多线程 线程队列的实现

参考他人的方法，自己做了简单修改，实现一个通用的线程队列。

 

#include <stdio.h>

#include <pthread.h>

#include <unistd.h>



#define POOL_SIZE 10

#define QUEUE_LEN 20

pthread_mutex_t queue_lock; //队列锁

pthread_cond_t  queue_cond; //条件变量



int head = 0, tail = 0;

int queue[QUEUE_LEN];



void delay(int x)

{

	int i,j;

	for(i = 0; i < x; i++)

		for(j = 0; j <x; j++);

}



void fun1(){

	printf("fun1 start\n");

	delay(1000);

	printf("fun1 end\n");

}



void fun2(){

	printf("fun2 start\n");

	delay(2000);

	printf("fun2 end\n");

}



void fun3(){

	printf("fun3 start\n");

	delay(3000);

	printf("fun3 end\n");

}



void fun4(){

	printf("fun4 start\n");

	delay(4000);

	printf("fun4 end\n");

}



int dequeue()//出对列函数

{

	int y;

	pthread_mutex_lock(&queue_lock);

	while(head == tail)//队列中 无情求时，等待

	{

		pthread_cond_wait(&queue_cond, &queue_lock);//自动释放锁		

	}

	y = queue[++head];//需做循环处理  queue[head] is NULL

	if(head >= QUEUE_LEN)

	  head = 0;

	pthread_mutex_unlock(&queue_lock);

	return y;

}



void * process_queue(void *arg)

{

	int x = 0;

	for(;;)

	{

		x = dequeue();

		printf("%d dequeue \n",x);

		switch(x)

		{

			case 1:

				fun1(); break;

			case 2:

				fun2(); break;

		    case 3:

				fun3(); break;

			default:

				fun4(); break;

		}		

	}

}



int enqueue(int x)//插入请求 

{

	int next;

	pthread_mutex_lock(&queue_lock);

	next = tail + 1;

	if(next >= QUEUE_LEN)

		next = 0;

	if(next == head)

	{

	 pthread_cond_signal(&queue_cond);//

	 pthread_mutex_unlock(&queue_lock);   

	 return 0;// 表示队列已满

	}

	queue[next] = x;

	tail = next;	

	pthread_cond_signal(&queue_cond);//激活

	pthread_mutex_unlock(&queue_lock);

	return 1;//入队成功		

}



int main()

{

	int i;

	int num = 0;

	pthread_t tid[POOL_SIZE];



	pthread_mutex_init(&queue_lock, NULL);

	pthread_cond_init(&queue_cond, NULL);



	for(i = 0; i < POOL_SIZE; i++)

		pthread_create(&tid[i], NULL, process_queue, NULL);



	while(1)

	{

		scanf("%d",&num);

		if(0 == num)

		//	break;

			return 0;

		printf("%d ",num);

		while(!enqueue(num))//队列满时 等待

		{

			printf("queue is full\n");

			sleep(1);

		}

	}



//	for(i = 0; i < POOL_SIZE; i++)

//		pthread_join(tid[i], NULL);



//	pthread_mutex_destory(&queue_lock);

//	pthread_cond_destroy(&queue_cond);



	return 0;

}

 

 

还有一些不足之处，随后补上。

测试方法：

键入 ：

4 3 2 1

结果：
4 3 2 1 4 dequeue
fun4 start
3 dequeue
fun3 start
2 dequeue
fun2 start
1 dequeue
fun1 start
fun1 end
fun2 end
fun3 end
fun4 end

键入：

0

退出函数