SAME_LINE_EX/@EntryValue">NEVER</s:String>
+	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_SIMPLE_ACCESSOR_ON_SINGLE_LINE/@EntryValue">False</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_SIMPLE_ANONYMOUSMETHOD_ON_SINGLE_LINE/@EntryValue">False</s:Boolean>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_SIMPLE_EMBEDDED_STATEMENT_ON_SAME_LINE/@EntryValue">NEVER</s:String>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_SIMPLE_INITIALIZER_ON_SINGLE_LINE/@EntryValue">False</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_SIMPLE_PROPERTY_PATTERN_ON_SINGLE_LINE/@EntryValue">False</s:Boolean>
+	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/PLACE_WHILE_ON_NEW_LINE/@EntryValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/SPACE_WITHIN_METHOD_CALL_PARENTHESES/@EntryValue">False</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/SPACE_WITHIN_METHOD_PARENTHESES/@EntryValue">False</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/SPACE_WITHIN_PARENTHESES/@EntryValue">False</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_AFTER_DECLARATION_LPAR/@EntryValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_AFTER_INVOCATION_LPAR/@EntryValue">True</s:Boolean>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_ARGUMENTS_STYLE/@EntryValue">CHOP_IF_LONG</s:String>
-	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_ARRAY_INITIALIZER_STYLE/@EntryValue">CHOP_IF_LONG</s:String>
+	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_ARRAY_INITIALIZER_STYLE/@EntryValue">CHOP_ALWAYS</s:String>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_CHAINED_METHOD_CALLS/@EntryValue">CHOP_IF_LONG</s:String>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_EXTENDS_LIST_STYLE/@EntryValue">CHOP_IF_LONG</s:String>
 	<s:Int64 x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_LIMIT/@EntryValue">180</s:Int64>
+	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_OBJECT_AND_COLLECTION_INITIALIZER_STYLE/@EntryValue">CHOP_ALWAYS</s:String>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_PARAMETERS_STYLE/@EntryValue">CHOP_IF_LONG</s:String>
+	<s:String x:Key="/Default/CodeStyle/CodeFormatting/CSharpFormat/WRAP_PROPERTY_PATTERN/@EntryValue">CHOP_ALWAYS</s:String>
 	<s:Boolean x:Key="/Default/CodeStyle/CodeFormatting/XmlDocFormatter/KeepUserLineBreaks/@EntryValue">True</s:Boolean>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/XmlDocFormatter/ProcessingInstructionAttributesFormat/@EntryValue">OnDifferentLines</s:String>
 	<s:String x:Key="/Default/CodeStyle/CodeFormatting/XmlDocFormatter/TagAttributesFormat/@EntryValue">OnDifferentLines</s:String>
@@ -240,7 +308,6 @@ See the LICENSE file in the project root for more information.</s:String>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002ECSharpPlaceAttributeOnSameLineMigration/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002EMigrateBlankLinesAroundFieldToBlankLinesAroundProperty/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002EMigrateThisQualifierSettings/@EntryIndexedValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/UserDictionary/Words/=catched/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=CONNACK/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=PINGREQ/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=PINGRESP/@EntryIndexedValue">True</s:Boolean>
@@ -50,22 +50,6 @@ MQTTnet is a high performance .NET library for MQTT based communication. It prov
 * A custom message interceptor can be added which allows transforming or extending every received application message
 * Validate subscriptions and deny subscribing of certain topics depending on requesting clients

-## Getting Started
-
-MQTTnet is delivered via <b>NuGet</b> package manager. You can find the packages here: https://www.nuget.org/packages/MQTTnet/
-
-Use these command in the Package Manager console to install MQTTnet manually:
-```
-Install-Package MQTTnet
-```
-
-Samples for using MQTTnet are part of this repository. For starters these samples are recommended:
-
- [Connect with a broker](https://github.com/dotnet/MQTTnet/blob/master/Samples/Client/Client_Connection_Samples.cs)
- [Subscribing to data](https://github.com/dotnet/MQTTnet/blob/master/Samples/Client/Client_Subscribe_Samples.cs)
- [Publishing data](https://github.com/dotnet/MQTTnet/blob/master/Samples/Client/Client_Publish_Samples.cs)
- [Host own broker](https://github.com/dotnet/MQTTnet/blob/master/Samples/Server/Server_Simple_Samples.cs)
-
 ## Code of Conduct

 This project has adopted the code of conduct defined by the Contributor Covenant to clarify expected behavior in our community.
@@ -7,7 +7,6 @@
 // ReSharper disable InconsistentNaming

 using System.Security.Authentication;
-using System.Security.Cryptography.X509Certificates;
 using MQTTnet.Client;
 using MQTTnet.Extensions.WebSocket4Net;
 using MQTTnet.Formatter;
@@ -136,15 +135,15 @@ public static class Client_Connection_Samples
        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("mqtt.fluux.io")
-                .WithTlsOptions(
+                .WithTls(
                    o =>
                    {
                        // The used public broker sometimes has invalid certificates. This sample accepts all
                        // certificates. This should not be used in live environments.
-                        o.WithCertificateValidationHandler(_ => true);
+                        o.CertificateValidationHandler = _ => true;

                        // The default value is determined by the OS. Set manually to force version.
-                        o.WithSslProtocols(SslProtocols.Tls12);
+                        o.SslProtocol = SslProtocols.Tls12;
                    })
                .Build();

@@ -171,7 +170,7 @@ public static class Client_Connection_Samples

        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.hivemq.com:8000/mqtt")).Build();
+            var mqttClientOptions = new MqttClientOptionsBuilder().WithWebSocketServer("broker.hivemq.com:8000/mqtt").Build();

            var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);

@@ -193,7 +192,7 @@ public static class Client_Connection_Samples

        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.hivemq.com:8000/mqtt")).Build();
+            var mqttClientOptions = new MqttClientOptionsBuilder().WithWebSocketServer("broker.hivemq.com:8000/mqtt").Build();

            var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);

@@ -216,11 +215,13 @@ public static class Client_Connection_Samples
        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 8883)
-                .WithTlsOptions(
-                    o => o.WithCertificateValidationHandler(
+                .WithTls(
+                    o =>
+                    {
                        // The used public broker sometimes has invalid certificates. This sample accepts all
                        // certificates. This should not be used in live environments.
-                        _ => true))
+                        o.CertificateValidationHandler = _ => true;
+                    })
                .Build();

            // In MQTTv5 the response contains much more information.
@@ -235,31 +236,6 @@ public static class Client_Connection_Samples
        }
    }

-    public static async Task Connect_With_Amazon_AWS()
-    {
-        /*
-         * This sample creates a simple MQTT client and connects to an Amazon Web Services broker.
-         *
-         * The broker requires special settings which are set here.
-         */
-
-        var mqttFactory = new MqttFactory();
-
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("amazon.web.services.broker")
-                // Disabling packet fragmentation is very important!  
-                .WithoutPacketFragmentation()
-                .Build();
-
-            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
-
-            Console.WriteLine("The MQTT client is connected.");
-
-            await mqttClient.DisconnectAsync();
-        }
-    }
-
    public static async Task Disconnect_Clean()
    {
        /*
@@ -315,19 +291,18 @@ public static class Client_Connection_Samples
        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("mqtt.fluux.io", 8883)
-                .WithTlsOptions(
+                .WithTls(
                    o =>
                    {
-                        o.WithCertificateValidationHandler(
-                            eventArgs =>
-                            {
-                                eventArgs.Certificate.Subject.DumpToConsole();
-                                eventArgs.Certificate.GetExpirationDateString().DumpToConsole();
-                                eventArgs.Chain.ChainPolicy.RevocationMode.DumpToConsole();
-                                eventArgs.Chain.ChainStatus.DumpToConsole();
-                                eventArgs.SslPolicyErrors.DumpToConsole();
-                                return true;
-                            });
+                        o.CertificateValidationHandler = eventArgs =>
+                        {
+                            eventArgs.Certificate.Subject.DumpToConsole();
+                            eventArgs.Certificate.GetExpirationDateString().DumpToConsole();
+                            eventArgs.Chain.ChainPolicy.RevocationMode.DumpToConsole();
+                            eventArgs.Chain.ChainStatus.DumpToConsole();
+                            eventArgs.SslPolicyErrors.DumpToConsole();
+                            return true;
+                        };
                    })
                .Build();

@@ -431,59 +406,6 @@ public static class Client_Connection_Samples
                        }
                    }
                });
-
-            Console.WriteLine("Press <Enter> to exit");
-            Console.ReadLine();
        }
    }
-
-    public static async Task ConnectTls_WithCaFile()
-    {
-        var mqttFactory = new MqttFactory();
-
-        X509Certificate2Collection caChain = new X509Certificate2Collection();
-        caChain.ImportFromPem(mosquitto_org); // from https://test.mosquitto.org/ssl/mosquitto.org.crt
-
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder()
-                .WithTcpServer("test.mosquitto.org", 8883)
-                .WithTlsOptions(new MqttClientTlsOptionsBuilder()
-                    .WithTrustChain(caChain) 
-                    .Build())
-                .Build();
-
-            var connAck = await mqttClient.ConnectAsync(mqttClientOptions);
-            Console.WriteLine("Connected to test.moquitto.org:8883 with CaFile mosquitto.org.crt: " + connAck.ResultCode);
-        }
-
-
-    }
-    const string mosquitto_org = @"
-----BEGIN CERTIFICATE-----
-MIIEAzCCAuugAwIBAgIUBY1hlCGvdj4NhBXkZ/uLUZNILAwwDQYJKoZIhvcNAQEL
-BQAwgZAxCzAJBgNVBAYTAkdCMRcwFQYDVQQIDA5Vbml0ZWQgS2luZ2RvbTEOMAwG
-A1UEBwwFRGVyYnkxEjAQBgNVBAoMCU1vc3F1aXR0bzELMAkGA1UECwwCQ0ExFjAU
-BgNVBAMMDW1vc3F1aXR0by5vcmcxHzAdBgkqhkiG9w0BCQEWEHJvZ2VyQGF0Y2hv
-by5vcmcwHhcNMjAwNjA5MTEwNjM5WhcNMzAwNjA3MTEwNjM5WjCBkDELMAkGA1UE
-BhMCR0IxFzAVBgNVBAgMDlVuaXRlZCBLaW5nZG9tMQ4wDAYDVQQHDAVEZXJieTES
-MBAGA1UECgwJTW9zcXVpdHRvMQswCQYDVQQLDAJDQTEWMBQGA1UEAwwNbW9zcXVp
-dHRvLm9yZzEfMB0GCSqGSIb3DQEJARYQcm9nZXJAYXRjaG9vLm9yZzCCASIwDQYJ
-KoZIhvcNAQEBBQADggEPADCCAQoCggEBAME0HKmIzfTOwkKLT3THHe+ObdizamPg
-UZmD64Tf3zJdNeYGYn4CEXbyP6fy3tWc8S2boW6dzrH8SdFf9uo320GJA9B7U1FW
-Te3xda/Lm3JFfaHjkWw7jBwcauQZjpGINHapHRlpiCZsquAthOgxW9SgDgYlGzEA
-s06pkEFiMw+qDfLo/sxFKB6vQlFekMeCymjLCbNwPJyqyhFmPWwio/PDMruBTzPH
-3cioBnrJWKXc3OjXdLGFJOfj7pP0j/dr2LH72eSvv3PQQFl90CZPFhrCUcRHSSxo
-E6yjGOdnz7f6PveLIB574kQORwt8ePn0yidrTC1ictikED3nHYhMUOUCAwEAAaNT
-MFEwHQYDVR0OBBYEFPVV6xBUFPiGKDyo5V3+Hbh4N9YSMB8GA1UdIwQYMBaAFPVV
-6xBUFPiGKDyo5V3+Hbh4N9YSMA8GA1UdEwEB/wQFMAMBAf8wDQYJKoZIhvcNAQEL
-BQADggEBAGa9kS21N70ThM6/Hj9D7mbVxKLBjVWe2TPsGfbl3rEDfZ+OKRZ2j6AC
-6r7jb4TZO3dzF2p6dgbrlU71Y/4K0TdzIjRj3cQ3KSm41JvUQ0hZ/c04iGDg/xWf
-+pp58nfPAYwuerruPNWmlStWAXf0UTqRtg4hQDWBuUFDJTuWuuBvEXudz74eh/wK
-sMwfu1HFvjy5Z0iMDU8PUDepjVolOCue9ashlS4EB5IECdSR2TItnAIiIwimx839
-LdUdRudafMu5T5Xma182OC0/u/xRlEm+tvKGGmfFcN0piqVl8OrSPBgIlb+1IKJE
-m/XriWr/Cq4h/JfB7NTsezVslgkBaoU=
-----END CERTIFICATE-----
-";
-
-}
+}
@@ -5,7 +5,6 @@
 // ReSharper disable UnusedType.Global
 // ReSharper disable UnusedMember.Global
 // ReSharper disable InconsistentNaming
-// ReSharper disable UnusedMember.Local

 using MQTTnet.Client;
 using MQTTnet.Packets;
@@ -177,62 +176,4 @@ public static class Client_Subscribe_Samples
            response.DumpToConsole();
        }
    }
-
-    static void ConcurrentProcessingDisableAutoAcknowledge(CancellationToken shutdownToken, IMqttClient mqttClient)
-    {
-        /*
-         * This sample shows how to achieve concurrent processing and not have message AutoAcknowledged
-         * This to have a proper QoS1 (at-least-once) experience for what at least MQTT specification can provide
-         */
-        mqttClient.ApplicationMessageReceivedAsync += ea =>
-        {
-            ea.AutoAcknowledge = false;
-
-            async Task ProcessAsync()
-            {
-                // DO YOUR WORK HERE!
-                await Task.Delay(1000, shutdownToken);
-                await ea.AcknowledgeAsync(shutdownToken);
-                // WARNING: If process failures are not transient the message will be retried on every restart of the client
-                //          A failed message will not be dispatched again to the client as MQTT does not have a NACK packet to let
-                //          the broker know processing failed
-                //
-                // Optionally: Use a framework like Polly to create a retry policy: https://github.com/App-vNext/Polly#retry
-            }
-
-            _ = Task.Run(ProcessAsync, shutdownToken);
-
-            return Task.CompletedTask;
-        };
-    }
-
-    static void ConcurrentProcessingWithLimit(CancellationToken shutdownToken, IMqttClient mqttClient)
-    {
-        /*
-         * This sample shows how to achieve concurrent processing, with:
-         * - a maximum concurrency limit based on Environment.ProcessorCount
-         */
-
-        var concurrent = new SemaphoreSlim(Environment.ProcessorCount);
-
-        mqttClient.ApplicationMessageReceivedAsync += async ea =>
-        {
-            await concurrent.WaitAsync(shutdownToken).ConfigureAwait(false);
-
-            async Task ProcessAsync()
-            {
-                try
-                {
-                    // DO YOUR WORK HERE!
-                    await Task.Delay(1000, shutdownToken);
-                }
-                finally
-                {
-                    concurrent.Release();
-                }
-            }
-
-            _ = Task.Run(ProcessAsync, shutdownToken);
-        };
-    }
 }
@@ -26,7 +26,7 @@ public static class PackageInspection_Samples
                .WithTcpServer("broker.hivemq.com")
                .Build();
            
-            mqttClient.InspectPacketAsync += OnInspectPacket;
+            mqttClient.InspectPackage += OnInspectPackage;
            
            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
            
@@ -39,7 +39,7 @@ public static class PackageInspection_Samples
        }
    }

-    static Task OnInspectPacket(InspectMqttPacketEventArgs eventArgs)
+    static Task OnInspectPackage(InspectMqttPacketEventArgs eventArgs)
    {
        if (eventArgs.Direction == MqttPacketFlowDirection.Inbound)
        {
@@ -2,7 +2,7 @@

    <PropertyGroup>
        <OutputType>Exe</OutputType>
-        <TargetFramework>net7.0</TargetFramework>
+        <TargetFramework>net6.0</TargetFramework>
        <ImplicitUsings>enable</ImplicitUsings>
        <Nullable>enable</Nullable>
        <IsPackable>false</IsPackable>
@@ -44,9 +44,9 @@ public sealed class Managed_Client_Simple_Samples
            Console.WriteLine("The managed MQTT client is connected.");
            
            // Wait until the queue is fully processed.
-            SpinWait.SpinUntil(() => managedMqttClient.PendingApplicationMessagesCount == 0, 10000);
+            SpinWait.SpinUntil(() => managedMqttClient.EnqueuedApplicationMessagesCount == 0, 10000);
            
-            Console.WriteLine($"Pending messages = {managedMqttClient.PendingApplicationMessagesCount}");
+            Console.WriteLine($"Pending messages = {managedMqttClient.EnqueuedApplicationMessagesCount}");
        }
    }
 }
@@ -4,13 +4,7 @@

 using System.Reflection;

-Console.BackgroundColor = ConsoleColor.White;
-Console.BackgroundColor = ConsoleColor.Red;
-Console.Title = "Samples - MQTTnet";
-Console.WriteLine("----------------------------------------------");
-Console.WriteLine("-         Welcome to MQTTnet samples!        -");
-Console.WriteLine("----------------------------------------------");
-Console.ResetColor();
+Console.WriteLine("Welcome to MQTTnet samples!");
 Console.WriteLine();

 var sampleClasses = Assembly.GetExecutingAssembly().GetExportedTypes().OrderBy(c => c.Name).ToList();
@@ -22,11 +16,7 @@ foreach (var sampleClass in sampleClasses)
    index++;
 }

-Console.WriteLine();
-Console.ForegroundColor = ConsoleColor.Green;
 Console.Write("Please choose sample class (press Enter to continue): ");
-Console.ResetColor();
-
 var input = Console.ReadLine();
 var selectedIndex = int.Parse(input ?? "0");
 var selectedSampleClass = sampleClasses[selectedIndex];
@@ -39,19 +29,12 @@ foreach (var sampleMethod in sampleMethods)
    index++;
 }

-Console.WriteLine();
-Console.ForegroundColor = ConsoleColor.Green;
 Console.Write("Please choose sample (press Enter to continue): ");
-Console.ResetColor();
-
 input = Console.ReadLine();
 selectedIndex = int.Parse(input ?? "0");
 var selectedSampleMethod = sampleMethods[selectedIndex];

-Console.WriteLine();
-Console.ForegroundColor = ConsoleColor.White;
 Console.WriteLine("Executing sample...");
-Console.ResetColor();
 Console.WriteLine();

 try
@@ -17,7 +17,7 @@ using MQTTnet.Server;

 namespace MQTTnet.Samples.Server;

-public static class Server_ASP_NET_Samples
+public static class Server_Asp_Net_Samples
 {
    public static Task Start_Server_With_WebSockets_Support()
    {
@@ -7,8 +7,6 @@
 // ReSharper disable InconsistentNaming

 using System.Text.Json;
-using MQTTnet.Packets;
-using MQTTnet.Protocol;

 namespace MQTTnet.Samples.Server;

@@ -34,10 +32,7 @@ public static class Server_Retained_Messages_Samples
            {
                try
                {
-                    var models = await JsonSerializer.DeserializeAsync<List<MqttRetainedMessageModel>>(File.OpenRead(storePath)) ?? new List<MqttRetainedMessageModel>();
-                    var retainedMessages = models.Select(m => m.ToApplicationMessage()).ToList();
-
-                    eventArgs.LoadedRetainedMessages = retainedMessages;
+                    eventArgs.LoadedRetainedMessages = await JsonSerializer.DeserializeAsync<List<MqttApplicationMessage>>(File.OpenRead(storePath));
                    Console.WriteLine("Retained messages loaded.");
                }
                catch (FileNotFoundException)
@@ -61,9 +56,7 @@ public static class Server_Retained_Messages_Samples
                    // used to write all retained messages to dedicated files etc. Then all files must be loaded and a full list
                    // of retained messages must be provided in the loaded event.

-                    var models = eventArgs.StoredRetainedMessages.Select(MqttRetainedMessageModel.Create);
-
-                    var buffer = JsonSerializer.SerializeToUtf8Bytes(models);
+                    var buffer = JsonSerializer.SerializeToUtf8Bytes(eventArgs.StoredRetainedMessages);
                    await File.WriteAllBytesAsync(storePath, buffer);
                    Console.WriteLine("Retained messages saved.");
                }
@@ -86,59 +79,4 @@ public static class Server_Retained_Messages_Samples
            Console.ReadLine();
        }
    }
-
-    sealed class MqttRetainedMessageModel
-    {
-        public string? ContentType { get; set; }
-        public byte[]? CorrelationData { get; set; }
-        public byte[]? Payload { get; set; }
-        public MqttPayloadFormatIndicator PayloadFormatIndicator { get; set; }
-        public MqttQualityOfServiceLevel QualityOfServiceLevel { get; set; }
-        public string? ResponseTopic { get; set; }
-        public string? Topic { get; set; }
-        public List<MqttUserProperty>? UserProperties { get; set; }
-
-        public static MqttRetainedMessageModel Create(MqttApplicationMessage message)
-        {
-            if (message == null)
-            {
-                throw new ArgumentNullException(nameof(message));
-            }
-
-            return new MqttRetainedMessageModel
-            {
-                Topic = message.Topic,
-
-                // Create a copy of the buffer from the payload segment because 
-                // it cannot be serialized and deserialized with the JSON serializer.
-                Payload = message.PayloadSegment.ToArray(),
-                UserProperties = message.UserProperties,
-                ResponseTopic = message.ResponseTopic,
-                CorrelationData = message.CorrelationData,
-                ContentType = message.ContentType,
-                PayloadFormatIndicator = message.PayloadFormatIndicator,
-                QualityOfServiceLevel = message.QualityOfServiceLevel
-
-                // Other properties like "Retain" are not if interest in the storage.
-                // That's why a custom model makes sense.
-            };
-        }
-
-        public MqttApplicationMessage ToApplicationMessage()
-        {
-            return new MqttApplicationMessage
-            {
-                Topic = Topic,
-                PayloadSegment = new ArraySegment<byte>(Payload ?? Array.Empty<byte>()),
-                PayloadFormatIndicator = PayloadFormatIndicator,
-                ResponseTopic = ResponseTopic,
-                CorrelationData = CorrelationData,
-                ContentType = ContentType,
-                UserProperties = UserProperties,
-                QualityOfServiceLevel = QualityOfServiceLevel,
-                Dup = false,
-                Retain = true
-            };
-        }
-    }
 }
@@ -1,75 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-// ReSharper disable UnusedType.Global
-// ReSharper disable UnusedMember.Global
-// ReSharper disable InconsistentNaming
-
-using System.Net;
-using System.Security.Cryptography;
-using System.Security.Cryptography.X509Certificates;
-using MQTTnet.Server;
-
-namespace MQTTnet.Samples.Server;
-
-public static class Server_TLS_Samples
-{
-    public static async Task Run_Server_With_Self_Signed_Certificate()
-    {
-        /*
-         * This sample starts a simple MQTT server which will accept any TCP connection.
-         * It also has an encrypted connection using a self signed TLS certificate.
-         *
-         * See sample "Run_Minimal_Server" for more details.
-         */
-
-        var mqttFactory = new MqttFactory();
-
-        // This certificate is self signed so that
-        var certificate = CreateSelfSignedCertificate("1.3.6.1.5.5.7.3.1");
-        
-        var mqttServerOptions = new MqttServerOptionsBuilder().WithEncryptionCertificate(certificate).WithEncryptedEndpoint().Build();
-
-        using (var mqttServer = mqttFactory.CreateMqttServer(mqttServerOptions))
-        {
-            await mqttServer.StartAsync();
-
-            Console.WriteLine("Press Enter to exit.");
-            Console.ReadLine();
-
-            // Stop and dispose the MQTT server if it is no longer needed!
-            await mqttServer.StopAsync();
-        }
-    }
-
-    static X509Certificate2 CreateSelfSignedCertificate(string oid)
-    {
-        var sanBuilder = new SubjectAlternativeNameBuilder();
-        sanBuilder.AddIpAddress(IPAddress.Loopback);
-        sanBuilder.AddIpAddress(IPAddress.IPv6Loopback);
-        sanBuilder.AddDnsName("localhost");
-
-        using (var rsa = RSA.Create())
-        {
-            var certRequest = new CertificateRequest("CN=localhost", rsa, HashAlgorithmName.SHA512, RSASignaturePadding.Pkcs1);
-
-            certRequest.CertificateExtensions.Add(
-                new X509KeyUsageExtension(X509KeyUsageFlags.DataEncipherment | X509KeyUsageFlags.KeyEncipherment | X509KeyUsageFlags.DigitalSignature, false));
-
-            certRequest.CertificateExtensions.Add(new X509EnhancedKeyUsageExtension(new OidCollection { new(oid) }, false));
-
-            certRequest.CertificateExtensions.Add(sanBuilder.Build());
-
-            using (var certificate = certRequest.CreateSelfSigned(DateTimeOffset.Now.AddMinutes(-10), DateTimeOffset.Now.AddMinutes(10)))
-            {
-                var pfxCertificate = new X509Certificate2(
-                    certificate.Export(X509ContentType.Pfx),
-                    (string)null!,
-                    X509KeyStorageFlags.MachineKeySet | X509KeyStorageFlags.Exportable);
-
-                return pfxCertificate;
-            }
-        }
-    }
-}
@@ -103,7 +103,7 @@ namespace MQTTnet.AspNetCore.Tests
            connection.Transport = pipe;
            var ctx = new MqttConnectionContext(serializer, connection);

-            await ctx.SendPacketAsync(new MqttPublishPacket { PayloadSegment = new ArraySegment<byte>(new byte[20_000]) }, CancellationToken.None).ConfigureAwait(false);
+            await ctx.SendPacketAsync(new MqttPublishPacket { Payload = new byte[20_000] }, CancellationToken.None).ConfigureAwait(false);

            var readResult = await pipe.Send.Reader.ReadAsync();
            Assert.IsTrue(readResult.Buffer.Length > 20000);
@@ -19,7 +19,7 @@ namespace MQTTnet.AspNetCore.Tests
        {
            var serializer = new MqttPacketFormatterAdapter(MqttProtocolVersion.V311, new MqttBufferWriter(4096, 65535));

-            var buffer = serializer.Encode(new MqttPublishPacket {Topic = "a", PayloadSegment = new byte[5]}).Join();
+            var buffer = serializer.Encode(new MqttPublishPacket {Topic = "a", Payload = new byte[5]}).Join();

            var sequence = new ReadOnlySequence<byte>(buffer.Array, buffer.Offset, buffer.Count);

@@ -33,11 +33,8 @@ namespace MQTTnet.AspNetCore
            PacketFormatterAdapter = packetFormatterAdapter ?? throw new ArgumentNullException(nameof(packetFormatterAdapter));
            _connection = connection ?? throw new ArgumentNullException(nameof(connection));

-            if (!(_connection is TcpConnection tcp) || tcp.IsConnected)
-            {
-                _input = connection.Transport.Input;
-                _output = connection.Transport.Output;
-            }
+            _input = connection.Transport.Input;
+            _output = connection.Transport.Output;
        }

        public long BytesReceived { get; private set; }
@@ -2,34 +2,38 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.

-using System;
-using System.Net.WebSockets;
-using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
 using MQTTnet.Adapter;
-using MQTTnet.Diagnostics;
 using MQTTnet.Formatter;
 using MQTTnet.Implementations;
 using MQTTnet.Server;
+using System;
+using System.Net.WebSockets;
+using System.Threading.Tasks;
+using MQTTnet.Diagnostics;

 namespace MQTTnet.AspNetCore
 {
    public sealed class MqttWebSocketServerAdapter : IMqttServerAdapter
    {
-        IMqttNetLogger _logger = MqttNetNullLogger.Instance;
-
+        IMqttNetLogger _logger = new MqttNetNullLogger();
+        
        public Func<IMqttChannelAdapter, Task> ClientHandler { get; set; }

-        public void Dispose()
+        public Task StartAsync(MqttServerOptions options, IMqttNetLogger logger)
        {
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+            return Task.CompletedTask;
+        }
+
+        public Task StopAsync()
+        {
+            return Task.CompletedTask;
        }

        public async Task RunWebSocketConnectionAsync(WebSocket webSocket, HttpContext httpContext)
        {
-            if (webSocket == null)
-            {
-                throw new ArgumentNullException(nameof(webSocket));
-            }
+            if (webSocket == null) throw new ArgumentNullException(nameof(webSocket));

            var endpoint = $"{httpContext.Connection.RemoteIpAddress}:{httpContext.Connection.RemotePort}";

@@ -44,7 +48,7 @@ namespace MQTTnet.AspNetCore
                    var formatter = new MqttPacketFormatterAdapter(new MqttBufferWriter(4096, 65535));
                    var channel = new MqttWebSocketChannel(webSocket, endpoint, isSecureConnection, clientCertificate);

-                    using (var channelAdapter = new MqttChannelAdapter(channel, formatter, _logger))
+                    using (var channelAdapter = new MqttChannelAdapter(channel, formatter, null, _logger))
                    {
                        await clientHandler(channelAdapter).ConfigureAwait(false);
                    }
@@ -56,15 +60,8 @@ namespace MQTTnet.AspNetCore
            }
        }

-        public Task StartAsync(MqttServerOptions options, IMqttNetLogger logger)
+        public void Dispose()
        {
-            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
-            return Task.CompletedTask;
-        }
-
-        public Task StopAsync()
-        {
-            return Task.CompletedTask;
        }
    }
 }
@@ -73,7 +73,7 @@ namespace MQTTnet.Benchmarks

            var channel = new MemoryMqttChannel(_stream);

-            _channelAdapter = new MqttChannelAdapter(channel, serializer, new MqttNetEventLogger());
+            _channelAdapter = new MqttChannelAdapter(channel, serializer, null, new MqttNetEventLogger());
        }

        static byte[] Join(params ArraySegment<byte>[] chunks)
@@ -30,17 +30,17 @@ namespace MQTTnet.Benchmarks
            
            var writer = new MqttBufferWriter(4096, 65535);
            writer.WriteString("A relative short string.");
-            writer.WriteBinary(_demoPayload);
+            writer.WriteBinaryData(_demoPayload);
            writer.WriteByte(0x01);
            writer.WriteByte(0x02);
            writer.WriteVariableByteInteger(5647382);
            writer.WriteString("A relative short string.");
            writer.WriteVariableByteInteger(8574489);
-            writer.WriteBinary(_demoPayload);
+            writer.WriteBinaryData(_demoPayload);
            writer.WriteByte(2);
            writer.WriteByte(0x02);
            writer.WriteString("fjgffiogfhgfhoihgoireghreghreguhreguireoghreouighreouighreughreguiorehreuiohruiorehreuioghreug");
-            writer.WriteBinary(_demoPayload);
+            writer.WriteBinaryData(_demoPayload);

            _readPayload = new ArraySegment<byte>(writer.GetBuffer(), 0, writer.Length).ToArray();
        }
@@ -83,11 +83,11 @@ namespace MQTTnet.Benchmarks
                writer.WriteVariableByteInteger(5647382);
                writer.WriteString("A relative short string.");
                writer.WriteVariableByteInteger(8574589);
-                writer.WriteBinary(_demoPayload);
+                writer.WriteBinaryData(_demoPayload);
                writer.WriteByte(2);
                writer.WriteByte(0x02);
                writer.WriteString("fjgffiogfhgfhoihgoireghreghreguhreguireoghreouighreouighreughreguiorehreuiohruiorehreuioghreug");
-                writer.WriteBinary(_demoPayload);
+                writer.WriteBinaryData(_demoPayload);

                writer.Reset(0);
            }
@@ -54,7 +54,7 @@ namespace MQTTnet.Benchmarks
        public void Deserialize_10000_Messages()
        {
            var channel = new BenchmarkMqttChannel(_serializedPacket);
-            var reader = new MqttChannelAdapter(channel, new MqttPacketFormatterAdapter(new MqttBufferWriter(4096, 65535)), new MqttNetEventLogger());
+            var reader = new MqttChannelAdapter(channel, new MqttPacketFormatterAdapter(new MqttBufferWriter(4096, 65535)), null, new MqttNetEventLogger());

            for (var i = 0; i < 10000; i++)
            {
@@ -1,52 +1,56 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
 using System;
-using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using MQTTnet.Client;
-using MQTTnet.Packets;

 namespace MQTTnet.Extensions.ManagedClient
 {
    public interface IManagedMqttClient : IDisposable
    {
+        event Func<ApplicationMessageDroppedEventArgs, Task> ApplicationMessageDroppedAsync;
+
+        event Func<EventArgs, Task> ApplicationMessageEnqueueingAsync;
+
        event Func<ApplicationMessageProcessedEventArgs, Task> ApplicationMessageProcessedAsync;
-        
+
        event Func<MqttApplicationMessageReceivedEventArgs, Task> ApplicationMessageReceivedAsync;
-        
-        event Func<ApplicationMessageSkippedEventArgs, Task> ApplicationMessageSkippedAsync;
-        
+
        event Func<MqttClientConnectedEventArgs, Task> ConnectedAsync;
-        
+
        event Func<ConnectingFailedEventArgs, Task> ConnectingFailedAsync;
-        
-        event Func<EventArgs, Task> ConnectionStateChangedAsync;
-        
+
        event Func<MqttClientDisconnectedEventArgs, Task> DisconnectedAsync;
-        
-        event Func<ManagedProcessFailedEventArgs, Task> SynchronizingSubscriptionsFailedAsync;
-        
+
+        event Func<SubscribeProcessedEventArgs, Task> SubscribeProcessedAsync;
+
+        event Func<UnsubscribeProcessedEventArgs, Task> UnsubscribeProcessedAsync;
+
+        int EnqueuedApplicationMessagesCount { get; }
+
        IMqttClient InternalClient { get; }
-        
+
        bool IsConnected { get; }
-        
+
        bool IsStarted { get; }
-        
+
        ManagedMqttClientOptions Options { get; }
-        
-        int PendingApplicationMessagesCount { get; }
-        
+
        Task EnqueueAsync(MqttApplicationMessage applicationMessage);
-        
+
        Task EnqueueAsync(ManagedMqttApplicationMessage applicationMessage);
-        
+
        Task PingAsync(CancellationToken cancellationToken = default);
-        
+
        Task StartAsync(ManagedMqttClientOptions options);
-        
-        Task StopAsync(bool cleanDisconnect = true);
-        
-        Task SubscribeAsync(ICollection<MqttTopicFilter> topicFilters);
-        
-        Task UnsubscribeAsync(ICollection<string> topics);
+
+        Task StopAsync(MqttClientDisconnectOptions options, CancellationToken cancellationToken);
+
+        Task SubscribeAsync(MqttClientSubscribeOptions options);
+
+        Task UnsubscribeAsync(MqttClientUnsubscribeOptions options);
    }
 }
@@ -2,9 +2,10 @@

