(二)Reactor模式

时间:2022-05-07
本文章向大家介绍(二)Reactor模式,主要内容包括其使用实例、应用技巧、基本知识点总结和需要注意事项,具有一定的参考价值,需要的朋友可以参考一下。

最近一直在看游双的《高性能linux服务器编程》一书,下载链接: http://download.csdn.net/detail/analogous_love/9673008

书上是这么介绍Reactor模式的:

按照这个思路,我写个简单的练习:

/**   *@desc:   用reactor模式练习服务器程序,main.cpp  *@author: zhangyl  *@date:   2016.11.23  */  
  #include <iostream>  #include <string.h>  #include <sys/types.h>  #include <sys/socket.h>  #include <netinet/in.h>  #include <arpa/inet.h>  //for htonl() and htons()  #include <unistd.h>  #include <fcntl.h>  #include <sys/epoll.h>  #include <signal.h>     //for signal()  #include <pthread.h>  #include <semaphore.h>  #include <list>  #include <errno.h>  #include <time.h>  #include <sstream>  #include <iomanip> //for std::setw()/setfill()  #include <stdlib.h>  
  
  #define WORKER_THREAD_NUM   5  
  #define min(a, b) ((a <= b) ? (a) : (b))   
  int g_epollfd = 0;  bool g_bStop = false;  int g_listenfd = 0;  pthread_t g_acceptthreadid = 0;  pthread_t g_threadid[WORKER_THREAD_NUM] = { 0 };  pthread_cond_t g_acceptcond;  pthread_mutex_t g_acceptmutex;  
  pthread_cond_t g_cond /*= PTHREAD_COND_INITIALIZER*/;  pthread_mutex_t g_mutex /*= PTHREAD_MUTEX_INITIALIZER*/;  
  pthread_mutex_t g_clientmutex;  
  std::list<int> g_listClients;  
  void prog_exit(int signo)  {  
    ::signal(SIGINT, SIG_IGN);  
    ::signal(SIGKILL, SIG_IGN);  
    ::signal(SIGTERM, SIG_IGN);  
  
    std::cout << "program recv signal " << signo << " to exit." << std::endl;  
  
    g_bStop = true;  
  
    ::epoll_ctl(g_epollfd, EPOLL_CTL_DEL, g_listenfd, NULL);  
  
    //TODO: 是否需要先调用shutdown()一下?  
    ::shutdown(g_listenfd, SHUT_RDWR);  
    ::close(g_listenfd);  
    ::close(g_epollfd);  
  
    ::pthread_cond_destroy(&g_acceptcond);  
    ::pthread_mutex_destroy(&g_acceptmutex);  
      
    ::pthread_cond_destroy(&g_cond);  
    ::pthread_mutex_destroy(&g_mutex);  
  
    ::pthread_mutex_destroy(&g_clientmutex);  }  
  bool create_server_listener(const char* ip, short port)  {  
    g_listenfd = ::socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, 0);  
    if (g_listenfd == -1)  
        return false;  
  
    int on = 1;  
    ::setsockopt(g_listenfd, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on));  
    ::setsockopt(g_listenfd, SOL_SOCKET, SO_REUSEPORT, (char *)&on, sizeof(on));  
  
    struct sockaddr_in servaddr;  
    memset(&servaddr, 0, sizeof(servaddr));   
    servaddr.sin_family = AF_INET;  
    servaddr.sin_addr.s_addr = inet_addr(ip);  
    servaddr.sin_port = htons(port);  
    if (::bind(g_listenfd, (sockaddr *)&servaddr, sizeof(servaddr)) == -1)  
        return false;  
  
    if (::listen(g_listenfd, 50) == -1)  
        return false;  
  
    g_epollfd = ::epoll_create(1);  
    if (g_epollfd == -1)  
        return false;  
  
    struct epoll_event e;  
    memset(&e, 0, sizeof(e));  
    e.events = EPOLLIN | EPOLLRDHUP;  
    e.data.fd = g_listenfd;  
    if (::epoll_ctl(g_epollfd, EPOLL_CTL_ADD, g_listenfd, &e) == -1)  
        return false;  
  
    return true;  }  
  void release_client(int clientfd)  {  
    if (::epoll_ctl(g_epollfd, EPOLL_CTL_DEL, clientfd, NULL) == -1)  
        std::cout << "release client socket failed as call epoll_ctl failed" << std::endl;  
  
