Bug 278356 – REGRESSION (280738@main) [WebCodecs] Audio and Video codecs can be garbage collected with pending work.

• Status: RESOLVED
• Resolution: FIXED
• Component: WebCore Misc.

[Anfernee Viduya]

http/wpt/webcodecs/hevc-encoder-config.https.any.html 
is a flaky failure.

HISTORY: 
https://results.webkit.org/?suite=layout-tests&test=http%2Fwpt%2Fwebcodecs%2Fhevc-encoder-config.https.any.html&platform=ios&platform=mac

DIFF: 
+
+Harness Error (TIMEOUT), message = null
 
 PASS Test that VideoEncoder.isConfigSupported() doesn't support config: Possible future HEVC codec string
-PASS Test that VideoEncoder.configure() doesn't support config: Possible future HEVC codec string
+TIMEOUT Test that VideoEncoder.configure() doesn't support config: Possible future HEVC codec string Test timed out
 
LINK:
https://build.webkit.org/results/Apple-Sonoma-Release-AppleSilicon-WK2-Tests/282441@main%20(5199)/http/wpt/webcodecs/hevc-encoder-config.https.any-diff.txt

DESCRIPTION:
In 270738@main, changes were made against WebCodecs.

[Radar WebKit Bug Importer]

<rdar://problem/134297589>

[Anfernee Viduya]

Correction in description: 280738@main is the intended commit that caused the regression

[Anfernee Viduya]

REPRODUCIBILITY: 
I was able to bisect the regression at 280738@main using command. 
run-webkit-tests http/wpt/webcodecs/hevc-encoder-config.https.any.html --iterations=10

[Ryan Reno]

It looks like the VideoEncoder is being prematurely garbage collected. Before my change, the error callback was a GC root and so wouldn't be collected along with the VideoEncoder. But, the encoder is no longer being kept alive while it has outstanding work in `VideoEncoder.configure` so it doesn't keep the error callback alive anymore and so the callback is never called and the test doesn't complete.

So this is a pre-existing bug that was uncovered by my changes to WebCodecs recently.

[Ryan Reno]

Pull request: https://github.com/WebKit/WebKit/pull/32483

[EWS]

Committed 282657@main (dcc8d978d725): <https://commits.webkit.org/282657@main>

Reviewed commits have been landed. Closing PR #32483 and removing active labels.

[EWS]

Committed 280938.266@safari-7619-branch (c0991b6fa1ed): <https://commits.webkit.org/280938.266@safari-7619-branch>

Reviewed commits have been landed. Closing PR #1643 and removing active labels.