From maintainers-request at octave dot org Tue Apr 26 15:05:15 2005
Subject: Memory leak with octave cygwin DLD calls
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: Andy Adler <adler at site dot uottawa dot ca>
Cc: octave-maintainers at bevo dot che dot wisc dot edu
Date: Tue, 26 Apr 2005 16:03:40 -0400

On 23-Apr-2005, Andy Adler <adler at site dot uottawa dot ca> wrote:

| I've been trying to debug a memory leak problem with
| cyginw octave. It's been there since at least 2.1.60 and
| is still in 2.9.2. I've now simplified it to this:
| 
| Using a simple DLD function like
|     $ cat zno.cpp
|     #include <octave/oct.h>
| 
|     DEFUN_DLD (zno, args, , " "  ) {
|         octave_value retval= 0.0;
|         return retval;
|     }
| 
| call octave like this
| 
|     echo 'for i=1:1e8; x=zno ;end'  | octave -qfH
| 
| and watch the process monitor size for octave climb.
| I calculate about 16 bytes leak per function call.
| 
| This also happens with builtin functions
| 
|     echo 'for i=1:1e8; x=sort(1) ;end'  | octave -qfH
| 
| If octave is compiled statically, there is no memory
| leak.
| 
| I'm not sure where to look to debug this.

I don't see the leak on a Debian system, so I'd guess that it is
something in a system library or (perhaps less likely) the code
generated by GCC on the Cygwin system.  I'm not sure precisely how to
debug it either.  Can you run something like valgrind to give some
clues?

jwe