Linux网络编程（六）-高并发服务器04：线程池【1个锁（用于锁住队列）、2个条件变量（一个用于阻塞“取任务线程”，一个用于阻塞“任务添加者线程（主线程）”）、1个任务循环队列（用于存放任务）】

淡淡的烟草味﹌ 2023-09-26 11:11 10阅读 0赞

## 一、线程池概述 ##

### 1、什么是线程池？ ###

线程池是一个抽象概念，可以简单的认为若干线程在一起运行，线程不退出，等待有任务处理。

### 2、为什么要有线程池？ ###

以网络编程服务器端为例,作为服务器端支持高并发,可以有多个客户端连接,发出请求,对于多个请求我们每次都去建立线程,这样线程会创建很多,而且线程执行完销毁也会有很大的系统开销,使用上效率很低。

之前在线程篇章中，我们也知道创建线程并非多多益善，所以我们的思路是提前创建好若干个线程，不退出，等待任务的产生，去接收任务处理后等待下一个任务。

### 3、线程池如何实现？ ###

需要思考2个问题？

1.  假设线程池创建了，线程们如何去协调接收任务并且处理？
2.  线程池上的线程如何能够执行不同的请求任务？

上述问题1就很像我们之前学过的生产者和消费者模型，客户端对应生产者，服务器端这边的线程池对应消费者，需要借助互斥锁和条件变量来搞定。

问题2解决思路就是利用回调机制，我们同样可以借助结构体的方式，对任务进行封装，比如任务的数据和任务处理回调都封装在结构体上，这样线程池的工作线程拿到任务的同时，也知道该如何执行了。

![abaa11fec97748e4a101decdfc052aef.png][]

## 二、线程池代码【简易版】 ##

threadpoolsimple.h

#ifndef _THREADPOOL_H
    #define _THREADPOOL_H
    
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <sys/types.h>
    #include <unistd.h>
    #include <pthread.h>
    
    
    typedef struct _PoolTask
    {
        int tasknum;//模拟任务编号
        void *arg;//回调函数参数
        void (*task_func)(void *arg);//任务的回调函数
    }PoolTask ;
    
    typedef struct _ThreadPool
    {
        int max_job_num;//最大任务个数
        int job_num;//实际任务个数
        PoolTask *tasks;//任务队列数组
        int job_push;//入队位置
        int job_pop;// 出队位置
    
        int thr_num;//线程池内线程个数
        pthread_t *threads;//线程池内线程数组
        int shutdown;//是否关闭线程池
        pthread_mutex_t pool_lock;//线程池的锁
        pthread_cond_t empty_task;//任务队列为空的条件
        pthread_cond_t not_empty_task;//任务队列不为空的条件
    
    }ThreadPool;
    
    void create_threadpool(int thrnum,int maxtasknum);//创建线程池--thrnum  代表线程个数，maxtasknum 最大任务个数
    void destroy_threadpool(ThreadPool *pool);//摧毁线程池
    void addtask(ThreadPool *pool);//添加任务到线程池
    void taskRun(void *arg);//任务回调函数
    
    #endif

threadpoolsimple.c

//简易版线程池
    #include "threadpoolsimple.h"
    
    ThreadPool *thrPool = NULL;
    
    int beginnum = 1000;
    
    void *thrRun(void *arg)
    {
        //printf("begin call %s-----\n",__FUNCTION__);
        ThreadPool *pool = (ThreadPool*)arg;
        int taskpos = 0;//任务位置
        PoolTask *task = (PoolTask *)malloc(sizeof(PoolTask));
    
        while(1)
    	{
            //获取任务，先要尝试加锁
            pthread_mutex_lock(&thrPool->pool_lock);
    
    		//无任务并且线程池不是要摧毁
            while(thrPool->job_num <= 0 && !thrPool->shutdown )
    		{
    			//如果没有任务，线程会阻塞
                pthread_cond_wait(&thrPool->not_empty_task,&thrPool->pool_lock);
            }
            
            if(thrPool->job_num)
    		{
                //有任务需要处理
                taskpos = (thrPool->job_pop++)%thrPool->max_job_num;
                //printf("task out %d...tasknum===%d tid=%lu\n",taskpos,thrPool->tasks[taskpos].tasknum,pthread_self());
    			//为什么要拷贝？避免任务被修改，生产者会添加任务
                memcpy(task,&thrPool->tasks[taskpos],sizeof(PoolTask));
                task->arg = task;
                thrPool->job_num--;
                //task = &thrPool->tasks[taskpos];
                pthread_cond_signal(&thrPool->empty_task);//通知生产者
            }
    
            if(thrPool->shutdown)
    		{
                //代表要摧毁线程池，此时线程退出即可
                //pthread_detach(pthread_self());//临死前分家
                pthread_mutex_unlock(&thrPool->pool_lock);
                free(task);
    			pthread_exit(NULL);
            }
    