    <PropertyGroup>
        <TargetFrameworks>netstandard1.3;netstandard2.0;netstandard2.1;netcoreapp3.1;net5.0;net6.0;net7.0</TargetFrameworks>
-        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net461;net48</TargetFrameworks>
+        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net461</TargetFrameworks>
        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' AND '$(MSBuildRuntimeType)' != 'Core' ">$(TargetFrameworks);uap10.0</TargetFrameworks>
-        
+
+        <LangVersion>7.3</LangVersion>
        <AssemblyName>MQTTnet.Extensions.ManagedClient</AssemblyName>
        <RootNamespace>MQTTnet.Extensions.ManagedClient</RootNamespace>
        <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
@@ -0,0 +1,4 @@
+<wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=new/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=new_005Cevents/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=new_005Coptions/@EntryIndexedValue">True</s:Boolean></wpf:ResourceDictionary>
@@ -6,10 +6,16 @@ using System;

 namespace MQTTnet.Extensions.ManagedClient
 {
-    public class ManagedMqttApplicationMessage
+    public sealed class ManagedMqttApplicationMessage
    {
-        public Guid Id { get; set; } = Guid.NewGuid();
+        public ManagedMqttApplicationMessage(string id, MqttApplicationMessage applicationMessage)
+        {
+            Id = id ?? throw new ArgumentNullException(nameof(id));
+            ApplicationMessage = applicationMessage ?? throw new ArgumentNullException(nameof(applicationMessage));
+        }
+        
+        public string Id { get; }

-        public MqttApplicationMessage ApplicationMessage { get; set; }
+        public MqttApplicationMessage ApplicationMessage { get; }
    }
 }
@@ -6,15 +6,19 @@ using System;

 namespace MQTTnet.Extensions.ManagedClient
 {
-    public class ManagedMqttApplicationMessageBuilder
+    public sealed class ManagedMqttApplicationMessageBuilder
    {
-        private Guid _id = Guid.NewGuid();
-        private MqttApplicationMessage _applicationMessage;
+        MqttApplicationMessage _applicationMessage;
+        string _id = Guid.NewGuid().ToString();

-        public ManagedMqttApplicationMessageBuilder WithId(Guid id)
+        public ManagedMqttApplicationMessage Build()
        {
-            _id = id;
-            return this;
+            if (_applicationMessage == null)
+            {
+                throw new InvalidOperationException("The ApplicationMessage cannot be null.");
+            }
+
+            return new ManagedMqttApplicationMessage(_id, _applicationMessage);
        }

        public ManagedMqttApplicationMessageBuilder WithApplicationMessage(MqttApplicationMessage applicationMessage)
@@ -25,7 +29,10 @@ namespace MQTTnet.Extensions.ManagedClient

        public ManagedMqttApplicationMessageBuilder WithApplicationMessage(Action<MqttApplicationMessageBuilder> builder)
        {
-            if (builder == null) throw new ArgumentNullException(nameof(builder));
+            if (builder == null)
+            {
+                throw new ArgumentNullException(nameof(builder));
+            }

            var internalBuilder = new MqttApplicationMessageBuilder();
            builder(internalBuilder);
@@ -34,18 +41,16 @@ namespace MQTTnet.Extensions.ManagedClient
            return this;
        }

-        public ManagedMqttApplicationMessage Build()
+        public ManagedMqttApplicationMessageBuilder WithId(Guid id)
        {
-            if (_applicationMessage == null)
-            {
-                throw new InvalidOperationException("The ApplicationMessage cannot be null.");
-            }
+            _id = id.ToString();
+            return this;
+        }

-            return new ManagedMqttApplicationMessage
-            {
-                Id = _id,
-                ApplicationMessage = _applicationMessage
-            };
+        public ManagedMqttApplicationMessageBuilder WithId(string id)
+        {
+            _id = id ?? throw new ArgumentNullException(nameof(id));
+            return this;
        }
    }
-}
+}
@@ -17,10 +17,10 @@ using MQTTnet.Server;

 namespace MQTTnet.Extensions.ManagedClient
 {
-    public sealed class ManagedMqttClient : Disposable, IManagedMqttClient
+    public sealed class ManagedMqttClient : Disposable
    {
        readonly AsyncEvent<ApplicationMessageProcessedEventArgs> _applicationMessageProcessedEvent = new AsyncEvent<ApplicationMessageProcessedEventArgs>();
-        readonly AsyncEvent<ApplicationMessageSkippedEventArgs> _applicationMessageSkippedEvent = new AsyncEvent<ApplicationMessageSkippedEventArgs>();
+        readonly AsyncEvent<ApplicationMessageDroppedEventArgs> _applicationMessageSkippedEvent = new AsyncEvent<ApplicationMessageDroppedEventArgs>();
        readonly AsyncEvent<ConnectingFailedEventArgs> _connectingFailedEvent = new AsyncEvent<ConnectingFailedEventArgs>();
        readonly AsyncEvent<EventArgs> _connectionStateChangedEvent = new AsyncEvent<EventArgs>();
        readonly AsyncEvent<ManagedProcessFailedEventArgs> _synchronizingSubscriptionsFailedEvent = new AsyncEvent<ManagedProcessFailedEventArgs>();
@@ -76,7 +76,7 @@ namespace MQTTnet.Extensions.ManagedClient
            _logger = logger.WithSource(nameof(ManagedMqttClient));
        }

-        public event Func<ApplicationMessageSkippedEventArgs, Task> ApplicationMessageSkippedAsync
+        public event Func<ApplicationMessageDroppedEventArgs, Task> ApplicationMessageSkippedAsync
        {
            add => _applicationMessageSkippedEvent.AddHandler(value);
            remove => _applicationMessageSkippedEvent.RemoveHandler(value);
@@ -118,12 +118,18 @@ namespace MQTTnet.Extensions.ManagedClient
            remove => InternalClient.DisconnectedAsync -= value;
        }

-        public event Func<ManagedProcessFailedEventArgs, Task> SynchronizingSubscriptionsFailedAsync
+        public event Func<SubscribeProcessedEventArgs, Task> SubscribeProcessedAsync;
+        
+        public event Func<UnsubscribeProcessedEventArgs, Task> UnsubscribeProcessedAsync;
+
+        public event Func<ManagedProcessFailedEventArgs, Task> SubscribedAsync
        {
            add => _synchronizingSubscriptionsFailedEvent.AddHandler(value);
            remove => _synchronizingSubscriptionsFailedEvent.RemoveHandler(value);
        }

+        public event Func<EventArgs, Task> ApplicationMessageEnqueued;
+
        public IMqttClient InternalClient { get; }

        public bool IsConnected => InternalClient.IsConnected;
@@ -164,7 +170,7 @@ namespace MQTTnet.Extensions.ManagedClient
            MqttTopicValidator.ThrowIfInvalid(applicationMessage.ApplicationMessage);

            ManagedMqttApplicationMessage removedMessage = null;
-            ApplicationMessageSkippedEventArgs applicationMessageSkippedEventArgs = null;
+            ApplicationMessageDroppedEventArgs applicationMessageDroppedEventArgs = null;

            try
            {
@@ -175,7 +181,7 @@ namespace MQTTnet.Extensions.ManagedClient
                        if (Options.PendingMessagesOverflowStrategy == MqttPendingMessagesOverflowStrategy.DropNewMessage)
                        {
                            _logger.Verbose("Skipping publish of new application message because internal queue is full.");
-                            applicationMessageSkippedEventArgs = new ApplicationMessageSkippedEventArgs(applicationMessage);
+                            applicationMessageDroppedEventArgs = new ApplicationMessageDroppedEventArgs(applicationMessage);
                            return;
                        }

@@ -183,7 +189,7 @@ namespace MQTTnet.Extensions.ManagedClient
                        {
                            removedMessage = _messageQueue.RemoveFirst();
                            _logger.Verbose("Removed oldest application message from internal queue because it is full.");
-                            applicationMessageSkippedEventArgs = new ApplicationMessageSkippedEventArgs(removedMessage);
+                            applicationMessageDroppedEventArgs = new ApplicationMessageDroppedEventArgs(removedMessage);
                        }
                    }

@@ -202,9 +208,9 @@ namespace MQTTnet.Extensions.ManagedClient
            }
            finally
            {
-                if (applicationMessageSkippedEventArgs != null && _applicationMessageSkippedEvent.HasHandlers)
+                if (applicationMessageDroppedEventArgs != null && _applicationMessageSkippedEvent.HasHandlers)
                {
-                    await _applicationMessageSkippedEvent.InvokeAsync(applicationMessageSkippedEventArgs).ConfigureAwait(false);
+                    await _applicationMessageSkippedEvent.InvokeAsync(applicationMessageDroppedEventArgs).ConfigureAwait(false);
                }
            }
        }
@@ -353,13 +359,13 @@ namespace MQTTnet.Extensions.ManagedClient
            return remainingTime < TimeSpan.Zero ? TimeSpan.Zero : remainingTime;
        }

-        async Task HandleSubscriptionExceptionAsync(Exception exception, List<MqttTopicFilter> addedSubscriptions, List<string> removedSubscriptions)
+        async Task HandleSubscriptionExceptionAsync(Exception exception)
        {
            _logger.Warning(exception, "Synchronizing subscriptions failed.");

            if (_synchronizingSubscriptionsFailedEvent.HasHandlers)
            {
-                await _synchronizingSubscriptionsFailedEvent.InvokeAsync(new ManagedProcessFailedEventArgs(exception, addedSubscriptions, removedSubscriptions)).ConfigureAwait(false);
+                await _synchronizingSubscriptionsFailedEvent.InvokeAsync(new ManagedProcessFailedEventArgs(exception)).ConfigureAwait(false);
            }
        }

@@ -457,13 +463,11 @@ namespace MQTTnet.Extensions.ManagedClient
        {
            _logger.Info("Publishing subscriptions at reconnect");

-            List<MqttTopicFilter> topicFilters = null;
-
            try
            {
                if (_reconnectSubscriptions.Any())
                {
-                    topicFilters = new List<MqttTopicFilter>();
+                    var topicFilters = new List<MqttTopicFilter>();

                    foreach (var sub in _reconnectSubscriptions)
                    {
@@ -481,7 +485,7 @@ namespace MQTTnet.Extensions.ManagedClient
            }
            catch (Exception exception)
            {
-                await HandleSubscriptionExceptionAsync(exception, topicFilters, null).ConfigureAwait(false);
+                await HandleSubscriptionExceptionAsync(exception).ConfigureAwait(false);
            }
        }

@@ -593,9 +597,6 @@ namespace MQTTnet.Extensions.ManagedClient
                    }

                    await InternalClient.UnsubscribeAsync(unsubscribeOptionsBuilder.Build()).ConfigureAwait(false);
-
-                    //clear because these worked, maybe the subscribe below will fail, only report those
-                    removedSubscriptions.Clear();
                }

                if (addedSubscriptions != null && addedSubscriptions.Any())
@@ -612,7 +613,7 @@ namespace MQTTnet.Extensions.ManagedClient
            }
            catch (Exception exception)
            {
-                await HandleSubscriptionExceptionAsync(exception, addedSubscriptions, removedSubscriptions).ConfigureAwait(false);
+                await HandleSubscriptionExceptionAsync(exception).ConfigureAwait(false);
            }
        }

@@ -3,8 +3,9 @@
 // See the LICENSE file in the project root for more information.

 using System;
-using System.Collections.Generic;
+using System.Threading;
 using System.Threading.Tasks;
+using MQTTnet.Client;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;

@@ -38,6 +39,35 @@ namespace MQTTnet.Extensions.ManagedClient
            return managedMqttClient.EnqueueAsync(applicationMessage);
        }

+        public static Task StopAsync(this IManagedMqttClient managedMqttClient, bool isClean = true, CancellationToken cancellationToken = default)
+        {
+            if (managedMqttClient == null)
+            {
+                throw new ArgumentNullException(nameof(managedMqttClient));
+            }
+
+            return managedMqttClient.StopAsync(new MqttClientDisconnectOptions
+            {
+                IsClean = isClean
+            }, cancellationToken);
+        }
+        
+        public static Task SubscribeAsync(this IManagedMqttClient managedMqttClient, MqttTopicFilter topicFilter)
+        {
+            if (managedMqttClient == null)
+            {
+                throw new ArgumentNullException(nameof(managedMqttClient));
+            }
+
+            if (topicFilter == null)
+            {
+                throw new ArgumentNullException(nameof(topicFilter));
+            }
+
+            var subscribeOptions = new MqttClientSubscribeOptionsBuilder().WithTopicFilter(topicFilter).Build();
+            return managedMqttClient.SubscribeAsync(subscribeOptions);
+        }
+
        public static Task SubscribeAsync(
            this IManagedMqttClient managedMqttClient,
            string topic,
@@ -53,11 +83,8 @@ namespace MQTTnet.Extensions.ManagedClient
                throw new ArgumentNullException(nameof(topic));
            }

-            return managedMqttClient.SubscribeAsync(
-                new List<MqttTopicFilter>
-                {
-                    new MqttTopicFilterBuilder().WithTopic(topic).WithQualityOfServiceLevel(qualityOfServiceLevel).Build()
-                });
+            var subscribeOptions = new MqttClientSubscribeOptionsBuilder().WithTopicFilter(topic, qualityOfServiceLevel).Build();
+            return managedMqttClient.SubscribeAsync(subscribeOptions);
        }

        public static Task UnsubscribeAsync(this IManagedMqttClient managedMqttClient, string topic)
@@ -72,7 +99,8 @@ namespace MQTTnet.Extensions.ManagedClient
                throw new ArgumentNullException(nameof(topic));
            }

-            return managedMqttClient.UnsubscribeAsync(new List<string> { topic });
+            var unsubscribeOptions = new MqttClientUnsubscribeOptionsBuilder().WithTopicFilter(topic).Build();
+            return managedMqttClient.UnsubscribeAsync(unsubscribeOptions);
        }
    }
 }
@@ -1,34 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using MQTTnet.Packets;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-
-namespace MQTTnet.Extensions.ManagedClient
-{
-    public class ManagedProcessFailedEventArgs : EventArgs
-    {
-        public ManagedProcessFailedEventArgs(Exception exception, List<MqttTopicFilter> addedSubscriptions, List<string> removedSubscriptions)
-        {
-            Exception = exception ?? throw new ArgumentNullException(nameof(exception));
-
-            if (addedSubscriptions != null)
-            {
-                AddedSubscriptions = new List<string>(addedSubscriptions.Select(item => item.Topic));
-            }
-
-            if (removedSubscriptions != null)
-            {
-                RemovedSubscriptions = new List<string>(removedSubscriptions);
-            }
-        }
-
-        public Exception Exception { get; }
-
-        public List<string> AddedSubscriptions { get; }
-        public List<string> RemovedSubscriptions { get; }
-    }
-}
@@ -10,6 +10,21 @@ namespace MQTTnet.Extensions.ManagedClient
 {
    public static class MqttFactoryExtensions
    {
+        public static IManagedMqttClient CreateManagedMqttClient(this MqttFactory factory, IMqttClient mqttClient, IMqttNetLogger logger)
+        {
+            if (factory == null)
+            {
+                throw new ArgumentNullException(nameof(factory));
+            }
+
+            if (mqttClient == null)
+            {
+                return new NewManagedMqttClient(factory.CreateMqttClient(), logger);
+            }
+
+            return new NewManagedMqttClient(mqttClient, logger);
+        }
+
        public static IManagedMqttClient CreateManagedMqttClient(this MqttFactory factory, IMqttClient mqttClient = null)
        {
            if (factory == null)
@@ -19,10 +34,10 @@ namespace MQTTnet.Extensions.ManagedClient

            if (mqttClient == null)
            {
-                return new ManagedMqttClient(factory.CreateMqttClient(), factory.DefaultLogger);
+                return new NewManagedMqttClient(factory.CreateMqttClient(), factory.DefaultLogger);
            }

-            return new ManagedMqttClient(mqttClient, factory.DefaultLogger);
+            return new NewManagedMqttClient(mqttClient, factory.DefaultLogger);
        }

        public static IManagedMqttClient CreateManagedMqttClient(this MqttFactory factory, IMqttNetLogger logger)
@@ -37,10 +52,10 @@ namespace MQTTnet.Extensions.ManagedClient
                throw new ArgumentNullException(nameof(logger));
            }

-            return new ManagedMqttClient(factory.CreateMqttClient(logger), logger);
+            return new NewManagedMqttClient(factory.CreateMqttClient(logger), logger);
        }

-        public static ManagedMqttClientOptionsBuilder CreateManagedMqttClientOptionsBuilder(this MqttFactory _)
+        public static ManagedMqttClientOptionsBuilder CreateManagedMqttClientOptionsBuilder(this MqttFactory factory)
        {
            return new ManagedMqttClientOptionsBuilder();
        }
@@ -0,0 +1,95 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using MQTTnet.Client;
+using MQTTnet.Diagnostics;
+using MQTTnet.Internal;
+
+namespace MQTTnet.Extensions.ManagedClient
+{
+    public sealed class ApplicationMessagesManager
+    {
+        readonly MqttNetSourceLogger _logger;
+
+        readonly Queue<ManagedMqttApplicationMessage> _messageQueue = new Queue<ManagedMqttApplicationMessage>();
+        readonly IMqttClient _mqttClient;
+
+        public ApplicationMessagesManager(IMqttClient mqttClient, IMqttNetLogger logger)
+        {
+            _mqttClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));
+
+            if (logger == null)
+            {
+                throw new ArgumentNullException(nameof(logger));
+            }
+
+            _logger = logger.WithSource<ApplicationMessagesManager>();
+        }
+
+        public AsyncEvent<ApplicationMessageDroppedEventArgs> ApplicationMessageDroppedEvent { get; } = new AsyncEvent<ApplicationMessageDroppedEventArgs>();
+
+        public AsyncEvent<ApplicationMessageEnqueueingEventArgs> ApplicationMessageEnqueueingEvent { get; } = new AsyncEvent<ApplicationMessageEnqueueingEventArgs>();
+
+        public int EnqueuedApplicationMessagesCount
+        {
+            get
+            {
+                lock (_messageQueue)
+                {
+                    return _messageQueue.Count;
+                }
+            }
+        }
+
+        public void Dequeue()
+        {
+            lock (_messageQueue)
+            {
+                _messageQueue.Dequeue();
+            }
+        }
+
+        public async Task Enqueue(ManagedMqttApplicationMessage applicationMessage)
+        {
+            if (applicationMessage == null)
+            {
+                throw new ArgumentNullException(nameof(applicationMessage));
+            }
+
+            // Fire the event first so that the handler can make sure that this message is 
+            // properly backed up in a suitable storage.
+            if (ApplicationMessageEnqueueingEvent.HasHandlers)
+            {
+                var eventArgs = new ApplicationMessageEnqueueingEventArgs(applicationMessage, 0);
+                await ApplicationMessageEnqueueingEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
+            }
+
+            lock (_messageQueue)
+            {
+                
+                // TODO: Drop if too much!
+                
+                _messageQueue.Enqueue(applicationMessage);
+            }
+        }
+
+        public bool TryPeek(out ManagedMqttApplicationMessage applicationMessage)
+        {
+            lock (_messageQueue)
+            {
+                if (_messageQueue.Count == 0)
+                {
+                    applicationMessage = null;
+                    return false;
+                }
+
+                applicationMessage = _messageQueue.Peek();
+                return true;
+            }
+        }
+    }
+}
@@ -6,13 +6,13 @@ using System;

 namespace MQTTnet.Extensions.ManagedClient
 {
-    public sealed class ApplicationMessageSkippedEventArgs : EventArgs
+    public sealed class ApplicationMessageDroppedEventArgs : EventArgs
    {
-        public ApplicationMessageSkippedEventArgs(ManagedMqttApplicationMessage applicationMessage)
+        public ApplicationMessageDroppedEventArgs(ManagedMqttApplicationMessage applicationMessage)
        {
            ApplicationMessage = applicationMessage ?? throw new ArgumentNullException(nameof(applicationMessage));
        }

        public ManagedMqttApplicationMessage ApplicationMessage { get; }
    }
-}
+}
@@ -0,0 +1,21 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+
+namespace MQTTnet.Extensions.ManagedClient
+{
+    public sealed class ApplicationMessageEnqueueingEventArgs : EventArgs
+    {
+        public ApplicationMessageEnqueueingEventArgs(ManagedMqttApplicationMessage applicationMessage, ushort packetIdentifier)
+        {
+            ApplicationMessage = applicationMessage ?? throw new ArgumentNullException(nameof(applicationMessage));
+            PacketIdentifier = packetIdentifier;
+        }
+
+        public ManagedMqttApplicationMessage ApplicationMessage { get; }
+
+        public ushort PacketIdentifier { get; }
+    }
+}
@@ -15,10 +15,12 @@ namespace MQTTnet.Extensions.ManagedClient
        }

        public ManagedMqttApplicationMessage ApplicationMessage { get; }
-        
+
        /// <summary>
-        /// Then this is _null_ the message was processed successfully without any error.
+        ///     Gets or sets the exception which was thrown while sending the message.
        /// </summary>
        public Exception Exception { get; }
+
+        public bool HasFailed => Exception != null;
    }
-}
+}
@@ -1,3 +1,7 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
 using System;
 using MQTTnet.Client;

@@ -12,7 +16,7 @@ namespace MQTTnet.Extensions.ManagedClient
        }

        /// <summary>
-        /// This is null when the connection was failing and the server was not reachable.
+        ///     This is null when the server was not reachable and thus no MQTT response was transmitted.
        /// </summary>
        public MqttClientConnectResult ConnectResult { get; }

@@ -0,0 +1,18 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+
+namespace MQTTnet.Extensions.ManagedClient
+{
+    public class ManagedProcessFailedEventArgs : EventArgs
+    {
+        public ManagedProcessFailedEventArgs(Exception exception)
+        {
+            Exception = exception ?? throw new ArgumentNullException(nameof(exception));
+        }
+
+        public Exception Exception { get; }
+    }
+}
@@ -0,0 +1,27 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using MQTTnet.Client;
+using MQTTnet.Packets;
+
+namespace MQTTnet.Extensions.ManagedClient
+{
+    public sealed class SubscribeProcessedEventArgs : EventArgs
+    {
+        public SubscribeProcessedEventArgs(MqttClientSubscribeOptions options, MqttClientSubscribeResultCode result, IReadOnlyCollection<MqttUserProperty> userProperties)
+        {
+            Options = options ?? throw new ArgumentNullException(nameof(options));
+            Result = result;
+            UserProperties = userProperties;
+        }
+
+        public MqttClientSubscribeOptions Options { get; }
+
+        public MqttClientSubscribeResultCode Result { get; }
+
+        public IReadOnlyCollection<MqttUserProperty> UserProperties { get; }
+    }
+}
@@ -0,0 +1,27 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using MQTTnet.Client;
+using MQTTnet.Packets;
+
+namespace MQTTnet.Extensions.ManagedClient
+{
+    public sealed class UnsubscribeProcessedEventArgs : EventArgs
+    {
+        public UnsubscribeProcessedEventArgs(MqttClientUnsubscribeOptions options, MqttClientUnsubscribeResultCode result, IReadOnlyCollection<MqttUserProperty> userProperties)
+        {
+            Options = options ?? throw new ArgumentNullException(nameof(options));
+            Result = result;
+            UserProperties = userProperties;
+        }
+
+        public MqttClientUnsubscribeOptions Options { get; }
+
+        public MqttClientUnsubscribeResultCode Result { get; }
+
+        public IReadOnlyCollection<MqttUserProperty> UserProperties { get; }
+    }
+}
@@ -2,10 +2,14 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.

