1503002 - Fix hal not initialized error when using dom.ipc.processPriorityManager.enabled

Status: RESOLVED FIXED

(Core :: DOM: Content Processes, enhancement)

Description

[Alex Thayer [:alexical] (she/her)]

We currently run into this assertion when adding an observer if the pref is on : https://searchfox.org/mozilla-central/rev/8848b9741fc4ee4e9bc3ae83ea0fc048da39979f/hal/Hal.cpp#341

See https://treeherder.mozilla.org/#/jobs?repo=try&selectedJob=203724772&revision=7584dc7444f0526cb0844d16b193c3431f876f27 for a very messy couple of patches that address the issue.

Comment 1

[Mike Conley (:mconley) (:⚙️)]

Taking this for now.

Comment 2

[Mike Conley (:mconley) (:⚙️)]

It looks like the wakelock stuff was added for b2g back in bug 999327, and ultimately what it appears to do now is set the mHighPriority boolean here:

https://searchfox.org/mozilla-central/rev/2e5e28f518524f8af5b158ddb605022b6a2d68cf/dom/ipc/ProcessPriorityManager.cpp#503,505

But that mHighPriority boolean doesn't appear to be used anywhere anymore. It _was_ used when bug 999327 originally landed, but stopped being used in bug 1119277.

I think we can just tear out this wakelock observer for the process priority manager for now, since it doesn't appear to be used by anyone (in particular, doesn't appear to be used by Fennec or GeckoView).

Comment 3

[Gabriele Svelto [:gsvelto]]

Yes, IIRC high-priority wakelocks were used exclusively for Firefox OS' dialer application so they're long gone.

Comment 4

[Mike Conley (:mconley) (:⚙️)]

Attachment: Bug 1503002 - Don't register WakeLockObserver for ProcessPriorityManagerImpl. r?gsvelto

The WakeLockObserver is being used to set a boolean that's never being read.

This also makes it so that dom.ipc.processPriorityManager.enabled can be set to
true by default. Without this patch, setting that pref to true by default means
that the WakeLockObserver attempts to be registered before Hal has had a chance
to initialize which causes an assertion failure.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ec0c3354ab22
Don't register WakeLockObserver for ProcessPriorityManagerImpl. r=gsvelto

Comment 6

[Razvan Maries]

https://hg.mozilla.org/mozilla-central/rev/ec0c3354ab22