Bug 159301 – [iOS] WebContent processes do not exit promptly

• Status: RESOLVED
• Resolution: FIXED
• Component: WebKit2

[Chris Dumez]

WebContent processes do not exit promptly, they hang around for 10 seconds until the watchdog forcefully calls exit().

[Chris Dumez]

<rdar://problem/26965488>

[Chris Dumez]

Created attachment 282445 [details]
WIP Patch

[Chris Dumez]

Comment on attachment 282445 [details]
WIP Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=282445&action=review

> Source/WebKit2/Shared/EntryPointUtilities/mac/XPCService/XPCServiceMain.mm:76
> +                xpc_object_t leakedReplyForBoosting = xpc_dictionary_create_reply(event);

Sadly, this does not appear to work in practice. While it no longer prevents XPC exit, the WebContent process no longer gets boosted either :/

[Chris Dumez]

Created attachment 282465 [details]
Patch

[Chris Dumez]

Created attachment 282474 [details]
Patch

[Chris Dumez]

Updated based on offline review feedback from Anders. It fixes the issue and is a bit nicer now.

[Chris Dumez]

Created attachment 282482 [details]
Patch

[Chris Dumez]

Created attachment 282488 [details]
Patch

[Build Bot]

Comment on attachment 282488 [details]
Patch

Attachment 282488 [details] did not pass mac-wk2-ews (mac-wk2):
Output: http://webkit-queues.webkit.org/results/1603188

Number of test failures exceeded the failure limit.

[Build Bot]

Created attachment 282490 [details]
Archive of layout-test-results from ews106 for mac-yosemite-wk2

The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: ews106  Port: mac-yosemite-wk2  Platform: Mac OS X 10.10.5

[Chris Dumez]

Created attachment 282491 [details]
Patch

[Chris Dumez]

Comment on attachment 282491 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=282491&action=review

> Source/WebKit2/Shared/EntryPointUtilities/mac/XPCService/XPCServiceEntryPoint.h:84
> +    parameters.priorityBoostMessage = priorityBoostMessage ? adoptOSObject(xpc_retain(priorityBoostMessage)) : nullptr;

The crashes on the Mac bots were because we only use priority boosting for the NetworkProcess on Mac. Therefore, for other processes would have a null priorityBoostMessage and calling xpc_retain() on nullptr crashes. I added a null check here.

> Source/WebKit2/Shared/EntryPointUtilities/mac/XPCService/XPCServiceMain.mm:74
> +                if (priorityBoostMessage)

Also added a null check to avoid calling xlc_release() on null.

[Chris Dumez]

Created attachment 282495 [details]
Patch

[Chris Dumez]

Comment on attachment 282495 [details]
Patch

Clearing flags on attachment: 282495

Committed r202723: <http://trac.webkit.org/changeset/202723>

[Chris Dumez]

All reviewed patches have been landed.  Closing bug.