    ::close(clientfd);  }  
  void* accept_thread_func(void* arg)  {     
    while (!g_bStop)  
    {  
        ::pthread_mutex_lock(&g_acceptmutex);  
        ::pthread_cond_wait(&g_acceptcond, &g_acceptmutex);  
        //::pthread_mutex_lock(&g_acceptmutex);  
  
        //std::cout << "run loop in accept_thread_func" << std::endl;  
  
        struct sockaddr_in clientaddr;  
        socklen_t addrlen;  
        int newfd = ::accept(g_listenfd, (struct sockaddr *)&clientaddr, &addrlen);  
        ::pthread_mutex_unlock(&g_acceptmutex);  
        if (newfd == -1)  
            continue;  
  
        std::cout << "new client connected: " << ::inet_ntoa(clientaddr.sin_addr) << ":" << ::ntohs(clientaddr.sin_port) << std::endl;  
  
        //将新socket设置为non-blocking  
        int oldflag = ::fcntl(newfd, F_GETFL, 0);  
        int newflag = oldflag | O_NONBLOCK;  
        if (::fcntl(newfd, F_SETFL, newflag) == -1)  
        {  
            std::cout << "fcntl error, oldflag =" << oldflag << ", newflag = " << newflag << std::endl;  
            continue;  
        }  
  
        struct epoll_event e;  
        memset(&e, 0, sizeof(e));  
        e.events = EPOLLIN | EPOLLRDHUP | EPOLLET;  
        e.data.fd = newfd;  
        if (::epoll_ctl(g_epollfd, EPOLL_CTL_ADD, newfd, &e) == -1)  
        {  
            std::cout << "epoll_ctl error, fd =" << newfd << std::endl;  
        }  
    }  
  
    return NULL;  }  
  
  void* worker_thread_func(void* arg)  {     
    while (!g_bStop)  
    {  
        int clientfd;  
        ::pthread_mutex_lock(&g_clientmutex);  
        while (g_listClients.empty())  
            ::pthread_cond_wait(&g_cond, &g_clientmutex);  
        clientfd = g_listClients.front();  
        g_listClients.pop_front();    
        pthread_mutex_unlock(&g_clientmutex);  
  
        //gdb调试时不能实时刷新标准输出,用这个函数刷新标准输出,使信息在屏幕上实时显示出来  
        std::cout << std::endl;  
  
        std::string strclientmsg;  
        char buff[256];  
        bool bError = false;  
        while (true)  
        {  
            memset(buff, 0, sizeof(buff));  
            int nRecv = ::recv(clientfd, buff, 256, 0);  
            if (nRecv == -1)  
            {  
                if (errno == EWOULDBLOCK)  
                    break;  
                else  
                {  
                    std::cout << "recv error, client disconnected, fd = " << clientfd << std::endl;  
                    release_client(clientfd);  
                    bError = true;  
                    break;  
                }  
                      
            }  
            //对端关闭了socket,这端也关闭。  
            else if (nRecv == 0)  
            {  
                std::cout << "peer closed, client disconnected, fd = " << clientfd << std::endl;  
                release_client(clientfd);  
                bError = true;  
                break;  
            }  
  
            strclientmsg += buff;  
        }  
  
        //出错了,就不要再继续往下执行了  
        if (bError)  
            continue;  
          
        std::cout << "client msg: " << strclientmsg;  
  
        //将消息加上时间标签后发回  
        time_t now = time(NULL);  
        struct tm* nowstr = localtime(&now);  
        std::ostringstream ostimestr;  
        ostimestr << "[" << nowstr->tm_year + 1900 << "-"   
                  << std::setw(2) << std::setfill('0') << nowstr->tm_mon + 1 << "-"   
                  << std::setw(2) << std::setfill('0') << nowstr->tm_mday << " "  
                  << std::setw(2) << std::setfill('0') << nowstr->tm_hour << ":"   
                  << std::setw(2) << std::setfill('0') << nowstr->tm_min << ":"   
                  << std::setw(2) << std::setfill('0') << nowstr->tm_sec << "]server reply: ";  
  
        strclientmsg.insert(0, ostimestr.str());  
          
        while (true)  
        {  
            int nSent = ::send(clientfd, strclientmsg.c_str(), strclientmsg.length(), 0);  
            if (nSent == -1)  
            {  
                if (errno == EWOULDBLOCK)  
                {  
                    ::sleep(10);  
                    continue;  
                }  
                else  
                {  
                    std::cout << "send error, fd = " << clientfd << std::endl;  
                    release_client(clientfd);  
                    break;  
                }  
                     
