c++线程池小例子
ThreadPool.h
#ifndef __THREADPOOL_H #define __THREADPOOL_H #define HAVE_STRUCT_TIMESPEC //#include "servant/Application.h" #include <vector> #include <string> #include <pthread.h> using namespace std; /** * 执行任务的类,设置任务数据、定义执行方法(纯虚函数) */ class CTask { protected: string m_strTaskName; //任务的名称 void* m_ptrData; //具体数据 public: CTask() {} CTask(string taskName) { m_strTaskName = taskName; m_ptrData = NULL; } virtual int Run() = 0; //任务执行方法 void SetData(void* data); //设置任务数据 public: virtual ~CTask() {} }; /** * 线程结构体 */ struct CThread { pthread_t pthread_id; //线程id int iStat; //线程状态 CThread() : iStat(0) { } bool operator == (const CThread &obj) const { return (long)&pthread_id == (long)&obj.pthread_id; } }; /** * 线程池管理类的实现 */ class CThreadPool { public: CThreadPool(int threadNum = 10); int AddTask(CTask *task); //把任务添加到任务队列中 int getTaskSize(); //获取当前任务队列中的任务数 int StopAll(); //使线程池中的线程退出 protected: int Create(); //创建线程池中的线程 static void* ThreadFunc(void * threadData); //新线程的线程回调函数 static int MoveToIdle(CThread *pThread); //线程执行结束后,状态置为空闲0 static int MoveToBusy(CThread *pThread); //线程开始执行,状态置为运行1 private: static vector<CTask*> m_vecTaskList; //任务列表 static bool shutdown; //线程退出标志 int m_iThreadNum; //线程池中启动的线程数 static vector<CThread> m_vecThread; //线程列表 static pthread_mutex_t m_pthreadMutex; //线程同步锁 static pthread_cond_t m_pthreadCond; //线程同步的条件变量 }; #endif
ThreadPool.cpp
#include "ThreadPool.h" #include <iostream> #include <algorithm> using namespace std; void CTask::SetData(void * data) { m_ptrData = data; } vector<CTask*> CThreadPool::m_vecTaskList; //任务列表 bool CThreadPool::shutdown = false; vector<CThread> CThreadPool::m_vecThread; //线程列表 pthread_mutex_t CThreadPool::m_pthreadMutex = PTHREAD_MUTEX_INITIALIZER; pthread_cond_t CThreadPool::m_pthreadCond = PTHREAD_COND_INITIALIZER; /** * 线程池管理类构造函数 */ CThreadPool::CThreadPool(int threadNum) { this->m_iThreadNum = threadNum; cout << "threadNum:" << threadNum << " threads will be created." << endl; Create(); //创建线程 } /** * 创建线程 */ int CThreadPool::Create() { m_vecThread.resize(m_iThreadNum); for (size_t i = 0; i < m_vecThread.size(); i++) { pthread_create(&m_vecThread[i].pthread_id, NULL, ThreadFunc, &m_vecThread[i]); } return 0; } /** * 线程回调函数 */ void* CThreadPool::ThreadFunc(void* threadData) { CThread *pThread = (CThread*)threadData; while (1) { pthread_mutex_lock(&m_pthreadMutex); //lock while (m_vecTaskList.size() == 0 && !shutdown) { pthread_cond_wait(&m_pthreadCond, &m_pthreadMutex); /* pthread_cond_wait前要先加锁 pthread_cond_wait把线程放进阻塞队列后,内部会解锁,然后等待条件变量被其它线程唤醒 pthread_cond_wait被唤醒后会再自动加锁 */ } if (shutdown) { pthread_mutex_unlock(&m_pthreadMutex); cout << "thread:" << (long)&pThread->pthread_id << " will exit." << endl; pthread_exit(NULL); } //线程状态置1 MoveToBusy(pThread); //取出一个任务 CTask* task = NULL; vector<CTask*>::iterator iter = m_vecTaskList.begin(); if (iter != m_vecTaskList.end()) { task = *iter; m_vecTaskList.erase(iter); } pthread_mutex_unlock(&m_pthreadMutex); //unlock //执行任务 if (task) { task->Run(); } //线程状态置0 MoveToIdle(pThread); } return (void*)0; } int CThreadPool::MoveToIdle(CThread *pThread) { vector<CThread>::iterator iter_thread = std::find(m_vecThread.begin(), m_vecThread.end(), *pThread); if (iter_thread != m_vecThread.end()) { iter_thread->iStat = 0; cout << "tid:" << (long)&pThread->pthread_id << " idle." << endl; } return 0; } int CThreadPool::MoveToBusy(CThread *pThread) { vector<CThread>::iterator iter_thread = std::find(m_vecThread.begin(), m_vecThread.end(), *pThread); if (iter_thread != m_vecThread.end()) { iter_thread->iStat = 1; cout << "tid:" << (long)&pThread->pthread_id << " run." << endl; } return 0; } /** * 往任务队列里边添加任务并发出线程同步信号 */ int CThreadPool::AddTask(CTask *task) { pthread_mutex_lock(&m_pthreadMutex); this->m_vecTaskList.push_back(task); pthread_cond_signal(&m_pthreadCond); pthread_mutex_unlock(&m_pthreadMutex); return 0; } /** * 获取当前队列中任务数 */ int CThreadPool::getTaskSize() { return m_vecTaskList.size(); } /** * 停止所有线程 */ int CThreadPool::StopAll() { /** 避免重复调用 */ if (shutdown) { return -1; } cout << "All threads will be stoped." << endl; /** 唤醒所有等待线程,线程池要销毁了 */ shutdown = true; pthread_cond_broadcast(&m_pthreadCond); /** 阻塞等待线程退出,否则就成僵尸了 */ for (size_t i = 0; i < m_vecThread.size(); i++) { pthread_join(m_vecThread[i].pthread_id, NULL); } m_vecThread.clear(); /** 销毁条件变量和互斥体 */ pthread_mutex_destroy(&m_pthreadMutex); pthread_cond_destroy(&m_pthreadCond); return 0; }
main.cpp
#include <iostream> #include "ThreadPool.h" using namespace std; class CMyTask : public CTask { public: CMyTask() {} inline int Run() { cout << (char*)this->m_ptrData << endl; return 0; } }; int main() { CThreadPool threadPool(10); CMyTask taskObj; char szTmp[] = "this is the first thread running"; taskObj.SetData((void*)szTmp); for (int i = 0; i < 10; i++) { threadPool.AddTask(&taskObj); } while (1) { cout << "there are still " << threadPool.getTaskSize() << " tasks need to handle" << endl; if (threadPool.getTaskSize() == 0) { if (threadPool.StopAll() == -1) { cout << "Now I will exit from main" << endl; return 0; } } } return 0; }
makeflie
TARGET:=threadpool INC:= -I./ LIB_PATH:= LIB:= -lpthread CFLAGS:=-Wall -g -O0 -D_REENTRANT -Wl,-rpath=./ $(INC) $(LIB_PATH) CPPFLAGS:=$(CFLAGS) SRC:=$(shell echo *.cpp) OBJ:=$(patsubst %.cpp,%.o,$(SRC)) all: $(TARGET) $(TARGET): $(OBJ) $(CXX) $^ $(CFLAGS) $(LIB) -o $@ clean: rm -f $(OBJ) rm -f $(TARGET)
windows下配置 pthread 参见:https://blog.csdn.net/qianchenglenger/article/details/16907821
线程同步、条件变量说明参见:https://www.cnblogs.com/zhangxuan/p/6526854.html