Re: [Help-glpk] multi-threading problems

[glpk xypron]

Dear Fábio,

unfortunately the GLPK library is not thread safe.

For details see the thread starting at
http://lists.gnu.org/archive/html/help-glpk/2010-04/msg00031.html

You could use separate processes to make utilize multiple
processor cores of your hardware.

Best regards

Xypron

-------- Original-Nachricht --------
> Datum: Mon, 19 Jul 2010 02:54:45 -0300
> Betreff: [Help-glpk] multi-threading problems

> Dear
> 
> I'm doing a big research project for university and I'm finding some
> problems.
>  I'm using Ubuntu 10.04, 64bit, updated, OpenJRE.
> 
> In my program I have to work around one million of linear programs.
> That can be solved in parallel, and its results will be compiled later.
> 
> I find no problem when I try to process in sequence, without using
> threads,
> but when I try to use threads, the program solves for about 100 LPs and
> then
> the program crashes with the following error
> (I supressed the last lines, that shows the memory)
> 
> I create 10 solves each one in one thread, each solver may solve 10000
> LPs.
> I belive that there is no mistake on the code, the threads dont uses the
> same variables.
> 
> *** glibc detected *** /usr/lib/jvm/java-6-sun-1.6.0.20/bin/java:
> malloc():
> memory corruption: 0x00007f3df4031100 ***
> ======= Backtrace: =========
> /lib/libc.so.6(+0x775b6)[0x7f3e267b05b6]
> /lib/libc.so.6(+0x7b6d8)[0x7f3e267b46d8]
> /lib/libc.so.6(__libc_malloc+0x6e)[0x7f3e267b558e]
> /lib/libglpk_jni.so(glp_lib_umalloc+0x54)[0x7f3dfbced784]
> ======= Memory map: ========
> 40000000-40009000 r-xp 00000000 08:01 1045972
>  /usr/lib/jvm/java-6-sun-1.6.0.20/jre/bin/java
> 40108000-4010a000 rwxp 00008000 08:01 1045972
>  /usr/lib/jvm/java-6-sun-1.6.0.20/jre/bin/java
> 40419000-4058e000 rwxp 00000000 00:00 0
>  [heap]
> 
> 
> Grateful,
> 
> Fábio Botler
> 
> -- 
> Fábio Botler
> +55 81 8687-9769

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