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From: philip@pescadero.Stanford.EDU (Philip Machanick)
Newsgroups: comp.sys.mac.programmer
Subject: Re: HLock interdiction??
Keywords: MacTutor, Memory Manager, DogCow
Message-ID: <1990Sep21.212502.14028@Neon.Stanford.EDU>
Date: 21 Sep 90 21:25:02 GMT
References: <16451@unix.SRI.COM> <1990Sep21.043054.24649@cunixf.cc.columbia.edu>
Sender: news@Neon.Stanford.EDU (USENET News System)
Reply-To: philip@pescadero.stanford.edu
Organization: Computer Science Department, Stanford University
Lines: 16

In article <16451@unix.SRI.COM>, mxmora@unix.SRI.COM (Matt Mora) writes:
> You need to use Hgetstate/Hsetstate to keep the handle as it were. If
you need
> to lock a handle by all means do it. Just save the state of the handle before
> hand and reset it back after you are done with it. Remeber that handles can 
> have more states than just being locked. Also you probably don't need to do 
> this with all handles, just the ones that you share with the ROM.

I actually prefer to use the Hgetstate/Hsetstate methodology generally. It's
easy to forget that a routine could be called from a place in your program
where a handle has already been locked. The only time I call hUnlock is
as part of initialization. After that, Hgetstate/Hsetstate will always get it
back to a safe condition after I've had to lock it.

Philip Machanick
philip@pescadero.stanford.edu