-namespace MQTTnet.Client
+namespace MQTTnet.Extensions.ManagedClient
 {
-    public interface IMqttClientCertificatesProvider
+    public enum MaintainConnectionResult
    {
-        System.Security.Cryptography.X509Certificates.X509CertificateCollection GetCertificates();
+        NoChange,
+
+        ConnectedEstablished,
+
+        NotConnected
    }
 }
@@ -0,0 +1,35 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Linq;
+using MQTTnet.Client;
+
+namespace MQTTnet.Extensions.ManagedClient
+{
+    public sealed class ManagedMqttSubscription
+    {
+        public ManagedMqttSubscription(MqttClientSubscribeOptions subscribeOptions)
+        {
+            SubscribeOptions = subscribeOptions ?? throw new ArgumentNullException(nameof(subscribeOptions));
+
+            Topic = subscribeOptions.TopicFilters.First().Topic;
+        }
+
+        public bool IsObsolete => UnsubscribeOptions != null;
+
+        public bool IsPending { get; set; } = true;
+
+        public MqttClientSubscribeOptions SubscribeOptions { get; }
+
+        public string Topic { get; }
+
+        public MqttClientUnsubscribeOptions UnsubscribeOptions { get; private set; }
+
+        public void MarkAsUnsubscribed(MqttClientUnsubscribeOptions options)
+        {
+            UnsubscribeOptions = options ?? throw new ArgumentNullException(nameof(options));
+        }
+    }
+}
@@ -0,0 +1,155 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Client;
+using MQTTnet.Diagnostics;
+using MQTTnet.Internal;
+using MQTTnet.Protocol;
+
+namespace MQTTnet.Extensions.ManagedClient
+{
+    public sealed class ManagedMqttSubscriptionsManager
+    {
+        readonly MqttNetSourceLogger _logger;
+        readonly IMqttClient _mqttClient;
+        
+        // Do not use a dictionary in order to preserve subscription ordering (retained messages).
+        readonly List<ManagedMqttSubscription> _subscriptions = new List<ManagedMqttSubscription>();
+
+        public ManagedMqttSubscriptionsManager(IMqttClient mqttClient, IMqttNetLogger logger)
+        {
+            _mqttClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));
+
+            if (logger == null)
+            {
+                throw new ArgumentNullException(nameof(logger));
+            }
+
+            _logger = logger.WithSource<ManagedMqttSubscriptionsManager>();
+        }
+
+        public AsyncEvent<SubscribeProcessedEventArgs> SubscribeProcessedEvent { get; } = new AsyncEvent<SubscribeProcessedEventArgs>();
+
+        public AsyncEvent<UnsubscribeProcessedEventArgs> UnsubscribeProcessedEvent { get; } = new AsyncEvent<UnsubscribeProcessedEventArgs>();
+
+        public void ResubscribeAll()
+        {
+            lock (_subscriptions)
+            {
+                foreach (var subscription in _subscriptions)
+                {
+                    subscription.IsPending = true;
+                }
+            }
+        }
+
+        public void Subscribe(MqttClientSubscribeOptions options)
+        {
+            if (options == null)
+            {
+                throw new ArgumentNullException(nameof(options));
+            }
+
+            if (options.TopicFilters.Count > 1)
+            {
+                throw new NotSupportedException("The managed client only supports subscribing to one topic at the same time.");
+            }
+
+            var topic = options.TopicFilters.First().Topic;
+            
+            lock (_subscriptions)
+            {
+                MqttTopicValidator.ThrowIfInvalidSubscribe(topic);
+
+                _subscriptions.RemoveAll(s => s.Topic.Equals(topic));
+                _subscriptions.Add(new ManagedMqttSubscription(options));
+            }
+        }
+
+        public async Task Synchronize(CancellationToken cancellationToken)
+        {
+            // TODO: Remember real changes.
+
+            List<ManagedMqttSubscription> pendingSubscriptions;
+            List<ManagedMqttSubscription> obsoleteSubscriptions;
+            lock (_subscriptions)
+            {
+                pendingSubscriptions = _subscriptions.Where(s => s.IsPending).ToList();
+                obsoleteSubscriptions = _subscriptions.Where(s => s.IsObsolete).ToList();
+            }
+
+            if (pendingSubscriptions.Count == 0 && obsoleteSubscriptions.Count == 0)
+            {
+                _logger.Verbose("No subscriptions to synchronize");
+                return;
+            }
+
+            foreach (var subscription in pendingSubscriptions)
+            {
+                var subscribeResult = await _mqttClient.SubscribeAsync(subscription.SubscribeOptions, cancellationToken).ConfigureAwait(false);
+                subscription.IsPending = false;
+                await FireSubscribeProcessedEvent(subscription, subscribeResult).ConfigureAwait(false);
+            }
+
+            foreach (var subscription in obsoleteSubscriptions)
+            {
+                var unsubscribeResult = await _mqttClient.UnsubscribeAsync(subscription.UnsubscribeOptions, cancellationToken).ConfigureAwait(false);
+                lock (_subscriptions)
+                {
+                    _subscriptions.Remove(subscription);
+                }
+
+                await FireUnsubscribeProcessedEvent(subscription, unsubscribeResult).ConfigureAwait(false);
+            }
+        }
+
+        public void Unsubscribe(MqttClientUnsubscribeOptions options)
+        {
+            if (options == null)
+            {
+                throw new ArgumentNullException(nameof(options));
+            }
+
+            lock (_subscriptions)
+            {
+                var topic = options.TopicFilters.First();
+                var existingSubscription = _subscriptions.FirstOrDefault(s => s.Topic.Equals(topic));
+
+                if (existingSubscription != null)
+                {
+                    existingSubscription.MarkAsUnsubscribed(options);
+                }
+            }
+        }
+
+        async Task FireSubscribeProcessedEvent(ManagedMqttSubscription subscription, MqttClientSubscribeResult subscribeResult)
+        {
+            _logger.Info("Subscribed topic '{0}'.", subscription.Topic);
+
+            if (SubscribeProcessedEvent.HasHandlers)
+            {
+                var resultCode = subscribeResult?.Items.First().ResultCode ?? MqttClientSubscribeResultCode.UnspecifiedError;
+                var eventArgs = new SubscribeProcessedEventArgs(subscription.SubscribeOptions, resultCode, subscribeResult?.UserProperties);
+                await SubscribeProcessedEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
+            }
+        }
+
+        async Task FireUnsubscribeProcessedEvent(ManagedMqttSubscription subscription, MqttClientUnsubscribeResult unsubscribeResult)
+        {
+            _logger.Info("Unsubscribed topic '{0}'.", subscription.Topic);
+
+            if (UnsubscribeProcessedEvent.HasHandlers)
+            {
+                var resultCode = unsubscribeResult?.Items.First().ResultCode ?? MqttClientUnsubscribeResultCode.UnspecifiedError;
+                var eventArgs = new UnsubscribeProcessedEventArgs(subscription.UnsubscribeOptions, resultCode, unsubscribeResult?.UserProperties);
+                await UnsubscribeProcessedEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
+            }
+        }
+    }
+}
@@ -0,0 +1,103 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Client;
+using MQTTnet.Diagnostics;
+using MQTTnet.Internal;
+
+namespace MQTTnet.Extensions.ManagedClient
+{
+    public sealed class MqttConnectionManager
+    {
+        readonly MqttNetSourceLogger _logger;
+        readonly IMqttClient _mqttClient;
+
+        bool _wasConnected;
+
+        public MqttConnectionManager(IMqttClient mqttClient, IMqttNetLogger logger)
+        {
+            _mqttClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));
+
+            if (logger == null)
+            {
+                throw new ArgumentNullException(nameof(logger));
+            }
+
+            _logger = logger.WithSource<MqttConnectionManager>();
+
+            _mqttClient.DisconnectedAsync += OnClientDisconnected;
+        }
+
+        public AsyncEvent<MqttClientConnectedEventArgs> ConnectedEvent { get; } = new AsyncEvent<MqttClientConnectedEventArgs>();
+
+        public AsyncEvent<ConnectingFailedEventArgs> ConnectingFailedEvent { get; } = new AsyncEvent<ConnectingFailedEventArgs>();
+
+        public AsyncEvent<MqttClientDisconnectedEventArgs> DisconnectedEvent { get; } = new AsyncEvent<MqttClientDisconnectedEventArgs>();
+
+        public async Task<MaintainConnectionResult> MaintainConnection(ManagedMqttClientOptions options, CancellationToken cancellationToken)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+            
+            if (_wasConnected)
+            {
+                try
+                {
+                    // The only valid way for testing the connection is to send a PING. So we start with this
+                    // in order to check if reconnecting etc. is require or not.
+                    await _mqttClient.PingAsync(cancellationToken).ConfigureAwait(false);
+
+                    // The client is properly connection. No further action required.
+                    return MaintainConnectionResult.NoChange;
+                }
+                catch (Exception exception)
+                {
+                    _logger.Error(exception, "Error while checking connection.");
+                }
+            }
+
+            MqttClientConnectResult connectResult = null;
+            try
+            {
+                // The PING was not successful so that there is no working connection. So we connect.
+                connectResult = await _mqttClient.ConnectAsync(options.ClientOptions, cancellationToken).ConfigureAwait(false);
+
+                _wasConnected = true;
+                _logger.Info("Connected.");
+
+                if (ConnectedEvent.HasHandlers)
+                {
+                    var eventArgs = new MqttClientConnectedEventArgs(connectResult);
+                    await ConnectedEvent.TryInvokeAsync(eventArgs, _logger).ConfigureAwait(false);
+                }
+
+                return MaintainConnectionResult.ConnectedEstablished;
+            }
+            catch (Exception exception)
+            {
+                if (!(exception is OperationCanceledException))
+                {
+                    _logger.Error(exception, "Error while connecting.");
+                }
+
+                if (ConnectingFailedEvent.HasHandlers)
+                {
+                    var eventArgs = new ConnectingFailedEventArgs(connectResult, exception);
+                    await ConnectingFailedEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
+                }
+            }
+
+            _wasConnected = false;
+            return MaintainConnectionResult.NotConnected;
+        }
+
+        Task OnClientDisconnected(MqttClientDisconnectedEventArgs arg)
+        {
+            _wasConnected = false;
+            return DisconnectedEvent?.InvokeAsync(arg);
+        }
+    }
+}
@@ -0,0 +1,309 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using MQTTnet.Client;
+using MQTTnet.Diagnostics;
+using MQTTnet.Internal;
+
+namespace MQTTnet.Extensions.ManagedClient
+{
+    public sealed class NewManagedMqttClient : Disposable, IManagedMqttClient
+    {
+        readonly AsyncEvent<ApplicationMessageProcessedEventArgs> _applicationMessageProcessedEvent = new AsyncEvent<ApplicationMessageProcessedEventArgs>();
+        readonly ApplicationMessagesManager _applicationMessagesManager;
+        readonly MqttConnectionManager _connectionManager;
+        readonly AsyncEvent<EventArgs> _isConnectedChangedEvent = new AsyncEvent<EventArgs>();
+        readonly MqttNetSourceLogger _logger;
+        readonly ManagedMqttSubscriptionsManager _subscriptionsManager;
+
+        readonly ManualResetEventSlim _workSignal = new ManualResetEventSlim();
+
+        CancellationTokenSource _workerCancellationToken;
+        Task _workerTask;
+
+        public NewManagedMqttClient(IMqttClient mqttClient, IMqttNetLogger logger)
+        {
+            InternalClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));
+
+            if (logger == null)
+            {
+                throw new ArgumentNullException(nameof(logger));
+            }
+
+            InternalClient.DisconnectedAsync += OnInternalClientDisconnected;
+
+            _logger = logger.WithSource(nameof(NewManagedMqttClient));
+
+            _connectionManager = new MqttConnectionManager(mqttClient, logger);
+            _subscriptionsManager = new ManagedMqttSubscriptionsManager(mqttClient, logger);
+            _applicationMessagesManager = new ApplicationMessagesManager(mqttClient, logger);
+
+            // TODO: Start timer for periodical connection checking.
+        }
+
+        public event Func<EventArgs, Task> ApplicationMessageEnqueueingAsync
+        {
+            add => _applicationMessagesManager.ApplicationMessageEnqueueingEvent.AddHandler(value);
+            remove => _applicationMessagesManager.ApplicationMessageEnqueueingEvent.RemoveHandler(value);
+        }
+
+        public event Func<ApplicationMessageProcessedEventArgs, Task> ApplicationMessageProcessedAsync
+        {
+            add => _applicationMessageProcessedEvent.AddHandler(value);
+            remove => _applicationMessageProcessedEvent.RemoveHandler(value);
+        }
+
+        public event Func<MqttApplicationMessageReceivedEventArgs, Task> ApplicationMessageReceivedAsync
+        {
+            add => InternalClient.ApplicationMessageReceivedAsync += value;
+            remove => InternalClient.ApplicationMessageReceivedAsync += value;
+        }
+
+        public event Func<ApplicationMessageDroppedEventArgs, Task> ApplicationMessageDroppedAsync
+        {
+            add => _applicationMessagesManager.ApplicationMessageDroppedEvent.AddHandler(value);
+            remove => _applicationMessagesManager.ApplicationMessageDroppedEvent.RemoveHandler(value);
+        }
+
+        public event Func<MqttClientConnectedEventArgs, Task> ConnectedAsync
+        {
+            add => _connectionManager.ConnectedEvent.AddHandler(value);
+            remove => _connectionManager.ConnectedEvent.RemoveHandler(value);
+        }
+
+        public event Func<ConnectingFailedEventArgs, Task> ConnectingFailedAsync
+        {
+            add => _connectionManager.ConnectingFailedEvent.AddHandler(value);
+            remove => _connectionManager.ConnectingFailedEvent.RemoveHandler(value);
+        }
+
+        public event Func<MqttClientDisconnectedEventArgs, Task> DisconnectedAsync
+        {
+            add => _connectionManager.DisconnectedEvent.AddHandler(value);
+            remove => _connectionManager.DisconnectedEvent.RemoveHandler(value);
+        }
+
+        public event Func<SubscribeProcessedEventArgs, Task> SubscribeProcessedAsync
+        {
+            add => _subscriptionsManager.SubscribeProcessedEvent.AddHandler(value);
+            remove => _subscriptionsManager.SubscribeProcessedEvent.RemoveHandler(value);
+        }
+
+        public event Func<UnsubscribeProcessedEventArgs, Task> UnsubscribeProcessedAsync
+        {
+            add => _subscriptionsManager.UnsubscribeProcessedEvent.AddHandler(value);
+            remove => _subscriptionsManager.UnsubscribeProcessedEvent.RemoveHandler(value);
+        }
+
+        public IMqttClient InternalClient { get; }
+
+        public bool IsConnected { get; private set; }
+
+        public bool IsStarted { get; private set; }
+
+        public ManagedMqttClientOptions Options { get; private set; }
+
+        public int EnqueuedApplicationMessagesCount => _applicationMessagesManager.EnqueuedApplicationMessagesCount;
+
+        public Task EnqueueAsync(MqttApplicationMessage applicationMessage)
+        {
+            return EnqueueAsync(new ManagedMqttApplicationMessage(Guid.NewGuid().ToString(), applicationMessage));
+        }
+
+        public async Task EnqueueAsync(ManagedMqttApplicationMessage applicationMessage)
+        {
+            if (applicationMessage == null)
+            {
+                throw new ArgumentNullException(nameof(applicationMessage));
+            }
+
+            await _applicationMessagesManager.Enqueue(applicationMessage).ConfigureAwait(false);
+            _workSignal.Set();
+        }
+
+        public Task PingAsync(CancellationToken cancellationToken = default)
+        {
+            return InternalClient.PingAsync(cancellationToken);
+        }
+
+        public Task StartAsync(ManagedMqttClientOptions options)
+        {
+            Options = options ?? throw new ArgumentNullException(nameof(options));
+
+            _workerCancellationToken = new CancellationTokenSource();
+
+            _workerTask = Task.Factory.StartNew(
+                () => WorkerLoop(_workerCancellationToken.Token),
+                _workerCancellationToken.Token,
+                TaskCreationOptions.PreferFairness,
+                TaskScheduler.Default);
+
+            _workSignal.Set();
+
+            return CompletedTask.Instance;
+        }
+
+        public async Task StopAsync(MqttClientDisconnectOptions options, CancellationToken cancellationToken = default)
+        {
+            if (options == null)
+            {
+                throw new ArgumentNullException(nameof(options));
+            }
+
+            // TODO: Send proper Disconnect signal.
+
+            try
+            {
+                await InternalClient.DisconnectAsync(options, cancellationToken).ConfigureAwait(false);
+            }
+            catch (Exception exception)
+            {
+                _logger.Error(exception, "Error while disconnecting.");
+            }
+
+            _workerCancellationToken?.Cancel(false);
+            _workerCancellationToken?.Dispose();
+
+            _workerCancellationToken = null;
+
+            if (_workerTask != null)
+            {
+            }
+        }
+
+        public Task SubscribeAsync(MqttClientSubscribeOptions options)
+        {
+            ThrowIfDisposed();
+
+            _subscriptionsManager.Subscribe(options);
+            _workSignal.Set();
+
+            return CompletedTask.Instance;
+        }
+
+        public Task UnsubscribeAsync(MqttClientUnsubscribeOptions options)
+        {
+            ThrowIfDisposed();
+
+            _subscriptionsManager.Unsubscribe(options);
+            _workSignal.Set();
+
+            return CompletedTask.Instance;
+        }
+
+        protected override void Dispose(bool disposing)
+        {
+            base.Dispose(disposing);
+
+            if (disposing)
+            {
+            }
+        }
+
+        Task OnInternalClientDisconnected(MqttClientDisconnectedEventArgs eventArgs)
+        {
+            _workSignal.Set();
+            return CompletedTask.Instance;
+        }
+
+        async Task UpdateConnectionStatus(MaintainConnectionResult maintainConnectionResult)
+        {
+            var isConnected = maintainConnectionResult != MaintainConnectionResult.NotConnected;
+
+            if (IsConnected.Equals(isConnected))
+            {
+                return;
+            }
+
+            IsConnected = isConnected;
+
+            if (_isConnectedChangedEvent.HasHandlers)
+            {
+                await _isConnectedChangedEvent.InvokeAsync(EventArgs.Empty).ConfigureAwait(false);
+            }
+        }
+
+        async Task WorkerLoop(CancellationToken cancellationToken)
+        {
+            try
+            {
+                IsStarted = true;
+
+                while (!cancellationToken.IsCancellationRequested)
+                {
+                    _workSignal.Wait(cancellationToken);
+                    _workSignal.Reset();
+
+                    var maintainConnectionResult = await _connectionManager.MaintainConnection(Options, cancellationToken).ConfigureAwait(false);
+                    await UpdateConnectionStatus(maintainConnectionResult).ConfigureAwait(false);
+
+                    if (maintainConnectionResult == MaintainConnectionResult.ConnectedEstablished && Options.ClientOptions.CleanSession)
+                    {
+                        // Since the session is clean the server will now know any subscription so that
+                        // we have to subscribe to all of them again.
+                        _subscriptionsManager.ResubscribeAll();
+                    }
+
+                    if (IsConnected)
+                    {
+                        await _subscriptionsManager.Synchronize(cancellationToken).ConfigureAwait(false);
+                    }
+
+                    if (IsConnected)
+                    {
+                        // TODO: Move into pending messages manager + locking.
+                        while (_applicationMessagesManager.TryPeek(out var nextPendingMessage))
+                        {
+                            Exception processingException = null;
+                            try
+                            {
+                                _logger.Verbose("Publishing managed application message {0}.", nextPendingMessage.Id);
+
+                                await InternalClient.PublishAsync(nextPendingMessage.ApplicationMessage, cancellationToken).ConfigureAwait(false);
+
+                                // The message was delivered successfully. So we can get rid of it.
+                                _applicationMessagesManager.Dequeue();
+                            }
+                            catch (Exception exception)
+                            {
+                                processingException = exception;
+                            }
+                            finally
+                            {
+                                if (_applicationMessageProcessedEvent.HasHandlers)
+                                {
+                                    var eventArgs = new ApplicationMessageProcessedEventArgs(nextPendingMessage, processingException);
+                                    await _applicationMessageProcessedEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+            catch (OperationCanceledException)
+            {
+            }
+#if !NETSTANDARD1_3
+            catch (ThreadAbortException)
+            {
+            }
+#endif
+            catch (Exception exception)
+            {
+                _logger.Error(exception, "Error while maintaining connection.");
+            }
+            finally
+            {
+                IsStarted = false;
+
+                await UpdateConnectionStatus(MaintainConnectionResult.NotConnected).ConfigureAwait(false);
+            }
+
+            // TODO: Disconnected!
+        }
+    }
+}
@@ -10,6 +10,15 @@ namespace MQTTnet.Extensions.ManagedClient
 {
    public sealed class ManagedMqttClientOptions
    {
+        public ManagedMqttClientOptions()
+        {
+        }
+
+        public ManagedMqttClientOptions(MqttClientOptions clientOptions)
+        {
+            ClientOptions = clientOptions;
+        }
+        
        public MqttClientOptions ClientOptions { get; set; }

        public TimeSpan AutoReconnectDelay { get; set; } = TimeSpan.FromSeconds(5);
@@ -24,7 +33,7 @@ namespace MQTTnet.Extensions.ManagedClient

        /// <summary>
        /// Defines the maximum amount of topic filters which will be sent in a SUBSCRIBE/UNSUBSCRIBE packet.
-        /// Amazon Web Services (AWS) limits this number to 8. The default is int.MaxValue.
+        /// Amazon AWS limits this number to 8. The default is int.MaxValue.
        /// </summary>
        public int MaxTopicFiltersInSubscribeUnsubscribePackets { get; set; } = int.MaxValue;
    }
@@ -8,7 +8,7 @@ using MQTTnet.Server;

 namespace MQTTnet.Extensions.ManagedClient
 {
-    public class ManagedMqttClientOptionsBuilder
+    public sealed class ManagedMqttClientOptionsBuilder
    {
        readonly ManagedMqttClientOptions _options = new ManagedMqttClientOptions();
        MqttClientOptionsBuilder _clientOptionsBuilder;
@@ -1,5 +1,4 @@
 using System;
-using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using MQTTnet.Protocol;
@@ -8,8 +7,8 @@ namespace MQTTnet.Extensions.Rpc
 {
    public interface IMqttRpcClient : IDisposable
    {
-        Task<byte[]> ExecuteAsync(TimeSpan timeout, string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, IDictionary<string,object> parameters = null);
+        Task<byte[]> ExecuteAsync(TimeSpan timeout, string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel);
        
-        Task<byte[]> ExecuteAsync(string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, IDictionary<string, object> parameters = null, CancellationToken cancellationToken = default);
+        Task<byte[]> ExecuteAsync(string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, CancellationToken cancellationToken = default);
    }
 }
@@ -2,7 +2,7 @@

    <PropertyGroup>
        <TargetFrameworks>netstandard1.3;netstandard2.0;netstandard2.1;netcoreapp3.1;net5.0;net6.0;net7.0</TargetFrameworks>
-        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net461;net48</TargetFrameworks>
+        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net461</TargetFrameworks>
        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' AND '$(MSBuildRuntimeType)' != 'Core' ">$(TargetFrameworks);uap10.0</TargetFrameworks>
        
        <AssemblyName>MQTTnet.Extensions.Rpc</AssemblyName>
@@ -4,8 +4,6 @@

 using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using MQTTnet.Client;
@@ -43,13 +41,13 @@ namespace MQTTnet.Extensions.Rpc
            _waitingCalls.Clear();
        }

-        public async Task<byte[]> ExecuteAsync(TimeSpan timeout, string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, IDictionary<string, object> parameters = null)
+        public async Task<byte[]> ExecuteAsync(TimeSpan timeout, string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel)
        {
            using (var timeoutToken = new CancellationTokenSource(timeout))
            {
                try
                {
-                    return await ExecuteAsync(methodName, payload, qualityOfServiceLevel, parameters, timeoutToken.Token).ConfigureAwait(false);
+                    return await ExecuteAsync(methodName, payload, qualityOfServiceLevel, timeoutToken.Token).ConfigureAwait(false);
                }
                catch (OperationCanceledException exception)
                {
@@ -63,14 +61,14 @@ namespace MQTTnet.Extensions.Rpc
            }
        }

-        public async Task<byte[]> ExecuteAsync(string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, IDictionary<string, object> parameters = null, CancellationToken cancellationToken = default)
+        public async Task<byte[]> ExecuteAsync(string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, CancellationToken cancellationToken = default)
        {
            if (methodName == null)
            {
                throw new ArgumentNullException(nameof(methodName));
            }

-            var context = new TopicGenerationContext(_mqttClient, _options, methodName, parameters, qualityOfServiceLevel);
+            var context = new TopicGenerationContext(_mqttClient, _options, methodName, qualityOfServiceLevel);
            var topicNames = _options.TopicGenerationStrategy.CreateRpcTopics(context);

            var requestTopic = topicNames.RequestTopic;
@@ -121,6 +119,7 @@ namespace MQTTnet.Extensions.Rpc
            finally
            {
                _waitingCalls.TryRemove(responseTopic, out _);
+
                await _mqttClient.UnsubscribeAsync(responseTopic, CancellationToken.None).ConfigureAwait(false);
            }
        }
@@ -132,8 +131,7 @@ namespace MQTTnet.Extensions.Rpc
                return CompletedTask.Instance;
            }

-            var payloadBuffer = eventArgs.ApplicationMessage.PayloadSegment.ToArray();
-            awaitable.TrySetResult(payloadBuffer);
+            awaitable.TrySetResult(eventArgs.ApplicationMessage.Payload);

            // Set this message to handled to that other code can avoid execution etc.
            eventArgs.IsHandled = true;
@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.

 using System;
-using System.Collections.Generic;
 using System.Text;
 using System.Threading.Tasks;
 using MQTTnet.Protocol;
@@ -12,13 +11,13 @@ namespace MQTTnet.Extensions.Rpc
 {
    public static class MqttRpcClientExtensions
    {
-        public static Task<byte[]> ExecuteAsync(this IMqttRpcClient client, TimeSpan timeout, string methodName, string payload, MqttQualityOfServiceLevel qualityOfServiceLevel, IDictionary<string,object> parameters = null)
+        public static Task<byte[]> ExecuteAsync(this IMqttRpcClient client, TimeSpan timeout, string methodName, string payload, MqttQualityOfServiceLevel qualityOfServiceLevel)
        {
            if (client == null) throw new ArgumentNullException(nameof(client));

            var buffer = Encoding.UTF8.GetBytes(payload ?? string.Empty);

-            return client.ExecuteAsync(timeout, methodName, buffer, qualityOfServiceLevel, parameters);
+            return client.ExecuteAsync(timeout, methodName, buffer, qualityOfServiceLevel);
        }
    }
 }
@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.

 using System;
-using System.Collections.Generic;
 using MQTTnet.Client;
 using MQTTnet.Protocol;

@@ -11,11 +10,9 @@ namespace MQTTnet.Extensions.Rpc
 {
    public sealed class TopicGenerationContext
    {
-        public TopicGenerationContext(IMqttClient mqttClient, MqttRpcClientOptions options, string methodName,
-            IDictionary<string, object> parameters, MqttQualityOfServiceLevel qualityOfServiceLevel)
+        public TopicGenerationContext(IMqttClient mqttClient, MqttRpcClientOptions options, string methodName, MqttQualityOfServiceLevel qualityOfServiceLevel)
        {
            MethodName = methodName ?? throw new ArgumentNullException(nameof(methodName));
-            Parameters = parameters;
            QualityOfServiceLevel = qualityOfServiceLevel;
            MqttClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));
            Options = options ?? throw new ArgumentNullException(nameof(options));
@@ -23,8 +20,6 @@ namespace MQTTnet.Extensions.Rpc

        public string MethodName { get; }

-        public IDictionary<string, object> Parameters { get; }
-
        public IMqttClient MqttClient { get; }

        public MqttRpcClientOptions Options { get; }
@@ -2,7 +2,7 @@

    <PropertyGroup>
        <TargetFrameworks>netstandard1.3;netstandard2.0;netstandard2.1;netcoreapp3.1;net5.0;net6.0;net7.0</TargetFrameworks>
-        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net461;net48</TargetFrameworks>
+        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net461</TargetFrameworks>
        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' AND '$(MSBuildRuntimeType)' != 'Core' ">$(TargetFrameworks);uap10.0</TargetFrameworks>
        
        <AssemblyName>MQTTnet.Extensions.WebSocket4Net</AssemblyName>
@@ -47,13 +47,13 @@ namespace MQTTnet.Extensions.WebSocket4Net
            var uri = _webSocketOptions.Uri;
            if (!uri.StartsWith("ws://", StringComparison.OrdinalIgnoreCase) && !uri.StartsWith("wss://", StringComparison.OrdinalIgnoreCase))
            {
-                if (_webSocketOptions.TlsOptions?.UseTls == true)
+                if (_webSocketOptions.TlsOptions?.UseTls == false)
                {
-                    uri = "wss://" + uri;
+                    uri = "ws://" + uri;
                }
                else
                {
-                    uri = "ws://" + uri;
+                    uri = "wss://" + uri;
                }
            }
            
@@ -92,7 +92,18 @@ namespace MQTTnet.Extensions.WebSocket4Net
            var webSocketVersion = WebSocketVersion.None;
            var receiveBufferSize = 0;

-            var certificates = _webSocketOptions.TlsOptions?.ClientCertificatesProvider?.GetCertificates();
+            var certificates = new X509CertificateCollection();
+            if (_webSocketOptions.TlsOptions?.Certificates != null)
+            {
+                foreach (var certificate in _webSocketOptions.TlsOptions.Certificates)
+                {
+#if WINDOWS_UWP
+                    certificates.Add(new X509Certificate(certificate));
+#else
+                    certificates.Add(certificate);
+#endif
+                }
+            }

            _webSocket = new WebSocket(uri, subProtocol, cookies, customHeaders, userAgent, origin, webSocketVersion, proxy, sslProtocols, receiveBufferSize)
            {
@@ -27,10 +27,8 @@ namespace MQTTnet.Extensions.WebSocket4Net
                    return new MqttChannelAdapter(
                        new MqttTcpChannel(options),
                        new MqttPacketFormatterAdapter(options.ProtocolVersion, new MqttBufferWriter(options.WriterBufferSize, options.WriterBufferSizeMax)),
-                        logger)
-                    {
-                        PacketInspector = packetInspector
-                    };
+                        packetInspector,
+                        logger);
                }

                case MqttClientWebSocketOptions webSocketOptions:
@@ -38,10 +36,8 @@ namespace MQTTnet.Extensions.WebSocket4Net
                    return new MqttChannelAdapter(
                        new WebSocket4NetMqttChannel(options, webSocketOptions),
                        new MqttPacketFormatterAdapter(options.ProtocolVersion, new MqttBufferWriter(options.WriterBufferSize, options.WriterBufferSizeMax)),
-                        logger)
-                    {
-                        PacketInspector = packetInspector
-                    };
+                        packetInspector,
+                        logger);
                }

                default:
@@ -33,18 +33,9 @@ namespace MQTTnet.TestApp

                client.ApplicationMessageReceivedAsync += e =>
                {
-                    var payloadText = string.Empty;
-                    if (e.ApplicationMessage.PayloadSegment.Count > 0)
-                    {
-                        payloadText = Encoding.UTF8.GetString(
-                            e.ApplicationMessage.PayloadSegment.Array,
-                            e.ApplicationMessage.PayloadSegment.Offset,
-                            e.ApplicationMessage.PayloadSegment.Count);
-                    }
-                    
                    Console.WriteLine("### RECEIVED APPLICATION MESSAGE ###");
                    Console.WriteLine($"+ Topic = {e.ApplicationMessage.Topic}");
-                    Console.WriteLine($"+ Payload = {payloadText}");
+                    Console.WriteLine($"+ Payload = {Encoding.UTF8.GetString(e.ApplicationMessage.Payload)}");
                    Console.WriteLine($"+ QoS = {e.ApplicationMessage.QualityOfServiceLevel}");
                    Console.WriteLine($"+ Retain = {e.ApplicationMessage.Retain}");
                    Console.WriteLine();
@@ -196,7 +196,7 @@ namespace MQTTnet.TestApp
            return new MqttApplicationMessage
            {
                Topic = "A/B/C",
-                PayloadSegment = new ArraySegment<byte>(Encoding.UTF8.GetBytes(Payload)),
+                Payload = Encoding.UTF8.GetBytes(Payload),
                QualityOfServiceLevel = MqttQualityOfServiceLevel.AtLeastOnce
            };
        }
@@ -229,7 +229,7 @@ namespace MQTTnet.TestApp
                var message = new MqttApplicationMessage
                {
                    Topic = "A/B/C",
-                    PayloadSegment = new ArraySegment<byte>(Encoding.UTF8.GetBytes("Hello World")),
+                    Payload = Encoding.UTF8.GetBytes("Hello World"),
                    QualityOfServiceLevel = MqttQualityOfServiceLevel.ExactlyOnce
                };

@@ -280,7 +280,7 @@ namespace MQTTnet.TestApp
                var message = new MqttApplicationMessage
                {
                    Topic = "A/B/C",
-                    PayloadSegment = new ArraySegment<byte>(Encoding.UTF8.GetBytes("Hello World")),
+                    Payload = Encoding.UTF8.GetBytes("Hello World"),
                    QualityOfServiceLevel = MqttQualityOfServiceLevel.AtLeastOnce
                };

@@ -331,7 +331,7 @@ namespace MQTTnet.TestApp
                var message = new MqttApplicationMessage
                {
                    Topic = "A/B/C",
-                    PayloadSegment = new ArraySegment<byte>(Encoding.UTF8.GetBytes("Hello World")),
+                    Payload = Encoding.UTF8.GetBytes("Hello World"),
                    QualityOfServiceLevel = MqttQualityOfServiceLevel.AtMostOnce
                };

@@ -20,25 +20,21 @@ namespace MQTTnet.TestApp
        {
 #if NET5_0_OR_GREATER
            // TLS13 is only available in Net5.0
-            var unsafeTls13 = new MqttClientTlsOptions
+            var unsafeTls13 = new MqttClientOptionsBuilderTlsParameters
            {
                UseTls = true,
                SslProtocol = SslProtocols.Tls13,
                // Don't use this in production code. This handler simply allows any invalid certificate to work.
-                AllowUntrustedCertificates = true,
-                IgnoreCertificateChainErrors = true,
-                CertificateValidationHandler = _ => true
+                CertificateValidationHandler = w => true
            };
 #endif
            // Also defining TLS12 for servers that don't seem no to support TLS13.
-            var unsafeTls12 = new MqttClientTlsOptions
+            var unsafeTls12 = new MqttClientOptionsBuilderTlsParameters
            {
                UseTls = true,
                SslProtocol = SslProtocols.Tls12,
                // Don't use this in production code. This handler simply allows any invalid certificate to work.
-                AllowUntrustedCertificates = true,
-                IgnoreCertificateChainErrors = true,
-                CertificateValidationHandler = _ => true
+                CertificateValidationHandler = w => true
            };

            // mqtt.eclipseprojects.io
@@ -48,16 +44,16 @@ namespace MQTTnet.TestApp

            await ExecuteTestAsync(
                "mqtt.eclipseprojects.io WS",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("mqtt.eclipseprojects.io:80/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).Build());
+                new MqttClientOptionsBuilder().WithWebSocketServer("mqtt.eclipseprojects.io:80/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).Build());

 #if NET5_0_OR_GREATER
            await ExecuteTestAsync("mqtt.eclipseprojects.io WS TLS13",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("mqtt.eclipseprojects.io:443/mqtt"))
-                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls13).Build());
+                new MqttClientOptionsBuilder().WithWebSocketServer("mqtt.eclipseprojects.io:443/mqtt")
+                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls13).Build());
            
            await ExecuteTestAsync("mqtt.eclipseprojects.io WS TLS13 (WebSocket4Net)",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("mqtt.eclipseprojects.io:443/mqtt"))
-                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls13).Build(),
+                new MqttClientOptionsBuilder().WithWebSocketServer("mqtt.eclipseprojects.io:443/mqtt")
+                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls13).Build(),
                    true);
 #endif

@@ -72,12 +68,12 @@ namespace MQTTnet.TestApp

            await ExecuteTestAsync(
                "test.mosquitto.org TCP TLS12",
-                new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 8883).WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls12).Build());
+                new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 8883).WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls12).Build());

 #if NET5_0_OR_GREATER
            await ExecuteTestAsync("test.mosquitto.org TCP TLS13",
                new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 8883)
-                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls13).Build());
+                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls13).Build());
 #endif

            await ExecuteTestAsync(
@@ -85,26 +81,26 @@ namespace MQTTnet.TestApp
                new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 8885)
                    .WithCredentials("rw", "readwrite")
                    .WithProtocolVersion(MqttProtocolVersion.V311)
-                    .WithTlsOptions(unsafeTls12)
+                    .WithTls(unsafeTls12)
                    .Build());

            await ExecuteTestAsync(
                "test.mosquitto.org WS",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("test.mosquitto.org:8080/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).Build());
+                new MqttClientOptionsBuilder().WithWebSocketServer("test.mosquitto.org:8080/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).Build());

            await ExecuteTestAsync(
                "test.mosquitto.org WS (WebSocket4Net)",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("test.mosquitto.org:8080/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).Build(),
+                new MqttClientOptionsBuilder().WithWebSocketServer("test.mosquitto.org:8080/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).Build(),
                true);

            await ExecuteTestAsync(
                "test.mosquitto.org WS TLS12",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("test.mosquitto.org:8081/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls12).Build());
+                new MqttClientOptionsBuilder().WithWebSocketServer("test.mosquitto.org:8081/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls12).Build());

-            await ExecuteTestAsync(
-                "test.mosquitto.org WS TLS12 (WebSocket4Net)",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("test.mosquitto.org:8081/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls12).Build(),
-                true);
+            // await ExecuteTestAsync(
+            //     "test.mosquitto.org WS TLS12 (WebSocket4Net)",
+            //     new MqttClientOptionsBuilder().WithWebSocketServer("test.mosquitto.org:8081/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls12).Build(),
+            //     true);

            // broker.emqx.io
            await ExecuteTestAsync(
@@ -113,30 +109,30 @@ namespace MQTTnet.TestApp

            await ExecuteTestAsync(
                "broker.emqx.io TCP TLS12",
-                new MqttClientOptionsBuilder().WithTcpServer("broker.emqx.io", 8883).WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls12).Build());
+                new MqttClientOptionsBuilder().WithTcpServer("broker.emqx.io", 8883).WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls12).Build());

 #if NET5_0_OR_GREATER
            await ExecuteTestAsync("broker.emqx.io TCP TLS13",
                new MqttClientOptionsBuilder().WithTcpServer("broker.emqx.io", 8883)
-                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls13).Build());
+                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls13).Build());
 #endif

            await ExecuteTestAsync(
                "broker.emqx.io WS",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.emqx.io:8083/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).Build());
+                new MqttClientOptionsBuilder().WithWebSocketServer("broker.emqx.io:8083/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).Build());

            await ExecuteTestAsync(
                "broker.emqx.io WS (WebSocket4Net)",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.emqx.io:8084/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).Build(),
+                new MqttClientOptionsBuilder().WithWebSocketServer("broker.emqx.io:8084/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).Build(),
                true);

            await ExecuteTestAsync(
                "broker.emqx.io WS TLS12",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.emqx.io:8084/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls12).Build());
+                new MqttClientOptionsBuilder().WithWebSocketServer("broker.emqx.io:8084/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls12).Build());

            await ExecuteTestAsync(
                "broker.emqx.io WS TLS12 (WebSocket4Net)",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.emqx.io:8084/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls12).Build(),
+                new MqttClientOptionsBuilder().WithWebSocketServer("broker.emqx.io:8084/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls12).Build(),
                true);

            // broker.hivemq.com
@@ -146,14 +142,15 @@ namespace MQTTnet.TestApp

            await ExecuteTestAsync(
                "broker.hivemq.com WS",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.hivemq.com:8000/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).Build());
+                new MqttClientOptionsBuilder().WithWebSocketServer("broker.hivemq.com:8000/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).Build());

            await ExecuteTestAsync(
                "broker.hivemq.com WS (WebSocket4Net)",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.hivemq.com:8000/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).Build(),
+                new MqttClientOptionsBuilder().WithWebSocketServer("broker.hivemq.com:8000/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).Build(),
                true);

            // mqtt.swifitch.cz: Does not seem to operate any more
+
            // cloudmqtt.com: Cannot test because it does not offer a free plan any more.

