Bug 77885 – Use CMClock as a timing source for PlatformClock where available.

• Component: New Bugs
• Status: RESOLVED FIXED

[Jer Noble]

Use CMClock as a timing source for PlatformClock where available.

[Jer Noble]

Created attachment 125671 [details]
Patch

[Jer Noble]

Created attachment 125672 [details]
Patch

[Eric Carlson]

Comment on attachment 125672 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=125672&action=review

> Source/WebCore/platform/mac/PlatformClockCM.mm:48
> +static const int32_t DefaultTimeScale = 1000;

Please include a comment explaining why 1000 is the best magic timescale.

> Source/WebCore/platform/mac/PlatformClockCM.mm:57
> +    CMAudioDeviceClockCreate(kCFAllocatorDefault, NULL, &rawClockPtr);
> +    RetainPtr<CMClockRef> clock(AdoptCF, rawClockPtr);
> +    initializeWithTimingSource(clock.get());

Is the temporary RetainPtr necessary?

[Jer Noble]

(In reply to comment #3)
> (From update of attachment 125672 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=125672&action=review
> 
> > Source/WebCore/platform/mac/PlatformClockCM.mm:48
> > +static const int32_t DefaultTimeScale = 1000;
> 
> Please include a comment explaining why 1000 is the best magic timescale.

Sure thing.

> > Source/WebCore/platform/mac/PlatformClockCM.mm:57
> > +    CMAudioDeviceClockCreate(kCFAllocatorDefault, NULL, &rawClockPtr);
> > +    RetainPtr<CMClockRef> clock(AdoptCF, rawClockPtr);
> > +    initializeWithTimingSource(clock.get());
> 
> Is the temporary RetainPtr necessary?

Not strictly, no.  But the RetainPtr takes care of null-checking before calling CFRelease, and does so even if an exception is thrown.  And I've been yelled at* for not using RetainPtrs for temporary variables before. ;)

*figuratively

[Jer Noble]

Committed r106978: <http://trac.webkit.org/changeset/106978>