/* gcc thisfile.c -lpthread */
#include <stdio.h>
#include <pthread.h>

#define NUM_THREADS 5
#define SLEEP_TIME  3
void *sleeping(void *);   /* thread routine */

int  main(int argc, char *argv[]) {

  int i;
  pthread_t tid[NUM_THREADS];      /* array of thread IDs */

  for ( i = 0; i < NUM_THREADS; i++)
    pthread_create(&tid[i], NULL, sleeping,
		   (void *)SLEEP_TIME);
  for ( i = 0; i < NUM_THREADS; i++)
    pthread_join(tid[i], NULL);
  printf("main() reporting that all %d threads have terminated\n", i);
  return (0);
}  /* main */

void * sleeping(void *arg)   {

  int sleep_time = (int)arg;
  printf("thread %ld sleeping %d seconds ...\n", pthread_self(), sleep_time);
  sleep(sleep_time);
  printf("\nthread %ld awakening\n", pthread_self());
  return (NULL);
}