1565 high cpu load from asyncsignal (#1566)

Source/MQTTnet.Tests/Internal/AsyncSignal_Tests.cs

@@ -52,12 +52,26 @@ namespace MQTTnet.Tests.Internal
         }
 
         [TestMethod]
-        public async Task Loop_Signal()
+        public async Task Reset_Signal()
         {
             var asyncSignal = new AsyncSignal();
 
+            // WaitAsync should fail because no signal is available.
             for (var i = 0; i < 10; i++)
             {
+                try
+                {
+                    using (var timeout = new CancellationTokenSource(TimeSpan.FromMilliseconds(100)))
+                    {
+                        await asyncSignal.WaitAsync(timeout.Token);
+                    }
+                    
+                    Assert.Fail("This must fail because the signal is not yet set.");
+                }
+                catch (OperationCanceledException)
+                {
+                }
+                
                 asyncSignal.Set();
                 
                 // WaitAsync should return directly because the signal is available.

Source/MQTTnet.Tests/Server/Load_Tests.cs

@@ -55,7 +55,7 @@ namespace MQTTnet.Tests.Server
                             });
                     }
 
-                    SpinWait.SpinUntil(() => receivedMessages == 100000, TimeSpan.FromSeconds(90));
+                    SpinWait.SpinUntil(() => receivedMessages == 100000, TimeSpan.FromSeconds(120));
 
                     Assert.AreEqual(100000, receivedMessages);
                 }

Source/MQTTnet.Tests/Server/Session_Tests.cs

@@ -150,7 +150,7 @@ namespace MQTTnet.Tests.Server
                 // Try to connect 50 clients at the same time.
                 var clients = await Task.WhenAll(Enumerable.Range(0, 50).Select(i => ConnectAndSubscribe(testEnvironment, options, OnReceive)));
 
-                await Task.Delay(5000);
+                await Task.Delay(TimeSpan.FromSeconds(10));
                 
                 var connectedClients = clients.Where(c => c?.TryPingAsync().GetAwaiter().GetResult() == true).ToList();
 
@@ -162,7 +162,7 @@ namespace MQTTnet.Tests.Server
                 var sendClient = await testEnvironment.ConnectClient(option2);
                 await sendClient.PublishStringAsync("aaa", "1");
 
-                await Task.Delay(3000);
+                await Task.Delay(TimeSpan.FromSeconds(5));
 
                 Assert.AreEqual(true, hasReceive);
             }