会有崩溃的问题，当时显示崩溃原因是重复释放内存。暂时没有找到原因

==================thrdpool.h===========================================

#ifndef __THREADPOOL_H_
#define __THREADPOOL_H_

typedef struct threadpool_t threadpool_t;

/*创建线程池*/
threadpool_t *threadpool_create(int min_thr_num, int max_thr_num, int queue_max_size);
/*释放线程池*/
int threadpool_free(threadpool_t *pool);
/*销毁线程池*/
int threadpool_destroy(threadpool_t *pool);
/*管理线程*/
void *admin_thread(void *threadpool);
/*线程是否存在*/
//int is_thread_alive(pthread_t tid);
/*工作线程*/
void *threadpool_thread(void *threadpool);
/*向线程池的任务队列中添加一个任务*/
int threadpool_add_task(threadpool_t *pool, void *(*function)(void *arg), void *arg);

#endif

==================thrdpool.c===========================================

#include <unistd.h>
#include "thrdpool_c2.h"
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <signal.h>
#include <assert.h>
#include <string.h>
#include <errno.h>

#define DEFAULT_TIME 1 /*默认时间10s*/
#define MIN_WAIT_TASK_NUM 10 /*当任务数超过了它，就该添加新线程了*/
#define DEFAULT_THREAD_NUM 10 /*每次创建或销毁的线程个数*/
#define true 1
#define false 0

enum {
EMPTY = 0,
WAITING = 1,
RUNNING = 2
};

/*任务*/
typedef struct {

void *(*function)(void *);

void *arg;
int task_state;
} threadpool_task_t;

 

 

/*线程池管理*/
struct threadpool_t{
pthread_mutex_t lock; /* 锁住整个结构体 */
pthread_mutex_t thread_counter; /* 用于使用忙线程数时的锁 */
pthread_cond_t queue_not_full; /* 条件变量，任务队列不为满 */
pthread_cond_t queue_not_empty; /* 任务队列不为空 */

pthread_t *threads; /* 存放线程的tid,实际上就是管理了线 数组 */
pthread_t admin_tid; /* 管理者线程tid */
threadpool_task_t *task_queue; /* 任务队列 */

/*线程池信息*/
int min_thr_num; /* 线程池中最小线程数 */
int max_thr_num; /* 线程池中最大线程数 */
int live_thr_num; /* 线程池中存活的线程数 */
int busy_thr_num; /* 忙线程，正在工作的线程 */
int wait_exit_thr_num; /* 需要销毁的线程数 */

/*任务队列信息*/
int queue_front; /* 队头 */
int queue_rear; /* 队尾 */
int queue_size;

/* 存在的任务数 */
int queue_max_size; /* 队列能容纳的最大任务数 */

/*状态*/
int shutdown; /* true为关闭 */
};

 

/* 函数原型 */

/*创建线程池*/
threadpool_t *threadpool_create(int min_thr_num, int max_thr_num, int queue_max_size);
/*释放线程池*/
int threadpool_free(threadpool_t *pool);
/*销毁线程池*/
int threadpool_destroy(threadpool_t *pool);
/*管理线程*/
void *admin_thread(void *threadpool);
/*线程是否存在*/
int is_thread_alive(pthread_t tid);
/*工作线程*/
void *threadpool_thread(void *threadpool);
/*向线程池的任务队列中添加一个任务*/
int threadpool_add_task(threadpool_t *pool, void *(*function)(void *arg), void *arg, int arg_len);

/* */

/*创建线程池*/
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 false; \n");
break;
}
memset(pool, 0, sizeof(threadpool_task_t)*queue_max_size);

/*信息初始化*/
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;
pool->wait_exit_thr_num = 0;
pool->queue_front = 0;
pool->queue_rear = 0;
pool->queue_size = 0;
pool->queue_max_size = queue_max_size;
pool->shutdown = false;

/*根据最大线程数，给工作线程数组开空间，清0*/
pool->threads = (pthread_t *)malloc(sizeof(pthread_t)*max_thr_num);
if (pool->threads == NULL)
{
printf("malloc threads false;\n");
break;
}
memset(pool->threads, 0, sizeof(pthread_t)*max_thr_num);

/*队列开空间*/
pool->task_queue = (threadpool_task_t *)malloc(sizeof(threadpool_task_t)*queue_max_size);
if (pool->task_queue == NULL)
{
printf("malloc task queue false;\n");
break;
}

memset(pool->task_queue, 0, sizeof(threadpool_task_t)*queue_max_size);

/*初始化互斥锁和条件变量*/
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 lock or cond false;\n");
break;
}

