Re: pthread problem

[Christopher Faylor <cgf-use-the-mailinglist-please at cygwin dot com>]

On Sat, Feb 06, 2010 at 12:13:59AM +0530, Gaurav Sachdeva wrote:
>Hi,
>
>I have written following code -
>
>#include<stdio.h>
>
>void *thread_func(void *data)
>{
>  printf("In thread\n");
>  pthread_exit(NULL);
>}
>
>int main()
>{
>  pthread_t mythread;
>  int rc;
>
>  rc = pthread_create(&mythread, NULL, thread_func, NULL);
>  if (rc){
>         printf("ERROR; return code from pthread_create() is %d\n", rc);
>         exit(-1);
>      }
>
>  printf("In main..\n");
>
>  pthread_exit(NULL);
>}
>
>It must print both "In main" and "In thread".
>But sometimes it prints one of these two and sometimes both.
>I tried in actual UNIX OS. It always prints both.
>
>I also tried in c++ in cygwin, problem exists there also.
>
>Is anyone aware of this problem and its solutions?

Looks like a bug in Cygwin.  From my reading of the pthread_exit man
page, it looks like it should wait for all available threads to exit
before the process exits.  Unfortunately that doesn't happen.

You can probably fix that by adding a pthread_join() before the
pthread_exit().

In the meantime, I'll look into fixing this.

cgf

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