线程池

来源：互联网发布：steam购买软件退货编辑：程序博客网时间：2024/05/16 18:05
实现了一个最简单的线程池，没有考虑惊群现象
#include "pthread.h"#include "semaphore.h"#include <list>#include <vector>#include <iostream>using std::list;using std::vector;struct thread_job{    void(*func)(void *);    void *arg;};class thread_pool{public:    thread_pool(int size_ = 10);    ~thread_pool();    void add_job(void (*func)(void*), void *arg);    static void * route_task(void *);//private:    void destroy();private:    int   max_threads;        // 线程池中最大线程数限制      int   curr_threads;       // 当前线程池中总的线程数      int   idle_threads;       // 当前线程池中空闲的线程数     pthread_mutex_t mutex;    pthread_cond_t cond;    sem_t sem;    list<thread_job*> job_list;    vector<pthread_t> thread_handle;    bool stop_flag;};thread_pool::thread_pool(int size_){    stop_flag = false;    max_threads = size_;    thread_handle.resize(max_threads);    curr_threads = 0;    idle_threads = size_;    if (pthread_cond_init(&(cond), NULL)) {        perror("pthread_mutex_init: ");    }    if (pthread_mutex_init(&(mutex), NULL)) {        perror("pthread_mutex_init: ");    }    for (int i = 0; i < max_threads; i++){        if (pthread_create(&(thread_handle[i]), NULL, route_task, this)) {            perror("pthread_create:");        }        //pthread_detach((thread_handle[i]));    }}void * thread_pool::route_task(void *arg){    thread_pool * pool = static_cast<thread_pool *>(arg);    pthread_mutex_lock(&(pool->mutex));    while (1)    {        if (pool->job_list.empty())        {            pool->idle_threads++;            if (pool->stop_flag){                pthread_mutex_unlock(&(pool->mutex));                break;            }            {                pthread_cond_wait(&pool->cond, &(pool->mutex));            }            if (pool->stop_flag){                pthread_mutex_unlock(&(pool->mutex));                break;            }        }        else        {            pool->idle_threads--;            thread_job* job = pool->job_list.front();            pool->job_list.pop_front();            pthread_mutex_unlock(&pool->mutex);            job->func(job->arg);            pool->idle_threads++;            delete job;            pthread_mutex_lock(&(pool->mutex));        }    }    return NULL;}void thread_pool::add_job(void (*func)(void*), void *arg){    thread_job* njob= new thread_job;    njob->arg = arg;    njob->func = func;    pthread_mutex_lock(&mutex);    if (job_list.empty())    {        job_list.push_back(njob);        pthread_cond_signal(&cond);    }    else    {        job_list.push_back(njob);    }    pthread_mutex_unlock(&mutex);}void thread_pool::destroy(){    stop_flag = true;    pthread_cond_broadcast(&cond);    for each (pthread_t var in thread_handle)    {        pthread_join(var, NULL);    }}thread_pool::~thread_pool(){    destroy();}int ans = 0;void add1(void *arg){    ans++;    std::cout << ans << std::endl;}int main(){    thread_pool pool(40);    for (int i = 0; i < 1000; i++)    {        pool.add_job(add1, NULL);    }    return 0;}
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