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From: carlton@aldebaran (Mike Carlton)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Need jGNEFilter help
Message-ID: <9330@pasteur.Berkeley.EDU>
Date: 29 Nov 90 23:40:22 GMT
References: <917@gagme.chi.il.us> <11380@goofy.Apple.COM>
Sender: news@pasteur.Berkeley.EDU
Reply-To: carlton@aldebaran (Mike Carlton)
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Organization: University of California at Berkeley
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In article <11380@goofy.Apple.COM> sean_parent.snarkmail_l_z@gateway.qm.apple.com (Sean Parent) writes:
>The problem with your patch is that it is a tail patch. (A tail patch is a 
>patch that does work after calling the original routine instead of 
>returning directly to the original caller.) This is breaking a come-from 
>patch that MultiFinder has installed. (A come from patch is a patch that 
>checks the return address to fix a routine in ROM.) There are a few 
>possible options that you could use ->
>
>1) Have your INIT install a driver to get time cleanly.
>2) Patch SystemTask (I think it is a better place to patch then 
>GetNextEvent and contrary to inside Mac it can move memory (because it can 
>call drivers and desk accessories) using a head patch.
>3) Patch GNE using a head patch.
...

Is option 2 correct?  I have a patch that needs to move memory and since
SystemTask isn't marked as moving memory, I felt I couldn't patch in there 
(altough SystemTask was the logical place for my patch).

Is this just an oversight in the documentation? -- the X-Ref book lists
SystemTask as not moving memory.  If I move memory on SystemTask, will
I get burnt on a future OS release?

thanks,
mike

Mike Carlton	carlton@cs.berkeley.edu