            //释放锁
            pthread_mutex_unlock(&thrPool->pool_lock);
            task->task_func(task->arg);//执行回调函数
        }
        
        //printf("end call %s-----\n",__FUNCTION__);
    }
    
    //创建线程池
    void create_threadpool(int thrnum,int maxtasknum)
    {
        printf("begin call %s-----\n",__FUNCTION__);
        thrPool = (ThreadPool*)malloc(sizeof(ThreadPool));
    
        thrPool->thr_num = thrnum;
        thrPool->max_job_num = maxtasknum;
        thrPool->shutdown = 0;//是否摧毁线程池，1代表摧毁
        thrPool->job_push = 0;//任务队列添加的位置
        thrPool->job_pop = 0;//任务队列出队的位置
        thrPool->job_num = 0;//初始化的任务个数为0
    
        thrPool->tasks = (PoolTask*)malloc((sizeof(PoolTask)*maxtasknum));//申请最大的任务队列
    
        //初始化锁和条件变量
        pthread_mutex_init(&thrPool->pool_lock,NULL);
        pthread_cond_init(&thrPool->empty_task,NULL);
        pthread_cond_init(&thrPool->not_empty_task,NULL);
    
        int i = 0;
        thrPool->threads = (pthread_t *)malloc(sizeof(pthread_t)*thrnum);//申请n个线程id的空间
    	
    	pthread_attr_t attr;
    	pthread_attr_init(&attr);
    	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
        for(i = 0;i < thrnum;i++)
    	{
            pthread_create(&thrPool->threads[i],&attr,thrRun,(void*)thrPool);//创建多个线程
        }
        //printf("end call %s-----\n",__FUNCTION__);
    }
    //摧毁线程池
    void destroy_threadpool(ThreadPool *pool)
    {
        pool->shutdown = 1;//开始自爆
        pthread_cond_broadcast(&pool->not_empty_task);//诱杀 
    
        int i = 0;
        for(i = 0; i < pool->thr_num ; i++)
    	{
            pthread_join(pool->threads[i],NULL);
        }
    
        pthread_cond_destroy(&pool->not_empty_task);
        pthread_cond_destroy(&pool->empty_task);
        pthread_mutex_destroy(&pool->pool_lock);
    
        free(pool->tasks);
        free(pool->threads);
        free(pool);
    }
    
    //添加任务到线程池
    void addtask(ThreadPool *pool)
    {
        //printf("begin call %s-----\n",__FUNCTION__);
        pthread_mutex_lock(&pool->pool_lock);
    
    	//实际任务总数大于最大任务个数则阻塞等待(等待任务被处理)
        while(pool->max_job_num <= pool->job_num)
    	{
            pthread_cond_wait(&pool->empty_task,&pool->pool_lock);
        }
    
        int taskpos = (pool->job_push++)%pool->max_job_num;
        //printf("add task %d  tasknum===%d\n",taskpos,beginnum);
        pool->tasks[taskpos].tasknum = beginnum++;
        pool->tasks[taskpos].arg = (void*)&pool->tasks[taskpos];
        pool->tasks[taskpos].task_func = taskRun;
        pool->job_num++;
    
        pthread_mutex_unlock(&pool->pool_lock);
    
        pthread_cond_signal(&pool->not_empty_task);//通知包身工
        //printf("end call %s-----\n",__FUNCTION__);
    }
    
    //任务回调函数
    void taskRun(void *arg)
    {
        PoolTask *task = (PoolTask*)arg;
        int num = task->tasknum;
        printf("task %d is runing %lu\n",num,pthread_self());
    
        sleep(1);
        printf("task %d is done %lu\n",num,pthread_self());
    }
    
    
    int main()
    {
        create_threadpool(3,20);
        int i = 0;
        for(i = 0;i < 50 ; i++)
    	{
            addtask(thrPool);//模拟添加任务
        }
    
        sleep(20);
        destroy_threadpool(thrPool);
    
        return 0;
    }

## 三、线程池代码【复杂版】 ##

pthreadpool.h

#ifndef __THREADPOOL_H_
    #define __THREADPOOL_H_
    
    typedef struct threadpool_t threadpool_t;
    