            }            
  
            std::cout << "send: " << strclientmsg;  
            strclientmsg.erase(0, nSent);  
  
            if (strclientmsg.empty())  
                break;  
        }  
    }  
  
    return NULL;  }  
  void daemon_run()  {  
    int pid;  
    signal(SIGCHLD, SIG_IGN);  
    //1)在父进程中,fork返回新创建子进程的进程ID;  
    //2)在子进程中,fork返回0;  
    //3)如果出现错误,fork返回一个负值;  
    pid = fork();  
    if (pid < 0)  
    {  
        std:: cout << "fork error" << std::endl;  
        exit(-1);  
    }  
    //父进程退出,子进程独立运行  
    else if (pid > 0) {  
        exit(0);  
    }  
    //之前parent和child运行在同一个session里,parent是会话(session)的领头进程,  
    //parent进程作为会话的领头进程,如果exit结束执行的话,那么子进程会成为孤儿进程,并被init收养。  
    //执行setsid()之后,child将重新获得一个新的会话(session)id。  
    //这时parent退出之后,将不会影响到child了。  
    setsid();  
    int fd;  
    fd = open("/dev/null", O_RDWR, 0);  
    if (fd != -1)  
    {  
        dup2(fd, STDIN_FILENO);  
        dup2(fd, STDOUT_FILENO);  
        dup2(fd, STDERR_FILENO);  
    }  
    if (fd > 2)  
        close(fd);  
   }  
  
  int main(int argc, char* argv[])  {    
    short port = 0;  
    int ch;  
    bool bdaemon = false;  
    while ((ch = getopt(argc, argv, "p:d")) != -1)  
    {  
        switch (ch)  
        {  
        case 'd':  
            bdaemon = true;  
            break;  
        case 'p':  
            port = atol(optarg);  
            break;  
        }  
    }  
  
    if (bdaemon)  
        daemon_run();  
  
  
    if (port == 0)  
        port = 12345;  
       
    if (!create_server_listener("0.0.0.0", port))  
    {  
        std::cout << "Unable to create listen server: ip=0.0.0.0, port=" << port << "." << std::endl;  
        return -1;  
    }  
  
      
    //设置信号处理  
    signal(SIGCHLD, SIG_DFL);  
    signal(SIGPIPE, SIG_IGN);  
    signal(SIGINT, prog_exit);  
    signal(SIGKILL, prog_exit);  
    signal(SIGTERM, prog_exit);  
  
    ::pthread_cond_init(&g_acceptcond, NULL);  
    ::pthread_mutex_init(&g_acceptmutex, NULL);  
  
    ::pthread_cond_init(&g_cond, NULL);  
    ::pthread_mutex_init(&g_mutex, NULL);  
  
    ::pthread_mutex_init(&g_clientmutex, NULL);  
       
    ::pthread_create(&g_acceptthreadid, NULL, accept_thread_func, NULL);  
    //启动工作线程  
    for (int i = 0; i < WORKER_THREAD_NUM; ++i)  
    {  
        ::pthread_create(&g_threadid[i], NULL, worker_thread_func, NULL);  
    }  
  
    while (!g_bStop)  
    {         
        struct epoll_event ev[1024];  
        int n = ::epoll_wait(g_epollfd, ev, 1024, 10);  
        if (n == 0)  
            continue;  
        else if (n < 0)  
        {  
            std::cout << "epoll_wait error" << std::endl;  
            continue;  
        }  
  
        int m = min(n, 1024);  
        for (int i = 0; i < m; ++i)  
        {  
            //通知接收连接线程接收新连接  
            if (ev[i].data.fd == g_listenfd)  
                pthread_cond_signal(&g_acceptcond);  
            //通知普通工作线程接收数据  
            else  
            {                 
                pthread_mutex_lock(&g_clientmutex);                
                g_listClients.push_back(ev[i].data.fd);  
                pthread_mutex_unlock(&g_clientmutex);  
                pthread_cond_signal(&g_cond);  
                //std::cout << "signal" << std::endl;  
            }  
                  
