X-Authentication-Warning: delorie.com: mailnull set sender to djgpp-bounces using -f
Date: Thu, 2 May 2002 17:03:24 +0200 (MEST)
From: ahelm AT gmx DOT net
To: djgpp AT delorie DOT com
MIME-Version: 1.0
Subject: segfault on context switch
X-Priority: 3 (Normal)
X-Authenticated-Sender: #0003579562 AT gmx DOT net
X-Authenticated-IP: [194.201.128.5]
Message-ID: <31542.1020351804@www41.gmx.net>
X-Mailer: WWW-Mail 1.5 (Global Message Exchange)
X-Flags: 0001
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Reply-To: djgpp AT delorie DOT com

Hi,

I'm having some troubles with a djgpp compiled program.

The program is reading/writing data from/to a com port using 
the svasync library. No problems in plain DOS, but when I'm
running WinNT4.0 and do a context switch (Alt-TAB) while the
program is running I get a segfault in malloc(). No problems
without context switch though ...

Does that ring a bell anywhere? Is this a known WinNT "feature"?

Usually it means that memory is corrupted somewhere before
malloc() is called, but why does this only happen on Alt-TAB???

The segfault doesn't happen at the same malloc() call each time. 
But so far I've only seen it originating from functions invoked 
by the bison parser I use for parsing the serial input (which
isn't really surprising as it is running most of the time).

I'm using DJGPP v2.03 with GCC v2.95.3, binaries about 6 months old.

Tony

-- 
GMX - Die Kommunikationsplattform im Internet.
http://www.gmx.net