Linux编程之多线程常用函数使用实例

　　Paul Chen     2006-03-16 BeiJing

//以下代码均来自《Linux C 编程》一书，本人对其中代码做了一些改进，使之更有利于系统学习GNU C标准库中Pthread。

//非凡注重：makefile中的编译选项中一定要包含-lpthread（即连接pthread库）

makefile:

demo:demo1.o
    gcc -o demo demo1.o -lpthread

demo1.o:demo1.c
    gcc -c demo1.c

clean:
    rm demo demo1.c

demo1.c:

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

//used in test1
pthread_once_t once=PTHREAD_ONCE_INIT;

//used in test2
pthread_mutex_t mutex;
pthread_cond_t cond;

//used in test3
pthread_key_t key;

void once_run(void)
{
printf("once_run in thread %d\n",pthread_self());
}

void * child1(void *arg)
{
int tid=pthread_self();
printf("thread child1 %d enter\n",tid);
pthread_once(&once,once_run);
//sleep(3);
printf("thread child1 %d returns\n",tid);
}

void * child2(void *arg)
{
int tid=pthread_self();
printf("thread child2 %d enter\n",tid);
pthread_once(&once,once_run);
//sleep(3);
printf("thread child2 %d returns\n",tid);
}

void * child3(void *arg)
{
   pthread_cleanup_push(pthread_mutex_unlock,&mutex); /* comment 1 */
   while(1){
      printf("thread child3 get running \n");
      printf("thread child3 pthread_mutex_lock returns %d\n",
      pthread_mutex_lock(&mutex));
      pthread_cond_wait(&cond,&mutex);
      printf("thread child3 condition applied\n");
      pthread_mutex_unlock(&mutex);
      sleep(5);
   }
   pthread_cleanup_pop(0); /* comment 2 */
}

void *child4(void *arg)
{
   while(1){
      sleep(3); /* comment 3 */
      printf("thread child4 get running.\n");

printf("thread child4 pthread_mutex_lock returns %d\n",
      pthread_mutex_lock(&mutex));
      pthread_cond_wait(&cond,&mutex);
      printf("thread child4 condition applied\n");
      pthread_mutex_unlock(&mutex);
      sleep(1);
   }
}

void echomsg(int t)
{
   printf("destrUCtor excuted in thread %d,param=%d\n",pthread_self(),t);
}

void * child5(void *arg)
{
    int tid=pthread_self();
    printf("thread child5 %d enter\n",tid);
    pthread_setspecific(key,(void *)tid);
    sleep(2);
    printf("thread child5 %d returns %d\n",tid,pthread_getspecific(key));
    sleep(5);
}

void * child6(void *arg)
{
    int tid=pthread_self();
    printf("thread child6 %d enter\n",tid);
    pthread_setspecific(key,(void *)tid);
    sleep(1);
    printf("thread child6 %d returns %d\n",tid,pthread_getspecific(key));
    sleep(5);
}

int main(void)
{
int tid1,tid2,tid3,tid4,tid5,tid6;
printf("hello\n");

printf("\n\n\n");

//test1:pthread_once,pthread_self
pthread_create(&tid1,NULL,child1,NULL);
pthread_create(&tid2,NULL,child2,NULL);
pthread_join(tid1,NULL);
pthread_join(tid2,NULL);

printf("\n\n\n");

//test3:pthread_key_create,pthread_setspecific,pthread_getspecific
pthread_key_create(&key,echomsg);
pthread_create(&tid5,NULL,child5,NULL);
pthread_create(&tid6,NULL,child6,NULL);
pthread_join(tid5,NULL);
pthread_join(tid6,NULL);
pthread_key_delete(key);

printf("\n\n\n");

//test2:pthread_mutex_lock,pthread_mutex_unlock,pthread_cond_wait,pthread_cleanup_pop \
          pthread_cond_signal,pthread_exit
pthread_create(&tid3,NULL,child3,NULL);
pthread_create(&tid4,NULL,child4,NULL);
pthread_join(tid3,NULL);
pthread_join(tid4,NULL);
do{
     sleep(2); /* comment 4 */
     pthread_cancel(tid3); /* comment 5 */

    sleep(2); /* comment 6 */
     pthread_cond_signal(&cond);
}while(1);
sleep(100);
pthread_exit(0);

printf("\n\n\n");

printf("main thread exit\n");
return 0;
}