        }  
  
    }  
      
    return 0;  } 

程序的功能一个简单的echo服务:客户端连接上服务器之后,给服务器发送信息,服务器加上时间戳等信息后返回给客户端。使用到的知识点有:

1. 条件变量

2.epoll的边缘触发模式

程序的大致框架是:

1. 主线程只负责监听侦听socket上是否有新连接,如果有新连接到来,交给一个叫accept的工作线程去接收新连接,并将新连接socket绑定到主线程使用epollfd上去。

2. 主线程如果侦听到客户端的socket上有可读事件,则通知另外五个工作线程去接收处理客户端发来的数据,并将数据加上时间戳后发回给客户端。

3. 可以通过传递-p port来设置程序的监听端口号;可以通过传递-d来使程序以daemon模式运行在后台。这也是标准linux daemon模式的书写方法。

程序难点和需要注意的地方是:

1. 条件变量为了防止虚假唤醒,一定要在一个循环里面调用pthread_cond_wait()函数,我在worker_thread_func()中使用了:

while (g_listClients.empty())  
            ::pthread_cond_wait(&g_cond, &g_clientmutex); 

在accept_thread_func()函数里面我没有使用循环,这样会有问题吗?

2. 使用条件变量pthread_cond_wait()函数的时候一定要先获得与该条件变量相关的mutex,即像下面这样的结构:

mutex_lock(...);  
  while (condition is true)  
    ::pthread_cond_wait(...);  
  //这里可以有其他代码...  mutex_unlock(...);  
  //这里可以有其他代码... 

因为pthread_cond_wait()如果阻塞的话,它解锁相关mutex和阻塞当前线程这两个动作加在一起是原子的。

3. 作为服务器端程序最好对侦听socket调用setsocketopt()设置SO_REUSEADDR和SO_REUSEPORT两个标志,因为服务程序有时候会需要重启(比如调试的时候就会不断重启),如果不设置这两个标志的话,绑定端口时就会调用失败。因为一个端口使用后,即使不再使用,因为四次挥手该端口处于TIME_WAIT状态,有大约2min的MSL(Maximum Segment Lifetime,最大存活期)。这2min内,该端口是不能被重复使用的。你的服务器程序上次使用了这个端口号,接着重启,因为这个缘故,你再次绑定这个端口就会失败(bind函数调用失败)。要不你就每次重启时需要等待2min后再试(这在频繁重启程序调试是难以接收的),或者设置这种SO_REUSEADDR和SO_REUSEPORT立即回收端口使用。

其实,SO_REUSEADDR在windows上和Unix平台上还有些细微的区别,我在libevent源码中看到这样的描述:

int evutil_make_listen_socket_reuseable(evutil_socket_t sock)  
{  
#ifndef WIN32  
    int one = 1;  
    /* REUSEADDR on Unix means, "don't hang on to this address after the 
     * listener is closed."  On Windows, though, it means "don't keep other 
     * processes from binding to this address while we're using it. */  
    return setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void*) &one,  
        (ev_socklen_t)sizeof(one));  
#else  
    return 0;  
#endif  
}  

注意注释部分,在Unix平台上设置这个选项意味着,任意进程可以复用该地址;而在windows,不要阻止其他进程复用该地址。也就是在在Unix平台上,如果不设置这个选项,任意进程在一定时间内,不能bind该地址;在windows平台上,在一定时间内,其他进程不能bind该地址,而本进程却可以再次bind该地址。

4. epoll_wait对新连接socket使用的是边缘触发模式EPOLLET(edge trigger),而不是默认的水平触发模式(level trigger)。因为如果采取水平触发模式的话,主线程检测到某个客户端socket数据可读时,通知工作线程去收取该socket上的数据,这个时候主线程继续循环,只要在工作线程没有将该socket上数据全部收完,或者在工作线程收取数据的过程中,客户端有新数据到来,主线程会继续发通知(通过pthread_cond_signal())函数,再次通知工作线程收取数据。这样会可能导致多个工作线程同时调用recv函数收取该客户端socket上的数据,这样产生的结果将会导致数据错乱。

相反,采取边缘触发模式,只有等某个工作线程将那个客户端socket上数据全部收取完毕,主线程的epoll_wait才可能会再次触发来通知工作线程继续收取那个客户端socket新来的数据。