            Write("Finished.", ConsoleColor.White);
@@ -200,10 +197,9 @@ namespace MQTTnet.TestApp

                Write("[OK]\n", ConsoleColor.Green);
            }
-            catch (Exception exception)
+            catch (Exception e)
            {
-                Write("[FAILED]" + Environment.NewLine, ConsoleColor.Red);
-                Write(exception + Environment.NewLine, ConsoleColor.Red);
+                Write("[FAILED] " + e.Message + "\n", ConsoleColor.Red);
            }
        }

@@ -5,7 +5,6 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using MQTTnet.Diagnostics;
@@ -101,7 +100,7 @@ namespace MQTTnet.TestApp
                    {
                        // Replace the payload with the timestamp. But also extending a JSON 
                        // based payload with the timestamp is a suitable use case.
-                        e.ApplicationMessage.PayloadSegment = new ArraySegment<byte>(Encoding.UTF8.GetBytes(DateTime.Now.ToString("O")));
+                        e.ApplicationMessage.Payload = Encoding.UTF8.GetBytes(DateTime.Now.ToString("O"));
                    }

                    if (e.ApplicationMessage.Topic == "not_allowed_topic")
@@ -144,16 +143,10 @@ namespace MQTTnet.TestApp
                
                mqttServer.InterceptingPublishAsync += e =>
                {
-                    var payloadText = string.Empty;
-                    if (e.ApplicationMessage.PayloadSegment.Count > 0)
-                    {
-                        payloadText = Encoding.UTF8.GetString(
-                            e.ApplicationMessage.PayloadSegment.Array,
-                            e.ApplicationMessage.PayloadSegment.Offset,
-                            e.ApplicationMessage.PayloadSegment.Count);
-                    }
+                    MqttNetConsoleLogger.PrintToConsole(
+                        $"'{e.ClientId}' reported '{e.ApplicationMessage.Topic}' > '{Encoding.UTF8.GetString(e.ApplicationMessage.Payload ?? new byte[0])}'",
+                        ConsoleColor.Magenta);
                    
-                    MqttNetConsoleLogger.PrintToConsole($"'{e.ClientId}' reported '{e.ApplicationMessage.Topic}' > '{payloadText}'", ConsoleColor.Magenta);
                    return CompletedTask.Instance;
                };

@@ -9,7 +9,6 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using MQTTnet.Client;
-using MQTTnet.Diagnostics;
 using MQTTnet.Extensions.ManagedClient;
 using MQTTnet.Formatter;
 using MQTTnet.Internal;
@@ -20,18 +19,17 @@ using MQTTnet.Tests.Mockups;
 namespace MQTTnet.Tests.Clients.ManagedMqttClient
 {
    [TestClass]
-    public sealed class ManagedMqttClient_Tests : BaseTestClass
+    public sealed class ManagedMqttClient_Connection_Tests : BaseTestClass
    {
        [TestMethod]
        public async Task Connect_To_Invalid_Server()
        {
            using (var testEnvironment = CreateTestEnvironment())
            {
-                testEnvironment.IgnoreClientLogErrors = true;
+                await testEnvironment.StartServer();
+                await LongTestDelay();

-                var mqttClient = testEnvironment.CreateClient();
-
-                var managedClient = testEnvironment.Factory.CreateManagedMqttClient(mqttClient);
+                var managedClient = testEnvironment.Factory.CreateManagedMqttClient(testEnvironment.CreateClient());

                ConnectingFailedEventArgs connectingFailedEventArgs = null;
                managedClient.ConnectingFailedAsync += args =>
@@ -57,112 +55,6 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
            }
        }

-        [TestMethod]
-        public async Task Drop_New_Messages_On_Full_Queue()
-        {
-            var factory = new MqttFactory();
-            var managedClient = factory.CreateManagedMqttClient();
-            try
-            {
-                var clientOptions = new ManagedMqttClientOptionsBuilder().WithMaxPendingMessages(5)
-                    .WithPendingMessagesOverflowStrategy(MqttPendingMessagesOverflowStrategy.DropNewMessage);
-
-                clientOptions.WithClientOptions(o => o.WithTcpServer("localhost"));
-
-                await managedClient.StartAsync(clientOptions.Build());
-
-                await managedClient.EnqueueAsync("1");
-                await managedClient.EnqueueAsync("2");
-                await managedClient.EnqueueAsync("3");
-                await managedClient.EnqueueAsync("4");
-                await managedClient.EnqueueAsync("5");
-                await managedClient.EnqueueAsync("6");
-                await managedClient.EnqueueAsync("7");
-                await managedClient.EnqueueAsync("8");
-
-                Assert.AreEqual(5, managedClient.PendingApplicationMessagesCount);
-            }
-            finally
-            {
-                await managedClient.StopAsync();
-            }
-        }
-
-        [TestMethod]
-        public async Task Expose_Custom_Connection_Error()
-        {
-            using (var testEnvironment = CreateTestEnvironment())
-            {
-                var server = await testEnvironment.StartServer();
-
-                server.ValidatingConnectionAsync += args =>
-                {
-                    args.ReasonCode = MqttConnectReasonCode.BadUserNameOrPassword;
-                    return CompletedTask.Instance;
-                };
-
-                var managedClient = testEnvironment.Factory.CreateManagedMqttClient();
-
-                MqttClientDisconnectedEventArgs disconnectedArgs = null;
-                managedClient.DisconnectedAsync += args =>
-                {
-                    disconnectedArgs = args;
-                    return CompletedTask.Instance;
-                };
-
-                var clientOptions = testEnvironment.Factory.CreateManagedMqttClientOptionsBuilder().WithClientOptions(testEnvironment.CreateDefaultClientOptions()).Build();
-                await managedClient.StartAsync(clientOptions);
-
-                await LongTestDelay();
-
-                Assert.IsNotNull(disconnectedArgs);
-                Assert.AreEqual(MqttClientConnectResultCode.BadUserNameOrPassword, disconnectedArgs.ConnectResult.ResultCode);
-            }
-        }
-
-        [TestMethod]
-        public async Task ManagedClients_Will_Message_Send()
-        {
-            using (var testEnvironment = CreateTestEnvironment())
-            {
-                await testEnvironment.StartServer();
-
-                var receivedMessagesCount = 0;
-
-                var clientOptions = new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1", testEnvironment.ServerPort)
-                    .WithWillTopic("My/last/will")
-                    .WithWillQualityOfServiceLevel(MqttQualityOfServiceLevel.AtMostOnce)
-                    .Build();
-
-                var dyingClient = testEnvironment.CreateClient();
-                var dyingManagedClient = new MQTTnet.Extensions.ManagedClient.ManagedMqttClient(dyingClient, testEnvironment.ClientLogger);
-
-                await dyingManagedClient.StartAsync(new ManagedMqttClientOptionsBuilder().WithClientOptions(clientOptions).Build());
-
-                // Wait until the managed client is fully set up and running.
-                await Task.Delay(1000);
-
-                var receivingClient = await testEnvironment.ConnectClient();
-
-                receivingClient.ApplicationMessageReceivedAsync += e =>
-                {
-                    Interlocked.Increment(ref receivedMessagesCount);
-                    return CompletedTask.Instance;
-                };
-
-                await receivingClient.SubscribeAsync("My/last/will");
-
-                // Disposing the client will not sent a DISCONNECT packet so that connection is terminated
-                // which will lead to the will publish.
-                dyingManagedClient.Dispose();
-
-                // Wait for arrival of the will message at the receiver.
-                await Task.Delay(5000);
-
-                Assert.AreEqual(1, receivedMessagesCount);
-            }
-        }
-
        [TestMethod]
        public async Task Receive_While_Not_Cleanly_Disconnected()
        {
@@ -231,18 +123,18 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
            {
                var server = await testEnvironment.StartServer();

-                var managedClient = new MQTTnet.Extensions.ManagedClient.ManagedMqttClient(testEnvironment.CreateClient(), new MqttNetEventLogger());
+                var managedClient = testEnvironment.CreateManagedClient();
                var clientOptions = new MqttClientOptionsBuilder().WithTcpServer("localhost", testEnvironment.ServerPort);

                var connected = GetConnectedTask(managedClient);

-                await managedClient.StartAsync(new ManagedMqttClientOptionsBuilder().WithClientOptions(clientOptions).Build());
+                await managedClient.StartAsync(testEnvironment.CreateDefaultManagedMqttClientOptions());

                await connected;

                await managedClient.StopAsync();

-                await Task.Delay(500);
+                await LongTestDelay();

                Assert.AreEqual(0, (await server.GetClientsAsync()).Count);
            }
@@ -258,7 +150,7 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient

                await testEnvironment.StartServer();

-                var managedClient = new MQTTnet.Extensions.ManagedClient.ManagedMqttClient(testEnvironment.CreateClient(), new MqttNetEventLogger());
+                var managedClient = testEnvironment.CreateManagedClient();
                var clientOptions = new MqttClientOptionsBuilder().WithTcpServer("localhost", testEnvironment.ServerPort);
                var storage = new ManagedMqttClientTestStorage();

@@ -298,6 +190,8 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
        {
            using (var testEnvironment = CreateTestEnvironment())
            {
+                await testEnvironment.StartServer();
+
                var unmanagedClient = testEnvironment.CreateClient();
                var managedClient = await CreateManagedClientAsync(testEnvironment, unmanagedClient);

@@ -314,7 +208,7 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
                await managedClient.SubscribeAsync("unsubscribedThenSubscribed");

                //wait a bit for the subscriptions to become established before the messages are published
-                await Task.Delay(500);
+                await LongTestDelay();

                var sendingClient = await testEnvironment.ConnectClient();

@@ -344,7 +238,7 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
                await connected;

                // wait a bit so that the managed client can reestablish the subscriptions
-                await Task.Delay(500);
+                await LongTestDelay();

                received = SetupReceivingOfMessages(managedClient, 2);

@@ -360,7 +254,7 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
        {
            using (var testEnvironment = CreateTestEnvironment())
            {
-                await testEnvironment.StartServer().ConfigureAwait(false);
+                var server = await testEnvironment.StartServer().ConfigureAwait(false);

                var sendingClient = await testEnvironment.ConnectClient().ConfigureAwait(false);
                await sendingClient.PublishStringAsync("topic", "A", retain: true);
@@ -370,10 +264,10 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient

                await sendingClient.DisconnectAsync();

+                // Prepare retained messages.
+                await server.InjectApplicationMessage(testEnvironment.Factory.CreateApplicationMessageBuilder().WithTopic("topic").WithPayload("payload").WithRetainFlag().Build());
+
                // Now use the managed client and check if subscriptions get cleared properly.
-
-                var clientOptions = new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1", testEnvironment.ServerPort);
-
                var receivedManagedMessages = new List<MqttApplicationMessage>();

                var managedClient = testEnvironment.Factory.CreateManagedMqttClient(testEnvironment.CreateClient());
@@ -385,7 +279,10 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient

                await managedClient.SubscribeAsync("topic");

-                await managedClient.StartAsync(new ManagedMqttClientOptionsBuilder().WithClientOptions(clientOptions).WithAutoReconnectDelay(TimeSpan.FromSeconds(0.5)).Build());
+                var managedClientOptions = testEnvironment.CreateDefaultManagedMqttClientOptions();
+                managedClientOptions.ClientOptions.CleanSession = false;
+                await managedClient.StartAsync(managedClientOptions);
+
                await LongTestDelay();

                Assert.AreEqual(1, receivedManagedMessages.Count);
@@ -393,7 +290,8 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
                await managedClient.StopAsync();
                await LongTestDelay();

-                await managedClient.StartAsync(new ManagedMqttClientOptionsBuilder().WithClientOptions(clientOptions).WithAutoReconnectDelay(TimeSpan.FromSeconds(0.5)).Build());
+                await managedClient.StartAsync(managedClientOptions);
+
                await LongTestDelay();

                // After reconnect and then some delay, the retained message must not be received,
@@ -415,13 +313,14 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
        {
            using (var testEnvironment = CreateTestEnvironment())
            {
+                await testEnvironment.StartServer();
+
                // Use a long connection check interval to verify that the subscriptions
                // do not depend on the connection check interval anymore
                var connectionCheckInterval = TimeSpan.FromSeconds(10);
                var receivingClient = await CreateManagedClientAsync(testEnvironment, null, connectionCheckInterval);
                var sendingClient = await testEnvironment.ConnectClient();
-
-                await sendingClient.PublishAsync(new MqttApplicationMessage { Topic = "topic", PayloadSegment = new ArraySegment<byte>(new byte[] { 1 }), Retain = true });
+                await sendingClient.PublishAsync(new MqttApplicationMessage { Topic = "topic", Payload = new byte[] { 1 }, Retain = true });

                var subscribeTime = DateTime.UtcNow;

@@ -445,7 +344,9 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
        {
            using (var testEnvironment = CreateTestEnvironment())
            {
-                var managedClient = await CreateManagedClientAsync(testEnvironment);
+                await testEnvironment.StartServer();
+
+                var managedClient = testEnvironment.CreateManagedClient();

                var sendingClient = await testEnvironment.ConnectClient();

@@ -454,7 +355,7 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
                //wait a bit for the subscription to become established
                await Task.Delay(500);

-                await sendingClient.PublishAsync(new MqttApplicationMessage { Topic = "topic", PayloadSegment = new ArraySegment<byte>(new byte[] { 1 }), Retain = true });
+                await sendingClient.PublishAsync(new MqttApplicationMessage { Topic = "topic", Payload = new byte[] { 1 }, Retain = true });

                var messages = await SetupReceivingOfMessages(managedClient, 1);

@@ -471,14 +372,52 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
            }
        }

-        async Task<MQTTnet.Extensions.ManagedClient.ManagedMqttClient> CreateManagedClientAsync(
+        [TestMethod]
+        public async Task Will_Message_Send()
+        {
+            using (var testEnvironment = CreateTestEnvironment())
+            {
+                await testEnvironment.StartServer();
+
+                // Prepare the receiving client.
+                var receivedMessagesCount = 0;
+
+                var receivingClient = await testEnvironment.ConnectClient();
+                receivingClient.ApplicationMessageReceivedAsync += e =>
+                {
+                    Interlocked.Increment(ref receivedMessagesCount);
+                    return CompletedTask.Instance;
+                };
+
+                await receivingClient.SubscribeAsync("My/last/will");
+
+                // Prepare the managed client.
+                var clientOptions = new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1", testEnvironment.ServerPort).WithWillTopic("My/last/will").Build();
+
+                var dyingClient = testEnvironment.CreateClient();
+                var dyingManagedClient = testEnvironment.CreateManagedMqttClient(dyingClient);
+                await dyingManagedClient.StartAsync(new ManagedMqttClientOptionsBuilder().WithClientOptions(clientOptions).Build());
+
+                // Wait until the managed client is fully set up and running.
+                await LongTestDelay();
+
+                // Disposing the client will not sent a DISCONNECT packet so that connection is terminated
+                // which will lead to the will publish.
+                dyingManagedClient.Dispose();
+
+                // Wait for arrival of the will message at the receiver.
+                await LongTestDelay();
+
+                Assert.AreEqual(1, receivedMessagesCount);
+            }
+        }
+
+        static async Task<IManagedMqttClient> CreateManagedClientAsync(
            TestEnvironment testEnvironment,
            IMqttClient underlyingClient = null,
            TimeSpan? connectionCheckInterval = null,
            string host = "localhost")
        {
-            await testEnvironment.StartServer();
-
            var clientOptions = new MqttClientOptionsBuilder().WithTcpServer(host, testEnvironment.ServerPort);

            var managedOptions = new ManagedMqttClientOptionsBuilder().WithClientOptions(clientOptions).Build();
@@ -488,7 +427,7 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
            // at connection check intervals
            managedOptions.ConnectionCheckInterval = connectionCheckInterval ?? TimeSpan.FromSeconds(0.1);

-            var managedClient = new MQTTnet.Extensions.ManagedClient.ManagedMqttClient(underlyingClient ?? testEnvironment.CreateClient(), new MqttNetEventLogger());
+            var managedClient = testEnvironment.CreateManagedMqttClient(underlyingClient ?? testEnvironment.CreateClient());

            var connected = GetConnectedTask(managedClient);

@@ -499,35 +438,20 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
            return managedClient;
        }

-        /// <summary>
-        ///     Returns a task that will finish when the
-        ///     <paramref
-        ///         name="managedClient" />
-        ///     has connected
-        /// </summary>
-        Task GetConnectedTask(MQTTnet.Extensions.ManagedClient.ManagedMqttClient managedClient)
+        static Task GetConnectedTask(IManagedMqttClient managedClient)
        {
-            var connected = new TaskCompletionSource<bool>();
+            var promise = new TaskCompletionSource<bool>();

            managedClient.ConnectedAsync += e =>
            {
-                connected.TrySetResult(true);
+                promise.TrySetResult(true);
                return CompletedTask.Instance;
            };

-            return connected.Task;
+            return promise.Task;
        }

-        /// <summary>
-        ///     Returns a task that will return the messages received on
-        ///     <paramref
-        ///         name="managedClient" />
-        ///     when
-        ///     <paramref
-        ///         name="expectedNumberOfMessages" />
-        ///     have been received
-        /// </summary>
-        Task<List<MqttApplicationMessage>> SetupReceivingOfMessages(MQTTnet.Extensions.ManagedClient.ManagedMqttClient managedClient, int expectedNumberOfMessages)
+        static Task<List<MqttApplicationMessage>> SetupReceivingOfMessages(IManagedMqttClient managedClient, int expectedNumberOfMessages)
        {
            var receivedMessages = new List<MqttApplicationMessage>();
            var result = new AsyncTaskCompletionSource<List<MqttApplicationMessage>>();
@@ -550,7 +474,7 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient

    public class ManagedMqttClientTestStorage : IManagedMqttClientStorage
    {
-        IList<ManagedMqttApplicationMessage> _messages;
+        IList<ManagedMqttApplicationMessage> _messages = new List<ManagedMqttApplicationMessage>();

        public int GetMessageCount()
        {
@@ -559,11 +483,6 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient

        public Task<IList<ManagedMqttApplicationMessage>> LoadQueuedMessagesAsync()
        {
-            if (_messages == null)
-            {
-                _messages = new List<ManagedMqttApplicationMessage>();
-            }
-
            return Task.FromResult(_messages);
        }

@@ -0,0 +1,178 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using MQTTnet.Extensions.ManagedClient;
+using MQTTnet.Internal;
+
+namespace MQTTnet.Tests.ManagedMqttClient
+{
+    [TestClass]
+    public sealed class ManagedMqttClient_Event_Tests : BaseTestClass
+    {
+        [TestMethod]
+        public async Task Connecting_Should_Fire_Event()
+        {
+            using (var testEnvironment = CreateTestEnvironment())
+            {
+                await testEnvironment.StartServer();
+
+                var managedClient = testEnvironment.CreateManagedClient();
+
+                var eventFired = false;
+                managedClient.ConnectedAsync += e =>
+                {
+                    eventFired = true;
+                    return CompletedTask.Instance;
+                };
+
+                await managedClient.StartAsync(testEnvironment.CreateDefaultManagedMqttClientOptions());
+
+                await LongTestDelay();
+
+                Assert.IsTrue(eventFired);
+            }
+        }
+
+        [TestMethod]
+        public async Task Connecting_To_Invalid_Server_Should_Fire_Event()
+        {
+            using (var testEnvironment = CreateTestEnvironment())
+            {
+                testEnvironment.IgnoreClientLogErrors = true;
+
+                var managedClient = testEnvironment.CreateManagedMqttClient();
+
+                ConnectingFailedEventArgs connectingFailedEventArgs = null;
+                managedClient.ConnectingFailedAsync += args =>
+                {
+                    connectingFailedEventArgs = args;
+                    return CompletedTask.Instance;
+                };
+
+                await managedClient.StartAsync(
+                    new ManagedMqttClientOptions
+                    {
+                        ClientOptions = testEnvironment.Factory.CreateClientOptionsBuilder().WithTimeout(TimeSpan.FromSeconds(2)).WithTcpServer("wrong_server", 1234).Build()
+                    });
+
+                SpinWait.SpinUntil(() => connectingFailedEventArgs != null, 10000);
+
+                // The wrong server must be reported in general.
+                Assert.IsNotNull(connectingFailedEventArgs);
+                Assert.IsNotNull(connectingFailedEventArgs.Exception);
+                Assert.IsNull(connectingFailedEventArgs.ConnectResult);
+            }
+        }
+
+        [TestMethod]
+        public async Task Disconnect_Should_Fire_Event()
+        {
+            using (var testEnvironment = CreateTestEnvironment())
+            {
+                var server = await testEnvironment.StartServer();
+
+                var managedClient = testEnvironment.CreateManagedClient();
+
+                var eventFired = false;
+                managedClient.DisconnectedAsync += e =>
+                {
+                    eventFired = true;
+                    return CompletedTask.Instance;
+                };
+
+                await managedClient.StartAsync(testEnvironment.CreateDefaultManagedMqttClientOptions());
+
+                await LongTestDelay();
+
+                await server.StopAsync();
+
+                await LongTestDelay();
+
+                Assert.IsTrue(eventFired);
+            }
+        }
+
+        [TestMethod]
+        public async Task Enqueueing_Should_Fire_Event()
+        {
+            using (var testEnvironment = CreateTestEnvironment())
+            {
+                await testEnvironment.StartServer();
+
+                var managedClient = testEnvironment.CreateManagedClient();
+
+                var eventFired = false;
+                managedClient.ApplicationMessageEnqueueingAsync += e =>
+                {
+                    eventFired = true;
+                    return CompletedTask.Instance;
+                };
+
+                await managedClient.EnqueueAsync("A");
+
+                Assert.IsTrue(eventFired);
+            }
+        }
+
+        [TestMethod]
+        public async Task Subscription_Should_Fire_Event()
+        {
+            using (var testEnvironment = CreateTestEnvironment())
+            {
+                await testEnvironment.StartServer();
+
+                var managedClient = testEnvironment.CreateManagedClient();
+
+                await managedClient.SubscribeAsync("A");
+
+                var eventFired = false;
+                managedClient.SubscribeProcessedAsync += e =>
+                {
+                    eventFired = e.Options.TopicFilters[0].Topic == "A";
+                    return CompletedTask.Instance;
+                };
+
+                await managedClient.StartAsync(testEnvironment.CreateDefaultManagedMqttClientOptions());
+
+                await LongTestDelay();
+
+                Assert.IsTrue(eventFired);
+            }
+        }
+
+        [TestMethod]
+        public async Task Unsubscription_Should_Fire_Event()
+        {
+            using (var testEnvironment = CreateTestEnvironment())
+            {
+                await testEnvironment.StartServer();
+
+                var managedClient = testEnvironment.CreateManagedClient();
+
+                await managedClient.SubscribeAsync("A");
+
+                var eventFired = false;
+                managedClient.UnsubscribeProcessedAsync += e =>
+                {
+                    eventFired = e.Options.TopicFilters[0] == "A";
+                    return CompletedTask.Instance;
+                };
+
+                await managedClient.StartAsync(testEnvironment.CreateDefaultManagedMqttClientOptions());
+
+                await LongTestDelay();
+
+                await managedClient.UnsubscribeAsync("A");
+
+                await LongTestDelay();
+
+                Assert.IsTrue(eventFired);
+            }
+        }
+    }
+}
@@ -0,0 +1,135 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using MQTTnet.Extensions.ManagedClient;
+using MQTTnet.Implementations;
+using MQTTnet.Internal;
+using MQTTnet.Server;
+
+namespace MQTTnet.Tests.ManagedMqttClient
+{
+    [TestClass]
+    public sealed class ManagedMqttClient_Messages_Tests : BaseTestClass
+    {
+        [TestMethod]
+        public async Task Drop_New_Messages_On_Full_Queue()
+        {
+            using (var testEnvironment = CreateTestEnvironment())
+            {
+                await testEnvironment.StartServer();
+
+                var managedClient = testEnvironment.CreateManagedMqttClient();
+
+                var clientOptions = new ManagedMqttClientOptionsBuilder().WithClientOptions(o => o.WithTcpServer("localhost"))
+                    .WithMaxPendingMessages(5)
+                    .WithPendingMessagesOverflowStrategy(MqttPendingMessagesOverflowStrategy.DropNewMessage);
+
+                await managedClient.StartAsync(clientOptions.Build());
+
+                await managedClient.EnqueueAsync("1");
+                await managedClient.EnqueueAsync("2");
+                await managedClient.EnqueueAsync("3");
+                await managedClient.EnqueueAsync("4");
+                await managedClient.EnqueueAsync("5");
+                await managedClient.EnqueueAsync("6");
+                await managedClient.EnqueueAsync("7");
+                await managedClient.EnqueueAsync("8");
+
+                Assert.AreEqual(5, managedClient.EnqueuedApplicationMessagesCount);
+            }
+        }
+
+        [TestMethod]
+        public async Task Drop_Old_Messages_On_Full_Queue()
+        {
+            using (var testEnvironment = CreateTestEnvironment())
+            {
+                await testEnvironment.StartServer();
+
+                var managedClient = testEnvironment.CreateManagedMqttClient();
+
+                var clientOptions = new ManagedMqttClientOptionsBuilder().WithClientOptions(o => o.WithTcpServer("localhost"))
+                    .WithMaxPendingMessages(5)
+                    .WithPendingMessagesOverflowStrategy(MqttPendingMessagesOverflowStrategy.DropOldestQueuedMessage);
+
+                await managedClient.StartAsync(clientOptions.Build());
+
+                await managedClient.EnqueueAsync("1");
+                await managedClient.EnqueueAsync("2");
+                await managedClient.EnqueueAsync("3");
+                await managedClient.EnqueueAsync("4");
+                await managedClient.EnqueueAsync("5");
+                await managedClient.EnqueueAsync("6");
+                await managedClient.EnqueueAsync("7");
+                await managedClient.EnqueueAsync("8");
+
+                Assert.AreEqual(5, managedClient.EnqueuedApplicationMessagesCount);
+            }
+        }
+
+        [TestMethod]
+        public async Task Preserve_Order_Of_Subscriptions()
+        {
+            using (var testEnvironment = CreateTestEnvironment())
+            {
+                var server = await testEnvironment.StartServer();
+
+                // Prepare the retained messages.
+                await server.InjectApplicationMessage(testEnvironment.Factory.CreateApplicationMessageBuilder().WithTopic("A").WithPayload("P").WithRetainFlag().Build());
+                await server.InjectApplicationMessage(testEnvironment.Factory.CreateApplicationMessageBuilder().WithTopic("B").WithPayload("P").WithRetainFlag().Build());
+                await server.InjectApplicationMessage(testEnvironment.Factory.CreateApplicationMessageBuilder().WithTopic("C").WithPayload("P").WithRetainFlag().Build());
+                await server.InjectApplicationMessage(testEnvironment.Factory.CreateApplicationMessageBuilder().WithTopic("3").WithPayload("P").WithRetainFlag().Build());
+                await server.InjectApplicationMessage(testEnvironment.Factory.CreateApplicationMessageBuilder().WithTopic("2").WithPayload("P").WithRetainFlag().Build());
+                await server.InjectApplicationMessage(testEnvironment.Factory.CreateApplicationMessageBuilder().WithTopic("1").WithPayload("P").WithRetainFlag().Build());
+
+                // Subscribe to the retained messages in a defined order.
+                var managedClient = testEnvironment.CreateManagedMqttClient();
+
+                var applicationMessages = new List<MqttApplicationMessage>();
+                managedClient.ApplicationMessageReceivedAsync += e =>
+                {
+                    applicationMessages.Add(e.ApplicationMessage);
+                    return CompletedTask.Instance;
+                };
+
+                await managedClient.SubscribeAsync("B");
+                await managedClient.SubscribeAsync("C");
+                await managedClient.SubscribeAsync("A");
+                await managedClient.SubscribeAsync("2");
+                await managedClient.SubscribeAsync("1");
+                await managedClient.SubscribeAsync("3");
+
+                await managedClient.StartAsync(testEnvironment.CreateDefaultManagedMqttClientOptions()).ConfigureAwait(false);
+
+                await LongTestDelay();
+
+                var order = string.Join(string.Empty, applicationMessages.Select(a => a.Topic));
+
+                Assert.AreEqual("BCA213", order);
+            }
+        }
+
+        [TestMethod]
+        public async Task Publish()
+        {
+            using (var testEnvironment = CreateTestEnvironment())
+            {
+                testEnvironment.TrackServerReceivedApplicationMessages = true;
+                await testEnvironment.StartServer();
+
+                var managedClient = await testEnvironment.StartManagedClient();
+
+                await managedClient.EnqueueAsync(testEnvironment.Factory.CreateApplicationMessageBuilder().WithTopic("TEST").Build());
+
+                await LongTestDelay();
+
+                Assert.AreEqual(1, testEnvironment.ServerReceivedApplicationMessages.Count);
+            }
+        }
+    }
+}
@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.

 using System;
-using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
@@ -11,7 +10,6 @@ using MQTTnet.Client;
 using MQTTnet.Exceptions;
 using MQTTnet.Formatter;
 using MQTTnet.Internal;
-using MQTTnet.Packets;
 using MQTTnet.Protocol;
 using MQTTnet.Server;

@@ -101,8 +99,6 @@ namespace MQTTnet.Tests.Clients.MqttClient
                // Perform a clean disconnect.
                await client.DisconnectAsync(disconnectOptions);

-                await LongTestDelay();
-
                Assert.IsNotNull(eventArgs);
                Assert.AreEqual(MqttClientDisconnectType.Clean, eventArgs.DisconnectType);
            }
@@ -129,8 +125,6 @@ namespace MQTTnet.Tests.Clients.MqttClient
                // Perform a clean disconnect.
                await client.DisconnectAsync(disconnectOptions);

-                await LongTestDelay();
-
                Assert.IsNotNull(eventArgs);
                Assert.AreEqual(MqttDisconnectReasonCode.MessageRateTooHigh, eventArgs.ReasonCode);
            }
@@ -156,9 +150,7 @@ namespace MQTTnet.Tests.Clients.MqttClient

                // Perform a clean disconnect.
                await client.DisconnectAsync(disconnectOptions);
-
-                await LongTestDelay();
-
+                
                Assert.IsNotNull(eventArgs);
                Assert.IsNotNull(eventArgs.UserProperties);
                Assert.AreEqual(1, eventArgs.UserProperties.Count);
@@ -166,89 +158,5 @@ namespace MQTTnet.Tests.Clients.MqttClient
                Assert.AreEqual("test_value", eventArgs.UserProperties[0].Value);
            }
        }
-
-        [TestMethod]
-        public async Task No_Unobserved_Exception()
-        {
-            using (var testEnvironment = CreateTestEnvironment())
-            {
-                testEnvironment.IgnoreClientLogErrors = true;
-
-                var client = testEnvironment.CreateClient();
-                var options = new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1").WithTimeout(TimeSpan.FromSeconds(2)).Build();
-
-                try
-                {
-                    using (var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(0.5)))
-                    {
-                        await client.ConnectAsync(options, timeout.Token);
-                    }
-                }
-                catch (OperationCanceledException)
-                {
-                }
-
-                client.Dispose();
-
-                // These delays and GC calls are required in order to make calling the finalizer reproducible.
-                GC.Collect();
-                GC.WaitForPendingFinalizers();
-                await LongTestDelay();
-                await LongTestDelay();
-                await LongTestDelay();
-            }
-        }
-
-        [TestMethod]
-        public async Task Return_Non_Success()
-        {
-            using (var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500))
-            {
-                var server = await testEnvironment.StartServer();
-
-                server.ValidatingConnectionAsync += args =>
-                {
-                    args.ResponseUserProperties = new List<MqttUserProperty>
-                    {
-                        new MqttUserProperty("Property", "Value")
-                    };
-
-                    args.ReasonCode = MqttConnectReasonCode.QuotaExceeded;
-
-                    return CompletedTask.Instance;
-                };
-
-                var client = testEnvironment.CreateClient();
-
-                var response = await client.ConnectAsync(testEnvironment.CreateDefaultClientOptionsBuilder().WithoutThrowOnNonSuccessfulConnectResponse().Build());
-
-                Assert.IsNotNull(response);
-                Assert.AreEqual(MqttClientConnectResultCode.QuotaExceeded, response.ResultCode);
-                Assert.AreEqual(response.UserProperties[0].Name, "Property");
-                Assert.AreEqual(response.UserProperties[0].Value, "Value");
-            }
-        }
-
-        [TestMethod]
-        public async Task Throw_Proper_Exception_When_Not_Connected()
-        {
-            try
-            {
-                var mqttFactory = new MqttFactory();
-                using (var mqttClient = mqttFactory.CreateMqttClient())
-                {
-                    await mqttClient.SubscribeAsync("test", MqttQualityOfServiceLevel.AtLeastOnce);
-                }
-            }
-            catch (MqttCommunicationException exception)
-            {
-                if (exception.Message == "The client is not connected.")
-                {
-                    return;
-                }
-            }
-
-            Assert.Fail();
-        }
    }
 }
@@ -296,7 +296,7 @@ namespace MQTTnet.Tests.Clients.MqttClient

                Assert.IsNotNull(receivedMessage);
                Assert.AreEqual("A", receivedMessage.Topic);
-                Assert.AreEqual(null, receivedMessage.PayloadSegment.Array);
+                Assert.AreEqual(null, receivedMessage.Payload);
            }
        }

