Bug 268581 – [iOS] 18 webgl/1.0.3/conformance/textures/* tests are consistently/flakily timing out.

• Component: WebGL
• Status: NEW

[Ben Schwartz]

Created attachment 469664 [details]
example-mediastream-test-crash-log.ips

The following webgl tests are consistently/flakily timing out on iOS 17:

webgl/1.0.3/conformance/textures/copy-tex-image-and-sub-image-2d.html
webgl/1.0.3/conformance/textures/gl-teximage.html
webgl/1.0.3/conformance/textures/tex-image-and-sub-image-2d-with-image-data-rgb565.html
webgl/1.0.3/conformance/textures/tex-image-and-sub-image-2d-with-image-data-rgba4444.html
webgl/1.0.3/conformance/textures/tex-image-and-sub-image-2d-with-image-data-rgba5551.html
webgl/1.0.3/conformance/textures/tex-image-and-sub-image-2d-with-image-data.html
webgl/1.0.3/conformance/textures/tex-image-and-sub-image-2d-with-image-rgb565.html
webgl/1.0.3/conformance/textures/tex-image-and-sub-image-2d-with-image-rgba4444.html
webgl/1.0.3/conformance/textures/tex-image-and-sub-image-2d-with-image-rgba5551.html
webgl/1.0.3/conformance/textures/tex-image-and-sub-image-2d-with-image.html
webgl/1.0.3/conformance/textures/tex-image-and-sub-image-2d-with-svg-image.html
webgl/1.0.3/conformance/textures/tex-image-and-sub-image-2d-with-video-rgb565.html
webgl/1.0.3/conformance/textures/tex-image-and-sub-image-2d-with-video-rgba4444.html
webgl/1.0.3/conformance/textures/tex-image-and-sub-image-2d-with-video-rgba5551.html
webgl/1.0.3/conformance/textures/tex-image-and-sub-image-2d-with-video.html
webgl/1.0.3/conformance/textures/tex-image-with-format-and-type.html
webgl/1.0.3/conformance/textures/texture-size-cube-maps.html
webgl/1.0.3/conformance/textures/texture-transparent-pixels-initialized.html

These timeouts are "all or nothing" -- when they time out, they all time out together. Conversely, when one passes, they all pass together.

HISTORY:

https://results.webkit.org/?platform=ios&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Fcopy-tex-image-and-sub-image-2d.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Fgl-teximage.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftex-image-and-sub-image-2d-with-image-data-rgb565.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftex-image-and-sub-image-2d-with-image-data-rgba4444.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftex-image-and-sub-image-2d-with-image-data-rgba5551.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftex-image-and-sub-image-2d-with-image-data.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftex-image-and-sub-image-2d-with-image-rgb565.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftex-image-and-sub-image-2d-with-image-rgba4444.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftex-image-and-sub-image-2d-with-image-rgba5551.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftex-image-and-sub-image-2d-with-image.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftex-image-and-sub-image-2d-with-svg-image.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftex-image-and-sub-image-2d-with-video-rgb565.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftex-image-and-sub-image-2d-with-video-rgba4444.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftex-image-and-sub-image-2d-with-video-rgba5551.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftex-image-and-sub-image-2d-with-video.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftex-image-with-format-and-type.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftexture-size-cube-maps.html&test=webgl%2F1.0.3%2Fconformance%2Ftextures%2Ftexture-transparent-pixels-initialized.html

OBSERVATION:

The vast majority of timeouts happen if a test under fast/mediastream has crashed earlier in the test run. Each fast/mediastream crash has the same crash signature (see below).

EXAMPLE CRASH:
 - Crashing Test: fast/mediastream/mediastreamtrack-video-zoom.html
 - On Build: https://build.webkit.org/#/builders/925/builds/1844
 - Signature: com.apple.MTLSimDriver: sendXPCMessageWithReplySync(NSObject<OS_xpc_object>*, NSObject<OS_xpc_object>*) 
 - Full Log: Attached
 - Log URL: https://build.webkit.org/results/Apple-iOS-17-Simulator-Release-WK2-Tests/273808@main%20(1844)/fast/mediastream/mediastreamtrack-video-zoom-crash-log.txt

Occasionally, there will also be a STDOUT of: XPC_ERROR_CONNECTION_INVALID

REPRODUCIBILITY:

I verified this issue does not reproduce on my local machine without a prior crashing test. I don't have a way to induce the crash locally, so I can't test to see if it triggers these tests to fail.

REGRESSION:

This issue was observed as far in the past as 269844@main; however, it is unlikely that this is the regression point. I will try to narrow the potential regression range.

[Radar WebKit Bug Importer]

<rdar://problem/122137203>

[EWS]

Test gardening commit 273961@main (5825791ede07): <https://commits.webkit.org/273961@main>

Reviewed commits have been landed. Closing PR #23706 and removing active labels.