/*
  Aaron Linville
  aaron linville.org
  http://www.linville.org

  thread.c

  A brief example of pthreads. A defined number of threads
  sleep for a set amount of time and then wakeup.
 */

#define NUM_THREADS 5

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

void *routine(void *);

int main(int argc, char *argv) {
  int i, ret;

  pthread_t pthread_id[NUM_THREADS];

  for(i = 0; i < NUM_THREADS; i++) {
    ret = pthread_create(pthread_id + i, NULL, routine, (void *) i);

    if(ret != 0) {
      fprintf(stderr, "Error creating thread %i. Error %i\n", i, ret);
    }
  }

  for(i = 0; i < NUM_THREADS; i++) {
    ret = pthread_join(pthread_id[i], NULL);

    if(ret != 0) {
      fprintf(stderr, "Error waiting for %i to join. Error %i.\n", i, ret);
    }
  }

  exit(0);
}

void *routine(void *num) {
  printf("%i going to sleep.\n", num);

  sleep(NUM_THREADS - (int) num);

  printf("%i waking up!\n", num);

  return;
}