Threading issues

tpp.c:63: __pthread_tpp_change_priority: Assertion is a known problem and solved:
https://sourceware.org/ml/libc-help/2008-05/msg00071.html
in brief, the problem is caused by repeated locking of a fast mutex, and solved by using a recursive mutex, and the default pthread_mutex_t is not recursive. Is it possible that there's pthread_mutex_t deeply inside the thread running code ??
BTW, to make the mutex recursive, plz set the mutex attribute with attribute PTHREAD_MUTEX_RECURSIVE_NP.

Here is your program cleaned up. It runs without the above assertion:

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <string.h>

static pthread_t th[5];

void *
tfunc (void *ptr)
{
  sleep (5);                    /* remove this to test it without the sleep */
  pthread_exit (NULL);
}

void
test ()
{
  int i;
  memset (th, 0, 5 * sizeof (pthread_t));

  for (i = 0; i < 5; i++)
    {
      if (pthread_create (&th[i], NULL, tfunc, NULL) < 0)
        perror ("pthread_create");
    }

  for (i = 0; i < 5; i++)
    {
      if (pthread_join (th[i], NULL) < 0)
        perror ("pthread_join");
    }
}

int
main (int argc, char **argv)
{
  while (1)
    {
      test ();
    }
  exit (0);
}

Here's what I noticed when cleaning it up:

• for( i = 0; i < 5, i++ ) comma not semicolon means loop may not have been working

• in test(), th was not zeroed meaning any failed pthread_create was using an old thread reference.

• In tfunc, you did a pthread_join if ( g_count == value_needed ), but then you exited anyway, i.e. you were always immediately doing the pthread_join or the equivalent. Note I also tested the version below without the sleep(), so exiting immediately now works.

• various other orthographic issues.

• no error handling

As there were a few compilation problems, I suspect that you may not have compiled the code you pasted above, but something more complicated. And I suspect it's part of that that's causing the issue.

If you post a minimal example of compilable code that actually causes the issue, I might be able to help you further.