@@ -507,7 +507,7 @@ namespace MQTTnet.Tests.Clients.MqttClient

                client2.ApplicationMessageReceivedAsync += e =>
                {
-                    client2TopicResults.Add(Encoding.UTF8.GetString(e.ApplicationMessage.PayloadSegment.ToArray()));
+                    client2TopicResults.Add(Encoding.UTF8.GetString(e.ApplicationMessage.Payload));
                    return CompletedTask.Instance;
                };

@@ -30,7 +30,7 @@ namespace MQTTnet.Tests.Diagnostics

                    var packets = new List<string>();
                    
-                    mqttClient.InspectPacketAsync += eventArgs =>
+                    mqttClient.InspectPackage += eventArgs =>
                    {
                        packets.Add(eventArgs.Direction + ":" + Convert.ToBase64String(eventArgs.Buffer));
                        return CompletedTask.Instance;
@@ -0,0 +1,98 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using MQTTnet.Exceptions;
+using MQTTnet.Internal;
+
+namespace MQTTnet.Tests
+{
+    [TestClass]
+    public class Extension_Tests
+    {
+        [ExpectedException(typeof(MqttCommunicationTimedOutException))]
+        [TestMethod]
+        public async Task TimeoutAfter()
+        {
+            await MqttTaskTimeout.WaitAsync(ct => Task.Delay(TimeSpan.FromMilliseconds(500), ct),
+                TimeSpan.FromMilliseconds(100), CancellationToken.None);
+        }
+
+        [ExpectedException(typeof(MqttCommunicationTimedOutException))]
+        [TestMethod]
+        public async Task TimeoutAfterWithResult()
+        {
+            await MqttTaskTimeout.WaitAsync(
+                ct => Task.Delay(TimeSpan.FromMilliseconds(500), ct).ContinueWith(t => 5, ct),
+                TimeSpan.FromMilliseconds(100), CancellationToken.None);
+        }
+        
+        [TestMethod]
+        public async Task TimeoutAfterWithInnerException()
+        {
+            try
+            {
+                await MqttTaskTimeout.WaitAsync(ct => Task.Run(() =>
+                {
+                    var iis = new int[0];
+                    iis[1] = 0;
+                }, ct), TimeSpan.FromSeconds(1), CancellationToken.None);
+
+                Assert.Fail();
+            }
+            catch (Exception e)
+            {
+                Assert.IsTrue(e is IndexOutOfRangeException);
+            }
+        }
+
+        [TestMethod]
+        public async Task TimeoutAfterWithInnerExceptionWithResult()
+        {
+            try
+            {
+                await MqttTaskTimeout.WaitAsync(ct => Task.Run(() =>
+                {
+                    var iis = new int[0];
+                    iis[1] = 0;
+                    return iis[0];
+                }, ct), TimeSpan.FromSeconds(1), CancellationToken.None);
+
+                Assert.Fail();
+            }
+            catch (Exception e)
+            {
+                Assert.IsTrue(e is IndexOutOfRangeException);
+            }
+        }
+
+        [TestMethod]
+        public async Task TimeoutAfterMemoryUsage()
+        {
+            var initialMemory = GC.GetTotalMemory(true);
+
+            var tasks = Enumerable.Range(0, 100000)
+                .Select(i =>
+                {
+                    return MqttTaskTimeout.WaitAsync(ct => Task.Delay(TimeSpan.FromMilliseconds(1), ct),
+                        TimeSpan.FromMinutes(1), CancellationToken.None);
+                });
+
+            await Task.WhenAll(tasks);
+            AssertIsLess(initialMemory + 2_000_000, GC.GetTotalMemory(true));
+        }
+
+        static void AssertIsLess(long bound, long actual)
+        {
+            if (bound < actual)
+            {
+                Assert.Fail($"value must be less than {bound:N0} but is {actual:N0}");
+            }
+        }
+    }
+}
@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.

 using System;
-using System.Collections.Generic;
 using System.Text;
 using System.Threading.Tasks;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
@@ -46,34 +45,6 @@ namespace MQTTnet.Tests.Extensions
            }
        }

-        [TestMethod]
-        public async Task Execute_Success_Parameters_Propagated_Correctly()
-        {
-            var paramValue = "123";
-            var parameters = new Dictionary<string, object>
-            {
-                { TestParametersTopicGenerationStrategy.ExpectedParamName, "123" }
-            };
-
-            using (var testEnvironment = CreateTestEnvironment())
-            {
-                await testEnvironment.StartServer();
-
-                var responseSender = await testEnvironment.ConnectClient(new MqttClientOptionsBuilder());
-                await responseSender.SubscribeAsync($"MQTTnet.RPC/+/ping/{paramValue}");
-
-                responseSender.ApplicationMessageReceivedAsync += e => responseSender.PublishStringAsync(e.ApplicationMessage.Topic + "/response", "pong");
-
-                using (var rpcClient = await testEnvironment.ConnectRpcClient(new MqttRpcClientOptionsBuilder()
-                           .WithTopicGenerationStrategy(new TestParametersTopicGenerationStrategy()).Build()))
-                {
-                    var response = await rpcClient.ExecuteAsync(TimeSpan.FromSeconds(5), "ping", "", MqttQualityOfServiceLevel.AtMostOnce, parameters);
-
-                    Assert.AreEqual("pong", Encoding.UTF8.GetString(response));
-                }
-            }
-        }
-
        [TestMethod]
        public Task Execute_Success_With_QoS_0()
        {
@@ -164,7 +135,7 @@ namespace MQTTnet.Tests.Extensions

                using (var rpcClient = new MqttRpcClient(requestSender, new MqttRpcClientOptionsBuilder().Build()))
                {
-                    await rpcClient.ExecuteAsync(TimeSpan.FromSeconds(2), "ping", "", MqttQualityOfServiceLevel.AtMostOnce);
+                    var response = await rpcClient.ExecuteAsync(TimeSpan.FromSeconds(2), "ping", "", MqttQualityOfServiceLevel.AtMostOnce);
                }
            }
        }
@@ -251,32 +222,5 @@ namespace MQTTnet.Tests.Extensions
                };
            }
        }
-
-        class TestParametersTopicGenerationStrategy : IMqttRpcClientTopicGenerationStrategy
-        {
-            internal const string ExpectedParamName = "test_param_name";
-
-            public MqttRpcTopicPair CreateRpcTopics(TopicGenerationContext context)
-            {
-                if (context.Parameters == null)
-                {
-                    throw new InvalidOperationException("Parameters dictionary expected to be not null");
-                }
-
-                if (!context.Parameters.TryGetValue(ExpectedParamName, out var paramValue))
-                {
-                    throw new InvalidOperationException($"Parameter with name {ExpectedParamName} not present");
-                }
-
-                var requestTopic = $"MQTTnet.RPC/{Guid.NewGuid():N}/{context.MethodName}/{paramValue}";
-                var responseTopic = requestTopic + "/response";
-
-                return new MqttRpcTopicPair
-                {
-                    RequestTopic = requestTopic,
-                    ResponseTopic = responseTopic
-                };
-            }
-        }
    }
 }
@@ -23,7 +23,7 @@ namespace MQTTnet.Tests.Extensions

            using (var client = factory.CreateMqttClient())
            {
-                var options = new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("ws://a.b/mqtt")).WithTimeout(TimeSpan.FromSeconds(2)).Build();
+                var options = new MqttClientOptionsBuilder().WithWebSocketServer("ws://a.b/mqtt").WithTimeout(TimeSpan.FromSeconds(2)).Build();
                await client.ConnectAsync(options).ConfigureAwait(false);
            }
        }
@@ -111,7 +111,7 @@ namespace MQTTnet.Tests.Formatter
                PacketIdentifier = 123,
                Dup = true,
                Retain = true,
-                PayloadSegment = new ArraySegment<byte>(Encoding.ASCII.GetBytes("HELLO")),
+                Payload = Encoding.ASCII.GetBytes("HELLO"),
                QualityOfServiceLevel = MqttQualityOfServiceLevel.AtLeastOnce,
                Topic = "A/B/C"
            };
@@ -318,9 +318,10 @@ namespace MQTTnet.Tests.Formatter
            var publishPacket = new MqttPublishPacket
            {
                Topic = "abcdefghijklmnopqrstuvwxyz0123456789",
-                PayloadSegment = new ArraySegment<byte>(payload)
+                Payload = payload
            };

+
            var serializationHelper = new MqttPacketSerializationHelper();

            var buffer = serializationHelper.Encode(publishPacket);
@@ -328,17 +329,17 @@ namespace MQTTnet.Tests.Formatter

            Assert.IsNotNull(publishPacketCopy);
            Assert.AreEqual(publishPacket.Topic, publishPacketCopy.Topic);
-            CollectionAssert.AreEqual(publishPacket.PayloadSegment.ToArray(), publishPacketCopy.PayloadSegment.ToArray());
+            CollectionAssert.AreEqual(publishPacket.Payload, publishPacketCopy.Payload);

            // Now modify the payload and test again.
-            publishPacket.PayloadSegment = new ArraySegment<byte>(Encoding.UTF8.GetBytes("MQTT"));
+            publishPacket.Payload = Encoding.UTF8.GetBytes("MQTT");

            buffer = serializationHelper.Encode(publishPacket);
            var publishPacketCopy2 = serializationHelper.Decode(buffer) as MqttPublishPacket;

            Assert.IsNotNull(publishPacketCopy2);
            Assert.AreEqual(publishPacket.Topic, publishPacketCopy2.Topic);
-            CollectionAssert.AreEqual(publishPacket.PayloadSegment.ToArray(), publishPacketCopy2.PayloadSegment.ToArray());
+            CollectionAssert.AreEqual(publishPacket.Payload, publishPacketCopy2.Payload);
        }

        [TestMethod]
@@ -462,7 +463,7 @@ namespace MQTTnet.Tests.Formatter
                PacketIdentifier = 123,
                Dup = true,
                Retain = true,
-                PayloadSegment = new ArraySegment<byte>(Encoding.ASCII.GetBytes("HELLO")),
+                Payload = Encoding.ASCII.GetBytes("HELLO"),
                QualityOfServiceLevel = MqttQualityOfServiceLevel.AtLeastOnce,
                Topic = "A/B/C"
            };
@@ -566,6 +567,7 @@ namespace MQTTnet.Tests.Formatter
                    using (var adapter = new MqttChannelAdapter(
                               channel,
                               new MqttPacketFormatterAdapter(protocolVersion, new MqttBufferWriter(4096, 65535)),
+                               null,
                               new MqttNetEventLogger()))
                    {
                        var receivedPacket = adapter.ReceivePacketAsync(CancellationToken.None).GetAwaiter().GetResult();
@@ -581,12 +583,19 @@ namespace MQTTnet.Tests.Formatter
        MqttProtocolVersion DeserializeAndDetectVersion(MqttPacketFormatterAdapter packetFormatterAdapter, byte[] buffer)
        {
            var channel = new MemoryMqttChannel(buffer);
-            var adapter = new MqttChannelAdapter(channel, packetFormatterAdapter, new MqttNetEventLogger());
+            var adapter = new MqttChannelAdapter(channel, packetFormatterAdapter, null, new MqttNetEventLogger());

            adapter.ReceivePacketAsync(CancellationToken.None).GetAwaiter().GetResult();
            return packetFormatterAdapter.ProtocolVersion;
        }

+        MqttBufferReader ReaderFactory(byte[] data)
+        {
+            var reader = new MqttBufferReader();
+            reader.SetBuffer(data, 0, data.Length);
+            return reader;
+        }
+
        TPacket Roundtrip<TPacket>(TPacket packet, MqttProtocolVersion protocolVersion = MqttProtocolVersion.V311, MqttBufferWriter bufferWriter = null) where TPacket : MqttPacket
        {
            var writer = bufferWriter ?? WriterFactory();
@@ -595,7 +604,7 @@ namespace MQTTnet.Tests.Formatter

            using (var channel = new MemoryMqttChannel(buffer.Join().ToArray()))
            {
-                var adapter = new MqttChannelAdapter(channel, new MqttPacketFormatterAdapter(protocolVersion, new MqttBufferWriter(4096, 65535)), new MqttNetEventLogger());
+                var adapter = new MqttChannelAdapter(channel, new MqttPacketFormatterAdapter(protocolVersion, new MqttBufferWriter(4096, 65535)), null, new MqttNetEventLogger());
                return (TPacket)adapter.ReceivePacketAsync(CancellationToken.None).GetAwaiter().GetResult();
            }
        }
@@ -2,9 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.

-using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using MQTTnet.Exceptions;
@@ -78,7 +76,7 @@ namespace MQTTnet.Tests.Formatter
            Assert.IsNull(deserialized.UserProperties); // Not supported in v3.1.1
        }
        
-        [TestMethod]
+                [TestMethod]
        public void Serialize_Full_MqttConnAckPacket_V310()
        {
            var connAckPacket = new MqttConnAckPacket
@@ -298,7 +296,7 @@ namespace MQTTnet.Tests.Formatter
                PacketIdentifier = 123,
                Dup = true,
                Retain = true,
-                PayloadSegment = new ArraySegment<byte>(Encoding.ASCII.GetBytes("Payload")),
+                Payload = Encoding.ASCII.GetBytes("Payload"),
                QualityOfServiceLevel = MqttQualityOfServiceLevel.AtLeastOnce,
                Topic = "Topic",
                ResponseTopic = "/Response",
@@ -322,7 +320,7 @@ namespace MQTTnet.Tests.Formatter
            Assert.AreEqual(publishPacket.PacketIdentifier, deserialized.PacketIdentifier);
            Assert.AreEqual(publishPacket.Dup, deserialized.Dup);
            Assert.AreEqual(publishPacket.Retain, deserialized.Retain);
-            CollectionAssert.AreEqual(publishPacket.PayloadSegment.ToArray(), deserialized.PayloadSegment.ToArray());
+            CollectionAssert.AreEqual(publishPacket.Payload, deserialized.Payload);
            Assert.AreEqual(publishPacket.QualityOfServiceLevel, deserialized.QualityOfServiceLevel);
            Assert.AreEqual(publishPacket.Topic, deserialized.Topic);
            Assert.AreEqual(null, deserialized.ResponseTopic); // Not supported in v3.1.1.
@@ -2,9 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.

-using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using MQTTnet.Formatter;
@@ -259,7 +257,7 @@ namespace MQTTnet.Tests.Formatter
                PacketIdentifier = 123,
                Dup = true,
                Retain = true,
-                PayloadSegment = new ArraySegment<byte>(Encoding.ASCII.GetBytes("Payload")),
+                Payload = Encoding.ASCII.GetBytes("Payload"),
                QualityOfServiceLevel = MqttQualityOfServiceLevel.AtLeastOnce,
                Topic = "Topic",
                ResponseTopic = "/Response",
@@ -283,7 +281,7 @@ namespace MQTTnet.Tests.Formatter
            Assert.AreEqual(publishPacket.PacketIdentifier, deserialized.PacketIdentifier);
            Assert.AreEqual(publishPacket.Dup, deserialized.Dup);
            Assert.AreEqual(publishPacket.Retain, deserialized.Retain);
-            CollectionAssert.AreEqual(publishPacket.PayloadSegment.ToArray(), deserialized.PayloadSegment.ToArray());
+            CollectionAssert.AreEqual(publishPacket.Payload, deserialized.Payload);
            Assert.AreEqual(publishPacket.QualityOfServiceLevel, deserialized.QualityOfServiceLevel);
            Assert.AreEqual(publishPacket.Topic, deserialized.Topic);
            Assert.AreEqual(publishPacket.ResponseTopic, deserialized.ResponseTopic);
@@ -1,7 +1,6 @@
 using System;
 using System.Linq;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
-using MQTTnet.Exceptions;
 using MQTTnet.Formatter;

 namespace MQTTnet.Tests.Formatter
@@ -48,32 +47,23 @@ namespace MQTTnet.Tests.Formatter
            Assert.AreEqual(1234U, reader.ReadVariableByteInteger());
            Assert.AreEqual(9876U, reader.ReadVariableByteInteger());
        }
-        
-        [TestMethod]
-        [ExpectedException(typeof(MqttProtocolViolationException))]
-        public void Throw_If_String_Too_Long()
-        {
-            var writer = new MqttBufferWriter(4096, 65535);
-            
-            writer.WriteString(string.Empty.PadLeft(65536));
-        }

        [TestMethod]
        public void Write_And_Read_Multiple_Times()
        {
            var writer = new MqttBufferWriter(4096, 65535);
            writer.WriteString("A relative short string.");
-            writer.WriteBinary(new byte[1234]);
+            writer.WriteBinaryData(new byte[1234]);
            writer.WriteByte(0x01);
            writer.WriteByte(0x02);
            writer.WriteVariableByteInteger(5647382);
            writer.WriteString("A relative short string.");
            writer.WriteVariableByteInteger(8574489);
-            writer.WriteBinary(new byte[48]);
+            writer.WriteBinaryData(new byte[48]);
            writer.WriteByte(2);
            writer.WriteByte(0x02);
            writer.WriteString("fjgffiogfhgfhoihgoireghreghreguhreguireoghreouighreouighreughreguiorehreuiohruiorehreuioghreug");
-            writer.WriteBinary(new byte[3]);
+            writer.WriteBinaryData(new byte[3]);

            var readPayload = new ArraySegment<byte>(writer.GetBuffer(), 0, writer.Length).ToArray();

@@ -1,8 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">

    <PropertyGroup>
-        <TargetFrameworks>netcoreapp3.1;net7.0</TargetFrameworks>
-        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net48</TargetFrameworks>
+        <TargetFrameworks>net452;net461;net48;netcoreapp3.1;net6.0;net7.0</TargetFrameworks>
        <IsPackable>false</IsPackable>
        <LangVersion>7.3</LangVersion>
        <EnableNETAnalyzers>false</EnableNETAnalyzers>
@@ -273,7 +273,7 @@ namespace MQTTnet.Tests.MQTTv5
                Assert.AreEqual(applicationMessage.ResponseTopic, receivedMessage.ResponseTopic);
                Assert.AreEqual(applicationMessage.MessageExpiryInterval, receivedMessage.MessageExpiryInterval);
                CollectionAssert.AreEqual(applicationMessage.CorrelationData, receivedMessage.CorrelationData);
-                CollectionAssert.AreEqual(applicationMessage.PayloadSegment.ToArray(), receivedMessage.PayloadSegment.ToArray());
+                CollectionAssert.AreEqual(applicationMessage.Payload, receivedMessage.Payload);
                CollectionAssert.AreEqual(applicationMessage.UserProperties, receivedMessage.UserProperties);
            }
        }
@@ -51,7 +51,10 @@ namespace MQTTnet.Tests.Mockups

        public void AssertReceivedCountEquals(int expectedCount)
        {
-            Assert.AreEqual(expectedCount, Count);
+            lock (_receivedEventArgs)
+            {
+                Assert.AreEqual(expectedCount, _receivedEventArgs.Count);
+            }
        }

        public string GeneratePayloadSequence()
@@ -2,6 +2,8 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.

+#region
+
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
@@ -19,14 +21,18 @@ using MQTTnet.LowLevelClient;
 using MQTTnet.Protocol;
 using MQTTnet.Server;

+#endregion
+
 namespace MQTTnet.Tests.Mockups
 {
    public sealed class TestEnvironment : IDisposable
    {
        readonly List<string> _clientErrors = new List<string>();
        readonly List<IMqttClient> _clients = new List<IMqttClient>();
+
        readonly List<Exception> _exceptions = new List<Exception>();
        readonly List<ILowLevelMqttClient> _lowLevelClients = new List<ILowLevelMqttClient>();
+        readonly List<IManagedMqttClient> _managedClients = new List<IManagedMqttClient>();
        readonly MqttProtocolVersion _protocolVersion;
        readonly List<string> _serverErrors = new List<string>();

@@ -39,8 +45,6 @@ namespace MQTTnet.Tests.Mockups
            _protocolVersion = protocolVersion;
            TestContext = testContext;

-            TaskScheduler.UnobservedTaskException += TrackUnobservedTaskException;
-
            ServerLogger.LogMessagePublished += (s, e) =>
            {
                if (Debugger.IsAttached)
@@ -66,12 +70,9 @@ namespace MQTTnet.Tests.Mockups

                if (e.LogMessage.Level == MqttNetLogLevel.Error)
                {
-                    if (!IgnoreClientLogErrors)
+                    lock (_clientErrors)
                    {
-                        lock (_clientErrors)
-                        {
-                            _clientErrors.Add(e.LogMessage.ToString());
-                        }
+                        _clientErrors.Add(e.LogMessage.ToString());
                    }
                }
            };
@@ -93,8 +94,12 @@ namespace MQTTnet.Tests.Mockups

        public int ServerPort { get; set; }

+        public List<MqttApplicationMessage> ServerReceivedApplicationMessages { get; } = new List<MqttApplicationMessage>();
+
        public TestContext TestContext { get; }

+        public bool TrackServerReceivedApplicationMessages { get; set; }
+
        public Task<IMqttClient> ConnectClient()
        {
            return ConnectClient(Factory.CreateClientOptionsBuilder().WithProtocolVersion(_protocolVersion));
@@ -216,31 +221,35 @@ namespace MQTTnet.Tests.Mockups

        public IMqttClient CreateClient()
        {
-            var logger = EnableLogger ? (IMqttNetLogger)ClientLogger : MqttNetNullLogger.Instance;
-
-            var client = Factory.CreateMqttClient(logger);
-
-            client.ConnectingAsync += e =>
-            {
-                if (TestContext != null)
-                {
-                    var clientOptions = e.ClientOptions;
-                    var existingClientId = clientOptions.ClientId;
-                    if (existingClientId != null && !existingClientId.StartsWith(TestContext.TestName))
-                    {
-                        clientOptions.ClientId = TestContext.TestName + "_" + existingClientId;
-                    }
-                }
-
-                return CompletedTask.Instance;
-            };
-
            lock (_clients)
            {
-                _clients.Add(client);
-            }
+                var logger = EnableLogger ? (IMqttNetLogger)ClientLogger : new MqttNetNullLogger();

-            return client;
+                var client = Factory.CreateMqttClient(logger);
+                _clients.Add(client);
+
+                client.ConnectingAsync += e =>
+                {
+                    if (TestContext != null)
+                    {
+                        var clientOptions = e.ClientOptions;
+                        var existingClientId = clientOptions.ClientId;
+                        if (existingClientId != null && !existingClientId.StartsWith(TestContext.TestName))
+                        {
+                            clientOptions.ClientId = TestContext.TestName + "_" + existingClientId;
+                        }
+                    }
+
+                    return CompletedTask.Instance;
+                };
+
+                return client;
+            }
+        }
+
+        public ManagedMqttClientOptions CreateDefaultManagedMqttClientOptions()
+        {
+            return Factory.CreateManagedMqttClientOptionsBuilder().WithClientOptions(Factory.CreateClientOptionsBuilder().WithTcpServer("127.0.0.1", ServerPort).Build()).Build();
        }

        public MqttClientOptions CreateDefaultClientOptions()
@@ -250,22 +259,33 @@ namespace MQTTnet.Tests.Mockups

        public MqttClientOptionsBuilder CreateDefaultClientOptionsBuilder()
        {
-            return Factory.CreateClientOptionsBuilder()
-                .WithProtocolVersion(_protocolVersion)
-                .WithTcpServer("127.0.0.1", ServerPort)
-                .WithClientId(TestContext.TestName + "_" + Guid.NewGuid());
+            return Factory.CreateClientOptionsBuilder().WithProtocolVersion(_protocolVersion).WithTcpServer("127.0.0.1", ServerPort);
        }

        public ILowLevelMqttClient CreateLowLevelClient()
        {
-            var client = Factory.CreateLowLevelMqttClient(ClientLogger);
-
-            lock (_lowLevelClients)
+            lock (_clients)
            {
+                var client = Factory.CreateLowLevelMqttClient(ClientLogger);
                _lowLevelClients.Add(client);
-            }

-            return client;
+                return client;
+            }
+        }
+
+        public IManagedMqttClient CreateManagedClient()
+        {
+            return Factory.CreateManagedMqttClient(CreateClient());
+        }
+
+        public IManagedMqttClient CreateManagedMqttClient()
+        {
+            return Factory.CreateManagedMqttClient(CreateClient(), ClientLogger);
+        }
+
+        public IManagedMqttClient CreateManagedMqttClient(IMqttClient client)
+        {
+            return Factory.CreateManagedMqttClient(client, ClientLogger);
        }

        public MqttServer CreateServer(MqttServerOptions options)
@@ -279,6 +299,11 @@ namespace MQTTnet.Tests.Mockups

            Server = Factory.CreateMqttServer(options, logger);

+            if (TrackServerReceivedApplicationMessages)
+            {
+                Server.InterceptingPublishAsync += ServerOnInterceptingPublishAsync;
+            }
+
            Server.ValidatingConnectionAsync += e =>
            {
                if (TestContext != null)
@@ -299,69 +324,65 @@ namespace MQTTnet.Tests.Mockups

        public void Dispose()
        {
-            try
+            foreach (var mqttClient in _clients)
            {
-                lock (_clients)
-                {
-                    foreach (var mqttClient in _clients)
-                    {
-                        try
-                        {
-                            //mqttClient.DisconnectAsync().GetAwaiter().GetResult();
-                        }
-                        catch
-                        {
-                            // This can happen when the test already disconnected the client.
-                        }
-                        finally
-                        {
-                            mqttClient?.Dispose();
-                        }
-                    }
-
-                    _clients.Clear();
-                }
-
-                lock (_lowLevelClients)
-                {
-                    foreach (var lowLevelMqttClient in _lowLevelClients)
-                    {
-                        lowLevelMqttClient.Dispose();
-                    }
-
-                    _lowLevelClients.Clear();
-                }
-
                try
                {
-                    Server?.StopAsync().GetAwaiter().GetResult();
+                    //mqttClient.DisconnectAsync().GetAwaiter().GetResult();
                }
                catch
                {
-                    // This can happen when the test already stopped the server.
+                    // This can happen when the test already disconnected the client.
                }
                finally
                {
-                    Server?.Dispose();
+                    mqttClient?.Dispose();
                }
+            }

-                Server = null;
-
-                ThrowIfLogErrors();
-
-                GC.Collect();
-                GC.WaitForFullGCComplete();
-                GC.WaitForPendingFinalizers();
-                
-                if (_exceptions.Any())
+            foreach (var managedMqttClient in _managedClients)
+            {
+                try
                {
-                    throw new Exception($"{_exceptions.Count} exceptions tracked.\r\n" + string.Join(Environment.NewLine, _exceptions));
+                    managedMqttClient.StopAsync().Wait();
                }
+                finally
+                {
+                    managedMqttClient.Dispose();
+                }
+            }
+
+            foreach (var lowLevelMqttClient in _lowLevelClients)
+            {
+                lowLevelMqttClient.Dispose();
+            }
+
+            try
+            {
+                Server?.StopAsync().GetAwaiter().GetResult();
+            }
+            catch
+            {
+                // This can happen when the test already stopped the server.
            }
            finally
            {
-                TaskScheduler.UnobservedTaskException -= TrackUnobservedTaskException;
+                Server?.Dispose();
            }
+
+            ThrowIfLogErrors();
+
+            if (_exceptions.Any())
+            {
+                throw new Exception($"{_exceptions.Count} exceptions tracked.\r\n" + string.Join(Environment.NewLine, _exceptions));
+            }
+        }
+
+        public async Task<IManagedMqttClient> StartManagedClient()
+        {
+            var managedClient = Factory.CreateManagedMqttClient(CreateClient());
+            await managedClient.StartAsync(CreateDefaultManagedMqttClientOptions());
+            return managedClient;
        }

        public Task<MqttServer> StartServer()
@@ -377,7 +398,7 @@ namespace MQTTnet.Tests.Mockups

            var options = optionsBuilder.Build();
            var server = CreateServer(options);
-            await server.StartAsync().ConfigureAwait(false);
+            await server.StartAsync();

            // The OS has chosen the port to we have to properly expose it to the tests.
            ServerPort = options.DefaultEndpointOptions.Port;
@@ -405,49 +426,43 @@ namespace MQTTnet.Tests.Mockups

        public void ThrowIfLogErrors()
        {
-            if (!IgnoreServerLogErrors)
+            lock (_serverErrors)
            {
-                lock (_serverErrors)
+                if (!IgnoreServerLogErrors && _serverErrors.Count > 0)
                {
-                    if (_serverErrors.Count > 0)
-                    {
-                        var message = $"Server had {_serverErrors.Count} errors (${string.Join(Environment.NewLine, _serverErrors)}).";
-                        Console.WriteLine(message);
-                        throw new Exception(message);
-                    }
+                    var message = $"Server had {_serverErrors.Count} errors (${string.Join(Environment.NewLine, _serverErrors)}).";
+                    Console.WriteLine(message);
+                    throw new Exception(message);
                }
            }

-            if (!IgnoreClientLogErrors)
+            lock (_clientErrors)
            {
-                lock (_clientErrors)
+                if (!IgnoreClientLogErrors && _clientErrors.Count > 0)
                {
-                    if (_clientErrors.Count > 0)
-                    {
-                        var message = $"Client(s) had {_clientErrors.Count} errors (${string.Join(Environment.NewLine, _clientErrors)})";
-                        Console.WriteLine(message);
-                        throw new Exception(message);
-                    }
+                    var message = $"Client(s) had {_clientErrors.Count} errors (${string.Join(Environment.NewLine, _clientErrors)})";
+                    Console.WriteLine(message);
+                    throw new Exception(message);
                }
            }
        }

        public void TrackException(Exception exception)
        {
-            if (exception == null)
-            {
-                return;
-            }
-
            lock (_exceptions)
            {
                _exceptions.Add(exception);
            }
        }

-        void TrackUnobservedTaskException(object sender, UnobservedTaskExceptionEventArgs e)
+        Task ServerOnInterceptingPublishAsync(InterceptingPublishEventArgs arg)
        {
-            TrackException(e.Exception);
+            lock (ServerReceivedApplicationMessages)
+            {
+                ServerReceivedApplicationMessages.Add(arg.ApplicationMessage);
+            }
+
+            return CompletedTask.Instance;
        }
    }
 }
@@ -4,7 +4,6 @@

 using System;
 using System.IO;
-using System.Linq;
 using System.Text;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using MQTTnet.Protocol;
@@ -12,7 +11,7 @@ using MQTTnet.Protocol;
 namespace MQTTnet.Tests
 {
    [TestClass]
-    public sealed class MqttApplicationMessageBuilder_Tests
+    public class MqttApplicationMessageBuilder_Tests
    {
        [TestMethod]
        public void CreateApplicationMessage_TopicOnly()
@@ -30,7 +29,7 @@ namespace MQTTnet.Tests
            Assert.AreEqual("xyz", message.Topic);
            Assert.IsFalse(message.Retain);
            Assert.AreEqual(MqttQualityOfServiceLevel.AtMostOnce, message.QualityOfServiceLevel);
-            Assert.AreEqual(Encoding.UTF8.GetString(message.PayloadSegment.ToArray()), "00:06:00");
+            Assert.AreEqual(Encoding.UTF8.GetString(message.Payload), "00:06:00");
        }

        [TestMethod]
@@ -42,7 +41,7 @@ namespace MQTTnet.Tests
            Assert.AreEqual("123", message.Topic);
            Assert.IsFalse(message.Retain);
            Assert.AreEqual(MqttQualityOfServiceLevel.AtMostOnce, message.QualityOfServiceLevel);
-            Assert.AreEqual(Encoding.UTF8.GetString(message.PayloadSegment.ToArray()), "Hello");
+            Assert.AreEqual(Encoding.UTF8.GetString(message.Payload), "Hello");
        }

        [TestMethod]
@@ -1,45 +0,0 @@
-#pragma warning disable CS0618 // Type or member is obsolete
-
-using Microsoft.VisualStudio.TestTools.UnitTesting;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace MQTTnet.Tests
-{
-    [TestClass]
-    public sealed class MqttApplicationMessageTest
-    {
-        [TestMethod]
-        public void PayloadSegment()
-        {
-            var message = new MqttApplicationMessage();
-            Assert.AreEqual(0, message.Payload.Length);
-            Assert.AreEqual(0, message.PayloadSegment.Count);
-
-            Assert.IsTrue(ReferenceEquals(message.Payload, message.PayloadSegment.Array));
-
-            message.Payload = new byte[] { 1, 2 };
-            Assert.AreEqual(2, message.Payload.Length);
-            Assert.AreEqual(2, message.PayloadSegment.Count);
-            Assert.IsTrue(ReferenceEquals(message.Payload, message.PayloadSegment.Array));
-
-            message.Payload = new byte[] { 1, 2, 3 };
-            Assert.AreEqual(3, message.Payload.Length);
-            Assert.AreEqual(3, message.PayloadSegment.Count);
-            Assert.IsTrue(ReferenceEquals(message.Payload, message.PayloadSegment.Array));
-
-            message.PayloadSegment = new ArraySegment<byte>(new byte[] { 1, 2, 3 });
-            Assert.AreEqual(3, message.Payload.Length);
-            Assert.AreEqual(3, message.PayloadSegment.Count);
-            Assert.IsTrue(ReferenceEquals(message.Payload, message.PayloadSegment.Array));
-
-            message.PayloadSegment = new ArraySegment<byte>(new byte[] { 1, 2, 3 }, 1, 1);
-            Assert.AreEqual(1, message.Payload.Length);
-            Assert.AreEqual(1, message.PayloadSegment.Count);
-            Assert.IsFalse(ReferenceEquals(message.Payload, message.PayloadSegment.Array));
-        }
-    }
-}
@@ -31,7 +31,7 @@ namespace MQTTnet.Tests
            {
                var formatterAdapter = new MqttPacketFormatterAdapter(_protocolVersion, new MqttBufferWriter(4096, 65535));

