thread_mutex.c

pthread的例子程序

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

#define THREAD_NUM 8

void *functionC();
pthread_mutex_t mutex1 = PTHREAD_MUTEX_INITIALIZER;
int  counter = 0;

main()
{
   pthread_t thread_id[THREAD_NUM];
   int i;

   /* Create independant threads each of which will execute functionC */

   for (i = 0 ; i < THREAD_NUM ; i++){
	   pthread_create(&thread_id[i], NULL, &functionC, NULL);
   }

   /* Wait till threads are complete before main continues. Unless we  */
   /* wait we run the risk of executing an exit which will terminate   */
   /* the process and all threads before the threads have completed.   */

   for (i = 0 ; i < THREAD_NUM ; i++){
	   pthread_join(thread_id[i], NULL);
   }

   exit(0);
}

void *functionC()
{
   int s_counter;

   //pthread_mutex_lock( &mutex1 );
   counter++;
   sleep(1);
   s_counter = counter * counter;
   printf("Counter value: %d\n", s_counter);
   //pthread_mutex_unlock( &mutex1 );
}