Bug 211297 – [iOS] ProcessThrottler fails to re-take ProcessAssertion if the previous one was invalidated

• Component: WebKit2
• Status: RESOLVED FIXED

[Chris Dumez]

Our ProcessAssertions may get invalidated upon backgrounding of the app. When the app becomes foreground and the ProcessThrottler tries to take a Foreground assertion as a result, it would incorrectly think it already had such assertion and not do anything, even though the previous one is no longer valid. As a result, the child processes would stay suspended even though the app was foregrounded.

[Chris Dumez]

<rdar://problem/62542463>

[Chris Dumez]

Created attachment 398194 [details]
Patch

[Chris Dumez]

Comment on attachment 398194 [details]
Patch

Clearing flags on attachment: 398194

Committed r261034: <https://trac.webkit.org/changeset/261034>

[Chris Dumez]

All reviewed patches have been landed.  Closing bug.

[Brent Fulgham]

Comment on attachment 398194 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=398194&action=review

> Source/WebKit/ChangeLog:15
> +        To address the issue, add a isValid() method to ProcessAssertion() and check it in

"add an isValid() ..."

> Source/WebKit/UIProcess/ios/ProcessAssertionIOS.mm:462
> +    bool shouldHoldBackgroundTask = isValid() && type() != ProcessAssertionType::Suspended;

It seems like this might be the only use of validity(). Should it be removed?

[Chris Dumez]

Comment on attachment 398194 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=398194&action=review

> Source/WebKit/UIProcess/ProcessAssertion.h:-77
> -    Validity validity() const { return m_validity; }

See removal here.

>> Source/WebKit/UIProcess/ios/ProcessAssertionIOS.mm:462
>> +    bool shouldHoldBackgroundTask = isValid() && type() != ProcessAssertionType::Suspended;
> 
> It seems like this might be the only use of validity(). Should it be removed?

It was removed.