1859786 - video_capture_impl.cc:122:7: warning: reading variable '_dataCallBacks' requires holding mutex 'api_lock_' [-Wthread-safety-analysis]

Status: RESOLVED FIXED

(Core :: WebRTC: Audio/Video, defect, P2)

Description

[Andreas Pehrson [:pehrsons]]

This is a warning in Mozilla-specific code inside libwebrtc, that started when _dataCallbacks got annotated with RTC_GUARDED_BY(api_lock_) in a commit on bug 1851693.

Note that this is still safe, since this lack of locking always happens on the only thread that can modify _dataCallbacks.

Comment 1

[Andreas Pehrson [:pehrsons]]

Attachment: Bug 1859786 - Fix lock annotation warning in Mozilla-specific edit on top of video_capture_impl.cc. r?#webrtc-reviewers

The annotations were added in M116:
https://hg.mozilla.org/mozilla-central/rev/9cd372df013948ad822ae936752d725d77474fb5

Note that this was never unsafe, since _dataCallbacks is only written on the
same thread that we are patching here. This patch however, adds helpful static
analysis.

Comment 2

[Andreas Pehrson [:pehrsons]]

Attachment: Bug 1859786 - Fix clang-tidy warning in video_capture_impl.cc. r?#webrtc-reviewers

clang-tidy says:
'auto dataCallBack' can be declared as 'auto *dataCallBack'

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

Set release status flags based on info from the regressing bug 1851693

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/56ff441b6444
Fix lock annotation warning in Mozilla-specific edit on top of video_capture_impl.cc. r=webrtc-reviewers,mjf
https://hg.mozilla.org/integration/autoland/rev/26c84d214137
Fix clang-tidy warning in video_capture_impl.cc. r=webrtc-reviewers,mjf

Comment 5

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/56ff441b6444
https://hg.mozilla.org/mozilla-central/rev/26c84d214137