5. 代码中有这样一行:

//gdb调试时不能实时刷新标准输出,用这个函数刷新标准输出,使信息在屏幕上实时显示出来  std::cout << std::endl;

如果不加上这一行,正常运行服务器程序,程序中要打印到控制台的信息都会打印出来,但是如果用gdb调试状态下,程序的所有输出就不显示了。我不知道这是不是gdb的一个bug,所以这里加上std::endl来输出一个换行符并flush标准输出,让输出显示出来。(std::endl不仅是输出一个换行符而且是同时刷新输出,相当于fflush()函数)。

程序我部署起来了,你可以使用linux的nc命令或自己写程序连接服务器来查看程序效果,当然也可以使用telnet命令,方法:

linux:

nc 120.55.94.78 12345

telnet 120.55.94.78 12345

然后就可以给服务器自由发送数据了,服务器会给你发送的信息加上时间戳返回给你。效果如图:

另外我将这个代码改写了成纯C++11版本,使用CMake编译,为了支持编译必须加上这-std=c++11:

CMakeLists.txt代码如下:

cmake_minimum_required(VERSION 2.8)  
  PROJECT(myreactorserver)  
  AUX_SOURCE_DIRECTORY(./ SRC_LIST)  SET(EXECUTABLE_OUTPUT_PATH ./)  
  ADD_DEFINITIONS(-g -W -Wall -Wno-deprecated -DLINUX -D_REENTRANT -D_FILE_OFFSET_BITS=64 -DAC_HAS_INFO -DAC_HAS_WARNING -DAC_HAS_ERROR -DAC_HAS_CRITICAL -DTIXML_USE_STL -DHAVE_CXX_STDHEADERS ${CMAKE_CXX_FLAGS} -std=c++11)  
  INCLUDE_DIRECTORIES(  ./  )  LINK_DIRECTORIES(  ./  )  
  set(  main.cpp  myreator.cpp  )  
  ADD_EXECUTABLE(myreactorserver ${SRC_LIST})  
  TARGET_LINK_LIBRARIES(myreactorserver pthread)  

myreactor.h文件内容:

/** *@desc: myreactor头文件, myreactor.h *@author: zhangyl *@date: 2016.12.03 */  #ifndef __MYREACTOR_H__  #define __MYREACTOR_H__  
  #include <list>  #include <memory>  #include <thread>  #include <mutex>  #include <condition_variable>  
  #define WORKER_THREAD_NUM   5  
  class CMyReactor  {  public:  
    CMyReactor();  
    ~CMyReactor();  
  
    bool init(const char* ip, short nport);  
    bool uninit();  
  
    bool close_client(int clientfd);  
  
    static void* main_loop(void* p);  
  private:  
    //no copyable  
    CMyReactor(const CMyReactor& rhs);  
    CMyReactor& operator = (const CMyReactor& rhs);  
  
    bool create_server_listener(const char* ip, short port);  
      
    static void accept_thread_proc(CMyReactor* pReatcor);  
    static void worker_thread_proc(CMyReactor* pReatcor);  
  private:  
    //C11语法可以在这里初始化  
    int                          m_listenfd = 0;  
    int                          m_epollfd  = 0;  
    bool                         m_bStop    = false;  
      
    std::shared_ptr<std::thread> m_acceptthread;  
    std::shared_ptr<std::thread> m_workerthreads[WORKER_THREAD_NUM];  
      
    std::condition_variable      m_acceptcond;  
    std::mutex                   m_acceptmutex;  
  
    std::condition_variable      m_workercond ;  
    std::mutex                   m_workermutex;  
  
    std::list<int>                 m_listClients;  };  
  #endif //!__MYREACTOR_H__ 

myreactor.cpp文件内容:

/**   *@desc: myreactor实现文件, myreactor.cpp  *@author: zhangyl  *@date: 2016.12.03  */  #include "myreactor.h"  #include <iostream>  #include <string.h>  #include <sys/types.h>  #include <sys/socket.h>  #include <netinet/in.h>  #include <arpa/inet.h>  //for htonl() and htons()  #include <fcntl.h>  #include <sys/epoll.h>  #include <list>  #include <errno.h>  #include <time.h>  #include <sstream>  #include <iomanip> //for std::setw()/setfill()  #include <unistd.h>  
  #define min(a, b) ((a <= b) ? (a) : (b))  
  CMyReactor::CMyReactor()  {  
    //m_listenfd = 0;  
    //m_epollfd = 0;  
    //m_bStop = false;  }  
  CMyReactor::~CMyReactor()  {  
  }  
  bool CMyReactor::init(const char* ip, short nport)  {  
    if (!create_server_listener(ip, nport))  
    {  
        std::cout << "Unable to bind: " << ip << ":" << nport << "." << std::endl;  
        return false;  
    }  
  
  
    std::cout << "main thread id = " << std::this_thread::get_id() << std::endl;  
  
    //启动接收新连接的线程  
    m_acceptthread.reset(new std::thread(CMyReactor::accept_thread_proc, this));  
      
    //启动工作线程  
    for (auto& t : m_workerthreads)  
    {  
        t.reset(new std::thread(CMyReactor::worker_thread_proc, this));  
    }  
  
  
    return true;  }  
  bool CMyReactor::uninit()  {  
    m_bStop = true;  
    m_acceptcond.notify_one();  
    m_workercond.notify_all();  
  
    m_acceptthread->join();  
    for (auto& t : m_workerthreads)  
    {  
        t->join();  
    }  
  
    ::epoll_ctl(m_epollfd, EPOLL_CTL_DEL, m_listenfd, NULL);  
  
    //TODO: 是否需要先调用shutdown()一下?  
    ::shutdown(m_listenfd, SHUT_RDWR);  
    ::close(m_listenfd);  
    ::close(m_epollfd);  
  
    return true;  }  
  bool CMyReactor::close_client(int clientfd)  {  
    if (::epoll_ctl(m_epollfd, EPOLL_CTL_DEL, clientfd, NULL) == -1)  
    {  
        std::cout << "close client socket failed as call epoll_ctl failed" << std::endl;  
        //return false;  
    }  
          
  
    ::close(clientfd);  
  
    return true;  }  
  
  void* CMyReactor::main_loop(void* p)  {  
    std::cout << "main thread id = " << std::this_thread::get_id() << std::endl;  
      
    CMyReactor* pReatcor = static_cast<CMyReactor*>(p);  
      
    while (!pReatcor->m_bStop)  
    {  
        struct epoll_event ev[1024];  
        int n = ::epoll_wait(pReatcor->m_epollfd, ev, 1024, 10);  
        if (n == 0)  
            continue;  
        else if (n < 0)  
        {  
            std::cout << "epoll_wait error" << std::endl;  
            continue;  
        }  
  
        int m = min(n, 1024);  
        for (int i = 0; i < m; ++i)  
        {  
            //通知接收连接线程接收新连接  
            if (ev[i].data.fd == pReatcor->m_listenfd)  
                pReatcor->m_acceptcond.notify_one();  
            //通知普通工作线程接收数据  
            else  
            {  
                {  
                    std::unique_lock<std::mutex> guard(pReatcor->m_workermutex);  
                    pReatcor->m_listClients.push_back(ev[i].data.fd);  
                }  
                                  
                pReatcor->m_workercond.notify_one();  
                //std::cout << "signal" << std::endl;  
            }// end if  
  
        }// end for-loop  
    }// end while  
  
    std::cout << "main loop exit ..." << std::endl;  
  
    return NULL;  }  
  void CMyReactor::accept_thread_proc(CMyReactor* pReatcor)  {  
    std::cout << "accept thread, thread id = " << std::this_thread::get_id() << std::endl;  
  
    while (true)  
    {  
        int newfd;  
        struct sockaddr_in clientaddr;  
        socklen_t addrlen;  
        {  
            std::unique_lock<std::mutex> guard(pReatcor->m_acceptmutex);  
            pReatcor->m_acceptcond.wait(guard);  
            if (pReatcor->m_bStop)  
                break;  
  
            //std::cout << "run loop in accept_thread_proc" << std::endl;  
              
            newfd = ::accept(pReatcor->m_listenfd, (struct sockaddr *)&clientaddr, &addrlen);  
        }  
        if (newfd == -1)  
            continue;  
  
        std::cout << "new client connected: " << ::inet_ntoa(clientaddr.sin_addr) << ":" << ::ntohs(clientaddr.sin_port) << std::endl;  
  
