线程池搭建(个人学习记录)

目录

0.分析

1).

2).任务节点创建

3).线程池创建

1.结构体创建

1).任务节点结构

2).线程池.临界资源的结构体

2.线程池初始化

3.工作线程

4.添加任务

5.线程的销毁

6.程序

---

0.分析

1).概念：

通俗的讲就是一个线程的池子，可以循环的完成任务的一组线程集合

2).必要性：

我们平时创建一个线程，完成某一个任务，等待线程的退出。但当需要创建大量的线程时，假设T1为创建线程时间，T2为在线程任务执行时间，T3为线程销毁时间，当 T1+T3 > T2，这时候就不划算了，使用线程池可以降低频繁创建和销毁线程所带来的开销，任务处理时间比较短的时候这个好处非常显著。

3).基本结构

任务队列，存储需要处理的任务，由工作线程来处理这些任务

线程池工作线程，它是任务队列任务的消费者，等待新任务的信号

4).任务节点创建

        

5).线程池创建

1.结构体创建

1).任务节点结构

typedef struct Task{
	void *(*(func))(int arg);
	int arg;
	struct Task *next;
}t;

2).线程池.临界资源的结构体

typedef struct ThreadPool{
	pthread_mutex_t mutex;
	pthread_cond_t cond;
	t *queue;
	int stat;
	pthread_t tid[N];
}threadpool;
threadpool *pool;

2.线程池初始化

void pool_init(void)
{
	//printf("pool_init run >>>\n");
	pool = (threadpool *)malloc(sizeof(threadpool));
	pthread_mutex_init(&pool->mutex, NULL);
	pthread_cond_init(&pool->cond, NULL);
	pool->queue = NULL;
	pool->stat = 0;
	for(int i=0; i<N; i++)
	{
		pthread_create(&pool->tid[i], NULL, my_thread, (void *)i);
	}
	//printf("pool_init end >>>\n");
}

3.工作线程

void *my_thread(void *arg)
{
	//printf("my_thread run %d >>>\n", arg);
	while(1)
	{
		pthread_mutex_lock(&pool->mutex);
		pthread_cond_wait(&pool->cond, &pool->mutex);
		t *q = pool->queue;
		pool->queue = pool->queue->next;
		pthread_mutex_unlock(&pool->mutex);
		// run my_task
		q->func(q->arg);
		pool->stat--;
	}
	//printf("my_thread end %d >>>\n", arg);
}

4.添加任务

void pool_add_task(int arg)
{
	//printf("pool_add_task run %d >>>\n",arg);
	t *newtask;
	pthread_mutex_lock(&pool->mutex);
	while(pool->stat >= N)
	{
		pthread_mutex_unlock(&pool->mutex);
		usleep(10000);
		pthread_mutex_lock(&pool->mutex);
	}
	pthread_mutex_unlock(&pool->mutex);
	newtask = (t*)malloc(sizeof(t));
	newtask->func = my_task;
	newtask->arg = arg;
	
	pthread_mutex_lock(&pool->mutex);
	t *q = pool->queue;
	if(NULL == pool->queue)
	{
		pool->queue = newtask;
	}else{
	while(q->next != NULL)
	{
		q = q->next;
	}
		q->next = newtask;
	}
	pool->stat++;
	pthread_cond_signal(&pool->cond);	
	pthread_mutex_unlock(&pool->mutex);
	//printf("pool_add_task end %d >>>\n",arg);
}

void *my_task(void *arg)
{
	printf("my_stask run %d >>>\n", (int)arg);
}

5.线程的销毁

void pool_destroy(void)
{
//	printf("pool_destroy run >>>\n");
	t *del_task;
	while(pool->queue != NULL)
	{
		del_task = pool->queue;
		pool->queue = pool->queue->next;
		free(del_task);
	}
	pthread_mutex_destroy(&pool->mutex);
	pthread_cond_destroy(&pool->cond);
	free(pool);
//	printf("pool_destroy end >>>\n");
}

6.程序

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

#define N 10
// task
typedef struct Task{
	void *(*(func))(int arg);
	int arg;
	struct Task *next;
}t;
typedef struct ThreadPool{
	pthread_mutex_t mutex;
	pthread_cond_t cond;
	t *queue;
	int stat;
	pthread_t tid[N];
}threadpool;
threadpool *pool;
void *my_thread(void *arg)
{
	//printf("my_thread run %d >>>\n", arg);
	while(1)
	{
		pthread_mutex_lock(&pool->mutex);
		pthread_cond_wait(&pool->cond, &pool->mutex);
		t *q = pool->queue;
		pool->queue = pool->queue->next;
		pthread_mutex_unlock(&pool->mutex);
		// run my_task
		q->func(q->arg);
		pool->stat--;
	}
	//printf("my_thread end %d >>>\n", arg);
}
void *my_task(void *arg)
{
	printf("my_stask run %d >>>\n", (int)arg);
}
void pool_add_task(int arg)
{
	//printf("pool_add_task run %d >>>\n",arg);
	t *newtask;
	pthread_mutex_lock(&pool->mutex);
	while(pool->stat >= N)
	{
		pthread_mutex_unlock(&pool->mutex);
		usleep(10000);
		pthread_mutex_lock(&pool->mutex);
	}
	pthread_mutex_unlock(&pool->mutex);
	newtask = (t*)malloc(sizeof(t));
	newtask->func = my_task;
	newtask->arg = arg;
	
	pthread_mutex_lock(&pool->mutex);
	t *q = pool->queue;
	if(NULL == pool->queue)
	{
		pool->queue = newtask;
	}else{
	while(q->next != NULL)
	{
		q = q->next;
	}
		q->next = newtask;
	}
	pool->stat++;
	pthread_cond_signal(&pool->cond);	
	pthread_mutex_unlock(&pool->mutex);
	//printf("pool_add_task end %d >>>\n",arg);
}
void pool_init(void)
{
	//printf("pool_init run >>>\n");
	pool = (threadpool *)malloc(sizeof(threadpool));
	pthread_mutex_init(&pool->mutex, NULL);
	pthread_cond_init(&pool->cond, NULL);
	pool->queue = NULL;
	pool->stat = 0;
	for(int i=0; i<N; i++)
	{
		pthread_create(&pool->tid[i], NULL, my_thread, (void *)i);
	}
	//printf("pool_init end >>>\n");
}
void pool_destroy(void)
{
//	printf("pool_destroy run >>>\n");
	t *del_task;
	while(pool->queue != NULL)
	{
		del_task = pool->queue;
		pool->queue = pool->queue->next;
		free(del_task);
	}
	pthread_mutex_destroy(&pool->mutex);
	pthread_cond_destroy(&pool->cond);
	free(pool);
//	printf("pool_destroy end >>>\n");
}

int main(int argc,char *argv[])
{
	pool_init();
	sleep(5);
	for(int i=1; i<=20; i++)
	{
		pool_add_task(i);
	}
	sleep(5);
	pool_destroy();


}