#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>
#include <string.h>
#include <signal.h>
#include <errno.h>
#define DEFAULT_TIME 10
#define DEFAULT_THREAD_VARY 10
#define MIN_WAIT_TASK_NUM 10
typedef struct threadpool_task {
void *(*function)(void *);
void *arg;
} threadpool_task_t;
typedef struct threadpool {
pthread_mutex_t lock; // 锁住本结构体
pthread_mutex_t thread_counter; // 记录忙状态线程个数的锁
pthread_cond_t queue_not_full; // 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; // 任务队列不为空，通知等待任务的线程
pthread_t *threads; // 存放线程池中的线程号tid
pthread_t adjust_tid; // 存管理线程tid
threadpool_task_t *task_queue; // 任务队列数组
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队列可容纳任务数量上限
int shutdown; // 线程池使用状态
} threadpool_t;
int is_thread_alive(pthread_t tid)
{
int kill_rc = pthread_kill(tid, 0);
if(kill_rc == ESRCH)
return 0;
else
return -1;
}
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_destory(threadpool_t *pool)
{
int i;
if(pool == NULL)
return -1;
pool->shutdown = 1;
pthread_join(pool->adjust_tid, NULL);
for(i = 0; i < pool->live_thr_num; i++)
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;
}
void *threadpool_thread(void *threadpool)
{
threadpool_t *pool = (threadpool_t *)threadpool;
threadpool_task_t task;
while(1)
{
pthread_mutex_lock(&(pool->lock));
while((pool->queue_size == 0) && (!pool->shutdown)){
printf("thread 0x%lx is waiting\n", pthread_self());
pthread_cond_wait(&(pool->queue_not_empty), &(pool->lock));
if(pool->wait_exit_thr_num > 0){
pool->wait_exit_thr_num--;
if(pool->live_thr_num > pool->min_thr_num){
printf("thread 0x%lx is exsiting\n", pthread_self());
pool->live_thr_num--;
pthread_mutex_unlock(&(pool->lock));
pthread_exit(NULL);
}
}
}
if(pool->shutdown){
pthread_mutex_unlock(&(pool->lock));
printf("thread 0x%lx is existing\n", pthread_self());
pthread_detach(pthread_self());
pthread_exit(NULL);
}
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;
pool->queue_size--;
pthread_cond_broadcast(&(pool->queue_not_full));
pthread_mutex_unlock(&(pool->lock));
printf("thread 0x%lx start working\n", pthread_self());
(*(task.function))(task.arg);
printf("thread 0x%lx end working\n", pthread_self());
pthread_mutex_lock(&(pool->thread_counter));
pool->busy_thr_num--;
pthread_mutex_unlock(&(pool->thread_counter));
}
pthread_exit(NULL);
}
void *adjust_thread(void *threadpool)
{
threadpool_t *pool = (threadpool_t *)threadpool;
int i;
while(!pool->shutdown) {
sleep(DEFAULT_TIME);
pthread_mutex_lock(&(pool->lock));
int queue_size = pool->queue_size;
int live_thr_num = pool->live_thr_num;
pthread_mutex_unlock(&(pool->lock));
pthread_mutex_lock(&(pool->thread_counter));
int busy_thr_num = pool->busy_thr_num;
pthread_mutex_unlock(&(pool->thread_counter));
if(queue_size >= MIN_WAIT_TASK_NUM && live_thr_num < pool->max_thr_num)
{
pthread_mutex_lock(&(pool->lock));
int add = 0;
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));
}
if((busy_thr_num *2) < live_thr_num && live_thr_num > pool->min_thr_num){
pthread_mutex_lock(&(pool->lock));
pool->wait_exit_thr_num = DEFAULT_THREAD_VARY;
pthread_mutex_unlock(&(pool->lock));
for(i = 0; i < DEFAULT_THREAD_VARY; i++){
pthread_cond_signal(&(pool->queue_not_empty));
}
}
}
return NULL;
}
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;
}
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->queue_size = 0;
pool->queue_max_size = queue_max_size;
pool->queue_front = 0;
pool->queue_rear = 0;
pool->shutdown = 0;
pool->threads = (pthread_t *)malloc(sizeof(pthread_t)*max_thr_num);
if(pool->threads == NULL)
{
printf("malloc threads fail\n");
break;
}
memset(pool->threads, 0, sizeof(pthread_t)*max_thr_num);
pool->task_queue = (threadpool_task_t*)malloc(sizeof(threadpool_task_t)*queue_max_size);
if(pool->task_queue == NULL)
{
printf("mallc task_queue fail\n");
break;
}
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 mutex or cond fail\n");
break;
}
for(i = 0; i < min_thr_num; i++)
{
pthread_create(&(pool->threads[i]), NULL, threadpool_thread, (void*)pool);
printf("start thread 0x%lx...\n", pool->threads[i]);
}
pthread_create(&(pool->adjust_tid), NULL, adjust_thread, (void*)pool);
return pool;
}while(0);
threadpool_free(pool);
return NULL;
}
void threadpool_add(threadpool_t *pool, void *(*func)(void*arg), void *arg)
{
pthread_mutex_lock(&(pool->lock));
// fang zhi qiang suo
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));
}
if(pool->task_queue[pool->queue_rear].arg != NULL)
pool->task_queue[pool->queue_rear].arg = NULL;
pool->task_queue[pool->queue_rear].function = func;
pool->task_queue[pool->queue_rear].arg = arg;
pool->queue_rear = (pool->queue_rear + 1) % pool->queue_max_size;
pool->queue_size++;
pthread_cond_signal(&(pool->queue_not_empty));
pthread_mutex_unlock(&(pool->lock));
}
void *process(void *arg)
{
printf("thread 0x%lx working on task %p\n", pthread_self(), arg);
sleep(1);
printf("task %p is end\n", arg);
return NULL;
}
int main(int argc, char** argv)
{
threadpool_t *thp = threadpool_create(3, 100, 100);
int num[20];
for(int i = 0; i < 20; i++)
{
num[i] = i;
threadpool_add(thp, process, (void*)&num[i]);
}
sleep(10);
threadpool_destory(thp);
return 0;
}