/*启动min_thr_num 个工作线程*/
for (i=0; i<min_thr_num; i++)
{
/*pool 指向当前线程池*/
pthread_create(&(pool->threads[i]), NULL, threadpool_thread, (void *)pool);
printf("start thread 0x%x... \n", (unsigned int)pool->threads[i]);
}
/*管理者线程*/
pthread_create(&(pool->admin_tid), NULL, admin_thread, (void *)pool);

return pool;
} while(0);

/*释放pool的空间*/
threadpool_free(pool);
return NULL;
}

/*释放线程池*/
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)); /*先锁住再销毁*/
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;
}

/*销毁线程池*/
int threadpool_destroy(threadpool_t *pool)
{
int i;
if (pool == NULL)
{
return -1;
}
pool->shutdown = true;

/*销毁管理者线程*/
pthread_join(pool->admin_tid, NULL);

//通知所有线程去自杀(在自己领任务的过程中)
for (i=0; i<pool->live_thr_num; i++)
{
pthread_cond_broadcast(&(pool->queue_not_empty));
}

/*等待线程结束 先是pthread_exit 然后等待其结束*/
for (i=0; i<pool->live_thr_num; i++)
{
pthread_join(pool->threads[i], NULL);
}

threadpool_free(pool);
return 0;
}

/*管理线程*/
void * admin_thread(void *threadpool)
{
int i;
threadpool_t *pool = (threadpool_t *)threadpool;
while (!pool->shutdown)
{
printf("admin -----------------\n");
sleep(DEFAULT_TIME); /*隔一段时间再管理*/
pthread_mutex_lock(&(pool->lock)); /*加锁*/
int queue_size = pool->queue_size; /*任务数*/
int live_thr_num = pool->live_thr_num; /*存活的线程数*/
pthread_mutex_unlock(&(pool->lock)); /*解锁*/

pthread_mutex_lock(&(pool->thread_counter));
int busy_thr_num = pool->busy_thr_num; /*忙线程数*/
pthread_mutex_unlock(&(pool->thread_counter));

printf("admin busy live -%d--%d-\n", busy_thr_num, live_thr_num);
/*创建新线程实际任务数量大于最小正在等待的任务数量，存活线程数小于最大线程数*/
if (queue_size >= MIN_WAIT_TASK_NUM && live_thr_num <= pool->max_thr_num)
{
printf("admin add-----------\n");
pthread_mutex_lock(&(pool->lock));
int add=0;

/*一次增加DEFAULT_THREAD_NUM 个线程*/
for (i=0; i<pool->max_thr_num && add<DEFAULT_THREAD_NUM
&& 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++;
printf("new thread -----------------------\n");
}
}

pthread_mutex_unlock(&(pool->lock));
}

/*销毁多余的线程忙线程x2 都小于存活线程，并且存活的大于最小线程数*/
if ((busy_thr_num*2) < live_thr_num && live_thr_num > pool->min_thr_num)
{
// printf("admin busy --%d--%d----\n", busy_thr_num, live_thr_num);
/*一
次销毁DEFAULT_THREAD_NUM 个线程*/
pthread_mutex_lock(&(pool->lock));
pool->wait_exit_thr_num = DEFAULT_THREAD_NUM;
pthread_mutex_unlock(&(pool->lock));

for (i=0; i<DEFAULT_THREAD_NUM; i++)
{
//通知正在处于空闲的线程，自杀
pthread_cond_signal(&(pool->queue_not_empty));
printf("admin cler --\n");
}
}
}

return NULL;
}

 

 

/*线程是否存活*/
int is_thread_alive(pthread_t tid)
{
int kill_rc = pthread_kill(tid, 0); //发送0号信号，测试是否存活
if (kill_rc == ESRCH) //线程不存在
{
return false;
}
return true;
}

 

/*工作线程*/
void * threadpool_thread(void *threadpool)
{
threadpool_t *pool = (threadpool_t *)threadpool;
threadpool_task_t task;

while (true)
{
pthread_mutex_lock(&(pool->lock));

//无任务则阻塞在 任务队列不为空 上，有任务则跳出
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));

//判断是否需要清除线程,自杀功能
if (pool->wait_exit_thr_num > 0)
{
pool->wait_exit_thr_num--;
//判断线程池中的线程数是否大于最小线程数，是则结束当前线程
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);//结束线程
}
}
}

//线程池开关状态
if (pool->shutdown) //关闭线程池
{
pthread_mutex_unlock(&(pool->lock));
printf("thread 0x%x is exiting \n", (unsigned int)pthread_self());
pthread_exit(NULL); //线程自己结束自己
}

