Linux多线程的一个小例子

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <pthread.h>



#define MAX_COUNT 9

pthread_mutex_t mutex;	//互斥变量

pthread_cond_t cond;	//条件变量

int count = 0;



void AddCount_Odd_Func(void);

void AddCount_Even_Func(void);



int main()

{

	int ret;

	pthread_t odd_thread, even_thread;	//两个线程

	pthread_attr_t thread_attr;			//线程的属性结构



	count = 0;

	pthread_mutex_init(&mutex, NULL);	//互斥变量的初始化

	pthread_cond_init(&cond, NULL);		//条件变量的初始化

	ret = pthread_attr_init(&thread_attr);	//属性结构体初始化

	if (ret != 0)

	{

		perror("Attribute Creation Failed!");

		exit(EXIT_FAILURE);

	}



	pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED);	//设置线程分离状态的函数，PTHREAD_CREATE_DETACHED(分离线程):不需要创建线程的线程等待

										//函数运行结束线程便终止，同时释放占用的系统资源

	ret = pthread_create(&odd_thread, &thread_attr, (void *)&AddCount_Odd_Func, NULL);

	if (ret != 0)

	{

		perror("Thread Creation Failed!");

		exit(EXIT_FAILURE);

	}

	ret = pthread_create(&even_thread, &thread_attr, (void *)&AddCount_Even_Func, NULL);

	if (ret != 0)

	{

		perror("Thread Creation Failed!");

		exit(EXIT_FAILURE);

	}



	while (count < MAX_COUNT);

	printf("Finished!\n");

	pthread_cond_destroy(&cond);		//销毁条件变量

	pthread_mutex_destroy(&mutex);

	return 0;

}



void AddCount_Odd_Func(void)

{

	pthread_mutex_lock(&mutex);

	while (count < MAX_COUNT)

	{

		if (count % 2 == 1)

		{

			count++;

			printf("AddCount_Odd_Func(): count = %d.\n", count);

			pthread_cond_signal(&cond);			//用来释放被阻塞在条件变量cond上的线程

		}

		else

			pthread_cond_wait(&cond, &mutex);	//使线程阻塞在条件变量cond上

	}

	pthread_mutex_unlock(&mutex);

}



void AddCount_Even_Func(void)

{

	pthread_mutex_lock(&mutex);

	while (count < MAX_COUNT)

	{

		if (count % 2 == 0)

		{

			count++;

			printf("AddCount_Even_Func(): count = %d.\n", count);

			pthread_cond_signal(&cond);

		}

		else

			pthread_cond_wait(&cond, &mutex);

	}

	pthread_mutex_unlock(&mutex);

}

gcc example.c -lpthread

运行结果如下：