Pthread question

Hi all,

I'm not sure if it is the right place to ask questions about pthread but here's my problem.

I'm trying to set the policy/priority for the threads. I read somewhere that I need to be superuser to change those info. Is that correct ? I tried the following:

Code:

  status = pthread_attr_init (&thread_attr);
  fprintf (stderr, "pthread_attr_init returns %d\n", status);
  status = pthread_attr_setschedpolicy(&thread_attr, SCHED_FIFO);
  fprintf (stderr, "pthread_attr_setschedpolicy returns %d\n", status);

  status = pthread_attr_setinheritsched(&thread_attr, PTHREAD_EXPLICIT_SCHED);

the status code of all the calls above are all 0's.

However, when I do pthread_create, it returns a positive 1 and when I do

Code:

      if (status == 1){
        perror ("pthread_create error");
        exit(1);
      }
pthread_create error: Numerical result out of range

If I remove pthread_attr_setinheritsched statement, the code runs to completion but just not changing the policy.

Any suggestion/comments are welcome. Thank you in advanced

Does this line also sets status to 0? Not clear, cause you don't have a fprintf() for this

Code:

status = pthread_attr_setinheritsched(&thread_attr, PTHREAD_EXPLICIT_SCHED);

Originally Posted by C_ntua

Does this line also sets status to 0? Not clear, cause you don't have a fprintf() for this

Code:

status = pthread_attr_setinheritsched(&thread_attr, PTHREAD_EXPLICIT_SCHED);

Yea I am sure I have a printf statement for that line too, I just forgot to paste but that status is 0 too

Post all the code, or at least the one that has pthread_create so people can spot the error