        //将新socket设置为non-blocking  
        int oldflag = ::fcntl(newfd, F_GETFL, 0);  
        int newflag = oldflag | O_NONBLOCK;  
        if (::fcntl(newfd, F_SETFL, newflag) == -1)  
        {  
            std::cout << "fcntl error, oldflag =" << oldflag << ", newflag = " << newflag << std::endl;  
            continue;  
        }  
  
        struct epoll_event e;  
        memset(&e, 0, sizeof(e));  
        e.events = EPOLLIN | EPOLLRDHUP | EPOLLET;  
        e.data.fd = newfd;  
        if (::epoll_ctl(pReatcor->m_epollfd, EPOLL_CTL_ADD, newfd, &e) == -1)  
        {  
            std::cout << "epoll_ctl error, fd =" << newfd << std::endl;  
        }  
    }  
  
    std::cout << "accept thread exit ..." << std::endl;  }  
  void CMyReactor::worker_thread_proc(CMyReactor* pReatcor)  {  
    std::cout << "new worker thread, thread id = " << std::this_thread::get_id() << std::endl;  
  
    while (true)  
    {  
        int clientfd;  
        {  
            std::unique_lock<std::mutex> guard(pReatcor->m_workermutex);  
            while (pReatcor->m_listClients.empty())  
            {  
                if (pReatcor->m_bStop)  
                {  
                    std::cout << "worker thread exit ..." << std::endl;  
                    return;  
                }  
                      
                pReatcor->m_workercond.wait(guard);  
            }  
                  
            clientfd = pReatcor->m_listClients.front();  
            pReatcor->m_listClients.pop_front();  
        }  
  
        //gdb调试时不能实时刷新标准输出,用这个函数刷新标准输出,使信息在屏幕上实时显示出来  
        std::cout << std::endl;  
  
        std::string strclientmsg;  
        char buff[256];  
        bool bError = false;  
        while (true)  
        {  
            memset(buff, 0, sizeof(buff));  
            int nRecv = ::recv(clientfd, buff, 256, 0);  
            if (nRecv == -1)  
            {  
                if (errno == EWOULDBLOCK)  
                    break;  
                else  
                {  
                    std::cout << "recv error, client disconnected, fd = " << clientfd << std::endl;  
                    pReatcor->close_client(clientfd);  
                    bError = true;  
                    break;  
                }  
  
            }  
            //对端关闭了socket,这端也关闭。  
            else if (nRecv == 0)  
            {  
                std::cout << "peer closed, client disconnected, fd = " << clientfd << std::endl;  
                pReatcor->close_client(clientfd);  
                bError = true;  
                break;  
            }  
  
            strclientmsg += buff;  
        }  
  
        //出错了,就不要再继续往下执行了  
        if (bError)  
            continue;  
  
        std::cout << "client msg: " << strclientmsg;  
  
        //将消息加上时间标签后发回  
        time_t now = time(NULL);  
        struct tm* nowstr = localtime(&now);  
        std::ostringstream ostimestr;  
        ostimestr << "[" << nowstr->tm_year + 1900 << "-"  
            << std::setw(2) << std::setfill('0') << nowstr->tm_mon + 1 << "-"  
            << std::setw(2) << std::setfill('0') << nowstr->tm_mday << " "  
            << std::setw(2) << std::setfill('0') << nowstr->tm_hour << ":"  
            << std::setw(2) << std::setfill('0') << nowstr->tm_min << ":"  
            << std::setw(2) << std::setfill('0') << nowstr->tm_sec << "]server reply: ";  
  
        strclientmsg.insert(0, ostimestr.str());  
  
        while (true)  
        {  
            int nSent = ::send(clientfd, strclientmsg.c_str(), strclientmsg.length(), 0);  
            if (nSent == -1)  
            {  
                if (errno == EWOULDBLOCK)  
                {  
                    std::this_thread::sleep_for(std::chrono::milliseconds(10));  
                    continue;  
                }  
                else  
                {  
                    std::cout << "send error, fd = " << clientfd << std::endl;  
                    pReatcor->close_client(clientfd);  
                    break;  
                }  
  