    /**
     * @function threadpool_create
     * @descCreates a threadpool_t object.
     * @param thr_num  thread num
     * @param max_thr_num  max thread size
     * @param queue_max_size   size of the queue.
     * @return a newly created thread pool or NULL
     */
    threadpool_t *threadpool_create(int min_thr_num, int max_thr_num, int queue_max_size);
    
    /**
     * @function threadpool_add
     * @desc add a new task in the queue of a thread pool
     * @param pool     Thread pool to which add the task.
     * @param function Pointer to the function that will perform the task.
     * @param argument Argument to be passed to the function.
     * @return 0 if all goes well,else -1
     */
    int threadpool_add(threadpool_t *pool, void*(*function)(void *arg), void *arg);
    
    /**
     * @function threadpool_destroy
     * @desc Stops and destroys a thread pool.
     * @param pool  Thread pool to destroy.
     * @return 0 if destory success else -1
     */
    int threadpool_destroy(threadpool_t *pool);
    
    /**
     * @desc get the thread num
     * @pool pool threadpool
     * @return # of the thread
     */
    int threadpool_all_threadnum(threadpool_t *pool);
    
    /**
     * desc get the busy thread num
     * @param pool threadpool
     * return # of the busy thread
     */
    int threadpool_busy_threadnum(threadpool_t *pool);
    
    #endif

threadpool.c

#include <stdlib.h>
    #include <pthread.h>
    #include <unistd.h>
    #include <assert.h>
    #include <stdio.h>
    #include <string.h>
    #include <signal.h>
    #include <errno.h>
    #include "threadpool.h"
    
    #define DEFAULT_TIME 10                 /*10s检测一次*/
    #define MIN_WAIT_TASK_NUM 10            /*如果queue_size > MIN_WAIT_TASK_NUM 添加新的线程到线程池*/ 
    #define DEFAULT_THREAD_VARY 10          /*每次创建和销毁线程的个数*/
    #define true 1
    #define false 0
    
    typedef struct 
    {
        void *(*function)(void *);          /* 函数指针，回调函数 */
        void *arg;                          /* 上面函数的参数 */
    } threadpool_task_t;                    /* 各子线程任务结构体 */
    
    /* 描述线程池相关信息 */
    struct threadpool_t 
    {
        pthread_mutex_t lock;               /* 用于锁住本结构体 */    
        pthread_mutex_t thread_counter;     /* 记录忙状态线程个数de琐 -- busy_thr_num */
    
        pthread_cond_t queue_not_full;      /* 当任务队列满时，添加任务的线程阻塞，等待此条件变量 */
        pthread_cond_t queue_not_empty;     /* 任务队列里不为空时，通知等待任务的线程 */
    
        pthread_t *threads;                 /* 存放线程池中每个线程的tid。数组 */
        pthread_t adjust_tid;               /* 存管理线程tid */
        threadpool_task_t *task_queue;      /* 任务队列(数组首地址) */
    
        int min_thr_num;                    /* 线程池最小线程数 */
        int max_thr_num;                    /* 线程池最大线程数 */
        int live_thr_num;                   /* 当前存活线程个数 */
        int busy_thr_num;                   /* 忙状态线程个数 */
        int wait_exit_thr_num;              /* 要销毁的线程个数 */
    
        int queue_front;                    /* task_queue队头下标 */
        int queue_rear;                     /* task_queue队尾下标 */
        int queue_size;                     /* task_queue队中实际任务数 */
        int queue_max_size;                 /* task_queue队列可容纳任务数上限 */
    
        int shutdown;                       /* 标志位，线程池使用状态，true或false */
    };
    
    void *threadpool_thread(void *threadpool);
    
    void *adjust_thread(void *threadpool);
    
    int is_thread_alive(pthread_t tid);
    int threadpool_free(threadpool_t *pool);
    
    //threadpool_create(3,100,100);  
    threadpool_t *threadpool_create(int min_thr_num, int max_thr_num, int queue_max_size)
    {
        int i;
        threadpool_t *pool = NULL;
        do 
    	{
            if((pool = (threadpool_t *)malloc(sizeof(threadpool_t))) == NULL) 
    		{  
                printf("malloc threadpool fail");
                break;                                      /*跳出do while*/
            }
    
            pool->min_thr_num = min_thr_num;
            pool->max_thr_num = max_thr_num;
            pool->busy_thr_num = 0;
            pool->live_thr_num = min_thr_num;               /* 活着的线程数 初值=最小线程数 */
            pool->wait_exit_thr_num = 0;
            pool->queue_size = 0;                           /* 有0个产品 */
            pool->queue_max_size = queue_max_size;
            pool->queue_front = 0;
            pool->queue_rear = 0;
            pool->shutdown = false;                         /* 不关闭线程池 */
    
