Pthreads

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

int sum; /* this data is shared by the thread(s) */
void *runner(void *param); /* the thread */

int main(int argc, char *argv[])
{
  pthread_t tid; /* the thread identifier */
  pthread_attr_t attr; /* set of thread attributes */

  if (argc != 2) {
    fprintf(stderr, "usage: a.out <integer value>\n");
    return -1;
  }

  if (atoi(argv [1]) < 0) {
    fprintf(stderr,"%d must be >= O\n",atoi(argv[1]));
    return -1;
  }

  /* get the default attributes */
  pthread_attr_init (&attr);
  /* create the thread */
  pthread_create(&tid,&attr,runner,argv[1]) ;
  /* wait for the thread to exit */
  pthread_join(tid,NULL) ;

  printf (" sum = %d\n", sum) ;
}

/* The thread will begin control in this function */
void *runner(void *param)
{
  int i, upper = atoi(param);
  sum = 0;

  for (i = 1; i <= upper; i++)
    sum += i;

  pthread_exit(0) ;
}
Cem Ozdogan 2011-02-14