commit a9d497b52dc21497fdfd0e8c03ab2f8559e02d15
author Michael Olbrich <m.olbrich@pengutronix.de> Thu Nov 09 15:37:06 2023
committer WebRTC LUCI CQ <webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com> Mon Nov 20 18:18:04 2023
tree 0d9b4e83baefce64749bd6e548364d8ba6a6e8d2
parent 136d3b0df3449c5dca4e321986543e27f858274c

Video capture PipeWire: fix thread and lock annotations

There are two threads involved here, the thread that calls the API
functions and the pipwire main loop. Using one race checker for both is
wrong and triggers aborts.

Use a different race checker for all variables that are used by the
pipewire main loop or guarded against concurrent access with the
thread_loop_lock.

In one case, two RTC_CHECK_RUNS_SERIALIZED() checks are needed, so
enhance the macro to generate unique variable names.

Bug: webrtc:15181
Change-Id: Ib41514eb7aa98fe85d830461aa0c71e42ba821bd
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/326781
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org>
Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#41198}

modules/video_capture/linux/video_capture_pipewire.cc

diff --git a/modules/video_capture/linux/video_capture_pipewire.cc b/modules/video_capture/linux/video_capture_pipewire.cc
index 7b79f15..9d47e3d 100644
--- a/modules/video_capture/linux/video_capture_pipewire.cc
+++ b/modules/video_capture/linux/video_capture_pipewire.cc
@@ -126,6 +126,7 @@
   RTC_LOG(LS_VERBOSE) << "Creating new PipeWire stream for node " << node_id_;
 
   PipeWireThreadLoopLock thread_loop_lock(session_->pw_main_loop_);
+  RTC_CHECK_RUNS_SERIALIZED(&pipewire_checker_);
   pw_properties* reuse_props =
       pw_properties_new_string("pipewire.client.reuse=1");
   stream_ = pw_stream_new(session_->pw_core_, "camera-stream", reuse_props);
@@ -178,6 +179,7 @@
   RTC_DCHECK_RUN_ON(&api_checker_);
 
   PipeWireThreadLoopLock thread_loop_lock(session_->pw_main_loop_);
+  RTC_CHECK_RUNS_SERIALIZED(&pipewire_checker_);
   if (stream_) {
     pw_stream_destroy(stream_);
     stream_ = nullptr;
@@ -210,14 +212,14 @@
   VideoCaptureModulePipeWire* that =
       static_cast<VideoCaptureModulePipeWire*>(data);
   RTC_DCHECK(that);
-  RTC_CHECK_RUNS_SERIALIZED(&that->capture_checker_);
+  RTC_CHECK_RUNS_SERIALIZED(&that->pipewire_checker_);
 
   if (format && id == SPA_PARAM_Format)
     that->OnFormatChanged(format);
 }
 
 void VideoCaptureModulePipeWire::OnFormatChanged(const struct spa_pod* format) {
-  RTC_CHECK_RUNS_SERIALIZED(&capture_checker_);
+  RTC_CHECK_RUNS_SERIALIZED(&pipewire_checker_);
 
   uint32_t media_type, media_subtype;
 
@@ -359,7 +361,7 @@
 }
 
 void VideoCaptureModulePipeWire::ProcessBuffers() {
-  RTC_CHECK_RUNS_SERIALIZED(&capture_checker_);
+  RTC_CHECK_RUNS_SERIALIZED(&pipewire_checker_);
 
   while (pw_buffer* buffer = pw_stream_dequeue_buffer(stream_)) {
     struct spa_meta_header* h;

modules/video_capture/linux/video_capture_pipewire.h

diff --git a/modules/video_capture/linux/video_capture_pipewire.h b/modules/video_capture/linux/video_capture_pipewire.h
index 316fb24..620ee52 100644
--- a/modules/video_capture/linux/video_capture_pipewire.h
+++ b/modules/video_capture/linux/video_capture_pipewire.h
@@ -43,15 +43,17 @@
   void OnFormatChanged(const struct spa_pod* format);
   void ProcessBuffers();
 
+  rtc::RaceChecker pipewire_checker_;
+
   const rtc::scoped_refptr<PipeWireSession> session_
       RTC_GUARDED_BY(capture_checker_);
   int node_id_ RTC_GUARDED_BY(capture_checker_);
   VideoCaptureCapability configured_capability_
-      RTC_GUARDED_BY(capture_checker_);
+      RTC_GUARDED_BY(pipewire_checker_);
   bool started_ RTC_GUARDED_BY(api_lock_);
 
-  struct pw_stream* stream_ RTC_GUARDED_BY(capture_checker_) = nullptr;
-  struct spa_hook stream_listener_ RTC_GUARDED_BY(capture_checker_);
+  struct pw_stream* stream_ RTC_GUARDED_BY(pipewire_checker_) = nullptr;
+  struct spa_hook stream_listener_ RTC_GUARDED_BY(pipewire_checker_);
 };
 }  // namespace videocapturemodule
 }  // namespace webrtc

rtc_base/race_checker.h

diff --git a/rtc_base/race_checker.h b/rtc_base/race_checker.h
index 4d57460..00bab52 100644
--- a/rtc_base/race_checker.h
+++ b/rtc_base/race_checker.h
@@ -62,9 +62,14 @@
 }  // namespace internal
 }  // namespace rtc
 
-#define RTC_CHECK_RUNS_SERIALIZED(x)               \
-  rtc::internal::RaceCheckerScope race_checker(x); \
-  RTC_CHECK(!race_checker.RaceDetected())
+#define RTC_CHECK_RUNS_SERIALIZED(x) RTC_CHECK_RUNS_SERIALIZED_NEXT(x, __LINE__)
+
+#define RTC_CHECK_RUNS_SERIALIZED_NEXT(x, suffix) \
+  RTC_CHECK_RUNS_SERIALIZED_IMPL(x, suffix)
+
+#define RTC_CHECK_RUNS_SERIALIZED_IMPL(x, suffix)          \
+  rtc::internal::RaceCheckerScope race_checker##suffix(x); \
+  RTC_CHECK(!race_checker##suffix.RaceDetected())
 
 #if RTC_DCHECK_IS_ON
 #define RTC_DCHECK_RUNS_SERIALIZED(x)              \