Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!apple!apple.com!stm
From: stm@apple.com (Steve Maller)
Newsgroups: comp.sys.mac.hypercard
Subject: Re: Protection against memory limitation
Message-ID: <1393@internal.Apple.COM>
Date: 15 Apr 89 01:06:38 GMT
References: <80078GFX@PSUVM>
Sender: usenet@Apple.COM
Organization: Apple Computer, Inc.
Lines: 22

In article <80078GFX@PSUVM> GFX@PSUVM.BITNET writes:
> Other than warning users that they need a full meg to use the stack, what
> could be done to 1) exit gracefully from a script if there is not enough
> memory to execute, 2) detect memory shortage before it creates any 
problem.
> Any other reaction, comment or suggestion? 

The HyperTalk function "the heapspace" returns the currently available 
amount of RAM. A little known (feature) of HyperCard is at every idle 
message, HyperCard checks to see that there is at least 32K of free 
memory. If it doesn't find it, it will complain and quit. But while a 
handler or an XCMD is executing, the amount of free memory can drop to 
zero.

Another recommendation is to make sure that you empty out any large 
HyperTalk globals that you allocate, such as text read in from a file.

Cheers,

       Steve Maller
       HyperCard Tools Engineer
       Apple Computer