线程池代码(加强版)
头文件head.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
main.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 */ 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 */ }; /** * @function void *threadpool_thread(void *threadpool) * @desc the worker thread * @param threadpool the pool which own the thread */ void *threadpool_thread(void *threadpool); /** * @function void *adjust_thread(void *threadpool); * @desc manager thread * @param threadpool the threadpool */ void *adjust_thread(void *threadpool); /** * check a thread is alive */ int is_thread_alive(pthread_t tid); int threadpool_free(threadpool_t *pool); 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->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"); 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"); break; } /* 启动 min_thr_num 个 work thread */ for (i = 0; i < min_thr_num; i++) { pthread_create(&(pool->threads[i]), NULL, threadpool_thread, (void *)pool);/*pool指向当前线程池*/ printf("start thread 0x%x...\n", (unsigned int)pool->threads[i]); } pthread_create(&(pool->adjust_tid), NULL, adjust_thread, (void *)pool);/* 启动管理者线程 */ return pool; } while (0); threadpool_free(pool); /* 前面代码调用失败时,释放poll存储空间 */ return NULL; } /* 向线程池中 添加一个任务 */ 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_mutex_unlock(&(pool->lock)); } /* 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) { free(pool->task_queue[pool->queue_rear].arg); 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)); /*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_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*/ if (pool->shutdown) { pthread_mutex_unlock(&(pool->lock)); printf("thread 0x%x is exiting\n", (unsigned int)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; }
学习版:https://www.cnblogs.com/cthon/p/9085026.html
通用版代码:https://www.cnblogs.com/cthon/p/9097007.html
难度升级版代码:https://www.cnblogs.com/cthon/p/9085623.html