Mail Archives: djgpp/1997/06/06/05:06:43

From: Gary Leavens <leavens AT cs DOT iastate DOT edu>
Newsgroups: comp.os.msdos.djgpp
Subject: Bohem-Demers-Weiser garbage collector (gc) with C++ under DJGPP
Date: Thu, 05 Jun 1997 17:37:59 -0500
Organization: Department of Computer Science, Iowa State Univ.
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Message-ID: <>
Mime-Version: 1.0
CC: boehm AT hoh DOT mti DOT sgi DOT com, xiaokun AT aero DOT gla DOT ac DOT uk
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

I'm trying to use the Boehm-Demers-Weiser garbage collector
with the C++ interface under DJGPP.  The C interface seems
to work, this is with the 4.12alpha1 release of the gc system from
and DJGPP 2.01 and GNU gcc version  This version of the gc
system has the latest fixes (from Kristian Kristensen and Fergus

What happens is that when I run C++ programs with the gc interface,
I get messages like:

 STACK_GROWS_DOWN is defd, but stack appears to grow up
 sp = 0x198f48, GC_stackbottom = 0xc0174
 stack direction = 3

Of course, I tried to compile it with STACK_GROWS_UP defined
instead, but then none of the tests passes at all.
(Perhaps the stack direction is different for C++ and C executables??)

Also, when I try to run the cordtest program that comes with
the gc system, that doesn't work either.

The program never behaves like this on Unix.

Here's some of the output from the makefile under djgpp.

 This appears to be a I386 running DJGPP
 Stack appears to grow down, which is the default.
 A good guess for STACKBOTTOM on this machine is 0x4D000.
 Note that this may vary between machines of ostensibly
 the same architecture (e.g. Sun 3/50s and 3/80s).
 On many machines the value is not fixed.
 A good guess for ALIGNMENT on this machine is 4.
 Generic mark_regs code may work
 Completed 1 tests
 Finalized 2206/2206 objects - finalization is probably ok
 Total number of bytes allocated is 55227928
 Final heap size is 4395008 bytes
 Collector appears to work

Notice that the STACKBOTTOM macro is not the same as the number
being reported in the Abort messages.

When I run go32-v2, I get the massage...

 DPMI memory available: 8407 Kb
 DPMI swap space available 23353 Kb

Any help would be appreciated.

	Gary Leavens
	229 Atanasoff Hall, Department of Computer Science
	Iowa State Univ., Ames, Iowa 50011-1040 USA / leavens AT cs DOT iastate DOT edu
	phone: (515)294-1580 fax: (515)294-0258 ftp site:

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