Mailing Lists: Apple Mailing Lists
Image of Mac OS face in stamp
 
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: HUnlock always after HLock?

Thanks for the response!

Dan

On 11/2/03 4:59 PM, "Steve Zellers" <email@hidden> wrote:

>> : Dan Crevier <email@hidden>
>
>>> But don't bother using HLock/HUnlock or HSetState on Mac OS X.
>>> (Unless
>>> you know that someone is going to explicitly look at those bits.) The
>>> handle will not move or be purged on OS X.
>>
>> Is this behavior guaranteed for the future? Is it documented anywhere?
>
> I can't seem to find any documentation that explicitly states this,
> however, I personally guarantee that if you're using handles for your
> own purposes, it will not move and will not require HLock. I'll see
> if we can't get that written up in a tech note or something.
>
> It is possible that there is some overlooked quicktime API that
> requires you pass it an HLock'd handle, or ptr to an HLock'd handle. I
> don't know of one off hand, however.
>
> If you do go through and remove all your HLocks, HUnlocks and
> HSetStates, be aware of one important gotcha: HLock sets MemErr as a
> side effect. If you remove an HLock or HSetState, make sure that
> you're not checking MemErr as a side effect.
>
> Later, in this thread:
>
>> Jonathan Brecher>>
>> Is this a recent-ish (Panther) change? I had entered rdar://2852119
>> because some system-level function was locking a PaletteHandle out
>> from underneath me, which caused subsequent resize attempts to fail.
>> That bug was marked as fixed in Panther, but of course I didn't get
>> any specifics about the nature of the change.
>>
>> Is the locked state of a handle now *totally* ignored on Mac OS X, or
>> were you only referring to the specific situation of disposing a
>> locked handle?
>
> The state, and the API, are both still completely implemented; however
> on OS X the SetHandleSize on a locked block behavior is a compatability
> issue more than anything else. If nobody ever called HLock (and nobody
> ever checked) the world would be a fine place.
>
> And to re-iterate: DisposeHandle on a locked handle is fine in Carbon
> on OS X, and OS 9. And OS 6, if you can remember that far back ;-)
>
> --smz
> _______________________________________________
> carbon-development mailing list | email@hidden
> Help/Unsubscribe/Archives:
> http://www.lists.apple.com/mailman/listinfo/carbon-development
> Do not post admin requests to the list. They will be ignored.
_______________________________________________
carbon-development mailing list | email@hidden
Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/carbon-development
Do not post admin requests to the list. They will be ignored.
References: 
 >Re: HUnlock always after HLock? (From: Steve Zellers <email@hidden>)



Visit the Apple Store online or at retail locations.
1-800-MY-APPLE

Contact Apple | Terms of Use | Privacy Policy

Copyright © 2007 Apple Inc. All rights reserved.