            }  
  
            std::cout << "send: " << strclientmsg;  
            strclientmsg.erase(0, nSent);  
  
            if (strclientmsg.empty())  
                break;  
        }  
    }  }  
  bool CMyReactor::create_server_listener(const char* ip, short port)  {  
    m_listenfd = ::socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, 0);  
    if (m_listenfd == -1)  
        return false;  
  
    int on = 1;  
    ::setsockopt(m_listenfd, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on));  
    ::setsockopt(m_listenfd, SOL_SOCKET, SO_REUSEPORT, (char *)&on, sizeof(on));  
  
    struct sockaddr_in servaddr;  
    memset(&servaddr, 0, sizeof(servaddr));  
    servaddr.sin_family = AF_INET;  
    servaddr.sin_addr.s_addr = inet_addr(ip);  
    servaddr.sin_port = htons(port);  
    if (::bind(m_listenfd, (sockaddr *)&servaddr, sizeof(servaddr)) == -1)  
        return false;  
  
    if (::listen(m_listenfd, 50) == -1)  
        return false;  
  
    m_epollfd = ::epoll_create(1);  
    if (m_epollfd == -1)  
        return false;  
  
    struct epoll_event e;  
    memset(&e, 0, sizeof(e));  
    e.events = EPOLLIN | EPOLLRDHUP;  
    e.data.fd = m_listenfd;  
    if (::epoll_ctl(m_epollfd, EPOLL_CTL_ADD, m_listenfd, &e) == -1)  
        return false;  
  
    return true;  }  

main.cpp文件内容:

/**  
 *@desc:   用reactor模式练习服务器程序 
 *@author: zhangyl 
 *@date:   2016.12.03 
 */  
  
#include <iostream>  
#include <signal.h>     //for signal()  
#include<unistd.h>  
#include <stdlib.h>       //for exit()  
#include <sys/types.h>  
#include <sys/stat.h>  
#include <fcntl.h>  
#include "myreactor.h"  
  
CMyReactor g_reator;  
  
void prog_exit(int signo)  
{  
    std::cout << "program recv signal " << signo << " to exit." << std::endl;   
  
    g_reator.uninit();  
}  
  
void daemon_run()  
{  
    int pid;  
    signal(SIGCHLD, SIG_IGN);  
    //1)在父进程中,fork返回新创建子进程的进程ID;  
    //2)在子进程中,fork返回0;  
    //3)如果出现错误,fork返回一个负值;  
    pid = fork();  
    if (pid < 0)  
    {  
        std:: cout << "fork error" << std::endl;  
        exit(-1);  
    }  
    //父进程退出,子进程独立运行  
    else if (pid > 0) {  
        exit(0);  
    }  
    //之前parent和child运行在同一个session里,parent是会话(session)的领头进程,  
    //parent进程作为会话的领头进程,如果exit结束执行的话,那么子进程会成为孤儿进程,并被init收养。  
    //执行setsid()之后,child将重新获得一个新的会话(session)id。  
    //这时parent退出之后,将不会影响到child了。  
    setsid();  
    int fd;  
    fd = open("/dev/null", O_RDWR, 0);  
    if (fd != -1)  
    {  
        dup2(fd, STDIN_FILENO);  
        dup2(fd, STDOUT_FILENO);  
        dup2(fd, STDERR_FILENO);  
    }  
    if (fd > 2)  
        close(fd);  
}  
  
  
int main(int argc, char* argv[])  
{    
    //设置信号处理  
    signal(SIGCHLD, SIG_DFL);  
    signal(SIGPIPE, SIG_IGN);  
    signal(SIGINT, prog_exit);  
    signal(SIGKILL, prog_exit);  
    signal(SIGTERM, prog_exit);  
      
    short port = 0;  
    int ch;  
    bool bdaemon = false;  
    while ((ch = getopt(argc, argv, "p:d")) != -1)  
    {  
        switch (ch)  
        {  
        case 'd':  
            bdaemon = true;  
            break;  
        case 'p':  
            port = atol(optarg);  
            break;  
        }  
    }  
  
    if (bdaemon)  
        daemon_run();  
  
  
    if (port == 0)  
        port = 12345;  
  
      
    if (!g_reator.init("0.0.0.0", 12345))  
        return -1;  
      
    g_reator.main_loop(&g_reator);  
  
    return 0;  
}  

完整实例代码下载地址:

普通版本:https://pan.baidu.com/s/1o82Mkno

C++11版本:https://pan.baidu.com/s/1dEJdrih