1583964 - make `IsOnCurrentThread` for thread pools constant-time

Status: RESOLVED FIXED

(Core :: XPCOM, task)

Comment 1

[Nathan Froyd [:froydnj]]

Attachment: Bug 1583964 - make `IsOnCurrentThread` for thread pools constant-time; r=kriswright

It's fairly common for clients to hold a pointer to some private thread
and then inquire about IsOnCurrentThread in debug checks. As we
migrate these private threads into some nsIEventTarget implementation
that might be running on thread pools, we need to ensure that those
IsOnCurrentThread continues to be relatively cheap. The current
implementation for thread pools is not particularly efficient.

The inefficiency comes from having to iterate over all the threads in
the pool. But there's no need to do this; we can just have each thread
set a particular thread-local variable to the thread pool it's running
on, and check the value of that thread-local variable instead.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/3d366bfc0508
make `IsOnCurrentThread` for thread pools constant-time; r=KrisWright

Comment 3

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/3d366bfc0508