/*这里找一个任务也需要循环找，有可能一个长时间任务会占用一个单元很长时间不释放，
* 所以应该用while循环结合queue_front的方法来寻找，另外需要一个标志这个单元是否
* 正在运行一个任务的标识符
*/
//否则该线程可以拿出任务
while (pool->task_queue[pool->queue_front].task_state != WAITING)
{ //YYY 如果有一个任务一直运行，就跳过这个单元.
pool->queue_front = (pool->queue_front + 1) % pool->queue_max_size;
}

printf("\n\t find waiting thread queue_front=%d \n", pool->queue_front);
task.function = pool->task_queue[pool->queue_front].function; //出队操作
task.arg = pool->task_queue[pool->queue_front].arg;

pool->queue_front = (pool->queue_front + 1) % pool->queue_max_size; //环型结构
pool->queue_size--;

//通知可以添加新任务
pthread_cond_broadcast(&(pool->queue_not_full));

//释放线程锁
pthread_mutex_unlock(&(pool->lock));

//执行刚才取出的任务
printf("thread 0x%x start working \n", (unsigned int)pthread_self());

pthread_mutex_lock(&(pool->thread_counter)); //锁住忙线程变量
pool->busy_thr_num++;
pool->task_queue[pool->queue_front].task_state = RUNNING; // YYY added
pthread_mutex_unlock(&(pool->thread_counter));

(*(task.function))(task.arg); //执行任务

//任务结束处理
printf("thread 0x%x end working \n", (unsigned int)pthread_self());
pthread_mutex_lock(&(pool->thread_counter));
pool->task_queue[pool->queue_front].task_state = EMPTY; // YYY added
pool->task_queue[pool->queue_front].function = NULL; // YYY added
if (pool->task_queue[pool->queue_front].arg != NULL)
{
free(pool->task_queue[pool->queue_front].arg);
pool->task_queue[pool->queue_front].arg = NULL;
}
pool->busy_thr_num--;
pthread_mutex_unlock(&(pool->thread_counter));
}

pthread_exit(NULL);
}

 

/*向线程池的任务队列中添加一个任务*/
int threadpool_add_task(threadpool_t *pool, void *(*function)(void *arg), void *arg, int arglen)
{
static int i = 0;
pthread_mutex_lock(&(pool->lock));
i++;
/*如果队列满了,调用wait阻塞*/
while ((pool->queue_size == pool->queue_max_size) && (!pool->shutdown))
{
printf("\n \t\t before wait queue_not_full:%d \n ", i);
pthread_cond_wait(&(pool->queue_not_full), &(pool->lock));
}

printf("\n \t\t AFTER wait queue_not_full:%d \n ", i);

/*如果线程池处于关闭状态*/
if (pool->shutdown)
{
pthread_mutex_unlock(&(pool->lock));
return -1;
}

/* 如果一个任务是长时间的任务，就可能占住一个任务单元，长时间不放，这就会导致问
* 题，所以应该用现在的queue_rear结合 while循环查找一个空任务单元。*/

while (pool->task_queue[pool->queue_rear].task_state != EMPTY)
{ // YYY added this code block for skip task_state long time task.
pool->queue_rear = (pool->queue_rear + 1) % pool->queue_max_size;
}

printf("\n add task queue rear:%d\n", pool->queue_rear);

/*清空工作线程的回调函数的参数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*/
pool->task_queue[pool->queue_rear].arg = malloc(arglen + 1); // YYY added
pool->task_queue[pool->queue_rear].function = function;
pool->task_queue[pool->queue_rear].task_state = WAITING;
// YYY removed pool->task_queue[pool->queue_rear].arg = arg;
memcpy(pool->task_queue[pool->queue_rear].arg, arg, arglen); // YYY added
pool->queue_rear = (pool->queue_rear + 1) % pool->queue_max_size; /* 逻辑环 */
pool->queue_size++;

/*添加完任务后,队列就不为空了,唤醒线程池中的一个线程*/
pthread_cond_signal(&(pool->queue_not_empty));
pthread_mutex_unlock(&(pool->lock));

return 0;
}

 

void *testprintf(void *args)
{
char *str;
str = (char *) args;
for (int idx= 0 ; idx < 5; idx++)
{
printf("\njob:%s\n",str);
sleep(1);
}
}

threadpool_t *g_thread_pool;

 

 

int main(int argc, char *argv[])
{

int idx2;
char buf[256];
int arg_len;

g_thread_pool = threadpool_create(10, 100, 100);
printf("\n create thread pool successfully! \n");
sleep(1);
for (idx2 = 0; idx2 < 120; idx2++)
{
snprintf(buf, 256, "circle:%d", idx2);
arg_len = strlen(buf);
threadpool_add_task(g_thread_pool, testprintf, (void *)buf, arg_len);
memset(buf, 0, 256);
printf("\n add task:%d \n", idx2);
//sleep(1);
}

sleep(1000);

threadpool_destroy(g_thread_pool);

}