1790611 - Investigate SendFinishShutdown (sent) cases

Status: RESOLVED FIXED

(Core :: DOM: Content Processes, task)

Description

[Jens Stutte [:jstutte]]

Roughly ~20% of the cases show the SendFinishShutdown (sent) annotation.

This means the child process did all its shutdown sequence and sent the success message to the parent process. But the parent process did not run it before the timer fired. We do not know if the parent process has just a long queue or if the last runnable that ran before the timer event is executed took very long.

This opens some interesting prioritization questions. We might be able to influence this by just raising the priority of FinishShutdown. It should be ok to run this event out of order, it just closes the top level actor of an already MarkAsDead process and frees some other object. I'd expect it also to be fast enough (O(1) in the parent process) to not matter in terms of performance.

Edit: This change breaks some existing tests (and probably also real usage). We must ensure that FinishShutdown is the very last event we try to process in the parent for this child process. Olli suggested to peek the message queue for a FinishShutdown message when the ForceKillTimer triggers such that we avoid a hard kill in this case (or at least avoid to send a report about it).

Comment 1

[Jens Stutte [:jstutte]]

Attachment: Bug 1790611 - Raise priority of FinishShutdown. r?smaug

Comment 2

[Jens Stutte [:jstutte]]

Attachment: Bug 1790611 - Add a high priority NotifyShutdownSuccess that avoids blaming the content process with a dump. r?smaug

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/567ef82d2b85
Add a high priority NotifyShutdownSuccess that avoids blaming the content process with a dump. r=smaug

Comment 4

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/567ef82d2b85