-                var adapter = new MqttChannelAdapter(channel, formatterAdapter, MqttNetNullLogger.Instance);
+                var adapter = new MqttChannelAdapter(channel, formatterAdapter, null, MqttNetNullLogger.Instance);
                return adapter.ReceivePacketAsync(CancellationToken.None).GetAwaiter().GetResult();
            }
        }
@@ -24,10 +24,10 @@ namespace MQTTnet.Tests
            writer.WriteString("1234567890");
            Assert.AreEqual(10 + 2, writer.Length);

-            writer.WriteBinary(new byte[300]);
+            writer.WriteBinaryData(new byte[300]);
            Assert.AreEqual(300 + 2 + 12, writer.Length);

-            writer.WriteBinary(new byte[5000]);
+            writer.WriteBinaryData(new byte[5000]);
            Assert.AreEqual(5000 + 2 + 300 + 2 + 12, writer.Length);
        }
    }
@@ -598,7 +598,8 @@ namespace MQTTnet.Tests.Server
                // c
                var c1 = await testEnvironment.ConnectClient(clientOptionsBuilder);

-                await LongTestDelay();
+                await Task.Delay(500);
+
                var flow = string.Join(string.Empty, events);
                Assert.AreEqual("c", flow);

@@ -606,8 +607,10 @@ namespace MQTTnet.Tests.Server
                // Connect client with same client ID. Should disconnect existing client.
                var c2 = await testEnvironment.ConnectClient(clientOptionsBuilder);

-                await LongTestDelay();
+                await Task.Delay(500);
+
                flow = string.Join(string.Empty, events);
+
                Assert.AreEqual("cdc", flow);

                c2.ApplicationMessageReceivedAsync += e =>
@@ -625,7 +628,8 @@ namespace MQTTnet.Tests.Server
                // r
                await c2.PublishStringAsync("topic");

-                await LongTestDelay();
+                await Task.Delay(500);
+
                flow = string.Join(string.Empty, events);
                Assert.AreEqual("cdcr", flow);

@@ -635,17 +639,16 @@ namespace MQTTnet.Tests.Server
                await c1.TryDisconnectAsync();
                Assert.AreEqual(false, c1.IsConnected);

-                await LongTestDelay();
+                await Task.Delay(500);

                // d
                Assert.AreEqual(true, c2.IsConnected);
                await c2.DisconnectAsync();

-                await LongTestDelay();
+                await Task.Delay(500);

                await server.StopAsync();

-                await LongTestDelay();
                flow = string.Join(string.Empty, events);
                Assert.AreEqual("cdcrd", flow);
            }
@@ -849,11 +852,11 @@ namespace MQTTnet.Tests.Server
                    return CompletedTask.Instance;
                };

-                // Stopping the server should disconnect the connection with the client
-                // which, it turn, will fire the disconnected event at the client.
+                await Task.Delay(100);
+
                await server.StopAsync();

-                await LongTestDelay();
+                await Task.Delay(100);

                Assert.AreEqual(1, disconnectCalled);
            }
@@ -951,7 +954,7 @@ namespace MQTTnet.Tests.Server

                var client = testEnvironment.CreateClient();

-                client.InspectPacketAsync += e =>
+                client.InspectPackage += e =>
                {
                    if (e.Buffer.Length > 0)
                    {
@@ -1,426 +0,0 @@
-#if !(NET452 || NET461 || NET48)
-using System;
-using System.Collections.Concurrent;
-using System.Diagnostics;
-using System.Linq;
-using System.Net;
-using System.Net.Security;
-using System.Security.Authentication;
-using System.Security.Cryptography;
-using System.Security.Cryptography.X509Certificates;
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
-using MQTTnet.Certificates;
-using MQTTnet.Client;
-using MQTTnet.Formatter;
-using MQTTnet.Protocol;
-using MQTTnet.Server;
-
-namespace MQTTnet.Tests.Server
-{
-    // missing certificate builder api means tests won't work for older frameworks
-
-    [TestClass]
-    public sealed class HotSwapCerts_Tests
-    {
-        static readonly TimeSpan DefaultTimeout = TimeSpan.FromSeconds(10);
-
-        [TestMethod]
-        public async Task ClientCertChangeWithoutServerUpdateFailsReconnect()
-        {
-            using (var server = new ServerTestHarness())
-            using (var client01 = new ClientTestHarness())
-            {
-                server.InstallNewClientCert(client01.GetCurrentClientCert());
-                client01.InstallNewServerCert(server.GetCurrentServerCert());
-
-                await server.StartServer();
-
-                await client01.Connect();
-
-                client01.WaitForConnectOrFail(DefaultTimeout);
-
-                client01.HotSwapClientCert();
-                server.ForceDisconnectAsync(client01).Wait(DefaultTimeout);
-                client01.WaitForDisconnectOrFail(DefaultTimeout);
-
-                client01.WaitForConnectToFail(DefaultTimeout);
-            }
-        }
-
-        [TestMethod]
-        public async Task ClientCertChangeWithServerUpdateAcceptsReconnect()
-        {
-            using (var server = new ServerTestHarness())
-            using (var client01 = new ClientTestHarness())
-            {
-                server.InstallNewClientCert(client01.GetCurrentClientCert());
-                client01.InstallNewServerCert(server.GetCurrentServerCert());
-
-                await server.StartServer();
-
-                await client01.Connect();
-
-                client01.WaitForConnectOrFail(DefaultTimeout);
-
-                client01.HotSwapClientCert();
-                server.ForceDisconnectAsync(client01).Wait(DefaultTimeout);
-                client01.WaitForDisconnectOrFail(DefaultTimeout);
-
-                server.InstallNewClientCert(client01.GetCurrentClientCert());
-
-                client01.WaitForConnectOrFail(DefaultTimeout);
-            }
-        }
-
-        [TestMethod]
-        public async Task ServerCertChangeWithClientCertUpdateAllowsReconnect()
-        {
-            using (var server = new ServerTestHarness())
-            using (var client01 = new ClientTestHarness())
-            {
-                server.InstallNewClientCert(client01.GetCurrentClientCert());
-                client01.InstallNewServerCert(server.GetCurrentServerCert());
-
-                await server.StartServer();
-                await client01.Connect();
-
-                client01.WaitForConnectOrFail(DefaultTimeout);
-                server.HotSwapServerCert();
-
-                server.ForceDisconnectAsync(client01).Wait(DefaultTimeout);
-                client01.WaitForDisconnectOrFail(DefaultTimeout);
-                client01.InstallNewServerCert(server.GetCurrentServerCert());
-
-                client01.WaitForConnectOrFail(DefaultTimeout);
-            }
-        }
-
-        [TestMethod]
-        public async Task ServerCertChangeWithoutClientCertUpdateFailsReconnect()
-        {
-            using (var server = new ServerTestHarness())
-            using (var client01 = new ClientTestHarness())
-            {
-                server.InstallNewClientCert(client01.GetCurrentClientCert());
-                client01.InstallNewServerCert(server.GetCurrentServerCert());
-
-                await server.StartServer();
-                await client01.Connect();
-
-                client01.WaitForConnectOrFail(DefaultTimeout);
-                server.HotSwapServerCert();
-
-                server.ForceDisconnectAsync(client01).Wait(DefaultTimeout);
-                client01.WaitForDisconnectOrFail(DefaultTimeout);
-
-                client01.WaitForConnectToFail(DefaultTimeout);
-            }
-        }
-
-        static X509Certificate2 CreateSelfSignedCertificate(string oid)
-        {
-            var sanBuilder = new SubjectAlternativeNameBuilder();
-            sanBuilder.AddIpAddress(IPAddress.Loopback);
-            sanBuilder.AddIpAddress(IPAddress.IPv6Loopback);
-            sanBuilder.AddDnsName("localhost");
-
-            using (var rsa = RSA.Create())
-            {
-                var certRequest = new CertificateRequest("CN=localhost", rsa, HashAlgorithmName.SHA512, RSASignaturePadding.Pkcs1);
-
-                certRequest.CertificateExtensions.Add(
-                    new X509KeyUsageExtension(X509KeyUsageFlags.DataEncipherment | X509KeyUsageFlags.KeyEncipherment | X509KeyUsageFlags.DigitalSignature, false));
-
-                certRequest.CertificateExtensions.Add(new X509EnhancedKeyUsageExtension(new OidCollection { new Oid(oid) }, false));
-
-                certRequest.CertificateExtensions.Add(sanBuilder.Build());
-
-                using (var certificate = certRequest.CreateSelfSigned(DateTimeOffset.Now.AddMinutes(-10), DateTimeOffset.Now.AddMinutes(10)))
-                {
-                    var pfxCertificate = new X509Certificate2(
-                        certificate.Export(X509ContentType.Pfx),
-                        (string)null,
-                        X509KeyStorageFlags.MachineKeySet | X509KeyStorageFlags.Exportable);
-
-                    return pfxCertificate;
-                }
-            }
-        }
-
-        sealed class ClientTestHarness : IDisposable
-        {
-            readonly HotSwappableClientCertProvider _hotSwapClient = new HotSwappableClientCertProvider();
-
-            IMqttClient _client;
-
-            public string ClientId => _client.Options.ClientId;
-
-            public Task Connect()
-            {
-                return Run_Client_Connection();
-            }
-
-            public void Dispose()
-            {
-                _client.Dispose();
-                _hotSwapClient.Dispose();
-            }
-
-            public X509Certificate2 GetCurrentClientCert()
-            {
-                var result = _hotSwapClient.GetCertificates()[0];
-                return new X509Certificate2(result);
-            }
-
-            public void HotSwapClientCert()
-            {
-                _hotSwapClient.HotSwapCert();
-            }
-
-            public void InstallNewServerCert(X509Certificate2 serverCert)
-            {
-                _hotSwapClient.InstallNewServerCert(serverCert);
-            }
-
-            public void WaitForConnectOrFail(TimeSpan timeout)
-            {
-                Thread.Sleep(100);
-
-                if (!_client.IsConnected)
-                {
-                    _client.ReconnectAsync().Wait(timeout);
-                }
-
-                WaitForConnect(timeout);
-
-                Assert.IsNotNull(_client, "Client was never initialized");
-                Assert.IsTrue(_client.IsConnected, $"Client connection failed after {timeout}");
-            }
-
-            public void WaitForConnectToFail(TimeSpan timeout)
-            {
-                Assert.IsFalse(_client.IsConnected, "Client should be disconnected before waiting for connect.");
-
-                WaitForConnect(timeout);
-
-                Assert.IsNotNull(_client, "Client was never initialized");
-                Assert.IsFalse(_client.IsConnected, "Client connection success but test wanted fail");
-            }
-
-            void WaitForDisconnect(TimeSpan timeout)
-            {
-                var timer = Stopwatch.StartNew();
-                while ((_client == null || _client.IsConnected) && timer.Elapsed < timeout)
-                {
-                    Thread.Sleep(100);
-                }
-            }
-
-            public void WaitForDisconnectOrFail(TimeSpan timeout)
-            {
-                WaitForDisconnect(timeout);
-
-                Assert.IsNotNull(_client, "Client was never initialized");
-                Assert.IsFalse(_client.IsConnected, $"Client connection should have disconnected after {timeout}");
-            }
-
-            async Task Run_Client_Connection()
-            {
-                var optionsBuilder = new MqttClientOptionsBuilder()
-                    .WithTlsOptions(
-                        o => o.WithClientCertificatesProvider(_hotSwapClient)
-                            .WithCertificateValidationHandler(_hotSwapClient.OnCertificateValidation)
-                            .WithSslProtocols(SslProtocols.Tls12))
-                    .WithTcpServer("localhost")
-                    .WithCleanSession()
-                    .WithProtocolVersion(MqttProtocolVersion.V500);
-
-                var mqttClientOptions = optionsBuilder.Build();
-
-                var factory = new MqttFactory();
-                var mqttClient = factory.CreateMqttClient();
-                _client = mqttClient;
-
-                await mqttClient.ConnectAsync(mqttClientOptions);
-            }
-
-            void WaitForConnect(TimeSpan timeout)
-            {
-                var timer = Stopwatch.StartNew();
-                while ((_client == null || !_client.IsConnected) && timer.Elapsed < timeout)
-                {
-                    Thread.Sleep(100);
-                }
-            }
-        }
-
-        sealed class ServerTestHarness : IDisposable
-        {
-            readonly HotSwappableServerCertProvider _hotSwapServer = new HotSwappableServerCertProvider();
-
-            MqttServer _server;
-
-            public void Dispose()
-            {
-                if (_server != null)
-                {
-                    _server.StopAsync().Wait();
-                    _server.Dispose();
-                }
-
-                _hotSwapServer?.Dispose();
-            }
-
-            public Task ForceDisconnectAsync(ClientTestHarness client)
-            {
-                return _server.DisconnectClientAsync(client.ClientId, MqttDisconnectReasonCode.UnspecifiedError);
-            }
-
-            public X509Certificate2 GetCurrentServerCert()
-            {
-                return _hotSwapServer.GetCertificate();
-            }
-
-            public void HotSwapServerCert()
-            {
-                _hotSwapServer.HotSwapCert();
-            }
-
-            public void InstallNewClientCert(X509Certificate2 serverCert)
-            {
-                _hotSwapServer.InstallNewClientCert(serverCert);
-            }
-
-            public Task StartServer()
-            {
-                var mqttFactory = new MqttFactory();
-
-                var mqttServerOptions = new MqttServerOptionsBuilder().WithEncryptionCertificate(_hotSwapServer)
-                    .WithRemoteCertificateValidationCallback(_hotSwapServer.RemoteCertificateValidationCallback)
-                    .WithEncryptedEndpoint()
-                    .Build();
-
-                mqttServerOptions.TlsEndpointOptions.ClientCertificateRequired = true;
-
-                _server = mqttFactory.CreateMqttServer(mqttServerOptions);
-                return _server.StartAsync();
-            }
-        }
-
-        class HotSwappableClientCertProvider : IMqttClientCertificatesProvider, IDisposable
-        {
-            X509Certificate2Collection _certificates;
-            ConcurrentBag<X509Certificate2> _serverCerts = new ConcurrentBag<X509Certificate2>();
-
-            public HotSwappableClientCertProvider()
-            {
-                _certificates = new X509Certificate2Collection(CreateSelfSignedCertificate("1.3.6.1.5.5.7.3.2"));
-            }
-            
-            public void Dispose()
-            {
-                if (_certificates != null)
-                {
-                    foreach (var certs in _certificates)
-                    {
-#if !NET452
-                        certs.Dispose();
-#endif
-                    }
-                }
-            }
-
-            public X509CertificateCollection GetCertificates()
-            {
-                return new X509Certificate2Collection(_certificates);
-            }
-
-            public void HotSwapCert()
-            {
-                _certificates = new X509Certificate2Collection(CreateSelfSignedCertificate("1.3.6.1.5.5.7.3.2"));
-            }
-
-            public void InstallNewServerCert(X509Certificate2 serverCert)
-            {
-                _serverCerts.Add(serverCert);
-            }
-
-            public bool OnCertificateValidation(MqttClientCertificateValidationEventArgs certContext)
-            {
-                var serverCerts = _serverCerts.ToArray();
-
-                var providedCert = certContext.Certificate.GetRawCertData();
-                for (int i = 0, n = serverCerts.Length; i < n; i++)
-                {
-                    var currentcert = serverCerts[i];
-
-                    if (currentcert.RawData.SequenceEqual(providedCert))
-                    {
-                        return true;
-                    }
-                }
-
-                return false;
-            }
-        }
-
-        sealed class HotSwappableServerCertProvider : ICertificateProvider, IDisposable
-        {
-            readonly ConcurrentBag<X509Certificate2> _clientCerts = new ConcurrentBag<X509Certificate2>();
-            X509Certificate2 _certificate;
-
-            public HotSwappableServerCertProvider()
-            {
-                _certificate = CreateSelfSignedCertificate("1.3.6.1.5.5.7.3.1");
-            }
-
-            public void Dispose()
-            {
-#if !NET452
-                _certificate.Dispose();
-#endif
-            }
-
-            public X509Certificate2 GetCertificate()
-            {
-                return _certificate;
-            }
-
-            public void HotSwapCert()
-            {
-                var newCert = CreateSelfSignedCertificate("1.3.6.1.5.5.7.3.1");
-                var oldCert = Interlocked.Exchange(ref _certificate, newCert);
-#if !NET452
-                oldCert.Dispose();
-#endif
-            }
-
-            public void InstallNewClientCert(X509Certificate2 certificate)
-            {
-                _clientCerts.Add(certificate);
-            }
-
-            public bool RemoteCertificateValidationCallback(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
-            {
-                var serverCerts = _clientCerts.ToArray();
-
-                var providedCert = certificate.GetRawCertData();
-                for (int i = 0, n = serverCerts.Length; i < n; i++)
-                {
-                    var currentCert = serverCerts[i];
-
-                    if (currentCert.RawData.SequenceEqual(providedCert))
-                    {
-                        return true;
-                    }
-                }
-
-                return false;
-            }
-        }
-    }
-}
-
-#endif
@@ -1,25 +0,0 @@
-using Microsoft.VisualStudio.TestTools.UnitTesting;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace MQTTnet.Tests.Server
-{
-    [TestClass]
-    public sealed class MqttRetainedMessageManager_Tests
-    {
-        [TestMethod]
-        public async Task MqttRetainedMessageManager_GetUndefinedTopic()
-        {
-            var logger = new Mockups.TestLogger();
-            var eventContainer = new MQTTnet.Server.MqttServerEventContainer();
-            var retainedMessagesManager = new MQTTnet.Server.MqttRetainedMessagesManager(eventContainer, logger);
-            var task = retainedMessagesManager.GetMessage("undefined");
-            Assert.IsNotNull(task, "Task should not be null");
-            var result = await task;
-            Assert.IsNull(result, "Null result expected");
-        }
-    }
-}
@@ -221,17 +221,14 @@ namespace MQTTnet.Tests.Server
            var eventContainer = new MqttServerEventContainer();
            var clientSessionManager = new MqttClientSessionsManager(options, retainedMessagesManager, eventContainer, logger);

-            var session = new MqttSession(new MqttConnectPacket
-            {
-                ClientId = ""
-            }, new ConcurrentDictionary<object, object>(), options, eventContainer, retainedMessagesManager, clientSessionManager);
+            var session = new MqttSession("", false, new ConcurrentDictionary<object, object>(), options, eventContainer, retainedMessagesManager, clientSessionManager);

            _subscriptionsManager = new MqttClientSubscriptionsManager(session, new MqttServerEventContainer(), retainedMessagesManager, clientSessionManager);
        }

        CheckSubscriptionsResult CheckSubscriptions(string topic, MqttQualityOfServiceLevel applicationMessageQoSLevel, string senderClientId)
        {
-            MqttTopicHash.Calculate(topic, out var topicHash, out _, out _);
+            MqttSubscription.CalculateTopicHash(topic, out var topicHash, out _, out _);
            return _subscriptionsManager.CheckSubscriptions(topic, topicHash, applicationMessageQoSLevel, senderClientId);
        }
    }
@@ -0,0 +1,58 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Threading.Tasks;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using MQTTnet.Client;
+using MQTTnet.Formatter;
+using MQTTnet.Protocol;
+
+namespace MQTTnet.Tests.Server
+{
+    [TestClass]
+    public sealed class Publish_Tests : BaseTestClass
+    {
+        [TestMethod]
+        public async Task Return_Success_When_Subscribed()
+        {
+            using (var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500))
+            {
+                await testEnvironment.StartServer();
+
+                var sender = await testEnvironment.ConnectClient();
+                var receiver = await testEnvironment.ConnectClient();
+
+                await receiver.SubscribeAsync("A");
+
+                // AtLeastOnce is required to get an ACK packet from the server.
+                var publishResult = await sender.PublishStringAsync("A", "Payload", MqttQualityOfServiceLevel.AtLeastOnce);
+                
+                Assert.AreEqual(MqttClientPublishReasonCode.Success, publishResult.ReasonCode);
+                
+                Assert.AreEqual(true, publishResult.IsSuccess);
+            }
+        }
+        
+        [TestMethod]
+        public async Task Return_NoMatchingSubscribers_When_Not_Subscribed()
+        {
+            using (var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500))
+            {
+                await testEnvironment.StartServer();
+
+                var sender = await testEnvironment.ConnectClient();
+                var receiver = await testEnvironment.ConnectClient();
+             
+                await receiver.SubscribeAsync("A");
+
+                // AtLeastOnce is required to get an ACK packet from the server.
+                var publishResult = await sender.PublishStringAsync("B", "Payload", MqttQualityOfServiceLevel.AtLeastOnce);
+                
+                Assert.AreEqual(MqttClientPublishReasonCode.NoMatchingSubscribers, publishResult.ReasonCode);
+                
+                Assert.AreEqual(true, publishResult.IsSuccess);
+            }
+        }
+    }
+}
@@ -5,8 +5,6 @@
 using System.Threading.Tasks;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using MQTTnet.Client;
-using MQTTnet.Formatter;
-using MQTTnet.Internal;
 using MQTTnet.Protocol;

 namespace MQTTnet.Tests.Server
@@ -29,118 +27,5 @@ namespace MQTTnet.Tests.Server
                await client.PublishStringAsync("test", qualityOfServiceLevel: MqttQualityOfServiceLevel.AtLeastOnce);
            }
        }
-
-        [TestMethod]
-        public async Task Return_NoMatchingSubscribers_When_Not_Subscribed()
-        {
-            using (var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500))
-            {
-                await testEnvironment.StartServer();
-
-                var sender = await testEnvironment.ConnectClient();
-                var receiver = await testEnvironment.ConnectClient();
-
-                await receiver.SubscribeAsync("A");
-
-                // AtLeastOnce is required to get an ACK packet from the server.
-                var publishResult = await sender.PublishStringAsync("B", "Payload", MqttQualityOfServiceLevel.AtLeastOnce);
-
-                Assert.AreEqual(MqttClientPublishReasonCode.NoMatchingSubscribers, publishResult.ReasonCode);
-
-                Assert.AreEqual(true, publishResult.IsSuccess);
-            }
-        }
-
-        [TestMethod]
-        public async Task Return_Success_When_Subscribed()
-        {
-            using (var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500))
-            {
-                await testEnvironment.StartServer();
-
-                var sender = await testEnvironment.ConnectClient();
-                var receiver = await testEnvironment.ConnectClient();
-
-                await receiver.SubscribeAsync("A");
-
-                // AtLeastOnce is required to get an ACK packet from the server.
-                var publishResult = await sender.PublishStringAsync("A", "Payload", MqttQualityOfServiceLevel.AtLeastOnce);
-
-                Assert.AreEqual(MqttClientPublishReasonCode.Success, publishResult.ReasonCode);
-
-                Assert.AreEqual(true, publishResult.IsSuccess);
-            }
-        }
-
-        [TestMethod]
-        public async Task Intercept_Client_Enqueue()
-        {
-            using (var testEnvironment = CreateTestEnvironment())
-            {
-                var server = await testEnvironment.StartServer();
-                
-                var sender = await testEnvironment.ConnectClient();
-                
-                var receiver = await testEnvironment.ConnectClient();
-                await receiver.SubscribeAsync("A");
-                var receivedMessages = testEnvironment.CreateApplicationMessageHandler(receiver);
-                
-                await sender.PublishStringAsync("A", "Payload", MqttQualityOfServiceLevel.AtLeastOnce);
-
-                await LongTestDelay();
-                
-                receivedMessages.AssertReceivedCountEquals(1);
-                
-                server.InterceptingClientEnqueueAsync += e =>
-                {
-                    e.AcceptEnqueue = false;
-                    return CompletedTask.Instance;
-                };
-                
-                await sender.PublishStringAsync("A", "Payload", MqttQualityOfServiceLevel.AtLeastOnce);
-
-                await LongTestDelay();
-                
-                // Do not increase because the internal enqueue to the target client is not accepted!
-                receivedMessages.AssertReceivedCountEquals(1);
-            }
-        }
-
-        [TestMethod]
-        public async Task Intercept_Client_Enqueue_Multiple_Clients_Subscribed_Messages_Are_Filtered()
-        {
-            using (var testEnvironment = CreateTestEnvironment())
-            {
-                var server = await testEnvironment.StartServer();
-
-                var sender = await testEnvironment.ConnectClient();
-
-                var receiverOne = await testEnvironment.ConnectClient(o => o.WithClientId("One"));
-                await receiverOne.SubscribeAsync("A");
-                var receivedMessagesOne = testEnvironment.CreateApplicationMessageHandler(receiverOne);
-
-                var receiverTwo = await testEnvironment.ConnectClient(o => o.WithClientId("Two"));
-                await receiverTwo.SubscribeAsync("A");
-                var receivedMessagesTwo = testEnvironment.CreateApplicationMessageHandler(receiverTwo);
-
-                var receiverThree = await testEnvironment.ConnectClient(o => o.WithClientId("Three"));
-                await receiverThree.SubscribeAsync("A");
-                var receivedMessagesThree = testEnvironment.CreateApplicationMessageHandler(receiverThree);
-
-                server.InterceptingClientEnqueueAsync += e =>
-                {
-                    if (e.ReceiverClientId.Contains("Two")) e.AcceptEnqueue = false;
-                    return CompletedTask.Instance;
-                };
-
-                await sender.PublishStringAsync("A", "Payload", MqttQualityOfServiceLevel.AtLeastOnce);
-
-                await LongTestDelay();
-
-                receivedMessagesOne.AssertReceivedCountEquals(1);
-                receivedMessagesTwo.AssertReceivedCountEquals(0);
-                receivedMessagesThree.AssertReceivedCountEquals(1);
-            }
-        }
    }
 }
@@ -164,7 +164,7 @@ namespace MQTTnet.Tests.Server

                var clientOptions = new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1", testEnvironment.ServerPort).WithCredentials(userName, password).Build();

-                var ex = await Assert.ThrowsExceptionAsync<MqttConnectingFailedException>(() => client.ConnectAsync(clientOptions));
+                var ex = await Assert.ThrowsExceptionAsync<MqttConnectingFailedException>(async () => await client.ConnectAsync(clientOptions));
                Assert.AreEqual(MqttClientConnectResultCode.BadUserNameOrPassword, ex.Result.ResultCode);
            }
        }
@@ -70,28 +70,6 @@ namespace MQTTnet.Tests.Server
            }
        }

-        [TestMethod]
-        public async Task Do_Not_Use_Expired_Session()
-        {
-            using (var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500))
-            {
-                await testEnvironment.StartServer(o => o.WithPersistentSessions());
-
-                var c1 = await testEnvironment.ConnectClient(o => o.WithClientId("Client1").WithCleanSession(false).WithSessionExpiryInterval(3));
-
-                // Kill the client connection and ensure that the session will stay there but is expired after 3 seconds!
-                c1.Dispose();
-
-                await Task.Delay(TimeSpan.FromSeconds(6));
-
-                c1 = testEnvironment.CreateClient();
-                var options = testEnvironment.CreateDefaultClientOptionsBuilder().WithClientId("Client1").WithCleanSession(false).WithSessionExpiryInterval(3).Build();
-
-                var connectResult = await c1.ConnectAsync(options);
-                Assert.AreEqual(false, connectResult.IsSessionPresent);
-            }
-        }
-
        [TestMethod]
        public async Task Fire_Deleted_Event()
        {
@@ -143,7 +121,7 @@ namespace MQTTnet.Tests.Server
                Assert.AreEqual(true, session.Items["can_subscribe_x"]);
            }
        }
-
+        
        [TestMethod]
        [DataRow(MqttProtocolVersion.V310)]
        [DataRow(MqttProtocolVersion.V311)]
@@ -156,12 +134,16 @@ namespace MQTTnet.Tests.Server

                await testEnvironment.StartServer();

-                var options = new MqttClientOptionsBuilder().WithClientId("1").WithTimeout(TimeSpan.FromSeconds(10)).WithProtocolVersion(protocolVersion);
+                var options = new MqttClientOptionsBuilder().WithClientId("1").WithTimeout(TimeSpan.FromSeconds(1)).WithProtocolVersion(protocolVersion);

                var hasReceive = false;
+
                void OnReceive()
                {
-                    hasReceive = true;
+                    if (!hasReceive)
+                    {
+                        hasReceive = true;
+                    }
                }

                // Try to connect 50 clients at the same time.
@@ -170,7 +152,7 @@ namespace MQTTnet.Tests.Server
                var connectedClients = clients.Where(c => c?.TryPingAsync().GetAwaiter().GetResult() == true).ToList();

                await LongTestDelay();
-
+                
                Assert.AreEqual(1, connectedClients.Count);

                var option2 = new MqttClientOptionsBuilder().WithClientId("2").WithKeepAlivePeriod(TimeSpan.FromSeconds(10));
@@ -182,7 +164,7 @@ namespace MQTTnet.Tests.Server
                Assert.AreEqual(true, hasReceive);
            }
        }
-
+ 
        [DataTestMethod]
        [DataRow(MqttQualityOfServiceLevel.ExactlyOnce)]
        [DataRow(MqttQualityOfServiceLevel.AtLeastOnce)]
@@ -373,8 +355,8 @@ namespace MQTTnet.Tests.Server
                    onReceive();
                    return CompletedTask.Instance;
                };
-
-                using (var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(30)))
+                
+                using (var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(5)))
                {
                    await client.SubscribeAsync("aaa", MqttQualityOfServiceLevel.AtMostOnce, timeout.Token).ConfigureAwait(false);
                }
@@ -62,7 +62,7 @@ namespace MQTTnet.Tests.Server
                }
            }
        }
-
+        
        [TestMethod]
        public async Task Deny_Invalid_Topic()
        {
@@ -90,29 +90,6 @@ namespace MQTTnet.Tests.Server
            }
        }

-        [TestMethod]
-        public async Task Intercept_Subscribe_With_User_Properties()
-        {
-            using (var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500))
-            {
-                var server = await testEnvironment.StartServer();
-
-                InterceptingSubscriptionEventArgs eventArgs = null;
-                server.InterceptingSubscriptionAsync += e =>
-                {
-                    eventArgs = e;
-                    return CompletedTask.Instance;
-                };
-
-                var client = await testEnvironment.ConnectClient();
-
-                var subscribeOptions = testEnvironment.Factory.CreateSubscribeOptionsBuilder().WithTopicFilter("X").WithUserProperty("A", "1").Build();
-                await client.SubscribeAsync(subscribeOptions);
-
-                CollectionAssert.AreEqual(subscribeOptions.UserProperties.ToList(), eventArgs.UserProperties);
-            }
-        }
-
        [TestMethod]
        [ExpectedException(typeof(MqttClientDisconnectedException))]
        public async Task Disconnect_While_Subscribing()
@@ -128,7 +105,7 @@ namespace MQTTnet.Tests.Server
                await client.SubscribeAsync("#");
            }
        }
-
+        
        [TestMethod]
        public async Task Enqueue_Message_After_Subscription()
        {
@@ -47,7 +47,7 @@ namespace MQTTnet.Tests.Server
                var topics = t.Value;
                foreach (var topic in topics)
                {
-                    MqttTopicHash.Calculate(topic, out var topicHash, out var hashMask, out var hasWildcard);
+                    MqttSubscription.CalculateTopicHash(topic, out var topicHash, out var hashMask, out var hasWildcard);

                    bucketDepths.TryGetValue(topicHash, out var currentValue);
                    ++currentValue;
@@ -96,7 +96,7 @@ namespace MQTTnet.Tests.Server
        {
            var topic = "asdfasdf/asdfasdf/asdfasdf/asdfasdf/asdfas/dfaf/assfdgsdfgdf/#";

-            MqttTopicHash.Calculate(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);
+            MqttSubscription.CalculateTopicHash(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);

            Assert.IsTrue(topicHasWildcard, "Wildcard not detected");
        }
@@ -110,7 +110,7 @@ namespace MQTTnet.Tests.Server
        {
            var topic = "asdfasdf/asdfasdf/asdfasdf/asdfasdf/asdfas/dfaf/assfdgsdfgdf/+";

-            MqttTopicHash.Calculate(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);
+            MqttSubscription.CalculateTopicHash(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);

            Assert.IsTrue(topicHasWildcard, "Wildcard not detected");
        }
@@ -150,7 +150,7 @@ namespace MQTTnet.Tests.Server

            // UInt64 is limited to 8 levels

-            MqttTopicHash.Calculate(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);
+            MqttSubscription.CalculateTopicHash(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);

