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From: zerkle@iris.ucdavis.edu (Dan Zerkle)
Newsgroups: comp.sys.amiga.programmer
Subject: Two questions about memory allocation
Message-ID: <8135@ucdavis.ucdavis.edu>
Date: 9 Jan 91 18:57:11 GMT
Sender: usenet@ucdavis.ucdavis.edu
Reply-To: zerkle@iris.ucdavis.edu (Dan Zerkle)
Organization: U.C. Davis - Department of Electrical Engineering and Computer Science
Lines: 25

I recently wrote a vector graphics package that had to allocate and
de-allocate huge amounts of small structures with malloc.  I noticed
that it seemed to be running awfully slowly for some reason.  When I
wrote my own memory manager instead, the program ran three times
faster.  People running similar stuff on Unix (for the same class)
noticed that their programs didn't spend a lot of time on memory
management (according to the profiler).

So:  Why does the Amiga spend so much time fooling around with memory
management?  Is the behavior I noted typical?

Also, this same program's memory manager would allocate a large chunk
of memory at the beginning of the program (and in the middle,
actually), but I never bothered to de-allocate the memory before
exiting.  I never noticed any problems with this, and the status line
showed as much memory before execution as after.  That doesn't mean
that there wasn't a potential for problems.  Does anybody know about
this?  Was I doing a bad thing?  Should I explicitly de-allocate the
memory before exiting, or just count on "the system" to take care of
it?

If it matters:  A3000 under 2.02, Aztec C 5.0d.

           Dan Zerkle  zerkle@iris.eecs.ucdavis.edu  (916) 754-0240
           Amiga...  Because life is too short for boring computers.