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From: woody@tybalt.caltech.edu (William Edward Woody)
Newsgroups: comp.sys.mac.programmer
Subject: Re: NewHandle(0L) ?
Message-ID: <1990Oct19.163128.28079@nntp-server.caltech.edu>
Date: 19 Oct 90 16:31:28 GMT
References: <32600007@inmet> <1990Oct19.151254.8197@ux1.cso.uiuc.edu>
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In article <1990Oct19.151254.8197@ux1.cso.uiuc.edu> scott@scotty (Scott Howard) writes:
>Why call a handle up before you need to? If you 
>pre-allocate it with 0L, you lose the advantage of being
>able to tuck it into an unobtrusive corner of your application's
>heap. At any rate, It ought to work as long as you don't try
>disposing it.


No cigar; spin again.

If you allocate a handle with size zero, and leave it unlocked, the OS
shouldn't have any problems moving the object around to an unobtrusive
area in your heap if need be; this is the reason why you use handles instead
of pointers.

If you allocate a handle with zero size, you will eventually need to
dispose it again in order to release the master pointer (if for no
other reason).

Manipulating handles with size 0 is like manipulating handles with any other
size; size 0 handles are just smaller, that's all.

BTW, handling 0 size pointers in the Macintosh memory manager model is just
like pointers of larger size, except that the size 0 pointers are smaller.

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