commit ca640fbffdb141aaa3bb89d89babc574be4476bf
author Tommi <tommi@webrtc.org> Tue Dec 23 16:36:19 2025
committer WebRTC LUCI CQ <webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com> Tue Dec 23 20:13:42 2025
tree 1bfe2b12ee31be0ccbe300642fe3909589937d8d
parent f37609610b40f115922b552fc521a5e75f735ace

Add async cancellation support to RTCStatsCollector

This reduces blocking call operations in the PC destructor down to a
consistent 2 and removes the synchronous Wait() operation in
RTCStatsCollector from that path (it's still in Close()).

The implementation uses PendingTaskSafetyFlag and SafeTask to invalidate
pending tasks across the signaling and network threads. When
CancelPendingRequest is called or the collector is destroyed, in-flight
tasks are safely dropped rather than being synchronously waited upon.

Key modifications:
- Integrate ScopedTaskSafety within RTCStatsCollector for signaling
  thread task management.
- Require a network thread safety flag during RTCStatsCollector
  initialization to ensure safe cross-thread operations.
- Replace WaitForPendingRequest with CancelPendingRequest in the
  PeerConnection destructor.
- Wrap cross-thread PostTask calls in SafeTask to prevent callbacks
  from executing after the collector has been cancelled or destroyed.

Bug: webrtc:42222804
Change-Id: I48f30e839d1d9b4d58ad829e3e9d29962d742a7b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/435440
Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#46536}