Is there a bug in MSC 5.1 malloc for far data?

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4 total messages Started by John R. Dudeck Sat, 10 Mar 1990 07:07

#1524

Author: John R. Dudeck
Date: Sat, 10 Mar 1990 07:07

19 lines
1370 bytes

I have been having trouble with a compiler project that I am doing in
MS C 5.1.  It appears that malloc() is sometimes getting hung in a very
tight loop.  It doesn't happen all the time.  If I run my program
right after rebooting it always works, but if I run it right after a
compile, sometimes malloc hangs.  If I run it in CodeView and this happens
I can stop it with Ctrl-Break, and step through the machine language,
and it is stuck in the library routine in a very tight (about 6 instructions)
loop.

I am using the compact memory model, on a 386/20, and MS-DOS 4.01.

Just wondering if this is a known bug, or a common programmer error of some
sort?

-- 
John Dudeck                           "You want to read the code closely..." 
jdudeck@Polyslo.CalPoly.Edu             -- C. Staley, in OS course, teaching 
ESL: 62013975 Tel: 805-545-9549          Tanenbaum's MINIX operating system.

Re: Is there a bug in MSC 5.1 malloc for far data?

#1536

Author: Charles Hannum
Date: Sun, 11 Mar 1990 08:37

13 lines
963 bytes

How do you expect anyone to help you if you don't include a sample of code
that demonstrates this "bug"?

I suspect it is programmer error, as I've never heard about this "bug" before.
(I don't use MSC myself, though I have it; I prefer Turbo C.)


Virtually,
- Charles Martin Hannum II       "Klein bottle for sale ... inquire within."
    (That's Charles to you!)     "To life immortal!"
  cmh117@psuvm.{bitnet,psu.edu}  "No noozzzz izzz netzzzsnoozzzzz..."
  c9h@psuecl.{bitnet,psu.edu}    "Mem'ry, all alone in the moonlight ..."

Re: Is there a bug in MSC 5.1 malloc for far data?

#1538

Author: Brett G. Person
Date: Sun, 11 Mar 1990 23:13

8 lines
771 bytes

It may be that the memory is not being free()'d properly.  I've seen this
happen before with my own code.  You really dont give a lot of detail, but I
suspect that this is what is happening.
-- 
Brett G. Person
North Dakota State University
uunet!plains!person | person@plains.bitnet | person@plains.nodak.edu

Re: Is there a bug in MSC 5.1 malloc for far data?

#1543

Author: John R. Dudeck
Date: Mon, 12 Mar 1990 19:32

13 lines
1267 bytes

Thanks to those that have responded to my query about malloc().  I asked
it because I wanted to know whether there was a "known bug", or whether
to look further in to my code.  In the end I found the problem totally
elsewhere in my program, where some pointer manipulation managed to
hose up MS-DOS (I was clobbering low addresses).  I found the problem
when I compiled it on a Unix system that gave me a core dump on the 
offending operations.

-- 
John Dudeck                           "You want to read the code closely..." 
jdudeck@Polyslo.CalPoly.Edu             -- C. Staley, in OS course, teaching 
ESL: 62013975 Tel: 805-545-9549          Tanenbaum's MINIX operating system.

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