            Assert.IsTrue(topicHasWildcard, "Wildcard not detected");

@@ -212,7 +212,7 @@ namespace MQTTnet.Tests.Server

            var topic = sb.ToString();

-            MqttTopicHash.Calculate(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);
+            MqttSubscription.CalculateTopicHash(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);

            Assert.IsFalse(topicHasWildcard, "Wildcard detected when not present");

@@ -269,7 +269,7 @@ namespace MQTTnet.Tests.Server

            var topic = sb.ToString();

-            MqttTopicHash.Calculate(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);
+            MqttSubscription.CalculateTopicHash(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);

            Assert.IsTrue(topicHasWildcard, "Wildcard not detected");

@@ -319,7 +319,7 @@ namespace MQTTnet.Tests.Server
            var l3 = "#";
            var topic = $"{l0}/{l1}/{l2}/{l3}";

-            MqttTopicHash.Calculate(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);
+            MqttSubscription.CalculateTopicHash(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);

            Assert.IsTrue(topicHasWildcard, "Wildcard not detected");

@@ -354,7 +354,7 @@ namespace MQTTnet.Tests.Server
            var l3 = "prop1";
            var topic = $"{l0}/{l1}/{l2}/{l3}";

-            MqttTopicHash.Calculate(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);
+            MqttSubscription.CalculateTopicHash(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);

            Assert.IsFalse(topicHasWildcard, "Wildcard detected when not wildcard present");

@@ -447,7 +447,7 @@ namespace MQTTnet.Tests.Server
            var l3 = "prop1";
            var topic = $"{l0}/{l1}/{l2}/{l3}";

-            MqttTopicHash.Calculate(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);
+            MqttSubscription.CalculateTopicHash(topic, out var topicHash, out var topicHashMask, out var topicHasWildcard);

            Assert.IsTrue(topicHasWildcard, "Wildcard not detected");

@@ -475,7 +475,7 @@ namespace MQTTnet.Tests.Server

        void CheckTopicHash(string topic, ulong expectedHash, ulong expectedHashMask)
        {
-            MqttTopicHash.Calculate(topic, out var topicHash, out var hashMask, out var hasWildcard);
+            MqttSubscription.CalculateTopicHash(topic, out var topicHash, out var hashMask, out var hasWildcard);

            Console.WriteLine();
            Console.WriteLine("Topic: " + topic);
@@ -501,7 +501,7 @@ namespace MQTTnet.Tests.Server
                {
                    var topicToFind = topicsToFind[countDown];

-                    MqttTopicHash.Calculate(topicToFind, out var topicHash, out _, out _);
+                    MqttSubscription.CalculateTopicHash(topicToFind, out var topicHash, out _, out _);

                    clientSession.TryCheckSubscriptions(topicToFind, topicHash, MqttQualityOfServiceLevel.AtMostOnce, "OtherClient", out var result);
                    if (result.IsSubscribed)
@@ -557,7 +557,7 @@ namespace MQTTnet.Tests.Server
            var eventContainer = new MqttServerEventContainer();
            var retainedMessagesManager = new MqttRetainedMessagesManager(eventContainer, logger);
            var sessionManager = new MqttClientSessionsManager(serverOptions, retainedMessagesManager, eventContainer, logger);
-            _clientSession = new MqttSession(new MqttConnectPacket{ ClientId = clientId }, new Dictionary<object, object>(), serverOptions, eventContainer, retainedMessagesManager, sessionManager);
+            _clientSession = new MqttSession(clientId, false, new Dictionary<object, object>(), serverOptions, eventContainer, retainedMessagesManager, sessionManager);

            List<string> topicsToSubscribe;

@@ -1,204 +0,0 @@
-#if !WINDOWS_UWP && (NET48_OR_GREATER || NET5_0_OR_GREATER)
-using System;
-using System.Linq;
-using System.Net;
-using System.Security.Authentication;
-using System.Security.Cryptography;
-using System.Security.Cryptography.X509Certificates;
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
-using MQTTnet.Certificates;
-using MQTTnet.Client;
-using MQTTnet.Formatter;
-using MQTTnet.Server;
-using MQTTnet.Tests.Mockups;
-
-namespace MQTTnet.Tests.Server
-{
-    [TestClass]
-    public sealed class Tls_Tests : BaseTestClass
-    {
-        static X509Certificate2 CreateCertificate(string oid)
-        {
-            var sanBuilder = new SubjectAlternativeNameBuilder();
-            sanBuilder.AddIpAddress(IPAddress.Loopback);
-            sanBuilder.AddIpAddress(IPAddress.IPv6Loopback);
-            sanBuilder.AddDnsName("localhost");
-            
-            using (var rsa = RSA.Create())
-            {
-                var certRequest = new CertificateRequest("CN=localhost", rsa, HashAlgorithmName.SHA512, RSASignaturePadding.Pkcs1);
-
-                certRequest.CertificateExtensions.Add(
-                    new X509KeyUsageExtension(X509KeyUsageFlags.DataEncipherment | X509KeyUsageFlags.KeyEncipherment | X509KeyUsageFlags.DigitalSignature, false));
-
-                certRequest.CertificateExtensions.Add(new X509EnhancedKeyUsageExtension(new OidCollection { new Oid(oid) }, false));
-
-                certRequest.CertificateExtensions.Add(sanBuilder.Build());
-
-                using (var certificate = certRequest.CreateSelfSigned(DateTimeOffset.Now.AddMinutes(-10), DateTimeOffset.Now.AddMinutes(10)))
-                {
-                    var pfxCertificate = new X509Certificate2(
-                        certificate.Export(X509ContentType.Pfx),
-                        (string)null,
-                        X509KeyStorageFlags.MachineKeySet | X509KeyStorageFlags.Exportable);
-
-                    return pfxCertificate;
-                }
-            }
-        }
-
-        [TestMethod]
-        public async Task Tls_Swap_Test()
-        {
-            var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500);
-            var serverOptionsBuilder = testEnvironment.Factory.CreateServerOptionsBuilder();
-
-            var firstOid = "1.3.6.1.5.5.7.3.1";
-            var secondOid = "1.3.6.1.5.5.7.3.2";
-
-            var certificateProvider = new CertificateProvider
-            {
-                CurrentCertificate = CreateCertificate(firstOid)
-            };
-
-            serverOptionsBuilder.WithoutDefaultEndpoint().WithEncryptedEndpoint().WithEncryptionSslProtocol(SslProtocols.Tls12).WithEncryptionCertificate(certificateProvider);
-
-            var serverOptions = serverOptionsBuilder.Build();
-
-            var server = testEnvironment.CreateServer(serverOptions);
-
-            var publishedCount = 0;
-            server.InterceptingPublishAsync += args =>
-            {
-                Interlocked.Increment(ref publishedCount);
-
-                return Task.CompletedTask;
-            };
-
-            await server.StartAsync();
-
-            var firstClient = await ConnectClientAsync(
-                testEnvironment,
-                args =>
-                {
-                    Assert.AreEqual(firstOid, ((X509Certificate2)args.Certificate).Extensions.OfType<X509EnhancedKeyUsageExtension>().First().EnhancedKeyUsages[0].Value);
-                    return true;
-                });
-
-            var firstClientReceivedCount = 0;
-            firstClient.ApplicationMessageReceivedAsync += args =>
-            {
-                Interlocked.Increment(ref firstClientReceivedCount);
-
-                return Task.CompletedTask;
-            };
-
-            await firstClient.SubscribeAsync("TestTopic1");
-
-            await firstClient.PublishAsync(
-                new MqttApplicationMessage
-                {
-                    Topic = "TestTopic1",
-                    Payload = new byte[] { 1, 2, 3, 4 }
-                });
-
-            await testEnvironment.Server.InjectApplicationMessage(
-                new InjectedMqttApplicationMessage(
-                    new MqttApplicationMessage
-                    {
-                        Topic = "TestTopic1",
-                        Payload = new byte[] { 1, 2, 3, 4 }
-                    }));
-
-            certificateProvider.CurrentCertificate = CreateCertificate(secondOid);
-
-            // Validate that the certificate was switched
-            var secondClient = await ConnectClientAsync(
-                testEnvironment,
-                args =>
-                {
-                    Assert.AreEqual(secondOid, ((X509Certificate2)args.Certificate).Extensions.OfType<X509EnhancedKeyUsageExtension>().First().EnhancedKeyUsages[0].Value);
-                    return true;
-                });
-
-            var secondClientReceivedCount = 0;
-            secondClient.ApplicationMessageReceivedAsync += args =>
-            {
-                Interlocked.Increment(ref secondClientReceivedCount);
-
-                return Task.CompletedTask;
-            };
-
-            await secondClient.SubscribeAsync("TestTopic2");
-
-            await firstClient.PublishAsync(
-                new MqttApplicationMessage
-                {
-                    Topic = "TestTopic2",
-                    Payload = new byte[] { 1, 2, 3, 4 }
-                });
-
-            await testEnvironment.Server.InjectApplicationMessage(
-                new InjectedMqttApplicationMessage(
-                    new MqttApplicationMessage
-                    {
-                        Topic = "TestTopic2",
-                        Payload = new byte[] { 1, 2, 3, 4 }
-                    }));
-
-            // Ensure first client still works
-            await firstClient.PublishAsync(
-                new MqttApplicationMessage
-                {
-                    Topic = "TestTopic1",
-                    Payload = new byte[] { 1, 2, 3, 4 }
-                });
-
-            await testEnvironment.Server.InjectApplicationMessage(
-                new InjectedMqttApplicationMessage(
-                    new MqttApplicationMessage
-                    {
-                        Topic = "TestTopic1",
-                        Payload = new byte[] { 1, 2, 3, 4 }
-                    }));
-
-            await Task.Delay(1000);
-
-            Assert.AreEqual(6, publishedCount);
-            Assert.AreEqual(4, firstClientReceivedCount);
-            Assert.AreEqual(2, secondClientReceivedCount);
-
-            await server.StopAsync();
-        }
-
-        static async Task<IMqttClient> ConnectClientAsync(TestEnvironment testEnvironment, Func<MqttClientCertificateValidationEventArgs, bool> certValidator)
-        {
-            var clientOptionsBuilder = testEnvironment.Factory.CreateClientOptionsBuilder();
-            clientOptionsBuilder.WithClientId(Guid.NewGuid().ToString())
-                .WithTcpServer("localhost", 8883)
-                .WithTls(
-                    tls =>
-                    {
-                        tls.UseTls = true;
-                        tls.SslProtocol = SslProtocols.Tls12;
-                        tls.CertificateValidationHandler = certValidator;
-                    });
-
-            var clientOptions = clientOptionsBuilder.Build();
-            return await testEnvironment.ConnectClient(clientOptions);
-        }
-        
-        sealed class CertificateProvider : ICertificateProvider
-        {
-            public X509Certificate2 CurrentCertificate { get; set; }
-
-            public X509Certificate2 GetCertificate()
-            {
-                return CurrentCertificate;
-            }
-        }
-    }
-}
-#endif
@@ -2,14 +2,10 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.

-using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using MQTTnet.Client;
-using MQTTnet.Formatter;
-using MQTTnet.Internal;
 using MQTTnet.Protocol;
-using MQTTnet.Server;

 namespace MQTTnet.Tests.Server
 {
@@ -32,28 +28,5 @@ namespace MQTTnet.Tests.Server
                await client.UnsubscribeAsync("#");
            }
        }
-
-        [TestMethod]
-        public async Task Intercept_Unsubscribe_With_User_Properties()
-        {
-            using (var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500))
-            {
-                var server = await testEnvironment.StartServer();
-
-                InterceptingUnsubscriptionEventArgs eventArgs = null;
-                server.InterceptingUnsubscriptionAsync += e =>
-                {
-                    eventArgs = e;
-                    return CompletedTask.Instance;
-                };
-
-                var client = await testEnvironment.ConnectClient();
-
-                var unsubscribeOptions = testEnvironment.Factory.CreateUnsubscribeOptionsBuilder().WithTopicFilter("X").WithUserProperty("A", "1").Build();
-                await client.UnsubscribeAsync(unsubscribeOptions);
-
-                CollectionAssert.AreEqual(unsubscribeOptions.UserProperties.ToList(), eventArgs.UserProperties);
-            }
-        }
    }
 }
@@ -150,8 +150,18 @@ namespace MQTTnet.Tests
        {
            Assert.AreEqual(expectedResult, MqttTopicFilterComparer.Compare(topic, filter));

-            MqttTopicHash.Calculate(topic, out var topicHash, out _, out _);
-            MqttTopicHash.Calculate(filter, out var filterTopicHash, out var filterTopicHashMask, out _);
+            ulong topicHash;
+            ulong topicHashMask;
+            bool topicHasWildcard;
+
+            MqttSubscription.CalculateTopicHash(topic, out topicHash, out topicHashMask, out topicHasWildcard);
+
+
+            ulong filterTopicHash;
+            ulong filterTopicHashMask;
+            bool filterTopicHasWildcard;
+
+            MqttSubscription.CalculateTopicHash(filter, out filterTopicHash, out filterTopicHashMask, out filterTopicHasWildcard);

            if (expectedResult == MqttTopicFilterCompareResult.IsMatch)
            {
@@ -26,14 +26,19 @@ namespace MQTTnet.Adapter
        readonly IMqttChannel _channel;
        readonly byte[] _fixedHeaderBuffer = new byte[2];
        readonly MqttNetSourceLogger _logger;
+
+        readonly MqttPacketInspector _packetInspector;
+
        readonly byte[] _singleByteBuffer = new byte[1];
+
        readonly AsyncLock _syncRoot = new AsyncLock();

-        Statistics _statistics; // mutable struct, don't make readonly!
+        Statistics _statistics;     // mutable struct, don't make readonly!

-        public MqttChannelAdapter(IMqttChannel channel, MqttPacketFormatterAdapter packetFormatterAdapter, IMqttNetLogger logger)
+        public MqttChannelAdapter(IMqttChannel channel, MqttPacketFormatterAdapter packetFormatterAdapter, MqttPacketInspector packetInspector, IMqttNetLogger logger)
        {
            _channel = channel ?? throw new ArgumentNullException(nameof(channel));
+            _packetInspector = packetInspector;

            PacketFormatterAdapter = packetFormatterAdapter ?? throw new ArgumentNullException(nameof(packetFormatterAdapter));

@@ -45,8 +50,6 @@ namespace MQTTnet.Adapter
            _logger = logger.WithSource(nameof(MqttChannelAdapter));
        }

-        public bool AllowPacketFragmentation { get; set; } = true;
-
        public long BytesReceived => Volatile.Read(ref _statistics._bytesReceived);

        public long BytesSent => Volatile.Read(ref _statistics._bytesSent);
@@ -61,8 +64,6 @@ namespace MQTTnet.Adapter

        public MqttPacketFormatterAdapter PacketFormatterAdapter { get; }

-        public MqttPacketInspector PacketInspector { get; set; }
-
        public async Task ConnectAsync(CancellationToken cancellationToken)
        {
            cancellationToken.ThrowIfCancellationRequested();
@@ -76,30 +77,12 @@ namespace MQTTnet.Adapter
                 * block forever. Even a cancellation token is not supported properly.
                 */

+                var connectTask = _channel.ConnectAsync(cancellationToken);
+
                var timeout = new TaskCompletionSource<object>();
                using (cancellationToken.Register(() => timeout.TrySetResult(null)))
                {
-                    var connectTask = Task.Run(
-                        async () =>
-                        {
-                            try
-                            {
-                                await _channel.ConnectAsync(cancellationToken).ConfigureAwait(false);
-                            }
-                            catch
-                            {
-                                // If the timeout is already reached the exception is no longer of interest and
-                                // must be catched. Otherwise it will arrive at the TaskScheduler.UnobservedTaskException.
-                                if (!timeout.Task.IsCompleted)
-                                {
-                                    throw;
-                                }
-                            }
-                        },
-                        CancellationToken.None);
-
                    await Task.WhenAny(connectTask, timeout.Task).ConfigureAwait(false);
-
                    if (timeout.Task.IsCompleted && !connectTask.IsCompleted)
                    {
                        throw new OperationCanceledException("MQTT connect canceled.", cancellationToken);
@@ -143,7 +126,7 @@ namespace MQTTnet.Adapter

            try
            {
-                PacketInspector?.BeginReceivePacket();
+                _packetInspector?.BeginReceivePacket();

                ReceivedMqttPacket receivedPacket;
                var receivedPacketTask = ReceiveAsync(cancellationToken);
@@ -161,7 +144,7 @@ namespace MQTTnet.Adapter
                    return null;
                }

-                PacketInspector?.EndReceivePacket();
+                _packetInspector?.EndReceivePacket();

                Interlocked.Add(ref _statistics._bytesSent, receivedPacket.TotalLength);

@@ -197,10 +180,7 @@ namespace MQTTnet.Adapter
            return null;
        }

-        public void ResetStatistics()
-        {
-            _statistics.Reset();
-        }
+        public void ResetStatistics() => _statistics.Reset();

        public async Task SendPacketAsync(MqttPacket packet, CancellationToken cancellationToken)
        {
@@ -217,19 +197,19 @@ namespace MQTTnet.Adapter
                try
                {
                    var packetBuffer = PacketFormatterAdapter.Encode(packet);
-                    PacketInspector?.BeginSendPacket(packetBuffer);
+                    _packetInspector?.BeginSendPacket(packetBuffer);

                    _logger.Verbose("TX ({0} bytes) >>> {1}", packetBuffer.Length, packet);

-                    if (packetBuffer.Payload.Count == 0 || !AllowPacketFragmentation)
-                    {
-                        await _channel.WriteAsync(packetBuffer.Join(), true, cancellationToken).ConfigureAwait(false);
-                    }
-                    else
+                    if (packetBuffer.Payload.Count > 0)
                    {
                        await _channel.WriteAsync(packetBuffer.Packet, false, cancellationToken).ConfigureAwait(false);
                        await _channel.WriteAsync(packetBuffer.Payload, true, cancellationToken).ConfigureAwait(false);
                    }
+                    else
+                    {
+                        await _channel.WriteAsync(packetBuffer.Packet, true, cancellationToken).ConfigureAwait(false);
+                    }

                    Interlocked.Add(ref _statistics._bytesReceived, packetBuffer.Length);
                }
@@ -290,7 +270,7 @@ namespace MQTTnet.Adapter
                    return 0;
                }

-                PacketInspector?.FillReceiveBuffer(_singleByteBuffer);
+                _packetInspector?.FillReceiveBuffer(_singleByteBuffer);

                encodedByte = _singleByteBuffer[0];

@@ -329,7 +309,7 @@ namespace MQTTnet.Adapter
                {
                    return ReadFixedHeaderResult.ConnectionClosed;
                }
-
+               
                if (cancellationToken.IsCancellationRequested)
                {
                    return ReadFixedHeaderResult.Canceled;
@@ -343,7 +323,7 @@ namespace MQTTnet.Adapter
                totalBytesRead += bytesRead;
            }

-            PacketInspector?.FillReceiveBuffer(buffer);
+            _packetInspector?.FillReceiveBuffer(buffer);

            var hasRemainingLength = buffer[1] != 0;
            if (!hasRemainingLength)
@@ -427,7 +407,7 @@ namespace MQTTnet.Adapter
                    bodyOffset += readBytes;
                } while (bodyOffset < bodyLength);

-                PacketInspector?.FillReceiveBuffer(body);
+                _packetInspector?.FillReceiveBuffer(body);

                var bodySegment = new ArraySegment<byte>(body, 0, bodyLength);
                return new ReceivedMqttPacket(fixedHeader.Flags, bodySegment, fixedHeader.TotalLength);
@@ -475,7 +455,7 @@ namespace MQTTnet.Adapter
            throw new MqttCommunicationException(exception);
        }

-        struct Statistics
+        private struct Statistics
        {
            public long _bytesReceived;
            public long _bytesSent;
@@ -11,110 +11,112 @@ namespace MQTTnet.Client
    public sealed class MqttClientConnectResult
    {
        /// <summary>
-        /// Gets the result code.
-        /// MQTTv5 only.
-        /// </summary>
-        public MqttClientConnectResultCode ResultCode { get; internal set; }
-
-        /// <summary>
-        /// Gets a value indicating whether a session was already available or not.
-        /// MQTTv5 only.
-        /// </summary>
-        public bool IsSessionPresent { get; internal set; }
-
-        /// <summary>
-        /// Gets a value indicating whether wildcards can be used in subscriptions at the current server.
-        /// MQTTv5 only.
-        /// </summary>
-        public bool WildcardSubscriptionAvailable { get; internal set; }
-
-        /// <summary>
-        /// Gets whether the server supports retained messages.
-        /// MQTTv5 only.
-        /// </summary>
-        public bool RetainAvailable { get; internal set; }
-
-        /// <summary>
-        /// Gets the client identifier which was chosen by the server.
-        /// MQTTv5 only.
+        ///     Gets the client identifier which was chosen by the server.
+        ///     MQTTv5 only.
        /// </summary>
        public string AssignedClientIdentifier { get; internal set; }

        /// <summary>
-        /// Gets the authentication method.
-        /// MQTTv5 only.
+        ///     Gets the authentication data.
+        ///     MQTTv5 only.
+        /// </summary>
+        public byte[] AuthenticationData { get; internal set; }
+
+        /// <summary>
+        ///     Gets the authentication method.
+        ///     MQTTv5 only.
        /// </summary>
        public string AuthenticationMethod { get; internal set; }

        /// <summary>
-        /// Gets the authentication data.
-        /// MQTTv5 only.
+        ///     Gets a value indicating whether a session was already available or not.
+        ///     MQTTv5 only.
        /// </summary>
-        public byte[] AuthenticationData { get; internal set; }
+        public bool IsSessionPresent { get; internal set; }

        public uint? MaximumPacketSize { get; internal set; }

        /// <summary>
-        /// Gets the reason string.
-        /// MQTTv5 only.
-        /// </summary>
-        public string ReasonString { get; internal set; }
-
-        public ushort? ReceiveMaximum { get; internal set; }
-        
-        /// <summary>
-        /// Gets the maximum QoS which is supported by the server.
-        /// MQTTv5 only.
+        ///     Gets the maximum QoS which is supported by the server.
+        ///     MQTTv5 only.
        /// </summary>
        public MqttQualityOfServiceLevel MaximumQoS { get; internal set; }

        /// <summary>
-        /// Gets the response information.
-        /// MQTTv5 only.
+        ///     Gets the reason string.
+        ///     MQTTv5 only.
+        /// </summary>
+        public string ReasonString { get; internal set; }
+
+        public ushort? ReceiveMaximum { get; internal set; }
+
+        /// <summary>
+        ///     Gets the response information.
+        ///     MQTTv5 only.
        /// </summary>
        public string ResponseInformation { get; internal set; }

        /// <summary>
-        /// Gets the maximum value for a topic alias. 0 means not supported.
-        /// MQTTv5 only.
+        ///     Gets the result code.
+        ///     MQTTv5 only.
        /// </summary>
-        public ushort TopicAliasMaximum { get; internal set; }
+        public MqttClientConnectResultCode ResultCode { get; internal set; }

        /// <summary>
-        /// Gets an alternate server which should be used instead of the current one.
-        /// MQTTv5 only.
+        ///     Gets whether the server supports retained messages.
+        ///     MQTTv5 only.
        /// </summary>
-        public string ServerReference { get; internal set; }
+        public bool RetainAvailable { get; internal set; }

        /// <summary>
-        /// MQTTv5 only.
-        /// Gets the keep alive interval which was chosen by the server instead of the
-        /// keep alive interval from the client CONNECT packet.
-        /// A value of 0 indicates that the feature is not used.
+        ///     MQTTv5 only.
+        ///     Gets the keep alive interval which was chosen by the server instead of the
+        ///     keep alive interval from the client CONNECT packet.
+        ///     A value of 0 indicates that the feature is not used.
        /// </summary>
        public ushort ServerKeepAlive { get; internal set; }

+        /// <summary>
+        ///     Gets an alternate server which should be used instead of the current one.
+        ///     MQTTv5 only.
+        /// </summary>
+        public string ServerReference { get; internal set; }
+
        public uint? SessionExpiryInterval { get; internal set; }

        /// <summary>
-        /// Gets a value indicating whether the subscription identifiers are available or not.
-        /// MQTTv5 only.
-        /// </summary>
-        public bool SubscriptionIdentifiersAvailable { get; internal set; }
-
-        /// <summary>
-        /// Gets a value indicating whether the shared subscriptions are available or not.
-        /// MQTTv5 only.
+        ///     Gets a value indicating whether the shared subscriptions are available or not.
+        ///     MQTTv5 only.
        /// </summary>
        public bool SharedSubscriptionAvailable { get; internal set; }

        /// <summary>
-        /// Gets the user properties.
-        /// In MQTT 5, user properties are basic UTF-8 string key-value pairs that you can append to almost every type of MQTT packet.
-        /// As long as you don’t exceed the maximum message size, you can use an unlimited number of user properties to add metadata to MQTT messages and pass information between publisher, broker, and subscriber.
-        /// The feature is very similar to the HTTP header concept.
-        /// MQTTv5 only.
+        ///     Gets a value indicating whether the subscription identifiers are available or not.
+        ///     MQTTv5 only.
+        /// </summary>
+        public bool SubscriptionIdentifiersAvailable { get; internal set; }
+
+        /// <summary>
+        ///     Gets the maximum value for a topic alias. 0 means not supported.
+        ///     MQTTv5 only.
+        /// </summary>
+        public ushort TopicAliasMaximum { get; internal set; }
+
+        /// <summary>
+        ///     Gets the user properties.
+        ///     In MQTT 5, user properties are basic UTF-8 string key-value pairs that you can append to almost every type of MQTT
+        ///     packet.
+        ///     As long as you don’t exceed the maximum message size, you can use an unlimited number of user properties to add
+        ///     metadata to MQTT messages and pass information between publisher, broker, and subscriber.
+        ///     The feature is very similar to the HTTP header concept.
+        ///     MQTTv5 only.
        /// </summary>
        public List<MqttUserProperty> UserProperties { get; internal set; }
+
+        /// <summary>
+        ///     Gets a value indicating whether wildcards can be used in subscriptions at the current server.
+        ///     MQTTv5 only.
+        /// </summary>
+        public bool WildcardSubscriptionAvailable { get; internal set; }
    }
-}
+}
@@ -9,9 +9,14 @@ namespace MQTTnet.Client
 {
    public sealed class MqttClientDisconnectOptions
    {
+        /// <summary>
+        /// Gets or sets whether this disconnect is a clean disconnect.
+        /// </summary>
+        public bool IsClean { get; set; }
+        
        /// <summary>
        ///     Gets or sets the reason code.
-        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
+        ///     Hint: MQTT 5 feature only.
        /// </summary>
        public MqttClientDisconnectOptionsReason Reason { get; set; } = MqttClientDisconnectOptionsReason.NormalDisconnection;

@@ -15,7 +15,7 @@ namespace MQTTnet.Client

        event Func<MqttClientDisconnectedEventArgs, Task> DisconnectedAsync;

-        event Func<InspectMqttPacketEventArgs, Task> InspectPacketAsync;
+        event Func<InspectMqttPacketEventArgs, Task> InspectPackage;

        bool IsConnected { get; }

@@ -1,18 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using MQTTnet.Diagnostics;
-using MQTTnet.Internal;
-
-namespace MQTTnet.Client.Internal
-{
-    public sealed class MqttClientEvents
-    {
-        public AsyncEvent<MqttApplicationMessageReceivedEventArgs> ApplicationMessageReceivedEvent { get; } = new AsyncEvent<MqttApplicationMessageReceivedEventArgs>();
-        public AsyncEvent<MqttClientConnectedEventArgs> ConnectedEvent { get; } = new AsyncEvent<MqttClientConnectedEventArgs>();
-        public AsyncEvent<MqttClientConnectingEventArgs> ConnectingEvent { get; } = new AsyncEvent<MqttClientConnectingEventArgs>();
-        public AsyncEvent<MqttClientDisconnectedEventArgs> DisconnectedEvent { get; } = new AsyncEvent<MqttClientDisconnectedEventArgs>();
-        public AsyncEvent<InspectMqttPacketEventArgs> InspectPacketEvent { get; } = new AsyncEvent<InspectMqttPacketEventArgs>();
-    }
-}
@@ -1,14 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-namespace MQTTnet.Client.Internal
-{
-    public static class MqttClientResultFactory
-    {
-        public static readonly MqttClientConnectResultFactory ConnectResult = new MqttClientConnectResultFactory();
-        public static readonly MqttClientPublishResultFactory PublishResult = new MqttClientPublishResultFactory();
-        public static readonly MqttClientSubscribeResultFactory SubscribeResult = new MqttClientSubscribeResultFactory();
-        public static readonly MqttClientUnsubscribeResultFactory UnsubscribeResult = new MqttClientUnsubscribeResultFactory();
-    }
-}
@@ -7,7 +7,6 @@ using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using MQTTnet.Adapter;
-using MQTTnet.Client.Internal;
 using MQTTnet.Diagnostics;
 using MQTTnet.Exceptions;
 using MQTTnet.Formatter;
@@ -21,9 +20,17 @@ namespace MQTTnet.Client
    public sealed class MqttClient : Disposable, IMqttClient
    {
        readonly IMqttClientAdapterFactory _adapterFactory;
+        readonly AsyncEvent<MqttApplicationMessageReceivedEventArgs> _applicationMessageReceivedEvent = new AsyncEvent<MqttApplicationMessageReceivedEventArgs>();

+        readonly MqttClientPublishResultFactory _clientPublishResultFactory = new MqttClientPublishResultFactory();
+        readonly MqttClientSubscribeResultFactory _clientSubscribeResultFactory = new MqttClientSubscribeResultFactory();
+        readonly MqttClientUnsubscribeResultFactory _clientUnsubscribeResultFactory = new MqttClientUnsubscribeResultFactory();
+
+        readonly AsyncEvent<MqttClientConnectedEventArgs> _connectedEvent = new AsyncEvent<MqttClientConnectedEventArgs>();
+        readonly AsyncEvent<MqttClientConnectingEventArgs> _connectingEvent = new AsyncEvent<MqttClientConnectingEventArgs>();
+        readonly AsyncEvent<MqttClientDisconnectedEventArgs> _disconnectedEvent = new AsyncEvent<MqttClientDisconnectedEventArgs>();
        readonly object _disconnectLock = new object();
-        readonly MqttClientEvents _events = new MqttClientEvents();
+        readonly AsyncEvent<InspectMqttPacketEventArgs> _inspectPacketEvent = new AsyncEvent<InspectMqttPacketEventArgs>();
        readonly MqttNetSourceLogger _logger;

        readonly MqttPacketIdentifierProvider _packetIdentifierProvider = new MqttPacketIdentifierProvider();
@@ -58,35 +65,35 @@ namespace MQTTnet.Client

        public event Func<MqttApplicationMessageReceivedEventArgs, Task> ApplicationMessageReceivedAsync
        {
-            add => _events.ApplicationMessageReceivedEvent.AddHandler(value);
-            remove => _events.ApplicationMessageReceivedEvent.RemoveHandler(value);
+            add => _applicationMessageReceivedEvent.AddHandler(value);
+            remove => _applicationMessageReceivedEvent.RemoveHandler(value);
        }

        public event Func<MqttClientConnectedEventArgs, Task> ConnectedAsync
        {
-            add => _events.ConnectedEvent.AddHandler(value);
-            remove => _events.ConnectedEvent.RemoveHandler(value);
+            add => _connectedEvent.AddHandler(value);
+            remove => _connectedEvent.RemoveHandler(value);
        }

        public event Func<MqttClientConnectingEventArgs, Task> ConnectingAsync
        {
-            add => _events.ConnectingEvent.AddHandler(value);
-            remove => _events.ConnectingEvent.RemoveHandler(value);
+            add => _connectingEvent.AddHandler(value);
+            remove => _connectingEvent.RemoveHandler(value);
        }

        public event Func<MqttClientDisconnectedEventArgs, Task> DisconnectedAsync
        {
-            add => _events.DisconnectedEvent.AddHandler(value);
-            remove => _events.DisconnectedEvent.RemoveHandler(value);
+            add => _disconnectedEvent.AddHandler(value);
+            remove => _disconnectedEvent.RemoveHandler(value);
        }

-        public event Func<InspectMqttPacketEventArgs, Task> InspectPacketAsync
+        public event Func<InspectMqttPacketEventArgs, Task> InspectPackage
        {
-            add => _events.InspectPacketEvent.AddHandler(value);
-            remove => _events.InspectPacketEvent.RemoveHandler(value);
+            add => _inspectPacketEvent.AddHandler(value);
+            remove => _inspectPacketEvent.RemoveHandler(value);
        }

-        public bool IsConnected => (MqttClientConnectionStatus)_connectionStatus == MqttClientConnectionStatus.Connected;
+        public bool IsConnected => _adapter != null && (MqttClientConnectionStatus)_connectionStatus == MqttClientConnectionStatus.Connected;

        public MqttClientOptions Options { get; private set; }

@@ -107,9 +114,9 @@ namespace MQTTnet.Client
            {
                Options = options;

