linux多线程示例

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

 typedef void* (*fun)(void*);

 fun fun1, fun2;

 pthread_mutex_t pmu = PTHREAD_MUTEX_INITIALIZER;
 pthread_cond_t cond;
 pthread_t pid1, pid2;
 int flag = ;
 int gnum = ;
 int gsub = ;

 void *  func1(void * para)
 {
     int k = (int)para;
     printf("func1, ******\n");
     while(gnum<=)
     {
         pthread_mutex_lock(&pmu);
         printf("gnum == %d", gnum);
         while(gnum==)
         {
             printf("suspend thread1 at gnum==50 !!! \n");
             pthread_cond_wait(&cond, &pmu);
             gnum++;
        }
         ++gnum;
         ++flag;
         ++k;
         //printf("flag = %d, k = %d\n", flag, k);
         pthread_mutex_unlock(&pmu);
         printf("I am func1\n");
     }
             pthread_exit((void*));

 }

 void * func2(void * para)
 {
     int f = (int)para;
     printf("f == %d\n", f);
     printf("pthread2 start running !\n");
     void * ret = NULL;
     while(gsub>=)
     {
         pthread_mutex_lock(&pmu);
         gsub--;
         printf("gsub= %d ", gsub);
         if(gsub == )
         {
             printf("now gsnb ==20, and send signal\n");
             pthread_cond_signal(&cond);
         }
         ++flag;
        ++f;
         printf("flag = %d, f = %d\n", flag, f);
         pthread_mutex_unlock(&pmu);
         printf("I am func2 \n");
     }
     //pthread_join(pid1, &ret);
     pthread_exit((void*));
 }

 int main()
 {
     int id = ;
     void * ret = NULL;
     int key = ;

     pthread_cond_init(&cond, NULL);  //属性设置NULL默认属性
     id = pthread_create(&pid1, NULL, func1, (void*)key);
     if(id != )
     {
         printf("pthread_create error !\n");
         exit();
     }

     if(pthread_create(&pid2, NULL, func2, (void*)key))
     {
         printf("pthread_create error ! \n");
         exit();
     }
87     pthread_join(pid2, &ret);　　　　　　//等待pid2线程退出
88     pthread_join(pid1, &ret);　　　　　　//等待pid1线程退出

　　　　//pthread_detach(pid1);　　　　　　　　//主线程与pid1线程进行分离，一般用来实现异步返回
　　　　//pthread_detach(pid2);　　　　　　　　//同上
     pthread_exit((void*));
 }

gcc test_thread.c -lpthread
./a.out

线程池实例代码：

 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <pthread.h>
 #include <assert.h>

 typedef struct worker
 {
     //回调函数，任务运行时会调用此函数，也可以声明为其他形式；
     void * (*process)(void *arg);   //该函数返回值是任意类型的；参数也是任意类型的；`
     void *arg;  //回调函数的参数；
     struct worker *next;
 }CThread_worker;

 //线程池结构
 typedef struct
 {
     pthread_mutex_t queue_lock;     //互斥量
     pthread_cond_t queue_ready;     //条件变量

     //链表结构， 线程池中所有等待任务
     CThread_worker *queue_head;

     //是否销毁线程池
     int shutdown;
     pthread_t *threadid;

     //线程池中允许的活动线程数目；
     //线程池中允许的活动线程数目；
     int max_thread_num;
     //当前等待队列的任务数目;
     int  cur_queue_size;

 }CThread_pool;

 int pool_add_worker(void * (*process)(void *arg), void *arg);
 void * thread_routine(void *arg);

 static CThread_pool *pool = NULL;
 void pool_init(int max_thread_num)
 {
     pool = (CThread_pool*)malloc(sizeof(CThread_pool));

 //初始化互斥量；
     pthread_mutex_init(&(pool->queue_lock), NULL);
 //初始化条件变量
     pthread_cond_init(&(pool->queue_ready), NULL);

     pool->queue_head = NULL;

 //最大线程数目
     pool->max_thread_num = max_thread_num;
 //当前线程数目
     pool->cur_queue_size = ;

     pool->shutdown = ;
     pool->threadid = (pthread_t*)malloc(max_thread_num * sizeof(pthread_t));
     int i = ;
     for(i=; i<max_thread_num;i++)
     {
         pthread_create(&(pool->threadid[i]), NULL, thread_routine, NULL);
     }
 }

