Thread deadlock problem with cout

[Craig Rodrigues <rodrigc at mediaone dot net>]

Hi,

I downloaded the latest snapshots of libstdc++ from rawhide.redhat.com.

I am running:
glibc-2.1.91-2.i386.rpm
gcc-2.96-33 .i386.rpm
gcc-c++-2.96-33.i386.rpm
libstdc++-2.96-33 

When I compile a C++ program, then do an ldd on that program:
ldd a.out
libpthread.so.0 => /lib/libpthread.so.0 (0x40022000)
libstdc++-libc6.2-2.so.3 => /usr/lib/libstdc++-libc6.2-2.so.3 (0x40038000)
libm.so.6 => /lib/libm.so.6 (0x4007b000)
libc.so.6 => /lib/libc.so.6 (0x4009a000)
/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)

Now, if I compile the attached program, it seems to deadlock on the
cout.  If I change the cout statement to a printf, it does not
deadlock, so I am assuming some threading problems in libstdc++.

Can anyone help identify the problem?

Thanks.

-- 
Craig Rodrigues        
http://www.gis.net/~craigr    
rodrigc@mediaone.net          
#include <stdio.h>

#include <pthread.h>
#include <sched.h>
#include <iostream>


void *Test(void *);      // Must be void *, defined in pthread.h !

int COUNT = 0;

/**********************************************************************/

int main (int argc, char **argv)

{ pthread_t tid[4];;
 int i,ret;

 // Create some threads

 ret = pthread_create(&(tid[0]), NULL, Test, (void *)"");
 ret = pthread_create(&(tid[1]), NULL, Test, (void *)"");

 printf( "Parent thread waiting...\n");

 // If we don't wait for the threads, they will be killed
 // before they can start...

 for (i = 0; i < 2; i++)
   {
     ret = pthread_join(tid[i],(void **)NULL);
   }

 printf( "Parent thread continuing\n");
 printf("COUNT = %d\n", COUNT);
}

/**********************************************************************/

void *Test(void *fname)

{ 
  pthread_mutex_t mutex;
  pthread_mutex_init(&mutex, NULL);
  int ret;

  int i=0;
  while ( i++ != 5)
    {
   
      ret = pthread_mutex_lock(&mutex);
      COUNT++;
      printf("%d\n", COUNT);   
      cout << "Hello in cout" << endl;
      ret = pthread_mutex_unlock(&mutex);
    }

}