服务器端编程心得（二）——Reactor模式
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：
服务器端编程心得（二）——Reactor模式
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
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：
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
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