1838779 - Improve the stability of keepalive decisions based on the ThreadsafeContentParentHandle

Status: RESOLVED FIXED

(Core :: DOM: Content Processes, task)

Description

[Jens Stutte [:jstutte]]

There is a time window between the first check in ContentParent::NotifyTabWillDestroy and the flagging of mThreadsafeHandle->mShutdownStarted in ContentParent::MaybeAsyncSendShutDownMessage during which a worker might have tried to register for our process. The entire sequence is happening in the same MT runnable processing, so the time window is small but exists.

This race would leave us with a process that is never told to shutdown and then killed directly by the ContentParent::ForceKillTimerCallback.

Comment 1

[Jens Stutte [:jstutte]]

Attachment: Bug 1838779 - Overhaul the thread safety and synchronization of our keepalive checks. r?#dom-worker-reviewers,smaug

Comment 2

[Jens Stutte [:jstutte]]

As we closed the other bug, I lift this dependency up to the parent.

Actually there are still some cases of "GetRunnableForMTTask seems to be stuck on mMainThreadCV.Wait();" after bug 1837467 landed, this bug might be one way to cause them.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/cc655f99b353
Overhaul the thread safety and synchronization of our keepalive checks.  r=dom-worker-reviewers,asuth,smaug

Comment 4

[Narcis Beleuzu [:NarcisB]]

Backed out for bc failure on RecursiveMutex.cpp

Backout link: https://hg.mozilla.org/integration/autoland/rev/ee06d59277b42e5c3ddb28abf800a6c4a8aca6b5
Log link: https://treeherder.mozilla.org/logviewer?job_id=420123719&repo=autoland&lineNumber=2757

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/81e6aadf9911
Overhaul the thread safety and synchronization of our keepalive checks.  r=dom-worker-reviewers,asuth,smaug

Comment 6

[Cristina Horotan [:chorotan]]

Backed out changeset 81e6aadf9911 (bug 1838779) for causing build bustage at ContentParent.cpp

Backout: https://hg.mozilla.org/integration/autoland/rev/c3a77b177cd08f50313ea3ff4c21c7ff0342590b

Failure push: https://treeherder.mozilla.org/jobs?repo=autoland&group_state=expanded&resultStatus=testfailed%2Cbusted%2Cexception&revision=81e6aadf991154de739cb0f9e29d430454bad8cb&selectedTaskRun=eE8Zi7gJTEmC5h2WFeZcMw.0

Failure log: https://treeherder.mozilla.org/logviewer?job_id=420156947&repo=autoland&lineNumber=11228

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/1cdafcfe4665
Overhaul the thread safety and synchronization of our keepalive checks.  r=dom-worker-reviewers,asuth,smaug

Comment 8

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/1cdafcfe4665