epoll实现Reactor模式

转自：http://blog.csdn.net/analogous_love/article/details/53319815

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：

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/**

*@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：

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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：

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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：

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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：

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//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

或

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：

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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：

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/**

*@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：

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/**

*@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：

[cpp] view
plain copy







/**

*@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