1564810 - [wpt-sync] Sync PR 17564 - Release the mozlog lock when starting test runner processes

Status: RESOLVED FIXED

(Testing :: web-platform-tests, task, P4)

Description

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Sync web-platform-tests PR 17564 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/17564
Details from upstream follow.

Josh Matthews <[e-mail]> wrote:

Release the mozlog lock when starting test runner processes

This is a follow up to #17433 which addresses a deadlock observed in Servo's CI in a PR that introduces the first fuzzy reftest results. The thread responsible for interpreting the pixels in the images deadlocks when initializing PIL which makes logging calls. Since this is in a separate process from the main wptrunner overseer, it seems logical that ensuring the mutex is released after spawning the test runner processes would make the deadlock disappear. I was able to successfully run the reftest in question many times in a row without deadlocking after making this change, whereas previously I would hit it on the first or second try.

Comment 1

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Pushed to try https://treeherder.mozilla.org/#/jobs?repo=try&revision=d035fd7f2911a342b911db706ddfd3222b54ae7c

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/81933c196142
[wpt PR 17564] - Release the mozlog lock when starting test runner processes, a=testonly

Comment 3

[Razvan Maries]

https://hg.mozilla.org/mozilla-central/rev/81933c196142