fix: prevent video callback crash during transport teardown

tests/video_callback_lifetime_test.cpp

@@ -0,0 +1,120 @@
+#include <filesystem>
+#include <fstream>
+#include <iostream>
+#include <sstream>
+#include <string>
+
+namespace {
+
+std::filesystem::path FindRepoRoot() {
+  std::filesystem::path current = std::filesystem::current_path();
+  while (!current.empty()) {
+    if (std::filesystem::exists(current / "xmake.lua") &&
+        std::filesystem::exists(
+            current / "submodules/minirtc/src/transport/ice_transport_controller.cpp")) {
+      return current;
+    }
+    current = current.parent_path();
+  }
+  return {};
+}
+
+std::string ReadFile(const std::filesystem::path& path) {
+  std::ifstream file(path, std::ios::binary);
+  if (!file) {
+    return {};
+  }
+
+  std::ostringstream stream;
+  stream << file.rdbuf();
+  return stream.str();
+}
+
+std::string ExtractSection(const std::string& source, const std::string& begin,
+                           const std::string& end) {
+  const size_t begin_pos = source.find(begin);
+  if (begin_pos == std::string::npos) {
+    return {};
+  }
+  const size_t end_pos = source.find(end, begin_pos + begin.size());
+  if (end_pos == std::string::npos) {
+    return {};
+  }
+  return source.substr(begin_pos, end_pos - begin_pos);
+}
+
+bool ExpectContains(const char* name, const std::string& value,
+                    const std::string& expected) {
+  if (value.find(expected) != std::string::npos) {
+    return true;
+  }
+
+  std::cerr << name << " missing expected text: " << expected << "\n";
+  return false;
+}
+
+bool ExpectNotContains(const char* name, const std::string& value,
+                       const std::string& unexpected) {
+  if (value.find(unexpected) == std::string::npos) {
+    return true;
+  }
+
+  std::cerr << name << " contains unsafe text: " << unexpected << "\n";
+  return false;
+}
+
+}  // namespace
+
+int main() {
+  const std::filesystem::path repo_root = FindRepoRoot();
+  if (repo_root.empty()) {
+    std::cerr << "failed to locate repository root\n";
+    return 1;
+  }
+
+  const std::string controller = ReadFile(
+      repo_root /
+      "submodules/minirtc/src/transport/ice_transport_controller.cpp");
+  const std::string destroy = ExtractSection(
+      controller, "void IceTransportController::Destroy()",
+      "uint32_t IceTransportController::AddVideoSendChannel");
+  const std::string send_video = ExtractSection(
+      controller, "int IceTransportController::SendVideo(",
+      "void IceTransportController::MaybeDegradeResolutionOnEncodeTime");
+  const std::string on_video_encoded = ExtractSection(
+      controller, "int IceTransportController::OnVideoEncoded(",
+      "int IceTransportController::SendAudio(");
+
+  bool ok = true;
+  ok &= ExpectContains("Destroy", destroy,
+                       "std::unique_lock lock(stream_senders_mutex_);");
+  ok &= ExpectContains("Destroy", destroy,
+                       "senders.swap(stream_senders_);");
+  ok &= ExpectContains("Destroy", destroy,
+                       "codecs.push_back(std::move(context->codec));");
+  ok &= ExpectContains("Destroy", destroy, "senders.clear();");
+  ok &= ExpectContains("Destroy", destroy, "codecs.clear();");
+  ok &= ExpectNotContains("Destroy", destroy,
+                          "std::shared_lock lock(stream_senders_mutex_);");
+
+  ok &= ExpectContains("SendVideo", send_video,
+                       "std::weak_ptr<IceTransportController> weak_self");
+  ok &= ExpectContains("SendVideo", send_video,
+                       "std::weak_ptr<StreamContext> weak_context");
+  ok &= ExpectContains(
+      "SendVideo", send_video,
+      "[weak_self, weak_context, channel_name, queue_delay_ms");
+  ok &= ExpectContains("SendVideo", send_video,
+                       "return self->OnVideoEncoded(");
+  ok &= ExpectNotContains("SendVideo", send_video,
+                          "[this, channel_name, context");
+
+  ok &= ExpectContains("OnVideoEncoded", on_video_encoded,
+                       "if (!is_running_.load())");
+  ok &= ExpectContains("OnVideoEncoded", on_video_encoded,
+                       "std::shared_lock lock(stream_senders_mutex_);");
+  ok &= ExpectContains("OnVideoEncoded", on_video_encoded,
+                       "it->second != context");
+
+  return ok ? 0 : 1;
+}

xmake/targets.lua

@@ -73,6 +73,11 @@ function setup_targets()
         set_default(false)
         add_files("tests/connection_status_protocol_test.cpp")
 
+    target("video_callback_lifetime_test")
+        set_kind("binary")
+        set_default(false)
+        add_files("tests/video_callback_lifetime_test.cpp")
+
     target("windows_manifest_resource_test")
         set_kind("binary")
         set_default(false)