Bug 193724 – Flaky AVEncoderBitRateKey symbol not found crash on imported/w3c/web-platform-tests/mediacapture-record/MediaRecorder-constructor.html

• Component: Media
• Status: RESOLVED FIXED

[Alexey Proskuryakov]

Not sure how this kind of an issue can be flaky, but it is. Happens on both High Sierra and Mojave, debug and release.

https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=imported/w3c/web-platform-tests/mediacapture-record/MediaRecorder-constructor.html

Happens as long as records go, since mid-December at least.

ASSERTION FAILED: dlsym(0x7fce1ed713b0, AVEncoderBitRateKey): symbol not found
constant
./platform/mediarecorder/cocoa/MediaRecorderPrivateWriterCocoa.mm(55) : NSString *initAVEncoderBitRateKey()
1   0x21fa0eb89 WTFCrash
2   0x20e91aea0 initAVEncoderBitRateKey()
3   0x20e90f0f7 WebCore::MediaRecorderPrivateWriter::setAudioInput()
4   0x20e90eca4 WebCore::MediaRecorderPrivateWriter::create(WebCore::MediaStreamTrackPrivate const*, WebCore::MediaStreamTrackPrivate const*)
5   0x2110a479a WebCore::MediaRecorderPrivateAVFImpl::create(WebCore::MediaStreamPrivate const&)
6   0x20f73f026 WebCore::MediaRecorder::getPrivateImpl(WebCore::MediaStreamPrivate const&)
7   0x20f73ed87 WebCore::MediaRecorder::create(WebCore::Document&, WTF::Ref<WebCore::MediaStream, WTF::DumbPtrTraits<WebCore::MediaStream> >&&, WebCore::MediaRecorder::Options&&)

[Radar WebKit Bug Importer]

<rdar://problem/47483831>

[Ryan Haddad]

Also frequently seen with http/wpt/mediarecorder/MediaRecorder-AV-audio-video-dataavailable.html:
https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=http%2Fwpt%2Fmediarecorder%2FMediaRecorder-AV-audio-video-dataavailable.html

[Eric Carlson]

Created attachment 365759 [details]
Patch

[Jer Noble]

Comment on attachment 365759 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=365759&action=review

> Source/WebCore/platform/mediarecorder/cocoa/MediaRecorderPrivateWriterCocoa.mm:86
> +#define AVEncoderBitRateKey myAVEncoderBitRateKey()
> +#define AVFormatIDKey myAVFormatIDKey()
> +#define AVNumberOfChannelsKey myAVNumberOfChannelsKey()
> +#define AVSampleRateKey myAVSampleRateKey()

"my" as a prefix isn't useful. Could these be changed to "get*WithFallback()"?

[Eric Carlson]

Created attachment 365761 [details]
Patch for landing

[WebKit Commit Bot]

Comment on attachment 365761 [details]
Patch for landing

Clearing flags on attachment: 365761

Committed r243404: <https://trac.webkit.org/changeset/243404>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Eric Carlson]

*** Bug 196166 has been marked as a duplicate of this bug. ***

[Alexey Proskuryakov]

Comment on attachment 365761 [details]
Patch for landing

View in context: https://bugs.webkit.org/attachment.cgi?id=365761&action=review

> Source/WebCore/ChangeLog:11
> +        The soft link macros occasionally fail to load constants from AVFoundation.framework
> +        which are actually in one of its sub-frameworks. While we investigate the cause
> +        cause of the failure, ise the SOFT_LINK_CONSTANT_MAY_FAIL so we can detect the failure

Thank you Eric for tackling this! What bug tracks finding the root cause?