 //向线程池中加入任务
 int pool_add_worker(void*(*process)(void *arg), void *arg)
 {
     //构建一个新任务
     CThread_worker *newworker = (CThread_worker *)malloc(sizeof(CThread_worker));
     newworker->process = process;
     newworker->arg = arg;
     //别忘了置空
     newworker->next = NULL;

 //加锁互斥量
     pthread_mutex_lock(&(pool->queue_lock));
     //将任务加入到等待队列中
     CThread_worker *member = pool->queue_head;
     if(member !=NULL)
     {
         while(member->next != NULL)
             member = member->next;
         member->next = newworker;
     }
     else
     {
         pool->queue_head = newworker;
     }

     assert(pool->queue_head != NULL);
     pool->cur_queue_size++;
     pthread_mutex_unlock(&(pool->queue_lock));

     //好了，等待队列中有任务了，唤醒一个等待线程；
     //     注意如果所有线程都在忙碌，这句没有任何作用
     pthread_cond_signal(&(pool->queue_ready));
     return ;
 }

 /*销毁线程池，等待队列中的任务不会再被执行，
 *但是正在运行的线程会一直 把任务运行完后 再退出；
 */

 int pool_destroy()
 {
     if(pool->shutdown)
         return -;   //防止两次调用
     pool->shutdown = ;

     //唤醒所有等待线程，线程池要销毁了
     pthread_cond_broadcast(&(pool->queue_ready));

     //阻塞等待线程退出， 否则就成僵尸了
     int i;
     for(i=; i<pool->max_thread_num; i++)
     {
         pthread_join(pool->threadid[i], NULL);
     }

     free(pool->threadid);

     //销毁等待队列
     CThread_worker *head = NULL;
     while(pool->queue_head != NULL)
     {
         head=pool->queue_head;
         pool->queue_head = pool->queue_head->next;
         free(head);
     }

     //条件变量和互斥量也别忘了销毁
     pthread_mutex_destroy(&(pool->queue_lock));
     pthread_cond_destroy(&(pool->queue_ready));

     free(pool);
      /*销毁后指针置空是个好习惯*/
     pool = NULL;
     return ;
 }

 void* thread_routine(void *arg)
 {
                    printf("start thread 0x%x\n", pthread_self());
     while()
     {
         pthread_mutex_lock(&(pool->queue_lock));
 /*如果等待队列为0并且不销毁线程池，则处于阻塞状态; 注意
  *pthread_cond_wait是一个原子操作，等待前会解锁，唤醒后会加锁*/
         while(pool->cur_queue_size ==  && !pool->shutdown)
         {
             printf("thread 0x%x is waiting \n", pthread_self());
             pthread_cond_wait(&(pool->queue_ready), &(pool->queue_lock));
         }

         //线程池要销毁了；
         if(pool->shutdown)
         {
             //遇到break,continue,return等跳转语句，千万不要忘记先解锁*/
             pthread_mutex_unlock(&(pool->queue_lock));
             printf("thread 0x %x will exit \n", pthread_self());
             pthread_exit(NULL);
         }

         printf("thread 0x %x is starting to work \n", pthread_self());

         //使用断言
         assert(pool->cur_queue_size!= );
         assert(pool->queue_head!= NULL);

         //等待队列长度减去1，并取出链表中的头元素
         pool->cur_queue_size--;
        CThread_worker *worker = pool->queue_head;
         pool->queue_head = worker->next;
         pthread_mutex_unlock(&(pool->queue_lock));

         //调用回调函数，执行任务
         (*(worker->process))(worker->arg);
         free(worker);
         worker = NULL;
     }
     //这一句正常情况下是不可达的
     pthread_exit(NULL);
 }

 //test code
 void *myprocess(void *arg)
 {
     printf("threadid is 0x%x, working on task %d\n", pthread_self(), *(int*)arg);
     sleep();  //休息一秒，延长任务的执行时间
     return NULL;
 }

 int main(int argc, char** argv)
 {
     pool_init(); /*线程池中最多三个活动线程*/

     //连续向线程池中放入10个任务；
     int *workingnum = (int*)malloc(sizeof(int)*);
     int i;
     for(i=; i< ;i++)
     {
         workingnum[i] = i;
         pool_add_worker(myprocess, &workingnum[i]);
     }

     sleep();
 //销毁线程池；
     pool_destroy();
     free(workingnum);

     return ;
 }