886791 - Deadlock can occur if nsThreadPool::Dispatch() is called under lock

Status: RESOLVED FIXED

(Core :: XPCOM, defect)

Description

[Michal Novotny [:michal]]

nsThreadPool::Dispatch() calls nsThreadPool::PutEvent() which can create and then possibly immediately shut down a new thread. nsIThread::Shutdown() processes pending events, so deadlock can occur.

Comment 1

[Michal Novotny [:michal]]

Attachment: fix

Comment 2

[Benjamin Smedberg]

Comment on attachment 767174 [details] [diff] [review]
fix

I feel like threadpool has other lock-ordering inconsistencies, but this will at least help short-term. I really don't think threadpool threads need to be XPCOM threads at all, but we can fix that elsewhere.

Comment 3

[Michal Novotny [:michal]]

tryserver looks good - https://tbpl.mozilla.org/?tree=Try&rev=2826a180bdad

Comment 4

[Michal Novotny [:michal]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/4af89f71d745

Comment 5

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/4af89f71d745