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From: rod@cpocd2.UUCP
Newsgroups: comp.sys.ibm.pc
Subject: Re: help in turbo pascal
Message-ID: <552@cpocd2.UUCP>
Date: Thu, 2-Apr-87 18:41:46 EST
Article-I.D.: cpocd2.552
Posted: Thu Apr  2 18:41:46 1987
Date-Received: Sun, 5-Apr-87 03:08:24 EST
References: <10629@topaz.RUTGERS.EDU>
Reply-To: rod@cpocd2.UUCP (Rod Rebello)
Organization: Intel, Santa Clara, CA
Lines: 32

In article <10629@topaz.RUTGERS.EDU> whoffman@topaz.UUCP writes:
>
>hello,
>
>     This is a question for all you turbo pascal users out there. any
>help (if i can be helped) would be appreciated. while running a turbo
>program that makes extensive recursive calls i stumble upon a runtime
>error "ff" which evidentily means i have a stack heap collision
>according to the manual. is there any way to overcome this problem
>without removing the recursion? (it isnt neccessarily a recursive call
>that fails, sometimes its just a call to another procedure from within
>a recursive call) . Thanks again for the info...
>					

The "heap" is where memory is allocated for such things as pointers,
records, etc.  This gets eaten up with calls to allocate new records
using the "new" procedure.  The "stack" is where Turbo allocates
memory for temporarily storing (pushing) the variables used within
your recursive procedure prior to calling itself, so that they can be 
restored upon re-entering (poping) the procedure from that call.
These two areas are at opposite ends of memory and 'grow' towards each 
other as space is allocated. The collision occurs when they meet.  

The only way I know of to prevent this is to limit the number of 
recursive calls, or if possible, reduce the amount of heap required
by reducing NEW calls.  Also try to reduce the number and size of 
variables that have to be saved before each recursive call.

-- 

	Rod Rebello
	...!intelca!mipos3!cpocd2!rod