-                if (_events.ConnectingEvent.HasHandlers)
+                if (_connectingEvent.HasHandlers)
                {
-                    await _events.ConnectingEvent.InvokeAsync(new MqttClientConnectingEventArgs(options));
+                    await _connectingEvent.InvokeAsync(new MqttClientConnectingEventArgs(options)).ConfigureAwait(false);
                }

                Cleanup();
@@ -120,12 +127,12 @@ namespace MQTTnet.Client
                _mqttClientAlive = new CancellationTokenSource();
                var mqttClientAliveToken = _mqttClientAlive.Token;

-                var adapter = _adapterFactory.CreateClientAdapter(options, new MqttPacketInspector(_events.InspectPacketEvent, _rootLogger), _rootLogger);
-                _adapter = adapter ?? throw new InvalidOperationException("The adapter factory did not provide an adapter.");
+                var adapter = _adapterFactory.CreateClientAdapter(options, new MqttPacketInspector(_inspectPacketEvent, _rootLogger), _rootLogger);
+                _adapter = adapter;

                if (cancellationToken.CanBeCanceled)
                {
-                    connectResult = await ConnectInternal(adapter, cancellationToken).ConfigureAwait(false);
+                    connectResult = await ConnectInternal(cancellationToken).ConfigureAwait(false);
                }
                else
                {
@@ -133,51 +140,46 @@ namespace MQTTnet.Client
                    // CancellationToken.None or similar.
                    using (var timeout = new CancellationTokenSource(Options.Timeout))
                    {
-                        connectResult = await ConnectInternal(adapter, timeout.Token).ConfigureAwait(false);
+                        connectResult = await ConnectInternal(timeout.Token).ConfigureAwait(false);
                    }
                }

-                if (connectResult.ResultCode != MqttClientConnectResultCode.Success)
-                {
-                    _logger.Warning("Connecting failed: {0}", connectResult.ResultCode);
-                    await DisconnectInternal(null, null, connectResult).ConfigureAwait(false);
-                    return connectResult;
-                }
-
                _lastPacketSentTimestamp = DateTime.UtcNow;

                var keepAliveInterval = Options.KeepAlivePeriod;
                if (connectResult.ServerKeepAlive > 0)
                {
-                    _logger.Info($"Using keep alive value ({connectResult.ServerKeepAlive}) sent from the server");
+                    _logger.Info($"Using keep alive value ({connectResult.ServerKeepAlive}) sent from the server.");
                    keepAliveInterval = TimeSpan.FromSeconds(connectResult.ServerKeepAlive);
                }

                if (keepAliveInterval != TimeSpan.Zero)
                {
-                    _keepAlivePacketsSenderTask = Task.Run(() => TrySendKeepAliveMessages(mqttClientAliveToken), mqttClientAliveToken);
+                    _keepAlivePacketsSenderTask = Task.Run(() => TrySendKeepAliveMessagesAsync(mqttClientAliveToken), mqttClientAliveToken);
                }

                CompareExchangeConnectionStatus(MqttClientConnectionStatus.Connected, MqttClientConnectionStatus.Connecting);

-                _logger.Info("Connected");
+                _logger.Info("Connected.");

-                await OnConnected(connectResult).ConfigureAwait(false);
+                if (_connectedEvent.HasHandlers)
+                {
+                    var eventArgs = new MqttClientConnectedEventArgs(connectResult);
+                    await _connectedEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
+                }

                return connectResult;
            }
            catch (Exception exception)
            {
-                if (exception is MqttConnectingFailedException connectingFailedException)
-                {
-                    connectResult = connectingFailedException.Result;
-                }
-
                _disconnectReason = (int)MqttClientDisconnectOptionsReason.UnspecifiedError;

-                _logger.Error(exception, "Error while connecting with server");
+                if (!(exception is OperationCanceledException))
+                {
+                    _logger.Error(exception, "Error while connecting with server.");
+                }

-                await DisconnectInternal(null, exception, connectResult).ConfigureAwait(false);
+                await DisconnectInternalAsync(null, exception, connectResult).ConfigureAwait(false);

                throw;
            }
@@ -220,38 +222,33 @@ namespace MQTTnet.Client

                if (cancellationToken.CanBeCanceled)
                {
-                    await Send(disconnectPacket, cancellationToken).ConfigureAwait(false);
+                    await SendAsync(disconnectPacket, cancellationToken).ConfigureAwait(false);
                }
                else
                {
                    using (var timeout = new CancellationTokenSource(Options.Timeout))
                    {
-                        await Send(disconnectPacket, timeout.Token).ConfigureAwait(false);
+                        await SendAsync(disconnectPacket, timeout.Token).ConfigureAwait(false);
                    }
                }
            }
            finally
            {
-                await DisconnectCore(null, null, null, clientWasConnected).ConfigureAwait(false);
+                await DisconnectCoreAsync(null, null, null, clientWasConnected).ConfigureAwait(false);
            }
        }

        public async Task PingAsync(CancellationToken cancellationToken = default)
        {
-            cancellationToken.ThrowIfCancellationRequested();
-            
-            ThrowIfDisposed();
-            ThrowIfNotConnected();
-
            if (cancellationToken.CanBeCanceled)
            {
-                await Request<MqttPingRespPacket>(MqttPingReqPacket.Instance, cancellationToken).ConfigureAwait(false);
+                await SendAndReceiveAsync<MqttPingRespPacket>(MqttPingReqPacket.Instance, cancellationToken).ConfigureAwait(false);
            }
            else
            {
                using (var timeout = new CancellationTokenSource(Options.Timeout))
                {
-                    await Request<MqttPingRespPacket>(MqttPingReqPacket.Instance, timeout.Token).ConfigureAwait(false);
+                    await SendAndReceiveAsync<MqttPingRespPacket>(MqttPingReqPacket.Instance, timeout.Token).ConfigureAwait(false);
                }
            }
        }
@@ -280,11 +277,11 @@ namespace MQTTnet.Client
                }
                case MqttQualityOfServiceLevel.AtLeastOnce:
                {
-                    return PublishAtLeastOnce(publishPacket, cancellationToken);
+                    return PublishAtLeastOnceAsync(publishPacket, cancellationToken);
                }
                case MqttQualityOfServiceLevel.ExactlyOnce:
                {
-                    return PublishExactlyOnce(publishPacket, cancellationToken);
+                    return PublishExactlyOnceAsync(publishPacket, cancellationToken);
                }
                default:
                {
@@ -312,7 +309,7 @@ namespace MQTTnet.Client
                UserProperties = data.UserProperties
            };

-            return Send(authPacket, cancellationToken);
+            return SendAsync(authPacket, cancellationToken);
        }

        public async Task<MqttClientSubscribeResult> SubscribeAsync(MqttClientSubscribeOptions options, CancellationToken cancellationToken = default)
@@ -327,31 +324,31 @@ namespace MQTTnet.Client
                MqttTopicValidator.ThrowIfInvalidSubscribe(topicFilter.Topic);
            }

-            ThrowIfDisposed();
-            ThrowIfNotConnected();
-            
            if (Options.ValidateFeatures)
            {
                MqttClientSubscribeOptionsValidator.ThrowIfNotSupported(options, _adapter.PacketFormatterAdapter.ProtocolVersion);
            }

+            ThrowIfDisposed();
+            ThrowIfNotConnected();
+
            var subscribePacket = MqttPacketFactories.Subscribe.Create(options);
            subscribePacket.PacketIdentifier = _packetIdentifierProvider.GetNextPacketIdentifier();

            MqttSubAckPacket subAckPacket;
            if (cancellationToken.CanBeCanceled)
            {
-                subAckPacket = await Request<MqttSubAckPacket>(subscribePacket, cancellationToken).ConfigureAwait(false);
+                subAckPacket = await SendAndReceiveAsync<MqttSubAckPacket>(subscribePacket, cancellationToken).ConfigureAwait(false);
            }
            else
            {
                using (var timeout = new CancellationTokenSource(Options.Timeout))
                {
-                    subAckPacket = await Request<MqttSubAckPacket>(subscribePacket, timeout.Token).ConfigureAwait(false);
+                    subAckPacket = await SendAndReceiveAsync<MqttSubAckPacket>(subscribePacket, timeout.Token).ConfigureAwait(false);
                }
            }

-            return MqttClientResultFactory.SubscribeResult.Create(subscribePacket, subAckPacket);
+            return _clientSubscribeResultFactory.Create(subscribePacket, subAckPacket);
        }

        public async Task<MqttClientUnsubscribeResult> UnsubscribeAsync(MqttClientUnsubscribeOptions options, CancellationToken cancellationToken = default)
@@ -380,17 +377,17 @@ namespace MQTTnet.Client
            MqttUnsubAckPacket unsubAckPacket;
            if (cancellationToken.CanBeCanceled)
            {
-                unsubAckPacket = await Request<MqttUnsubAckPacket>(unsubscribePacket, cancellationToken).ConfigureAwait(false);
+                unsubAckPacket = await SendAndReceiveAsync<MqttUnsubAckPacket>(unsubscribePacket, cancellationToken).ConfigureAwait(false);
            }
            else
            {
                using (var timeout = new CancellationTokenSource(Options.Timeout))
                {
-                    unsubAckPacket = await Request<MqttUnsubAckPacket>(unsubscribePacket, timeout.Token).ConfigureAwait(false);
+                    unsubAckPacket = await SendAndReceiveAsync<MqttUnsubAckPacket>(unsubscribePacket, timeout.Token).ConfigureAwait(false);
                }
            }

-            return MqttClientResultFactory.UnsubscribeResult.Create(unsubscribePacket, unsubAckPacket);
+            return _clientUnsubscribeResultFactory.Create(unsubscribePacket, unsubAckPacket);
        }

        protected override void Dispose(bool disposing)
@@ -414,7 +411,7 @@ namespace MQTTnet.Client
                if (!eventArgs.ProcessingFailed)
                {
                    var pubAckPacket = MqttPacketFactories.PubAck.Create(eventArgs);
-                    return Send(pubAckPacket, cancellationToken);
+                    return SendAsync(pubAckPacket, cancellationToken);
                }
            }
            else if (eventArgs.PublishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.ExactlyOnce)
@@ -422,7 +419,7 @@ namespace MQTTnet.Client
                if (!eventArgs.ProcessingFailed)
                {
                    var pubRecPacket = MqttPacketFactories.PubRec.Create(eventArgs);
-                    return Send(pubRecPacket, cancellationToken);
+                    return SendAsync(pubRecPacket, cancellationToken);
                }
            }
            else
@@ -433,50 +430,27 @@ namespace MQTTnet.Client
            return CompletedTask.Instance;
        }

-        async Task<MqttClientConnectResult> Authenticate(IMqttChannelAdapter channelAdapter, MqttClientOptions options, CancellationToken cancellationToken)
+        async Task<MqttClientConnectResult> AuthenticateAsync(MqttClientOptions options, CancellationToken cancellationToken)
        {
            MqttClientConnectResult result;

            try
            {
                var connectPacket = MqttPacketFactories.Connect.Create(options);
-                await Send(connectPacket, cancellationToken).ConfigureAwait(false);

-                var receivedPacket = await Receive(cancellationToken).ConfigureAwait(false);
+                var connAckPacket = await SendAndReceiveAsync<MqttConnAckPacket>(connectPacket, cancellationToken).ConfigureAwait(false);

-                if (receivedPacket is MqttConnAckPacket connAckPacket)
-                {
-                    result = MqttClientResultFactory.ConnectResult.Create(connAckPacket, channelAdapter.PacketFormatterAdapter.ProtocolVersion);
-                }
-                else if (receivedPacket is MqttAuthPacket)
-                {
-                    throw new NotSupportedException("Extended authentication handler is not yet supported");
-                }
-                else if (receivedPacket == null)
-                {
-                    throw new MqttCommunicationException("Connection closed.");
-                }
-                else
-                {
-                    throw new InvalidOperationException($"Received an unexpected MQTT packet ({receivedPacket}).");
-                }
+                var clientConnectResultFactory = new MqttClientConnectResultFactory();
+                result = clientConnectResultFactory.Create(connAckPacket, _adapter.PacketFormatterAdapter.ProtocolVersion);
            }
            catch (Exception exception)
            {
                throw new MqttConnectingFailedException($"Error while authenticating. {exception.Message}", exception, null);
            }

-            // This is no feature. It is basically a backward compatibility option and should be removed in the future.
-            // The client should not throw any exception if the transport layer connection was successful and the server
-            // did send a proper ACK packet with a non success response.
-            if (options.ThrowOnNonSuccessfulConnectResponse)
+            if (result.ResultCode != MqttClientConnectResultCode.Success)
            {
-                if (result.ResultCode != MqttClientConnectResultCode.Success)
-                {
-                    _logger.Warning(
-                        "Client will now throw an _MqttConnectingFailedException_. This is obsolete and will be removed in the future. Consider setting _ThrowOnNonSuccessfulResponseFromServer=False_ in client options.");
-                    throw new MqttConnectingFailedException($"Connecting with MQTT server failed ({result.ResultCode}).", null, result);
-                }
+                throw new MqttConnectingFailedException($"Connecting with MQTT server failed ({result.ResultCode}).", null, result);
            }

            _logger.Verbose("Authenticated MQTT connection with server established.");
@@ -511,31 +485,27 @@ namespace MQTTnet.Client
            return (MqttClientConnectionStatus)Interlocked.CompareExchange(ref _connectionStatus, (int)value, (int)comparand);
        }

-        async Task<MqttClientConnectResult> ConnectInternal(IMqttChannelAdapter channelAdapter, CancellationToken cancellationToken)
+        async Task<MqttClientConnectResult> ConnectInternal(CancellationToken cancellationToken)
        {
            var backgroundCancellationToken = _mqttClientAlive.Token;

            using (var effectiveCancellationToken = CancellationTokenSource.CreateLinkedTokenSource(backgroundCancellationToken, cancellationToken))
            {
-                _logger.Verbose("Trying to connect with server '{0}'", Options.ChannelOptions);
-                await channelAdapter.ConnectAsync(effectiveCancellationToken.Token).ConfigureAwait(false);
-                _logger.Verbose("Connection with server established");
+                _logger.Verbose("Trying to connect with server '{0}'.", Options.ChannelOptions);
+                await _adapter.ConnectAsync(effectiveCancellationToken.Token).ConfigureAwait(false);
+                _logger.Verbose("Connection with server established.");

                _publishPacketReceiverQueue?.Dispose();
                _publishPacketReceiverQueue = new AsyncQueue<MqttPublishPacket>();

-                var connectResult = await Authenticate(channelAdapter, Options, effectiveCancellationToken.Token).ConfigureAwait(false);
-                if (connectResult.ResultCode == MqttClientConnectResultCode.Success)
-                {
-                    _publishPacketReceiverTask = Task.Run(() => ProcessReceivedPublishPackets(backgroundCancellationToken), backgroundCancellationToken);
-                    _packetReceiverTask = Task.Run(() => ReceivePacketsLoop(backgroundCancellationToken), backgroundCancellationToken);
-                }
+                _publishPacketReceiverTask = Task.Run(() => ProcessReceivedPublishPackets(backgroundCancellationToken), backgroundCancellationToken);
+                _packetReceiverTask = Task.Run(() => TryReceivePacketsAsync(backgroundCancellationToken), backgroundCancellationToken);

-                return connectResult;
+                return await AuthenticateAsync(Options, effectiveCancellationToken.Token).ConfigureAwait(false);
            }
        }

-        async Task DisconnectCore(Task sender, Exception exception, MqttClientConnectResult connectResult, bool clientWasConnected)
+        async Task DisconnectCoreAsync(Task sender, Exception exception, MqttClientConnectResult connectResult, bool clientWasConnected)
        {
            TryInitiateDisconnect();

@@ -560,7 +530,7 @@ namespace MQTTnet.Client

            try
            {
-                _packetDispatcher?.Dispose(new MqttClientDisconnectedException(exception));
+                _packetDispatcher.Dispose(new MqttClientDisconnectedException(exception));

                var receiverTask = _packetReceiverTask.WaitAsync(sender, _logger);
                var publishPacketReceiverTask = _publishPacketReceiverTask.WaitAsync(sender, _logger);
@@ -590,17 +560,17 @@ namespace MQTTnet.Client

                // This handler must be executed in a new thread because otherwise a dead lock may happen
                // when trying to reconnect in that handler etc.
-                Task.Run(() => _events.DisconnectedEvent.InvokeAsync(eventArgs)).RunInBackground(_logger);
+                Task.Run(() => _disconnectedEvent.InvokeAsync(eventArgs)).RunInBackground(_logger);
            }
        }

-        Task DisconnectInternal(Task sender, Exception exception, MqttClientConnectResult connectResult)
+        Task DisconnectInternalAsync(Task sender, Exception exception, MqttClientConnectResult connectResult)
        {
            var clientWasConnected = IsConnected;

            if (!DisconnectIsPendingOrFinished())
            {
-                return DisconnectCore(sender, exception, connectResult, clientWasConnected);
+                return DisconnectCoreAsync(sender, exception, connectResult, clientWasConnected);
            }

            return CompletedTask.Instance;
@@ -630,7 +600,8 @@ namespace MQTTnet.Client
                        connectionStatus = curStatus;
                        break;
                }
-            } while (true);
+            }
+            while (true);
        }

        void EnqueueReceivedPublishPacket(MqttPublishPacket publishPacket)
@@ -645,26 +616,15 @@ namespace MQTTnet.Client
            }
        }

-        async Task<MqttApplicationMessageReceivedEventArgs> HandleReceivedApplicationMessage(MqttPublishPacket publishPacket)
+        async Task<MqttApplicationMessageReceivedEventArgs> HandleReceivedApplicationMessageAsync(MqttPublishPacket publishPacket)
        {
            var applicationMessage = MqttApplicationMessageFactory.Create(publishPacket);
            var eventArgs = new MqttApplicationMessageReceivedEventArgs(Options.ClientId, applicationMessage, publishPacket, AcknowledgeReceivedPublishPacket);
-            await _events.ApplicationMessageReceivedEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
+            await _applicationMessageReceivedEvent.InvokeAsync(eventArgs).ConfigureAwait(false);

            return eventArgs;
        }

-        Task OnConnected(MqttClientConnectResult connectResult)
-        {
-            if (_events.ConnectedEvent.HasHandlers)
-            {
-                var eventArgs = new MqttClientConnectedEventArgs(connectResult);
-                return _events.ConnectedEvent.InvokeAsync(eventArgs);
-            }
-
-            return CompletedTask.Instance;
-        }
-
        Task ProcessReceivedAuthPacket(MqttAuthPacket authPacket)
        {
            var extendedAuthenticationExchangeHandler = Options.ExtendedAuthenticationExchangeHandler;
@@ -685,7 +645,7 @@ namespace MQTTnet.Client
            // Also dispatch disconnect to waiting threads to generate a proper exception.
            _packetDispatcher.Dispose(new MqttClientUnexpectedDisconnectReceivedException(disconnectPacket));

-            return DisconnectInternal(_packetReceiverTask, null, null);
+            return DisconnectInternalAsync(_packetReceiverTask, null, null);
        }

        async Task ProcessReceivedPublishPackets(CancellationToken cancellationToken)
@@ -701,16 +661,13 @@ namespace MQTTnet.Client
                    }

                    var publishPacket = publishPacketDequeueResult.Item;
-                    var eventArgs = await HandleReceivedApplicationMessage(publishPacket).ConfigureAwait(false);
+                    var eventArgs = await HandleReceivedApplicationMessageAsync(publishPacket).ConfigureAwait(false);

                    if (eventArgs.AutoAcknowledge)
                    {
                        await eventArgs.AcknowledgeAsync(cancellationToken).ConfigureAwait(false);
                    }
                }
-                catch (ObjectDisposedException)
-                {
-                }
                catch (OperationCanceledException)
                {
                }
@@ -728,7 +685,7 @@ namespace MQTTnet.Client
                // The packet is unknown. Probably due to a restart of the client.
                // So wen send this to the server to trigger a full resend of the message.
                var pubRelPacket = MqttPacketFactories.PubRel.Create(pubRecPacket, MqttApplicationMessageReceivedReasonCode.PacketIdentifierNotFound);
-                return Send(pubRelPacket, cancellationToken);
+                return SendAsync(pubRelPacket, cancellationToken);
            }

            return CompletedTask.Instance;
@@ -737,119 +694,42 @@ namespace MQTTnet.Client
        Task ProcessReceivedPubRelPacket(MqttPubRelPacket pubRelPacket, CancellationToken cancellationToken)
        {
            var pubCompPacket = MqttPacketFactories.PubComp.Create(pubRelPacket, MqttApplicationMessageReceivedReasonCode.Success);
-            return Send(pubCompPacket, cancellationToken);
+            return SendAsync(pubCompPacket, cancellationToken);
        }

-        async Task<MqttClientPublishResult> PublishAtLeastOnce(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
+        async Task<MqttClientPublishResult> PublishAtLeastOnceAsync(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
        {
            publishPacket.PacketIdentifier = _packetIdentifierProvider.GetNextPacketIdentifier();

-            var pubAckPacket = await Request<MqttPubAckPacket>(publishPacket, cancellationToken).ConfigureAwait(false);
-            return MqttClientResultFactory.PublishResult.Create(pubAckPacket);
+            var pubAckPacket = await SendAndReceiveAsync<MqttPubAckPacket>(publishPacket, cancellationToken).ConfigureAwait(false);
+            return _clientPublishResultFactory.Create(pubAckPacket);
        }

        async Task<MqttClientPublishResult> PublishAtMostOnce(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
        {
            // No packet identifier is used for QoS 0 [3.3.2.2 Packet Identifier]
-            await Send(publishPacket, cancellationToken).ConfigureAwait(false);
+            await SendAsync(publishPacket, cancellationToken).ConfigureAwait(false);

-            return MqttClientResultFactory.PublishResult.Create(null);
+            return _clientPublishResultFactory.Create(null);
        }

-        async Task<MqttClientPublishResult> PublishExactlyOnce(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
+        async Task<MqttClientPublishResult> PublishExactlyOnceAsync(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
        {
            publishPacket.PacketIdentifier = _packetIdentifierProvider.GetNextPacketIdentifier();

-            var pubRecPacket = await Request<MqttPubRecPacket>(publishPacket, cancellationToken).ConfigureAwait(false);
+            var pubRecPacket = await SendAndReceiveAsync<MqttPubRecPacket>(publishPacket, cancellationToken).ConfigureAwait(false);

            var pubRelPacket = MqttPacketFactories.PubRel.Create(pubRecPacket, MqttApplicationMessageReceivedReasonCode.Success);

-            var pubCompPacket = await Request<MqttPubCompPacket>(pubRelPacket, cancellationToken).ConfigureAwait(false);
+            var pubCompPacket = await SendAndReceiveAsync<MqttPubCompPacket>(pubRelPacket, cancellationToken).ConfigureAwait(false);

-            return MqttClientResultFactory.PublishResult.Create(pubRecPacket, pubCompPacket);
+            return _clientPublishResultFactory.Create(pubRecPacket, pubCompPacket);
        }

-        async Task<MqttPacket> Receive(CancellationToken cancellationToken)
-        {
-            var packetTask = _adapter.ReceivePacketAsync(cancellationToken);
-
-            MqttPacket packet;
-            if (packetTask.IsCompleted)
-            {
-                packet = packetTask.Result;
-            }
-            else
-            {
-                packet = await packetTask.ConfigureAwait(false);
-            }
-
-            return packet;
-        }
-
-        async Task ReceivePacketsLoop(CancellationToken cancellationToken)
-        {
-            try
-            {
-                _logger.Verbose("Start receiving packets");
-
-                while (!cancellationToken.IsCancellationRequested)
-                {
-                    var packet = await Receive(cancellationToken).ConfigureAwait(false);
-
-                    if (cancellationToken.IsCancellationRequested)
-                    {
-                        return;
-                    }
-
-                    if (packet == null)
-                    {
-                        await DisconnectInternal(_packetReceiverTask, null, null).ConfigureAwait(false);
-
-                        return;
-                    }
-
-                    await TryProcessReceivedPacket(packet, cancellationToken).ConfigureAwait(false);
-                }
-            }
-            catch (Exception exception)
-            {
-                if (_cleanDisconnectInitiated)
-                {
-                    return;
-                }
-
-                if (exception is AggregateException aggregateException)
-                {
-                    exception = aggregateException.GetBaseException();
-                }
-
-                if (exception is OperationCanceledException)
-                {
-                }
-                else if (exception is MqttCommunicationException)
-                {
-                    _logger.Warning(exception, "Communication error while receiving packets");
-                }
-                else
-                {
-                    _logger.Error(exception, "Error while receiving packets");
-                }
-
-                // The packet dispatcher is set to null when the client is being disposed so it may
-                // already being gone!
-                _packetDispatcher?.FailAll(exception);
-
-                await DisconnectInternal(_packetReceiverTask, exception, null).ConfigureAwait(false);
-            }
-            finally
-            {
-                _logger.Verbose("Stopped receiving packets");
-            }
-        }
-
-        async Task<TResponsePacket> Request<TResponsePacket>(MqttPacket requestPacket, CancellationToken cancellationToken) where TResponsePacket : MqttPacket
+        async Task<TResponsePacket> SendAndReceiveAsync<TResponsePacket>(MqttPacket requestPacket, CancellationToken cancellationToken) where TResponsePacket : MqttPacket
        {
            cancellationToken.ThrowIfCancellationRequested();
+            ThrowIfNoAdapter();

            ushort packetIdentifier = 0;
            if (requestPacket is MqttPacketWithIdentifier packetWithIdentifier)
@@ -861,7 +741,7 @@ namespace MQTTnet.Client
            {
                try
                {
-                    await Send(requestPacket, cancellationToken).ConfigureAwait(false);
+                    await SendAsync(requestPacket, cancellationToken).ConfigureAwait(false);
                }
                catch (Exception exception)
                {
@@ -885,12 +765,12 @@ namespace MQTTnet.Client
            }
        }

-        Task Send(MqttPacket packet, CancellationToken cancellationToken)
+        Task SendAsync(MqttPacket packet, CancellationToken cancellationToken)
        {
            cancellationToken.ThrowIfCancellationRequested();
+            ThrowIfNoAdapter();

            _lastPacketSentTimestamp = DateTime.UtcNow;
-
            return _adapter.SendPacketAsync(packet, cancellationToken);
        }

@@ -902,6 +782,16 @@ namespace MQTTnet.Client
            }
        }

+        void ThrowIfNoAdapter()
+        {
+            // Having no adapter indicates that the connection is closed or still being created.
+            // Thus the client is disconnected.
+            if (_adapter == null)
+            {
+                ThrowNotConnected();
+            }
+        }
+
        void ThrowIfNotConnected()
        {
            if (!IsConnected)
@@ -948,7 +838,7 @@ namespace MQTTnet.Client
            }
        }

-        async Task TryProcessReceivedPacket(MqttPacket packet, CancellationToken cancellationToken)
+        async Task TryProcessReceivedPacketAsync(MqttPacket packet, CancellationToken cancellationToken)
        {
            try
            {
@@ -1009,11 +899,80 @@ namespace MQTTnet.Client

                _packetDispatcher.FailAll(exception);

-                await DisconnectInternal(_packetReceiverTask, exception, null).ConfigureAwait(false);
+                await DisconnectInternalAsync(_packetReceiverTask, exception, null).ConfigureAwait(false);
            }
        }

-        async Task TrySendKeepAliveMessages(CancellationToken cancellationToken)
+        async Task TryReceivePacketsAsync(CancellationToken cancellationToken)
+        {
+            try
+            {
+                _logger.Verbose("Start receiving packets.");
+
+                while (!cancellationToken.IsCancellationRequested)
+                {
+                    MqttPacket packet;
+                    var packetTask = _adapter.ReceivePacketAsync(cancellationToken);
+
+                    if (packetTask.IsCompleted)
+                    {
+                        packet = packetTask.Result;
+                    }
+                    else
+                    {
+                        packet = await packetTask.ConfigureAwait(false);
+                    }
+
+                    if (cancellationToken.IsCancellationRequested)
+                    {
+                        return;
+                    }
+
+                    if (packet == null)
+                    {
+                        await DisconnectInternalAsync(_packetReceiverTask, null, null).ConfigureAwait(false);
+
+                        return;
+                    }
+
+                    await TryProcessReceivedPacketAsync(packet, cancellationToken).ConfigureAwait(false);
+                }
+            }
+            catch (Exception exception)
+            {
+                if (_cleanDisconnectInitiated)
+                {
+                    return;
+                }
+
+                if (exception is AggregateException aggregateException)
+                {
+                    exception = aggregateException.GetBaseException();
+                }
+
+                if (exception is OperationCanceledException)
+                {
+                }
+                else if (exception is MqttCommunicationException)
+                {
+                    _logger.Warning(exception, "Communication error while receiving packets.");
+                }
+                else
+                {
+                    _logger.Error(exception, "Error while receiving packets.");
+                }
+
+                _packetDispatcher.FailAll(exception);
+
+                await DisconnectInternalAsync(_packetReceiverTask, exception, null).ConfigureAwait(false);
+            }
+            finally
+            {
+                _logger.Verbose("Stopped receiving packets.");
+            }
+        }
+
+        async Task TrySendKeepAliveMessagesAsync(CancellationToken cancellationToken)
        {
            try
            {
@@ -1062,7 +1021,7 @@ namespace MQTTnet.Client
                    _logger.Error(exception, "Error exception while sending/receiving keep alive packets.");
                }

-                await DisconnectInternal(_keepAlivePacketsSenderTask, exception, null).ConfigureAwait(false);
+                await DisconnectInternalAsync(_keepAlivePacketsSenderTask, exception, null).ConfigureAwait(false);
            }
            finally
            {
@@ -1070,4 +1029,4 @@ namespace MQTTnet.Client
            }
        }
    }
-}
+}
@@ -1,36 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System.Collections.Generic;
-using System.Security.Cryptography.X509Certificates;
-
-namespace MQTTnet.Client
-{
-    public sealed class DefaultMqttCertificatesProvider : IMqttClientCertificatesProvider
-    {
-        readonly X509Certificate2Collection _certificates;
-
-        public DefaultMqttCertificatesProvider(X509Certificate2Collection certificates)
-        {
-            _certificates = certificates;
-        }
-
-        public DefaultMqttCertificatesProvider(IEnumerable<X509Certificate> certificates)
-        {
-            if (certificates != null)
-            {
-                _certificates = new X509Certificate2Collection();
-                foreach (var certificate in certificates)
-                {
-                    _certificates.Add(certificate);
-                }
-            }
-        }
-
-        public X509CertificateCollection GetCertificates()
-        {
-            return _certificates;
-        }
-    }
-}
@@ -14,14 +14,8 @@ namespace MQTTnet.Client

        public X509Chain Chain { get; set; }

-        public IMqttClientChannelOptions ClientOptions { get; set; }
-#if NET452 || NET461 || NET48
-        /// <summary>
-        ///     Can be a host string name or an object derived from WebRequest.
-        /// </summary>
-        public object Sender { get; set; }
-#endif
-
        public SslPolicyErrors SslPolicyErrors { get; set; }
+
+        public IMqttClientChannelOptions ClientOptions { get; set; }
    }
-}
+}
@@ -12,14 +12,6 @@ namespace MQTTnet.Client
 {
    public sealed class MqttClientOptions
    {
-        /// <summary>
-        ///     Usually the MQTT packets can be send partially. This is done by using multiple TCP packets
-        ///     or WebSocket frames etc. Unfortunately not all brokers (like Amazon Web Services (AWS)) do support this feature and
-        ///     will close the connection when receiving such packets. If such a service is used this flag must
-        ///     be set to _false_.
-        /// </summary>
-        public bool AllowPacketFragmentation { get; set; } = true;
-
        /// <summary>
        ///     Gets or sets the authentication data.
        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
@@ -100,11 +92,6 @@ namespace MQTTnet.Client
        /// </summary>
        public uint SessionExpiryInterval { get; set; }

-        /// <summary>
-        ///     Gets or sets whether an exception should be thrown when the server has sent a non success ACK packet.
-        /// </summary>
-        public bool ThrowOnNonSuccessfulConnectResponse { get; set; } = true;
-
        /// <summary>
        ///     Gets or sets the timeout which will be applied at socket level and internal operations.
        ///     The default value is the same as for sockets in .NET in general.
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Christian	25b42df85c	Refactor code	2023-01-19 20:53:57 +01:00
Christian	f8d614e71f	Merge branch 'master' into Managed-Client-V2	2023-01-19 20:50:34 +01:00
Christian	7bb29d3c92	Merge master	2022-12-28 14:15:27 +01:00
Christian	4d81d3f3d9	Merge branch 'master' into Managed-Client-V2	2022-12-28 14:15:21 +01:00
Christian	3937aa76e3	Fix merge conflicts	2022-11-13 18:41:28 +01:00
Christian	2090b08547	Merge branch 'master' into Managed-Client-V2	2022-11-13 18:13:23 +01:00
Christian	7c3fad6147	Implement new managed client.	2022-09-29 18:38:29 +02:00