            /* 根据最大线程上限数， 给工作线程数组开辟空间, 并清零 */
            pool->threads = (pthread_t *)malloc(sizeof(pthread_t)*max_thr_num); 
            if (pool->threads == NULL) 
    		{
                printf("malloc threads fail");
                break;
            }
            memset(pool->threads, 0, sizeof(pthread_t)*max_thr_num);
    
            /* 队列开辟空间 */
            pool->task_queue = (threadpool_task_t *)malloc(sizeof(threadpool_task_t)*queue_max_size);
            if (pool->task_queue == NULL) 
    		{
                printf("malloc task_queue fail\n");
                break;
            }
    
            /* 初始化互斥琐、条件变量 */
            if (pthread_mutex_init(&(pool->lock), NULL) != 0
                    || pthread_mutex_init(&(pool->thread_counter), NULL) != 0
                    || pthread_cond_init(&(pool->queue_not_empty), NULL) != 0
                    || pthread_cond_init(&(pool->queue_not_full), NULL) != 0)
            {
                printf("init the lock or cond fail\n");
                break;
            }
    
    		//启动工作线程
    		pthread_attr_t attr;
    		pthread_attr_init(&attr);
    		pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
            for (i = 0; i < min_thr_num; i++) 
    		{
                pthread_create(&(pool->threads[i]), &attr, threadpool_thread, (void *)pool);/*pool指向当前线程池*/
                printf("start thread 0x%x...\n", (unsigned int)pool->threads[i]);
            }
    
    		//创建管理者线程
            pthread_create(&(pool->adjust_tid), &attr, adjust_thread, (void *)pool);
    
            return pool;
    
        } while (0);
    
    	/* 前面代码调用失败时,释放poll存储空间 */
        threadpool_free(pool);
    
        return NULL;
    }
    
    /* 向线程池中 添加一个任务 */
    //threadpool_add(thp, process, (void*)&num[i]);   /* 向线程池中添加任务 process: 小写---->大写*/
    
    int threadpool_add(threadpool_t *pool, void*(*function)(void *arg), void *arg)
    {
        pthread_mutex_lock(&(pool->lock));
    
        /* ==为真，队列已经满， 调wait阻塞 */
        while ((pool->queue_size == pool->queue_max_size) && (!pool->shutdown)) 
    	{
            pthread_cond_wait(&(pool->queue_not_full), &(pool->lock));
        }
    
        if (pool->shutdown) 
    	{
            pthread_cond_broadcast(&(pool->queue_not_empty));
            pthread_mutex_unlock(&(pool->lock));
            return 0;
        }
    
        /* 清空 工作线程 调用的回调函数 的参数arg */
        if (pool->task_queue[pool->queue_rear].arg != NULL) 
    	{
            pool->task_queue[pool->queue_rear].arg = NULL;
        }
    
        /*添加任务到任务队列里*/
        pool->task_queue[pool->queue_rear].function = function;
        pool->task_queue[pool->queue_rear].arg = arg;
        pool->queue_rear = (pool->queue_rear + 1) % pool->queue_max_size;       /* 队尾指针移动, 模拟环形 */
        pool->queue_size++;
    
        /*添加完任务后，队列不为空，唤醒线程池中 等待处理任务的线程*/
        pthread_cond_signal(&(pool->queue_not_empty));
        pthread_mutex_unlock(&(pool->lock));
    
        return 0;
    }
    
    /* 线程池中各个工作线程 */
    void *threadpool_thread(void *threadpool)
    {
        threadpool_t *pool = (threadpool_t *)threadpool;
        threadpool_task_t task;
    
        while (true) 
    	{
            /* Lock must be taken to wait on conditional variable */
            /*刚创建出线程，等待任务队列里有任务，否则阻塞等待任务队列里有任务后再唤醒接收任务*/
            pthread_mutex_lock(&(pool->lock));
    
