pthreads/pthread_create.c

   1 /* compile with:
   2    gcc pthread_create.c -o pthread_create -lpthread -Wall -W -Wextra -ansi -pedantic */
   3
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <pthread.h>
   7
   8 #define NUM_THREADS 20
   9
  10 /* function prototypes */
  11 void *threadfun(void *arg);
  12 void diep(const char *s);
  13
  14 int main(void)
  15 {
  16     pthread_t tid[NUM_THREADS];
  17     int cnt[NUM_THREADS], i;
  18
  19     for (i = 0; i < NUM_THREADS; i++) {
  20         cnt[i] = i;
  21         printf("Creating thread: %d\n", i);
  22         if (pthread_create(&tid[i], NULL, threadfun, (void *)&cnt[i]))
  23             diep("pthread_create() error\n");
  24     }
  25
  26     /* make sure all threads are done */
  27     for (i = 0; i < NUM_THREADS; i++)
  28         if (pthread_join(tid[i], NULL))
  29             diep("pthread_join");
  30
  31     return EXIT_SUCCESS;
  32 }
  33
  34 void *threadfun(void *arg)
  35 {
  36     printf("Hello! I am thread: %d\n", *(int *) arg);
  37     pthread_exit(NULL);
  38 }
  39
  40 void diep(const char *s)
  41 {
  42     perror(s);
  43     exit(EXIT_FAILURE);
  44 }