thread_pool.h
#ifndef THREAD_POOL_H_ #define THREAD_POOL_H_ #include <map> #include <vector> #include "command.h" #define MAX_THREAD_NUM 50 // 该值目前需要设定为初始线程数的整数倍 #define ADD_FACTOR 40 // 该值表示一个线程可以处理的最大任务数 #define THREAD_NUM 10 // 初始线程数 class ThreadPool { public: ThreadPool() {}; static void InitializeThreads(); void AddWork(Command command); void ThreadDestroy(int iwait = 2); private: static void* Process(void* arg); static void AddThread(); static void DeleteThread(); static bool bshutdown_; static int icurr_thread_num_; static std::map<pthread_t,int> thread_id_map_; static std::vector<Command> command_; static pthread_mutex_t command_mutex_; static pthread_cond_t command_cond_; }; #endif /* THREAD_POOL_H_ */thread_pool.cpp
#include <pthread.h> #include <stdlib.h> #include "thread_pool.h" #include "thread_process.h" #include "command.h" bool ThreadPool::bshutdown_ = false; int ThreadPool::icurr_thread_num_ = THREAD_NUM; std::vector<Command> ThreadPool::command_; std::map<pthread_t,int> ThreadPool::thread_id_map_; pthread_mutex_t ThreadPool::command_mutex_ = PTHREAD_MUTEX_INITIALIZER; pthread_cond_t ThreadPool::command_cond_ = PTHREAD_COND_INITIALIZER; void ThreadPool::InitializeThreads() { for (int i = 0; i < THREAD_NUM ; ++i) { pthread_t tempThread; pthread_create(&tempThread, NULL, ThreadPool::Process, NULL); thread_id_map_[tempThread] = 0; } } void* ThreadPool::Process(void* arg) { ThreadProcess threadprocess; Command command; while (true) { pthread_mutex_lock(&command_mutex_); // 如果线程需要退出，则此时退出 if (1 == thread_id_map_[pthread_self()]) { pthread_mutex_unlock(&command_mutex_); printf("thread %u will exit\n", pthread_self()); pthread_exit(NULL); } // 当线程不需要退出且没有需要处理的任务时，需要缩容的则缩容，不需要的则等待信号 if (0 == command_.size() && !bshutdown_) { if(MAX_THREAD_NUM != THREAD_NUM) { DeleteThread(); if (1 == thread_id_map_[pthread_self()]) { pthread_mutex_unlock(&command_mutex_); printf("thread %u will exit\n", pthread_self()); pthread_exit(NULL); } } pthread_cond_wait(&command_cond_,&command_mutex_); } // 线程池需要关闭，关闭已有的锁，线程退出 if(bshutdown_) { pthread_mutex_unlock (&command_mutex_); printf ("thread %u will exit\n", pthread_self ()); pthread_exit (NULL); } // 如果线程池的最大线程数不等于初始线程数，则表明需要扩容 if(MAX_THREAD_NUM != THREAD_NUM) { AddThread(); } // 从容器中取出待办任务 std::vector<Command>::iterator iter = command_.begin(); command.set_arg(iter->get_arg()); command.set_cmd(iter->get_cmd()); command_.erase(iter); pthread_mutex_unlock(&command_mutex_); // 开始业务处理 switch(command.get_cmd()) { case 0: threadprocess.Process0(command.get_arg()); break; case 1: threadprocess.Process1(command.get_arg()); break; case 2: threadprocess.Process2(command.get_arg()); break; default: break; } } return NULL; // 完全为了消除警告(eclipse编写的代码，警告很烦人) } void ThreadPool::AddWork(Command command) { bool bsignal = false; pthread_mutex_lock(&command_mutex_); if (0 == command_.size()) { bsignal = true; } command_.push_back(command); pthread_mutex_unlock(&command_mutex_); if (bsignal) { pthread_cond_signal(&command_cond_); } } void ThreadPool::ThreadDestroy(int iwait) { while(0 != command_.size()) { sleep(abs(iwait)); } bshutdown_ = true; pthread_cond_broadcast(&command_cond_); std::map<pthread_t,int>::iterator iter = thread_id_map_.begin(); for (; iter!=thread_id_map_.end(); ++iter) { pthread_join(iter->first,NULL); } pthread_mutex_destroy(&command_mutex_); pthread_cond_destroy(&command_cond_); } void ThreadPool::AddThread() { if(((icurr_thread_num_*ADD_FACTOR) < command_.size()) && (MAX_THREAD_NUM != icurr_thread_num_)) { InitializeThreads(); icurr_thread_num_ += THREAD_NUM; } } void ThreadPool::DeleteThread() { int size = icurr_thread_num_ - THREAD_NUM; std::map<pthread_t,int>::iterator iter = thread_id_map_.begin(); for(int i=0; i<size; ++i,++iter) { iter->second = 1; } }