            /*queue_size == 0 说明没有任务，调 wait 阻塞在条件变量上, 若有任务，跳过该while*/
            while ((pool->queue_size == 0) && (!pool->shutdown)) 
    		{  
                printf("thread 0x%x is waiting\n", (unsigned int)pthread_self());
                pthread_cond_wait(&(pool->queue_not_empty), &(pool->lock));//暂停到这
    
                /*清除指定数目的空闲线程，如果要结束的线程个数大于0，结束线程*/
                if (pool->wait_exit_thr_num > 0) 
    			{
                    pool->wait_exit_thr_num--;
    
                    /*如果线程池里线程个数大于最小值时可以结束当前线程*/
                    if (pool->live_thr_num > pool->min_thr_num) 
    				{
                        printf("thread 0x%x is exiting\n", (unsigned int)pthread_self());
                        pool->live_thr_num--;
                        pthread_mutex_unlock(&(pool->lock));
    					//pthread_detach(pthread_self());
                        pthread_exit(NULL);
                    }
                }
            }
    
            /*如果指定了true，要关闭线程池里的每个线程，自行退出处理---销毁线程池*/
            if (pool->shutdown) 
    		{
                pthread_mutex_unlock(&(pool->lock));
                printf("thread 0x%x is exiting\n", (unsigned int)pthread_self());
                //pthread_detach(pthread_self());
                pthread_exit(NULL);     /* 线程自行结束 */
            }
    
            /*从任务队列里获取任务, 是一个出队操作*/
            task.function = pool->task_queue[pool->queue_front].function;
            task.arg = pool->task_queue[pool->queue_front].arg;
    
            pool->queue_front = (pool->queue_front + 1) % pool->queue_max_size;       /* 出队，模拟环形队列 */
            pool->queue_size--;
    
            /*通知可以有新的任务添加进来*/
            pthread_cond_broadcast(&(pool->queue_not_full));
    
            /*任务取出后，立即将 线程池琐 释放*/
            pthread_mutex_unlock(&(pool->lock));
    
            /*执行任务*/ 
            printf("thread 0x%x start working\n", (unsigned int)pthread_self());
            pthread_mutex_lock(&(pool->thread_counter));                            /*忙状态线程数变量琐*/
            pool->busy_thr_num++;                                                   /*忙状态线程数+1*/
            pthread_mutex_unlock(&(pool->thread_counter));
    
            (*(task.function))(task.arg);                                           /*执行回调函数任务*/
            //task.function(task.arg);                                              /*执行回调函数任务*/
    
            /*任务结束处理*/ 
            printf("thread 0x%x end working\n", (unsigned int)pthread_self());
            pthread_mutex_lock(&(pool->thread_counter));
            pool->busy_thr_num--;                                       /*处理掉一个任务，忙状态数线程数-1*/
            pthread_mutex_unlock(&(pool->thread_counter));
        }
    
        pthread_exit(NULL);
    }
    
    /* 管理线程 */
    void *adjust_thread(void *threadpool)
    {
        int i;
        threadpool_t *pool = (threadpool_t *)threadpool;
        while (!pool->shutdown) 
    	{
    
            sleep(DEFAULT_TIME);                                    /*定时 对线程池管理*/
    
            pthread_mutex_lock(&(pool->lock));
            int queue_size = pool->queue_size;                      /* 关注 任务数 */
            int live_thr_num = pool->live_thr_num;                  /* 存活 线程数 */
            pthread_mutex_unlock(&(pool->lock));
    
            pthread_mutex_lock(&(pool->thread_counter));
            int busy_thr_num = pool->busy_thr_num;                  /* 忙着的线程数 */
            pthread_mutex_unlock(&(pool->thread_counter));
    
            /* 创建新线程 算法： 任务数大于最小线程池个数, 且存活的线程数少于最大线程个数时 如：30>=10 && 40<100*/
            if (queue_size >= MIN_WAIT_TASK_NUM && live_thr_num < pool->max_thr_num) 
    		{
                pthread_mutex_lock(&(pool->lock));  
                int add = 0;
    
