Subj : Re: Strange behaviour
To   : comp.programming.threads
From : Loic Domaigne
Date : Tue Apr 19 2005 11:46 pm

Hello Sunglo,

> I have the following simple code (I know it's ugly, and many things are
> missing, like error checks, etc.):

> #include <pthread.h>
> #include <stdio.h>
> #include <stdlib.h>
> #include <unistd.h>
> 
> #define THREADS 5

[snip]

This code looks fine, actually.


> I'm using linux 2.6 with NPTL. 

On which distro?


> When this code runs, sometimes it
> executes all the threads (ie, the messages from main() *AND* those from
> the threads are printed, and the process waits about 5 secs. before
> terminating), some other times it terminates immediately (only the
> messages from main() are printed, and then it terminates). It almost
> seems that, under certain conditions, the call to pthread_exit() from
> main() terminates the whole process.

Did you got that behavior with LinuxThreads? (export the environment 
variable LD_ASSUME_KERNEL to 2.4.19 before executing your process).


> I believe that calling pthread_exit() from main() should not terminate
> the whole process...unless, perhaps, at the time main() calls
> pthread_exit(), no other thread has actually been created, so, being
> main() the only thread, pthread_exit() terminates the process? (just a
> guess, I hope you have some better explanation).

Seems to be an issue in the NPTL you are using.


Cheers,
Loic.

.