1805147 - Potential deadlock in nsAvailableMemoryWatcher::Observe

Status: RESOLVED FIXED

(Core :: Widget: Gtk, defect)

Description

[Jens Stutte [:jstutte]]

From https://treeherder.mozilla.org/logviewer?job_id=398938924&repo=autoland&lineNumber=8890 it seems that we:

• lock mMutex on the main thread before calling shutdown which then wants to shutdown the MemoryPoller thread
• try to lock the same mMutex inside nsAvailableMemoryWatcher::MaybeHandleHighMemory on the MemoryPoller thread while processing the last events there, causing a deadlock

I wonder why the shutdown method needs to lock that mutex at all?

Comment 1

[Jens Stutte [:jstutte]]

Attachment: Bug 1805147 - Do not hold a lock on mMutex while waiting for the thread to shut down. r?gsvelto

Comment 2

[Jens Stutte [:jstutte]]

From code reading it seems that Windows and MacOS are not affected by this.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/912e096ae1de
Do not hold a lock on mMutex while waiting for the thread to shut down. r=gsvelto

Comment 4

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/912e096ae1de