                /*一次增加 DEFAULT_THREAD 个线程*/
                for (i = 0; i < pool->max_thr_num && add < DEFAULT_THREAD_VARY
                        && pool->live_thr_num < pool->max_thr_num; i++) 
    			{
                    if (pool->threads[i] == 0 || !is_thread_alive(pool->threads[i])) 
    				{
                        pthread_create(&(pool->threads[i]), NULL, threadpool_thread, (void *)pool);
                        add++;
                        pool->live_thr_num++;
                    }
                }
    
                pthread_mutex_unlock(&(pool->lock));
            }
    
            /* 销毁多余的空闲线程 算法：忙线程X2 小于 存活的线程数 且 存活的线程数 大于 最小线程数时*/
            if ((busy_thr_num * 2) < live_thr_num  &&  live_thr_num > pool->min_thr_num) 
    		{
                /* 一次销毁DEFAULT_THREAD个线程, 隨機10個即可 */
                pthread_mutex_lock(&(pool->lock));
                pool->wait_exit_thr_num = DEFAULT_THREAD_VARY;      /* 要销毁的线程数 设置为10 */
                pthread_mutex_unlock(&(pool->lock));
    
                for (i = 0; i < DEFAULT_THREAD_VARY; i++) 
    			{
                    /* 通知处在空闲状态的线程, 他们会自行终止*/
                    pthread_cond_signal(&(pool->queue_not_empty));
                }
            }
        }
    
        return NULL;
    }
    
    int threadpool_destroy(threadpool_t *pool)
    {
        int i;
        if (pool == NULL) 
    	{
            return -1;
        }
        pool->shutdown = true;
    
        /*先销毁管理线程*/
        //pthread_join(pool->adjust_tid, NULL);
    
        for (i = 0; i < pool->live_thr_num; i++) 
    	{
            /*通知所有的空闲线程*/
            pthread_cond_broadcast(&(pool->queue_not_empty));
        }
    
        /*for (i = 0; i < pool->live_thr_num; i++) 
    	{
            pthread_join(pool->threads[i], NULL);
        }*/
    
        threadpool_free(pool);
    
        return 0;
    }
    
    int threadpool_free(threadpool_t *pool)
    {
        if (pool == NULL) 
    	{
            return -1;
        }
    
        if (pool->task_queue) 
    	{
            free(pool->task_queue);
        }
    
        if (pool->threads) 
    	{
            free(pool->threads);
            pthread_mutex_lock(&(pool->lock));
            pthread_mutex_destroy(&(pool->lock));
            pthread_mutex_lock(&(pool->thread_counter));
            pthread_mutex_destroy(&(pool->thread_counter));
            pthread_cond_destroy(&(pool->queue_not_empty));
            pthread_cond_destroy(&(pool->queue_not_full));
        }
    
        free(pool);
        pool = NULL;
    
        return 0;
    }
    
    int threadpool_all_threadnum(threadpool_t *pool)
    {
        int all_threadnum = -1;
    
        pthread_mutex_lock(&(pool->lock));
        all_threadnum = pool->live_thr_num;
        pthread_mutex_unlock(&(pool->lock));
    
        return all_threadnum;
    }
    
    int threadpool_busy_threadnum(threadpool_t *pool)
    {
        int busy_threadnum = -1;
    
        pthread_mutex_lock(&(pool->thread_counter));
        busy_threadnum = pool->busy_thr_num;
        pthread_mutex_unlock(&(pool->thread_counter));
    
        return busy_threadnum;
    }
    
    int is_thread_alive(pthread_t tid)
    {
        int kill_rc = pthread_kill(tid, 0);     //发0号信号，测试线程是否存活
        if (kill_rc == ESRCH) 
    	{
            return false;
        }
    
        return true;
    }
    
    /*测试*/ 
    
    #if 1
    /* 线程池中的线程，模拟处理业务 */
    void *process(void *arg)
    {
        printf("thread 0x%x working on task %d\n ",(unsigned int)pthread_self(),*(int *)arg);
        sleep(1);
        printf("task %d is end\n", *(int *)arg);
    
        return NULL;
    }
    
    int main(void)
    {
        /*threadpool_t *threadpool_create(int min_thr_num, int max_thr_num, int queue_max_size);*/
        threadpool_t *thp = threadpool_create(3,100,100);   /*创建线程池，池里最小3个线程，最大100，队列最大100*/
        printf("pool inited");
    
        //int *num = (int *)malloc(sizeof(int)*20);
        int num[20], i;
        for (i = 0; i < 20; i++) 
    	{
            num[i]=i;
            printf("add task %d\n",i);
            threadpool_add(thp, process, (void*)&num[i]);   /* 向线程池中添加任务 */
        }
    
        sleep(10);                                          /* 等子线程完成任务 */
        threadpool_destroy(thp);
    
        return 0;
    }
    
    #endif

[abaa11fec97748e4a101decdfc052aef.png]: https://img-blog.csdnimg.cn/abaa11fec97748e4a101decdfc052aef.png