1867604 - RequestedFrameRefreshObserver uses threadsafe refcounting macro despite only being used on main thread

Status: RESOLVED FIXED

(Core :: Graphics: CanvasWebGL, defect)

Description

[Daniel Holbert [:dholbert]]

When reviewing refresh-observer logic, hiro noticed that RequestedFrameRefreshObserver uses the threadsafe version of the refcounting-method-declaration-macro which seems unnecessary since this seems to be a main-thread-only object.

I chatted with :pehrsons about it and it seems there's no reason we need threadsafe refcounting here.

Let's switch from NS_INLINE_DECL_THREADSAFE_REFCOUNTING to the NS_INLINE_DECL_REFCOUNTING macro here, for performance and to avoid giving the mistaken impression that this object is used off-main-thread.

Comment 1

[Daniel Holbert [:dholbert]]

For reference, we have several other nsARefreshObserver subclasses that use the simpler NS_INLINE_DECL_REFCOUNTING macro:
https://searchfox.org/mozilla-central/rev/12ea2c521cdd071a6d25b0894f31f8f23b18b76a/widget/SwipeTracker.h#48-50
https://searchfox.org/mozilla-central/rev/12ea2c521cdd071a6d25b0894f31f8f23b18b76a/dom/ipc/CoalescedInputData.h#53,59

Just mentioning for added-confidence that this is a reasonable thing to do (for main-thread-only objects).

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: Bug 1867604: Use regular refcounting macro (not threadsafe one) for RequestedFrameRefreshObserver, since it's only used on the main thread. r?pehrsons

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/05fa00c2dc57
Use regular refcounting macro (not threadsafe one) for RequestedFrameRefreshObserver, since it's only used on the main thread. r=pehrsons

Comment 4

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/05fa00c2dc57