[iOS] The UIProcess may get killed for trying to stay runnable in the background for more than 30 seconds

• Component: WebKit2
• Status: RESOLVED FIXED

[Chris Dumez]

The UIProcess may get killed for trying to stay runnable in the background for more than 30 seconds.

[Chris Dumez]

<rdar://problem/50001505>

[Chris Dumez]

Created attachment 368490 [details]
Patch

[Geoffrey Garen]

Comment on attachment 368490 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=368490&action=review

> Source/WebKit/UIProcess/ios/ProcessAssertionIOS.mm:72
> +        [self _updateBackgroundTask];

I think you need to capture a weak reference to self, otherwise you have a memory leak (the global Notification Center has a reference to self, and never goes away).

Once that leak is fixed, don't we also need to unregister for this notification in our dealloc method?

[Chris Dumez]

Comment on attachment 368490 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=368490&action=review

>> Source/WebKit/UIProcess/ios/ProcessAssertionIOS.mm:72
>> +        [self _updateBackgroundTask];
> 
> I think you need to capture a weak reference to self, otherwise you have a memory leak (the global Notification Center has a reference to self, and never goes away).
> 
> Once that leak is fixed, don't we also need to unregister for this notification in our dealloc method?

self is a static object though, so I would not expect the dealloc method to ever get called.

[Chris Dumez]

Comment on attachment 368490 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=368490&action=review

>>> Source/WebKit/UIProcess/ios/ProcessAssertionIOS.mm:72
>>> +        [self _updateBackgroundTask];
>> 
>> I think you need to capture a weak reference to self, otherwise you have a memory leak (the global Notification Center has a reference to self, and never goes away).
>> 
>> Once that leak is fixed, don't we also need to unregister for this notification in our dealloc method?
> 
> self is a static object though, so I would not expect the dealloc method to ever get called.

I mean that WKProcessAssertionBackgroundTaskManager (self) is a singleton, so "leaking" it is the expectation.

[Geoffrey Garen]

Comment on attachment 368490 [details]
Patch

r=me

[WebKit Commit Bot]

Comment on attachment 368490 [details]
Patch

Clearing flags on attachment: 368490

Committed r244761: <https://trac.webkit.org/changeset/244761>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.