Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!ukc!sys.uea!jrk
From: jrk@sys.uea.ac.uk (Richard Kennaway)
Newsgroups: comp.sys.mac.programmer
Subject: How do you expand the stack?
Message-ID: <1311@sys.uea.ac.uk>
Date: 21 Feb 90 13:00:26 GMT
Reply-To: jrk@uea-sys.UUCP (Richard Kennaway)
Organization: University of East Anglia, Norwich
Lines: 32

How do you change the stack size of a Mac application?  The default is
only 8k, and I have a program that needs much more.  I havent found any
explicit description in IM or the TNs; all I can find is the description
in the Memory Manager chapter of IM vol2 of GetApplLimit and
SetApplLimit.  From that it appears that this should do it:

void GetMoreStack( extraStack )
long extraStack;	/* long = 32 bits */
{
Ptr heapLimit;

    heapLimit = GetApplLimit();
    if (extraStack > 0) SetApplLimit( heapLimit - extraStack );
}

This is the very first thing the application does.  Is this the right
way?  If not, what is?

I am having the problem that the program intermittently crashes when
starting up, which suggests some bad memory access.  It didnt happen
before I added the call to the above routine.  I've made other
changes as well, so it may be something else, but I'd like to at least
get confirmation that this part is ok.  When it does run, it seems to
get the extra stack space (i.e. it no longer gets the stack-has-collided-
with-heap bomb).

MPW C version 3, System 6.0.4, MultiFinder 6.1b7, a zillion inits, but
they all work with everything else.

--
Richard Kennaway          SYS, University of East Anglia, Norwich, U.K.
Internet:  jrk@sys.uea.ac.uk		uucp:  ...mcvax!ukc!uea-sys!jrk