1651249 - nsTimer should dispatch to the current serial event loop by default

Status: RESOLVED FIXED

(Core :: XPCOM, defect)

Description

[Jean-Yves Avenard [:jya]]

In bug 1650277, I removed a Google's MessageLoop to use a TaskQueue instead (a background taskqueue)

I was hit with high intermittent failures, they turned out to be due to the use of nsTimer which by default dispatch a task on the current EventTarget, not the current SerialEventTarget.

This is problematic as it will lead the called code to run outside the taskqueue and can lead to data races.

When not specifying the event target the nsTimer should be using, we should default to the current SerialEventTarget as it prevents shooting yourself in the foot.

Comment 1

[Jean-Yves Avenard [:jya]]

Attachment: Bug 1651249 - Dispatch to the current SerialEventTarget by default. r?froydnj

Dispatching to the underlying thread of what could be a thread-pool can lead to data-race as the code won't be run where you expect it to.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/15f79cf4a022
Dispatch to the current SerialEventTarget by default. r=froydnj

Comment 3

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/15f79cf4a022