epoll代码示例

 #include <errno.h>
 #include <string.h>
 #include <stdlib.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <iostream>
 #include <sys/epoll.h>

 using namespace std;

 int main(int argc, char *argv[])
 {
     if (argc != )
     {
         cout << "usage: " << argv[] << " ip port" << endl;
         return -;
     }

     char *szIp = argv[];
     in_addr_t iIp = inet_addr(szIp);
     if (iIp == INADDR_NONE)
     {
         cerr << "fail to parse ip: " << szIp << endl;
         return -;
     }
     char *pEnd = NULL;
     uint16_t usPort = strtoul(argv[], &pEnd, );
     if (*pEnd != '\0')
     {
         cerr << "fail to parse port: " << argv[] << endl;
         return -;
     }

     int iSockFd = socket(AF_INET, SOCK_STREAM, );
     if (iSockFd < )
     {
         cerr << "fail to create socket, err: " << strerror(errno) << endl;
         return -;
     }
     cout << "create socket fd " << iSockFd << endl;

     sockaddr_in oAddr;
     memset(&oAddr, , sizeof(oAddr));
     oAddr.sin_family = AF_INET;
     oAddr.sin_addr.s_addr = iIp;
     oAddr.sin_port = htons(usPort);
     if (bind(iSockFd, (sockaddr *)&oAddr, sizeof(oAddr)) < )
     {
         cerr << "fail to bind addr " << szIp << ":" << usPort << ", err: " << strerror(errno) << endl;
         return -;
     }
     cout << "bind addr " << szIp << ":" << usPort << endl;

     if (listen(iSockFd, ) < )
     {
         cerr << "fail to listen on " << szIp << ":" << usPort << ", err: " << strerror(errno) << endl;
     }
     cout << "listen on socket fd " << iSockFd << endl;

     int iEpollFd = epoll_create();
     if (iEpollFd < )
     {
         cerr << "fail to create epoll, err: " << strerror(errno) << endl;
         return -;
     }

     epoll_event oEvent;
     oEvent.events = EPOLLIN;
     oEvent.data.fd = iSockFd;
     if (epoll_ctl(iEpollFd, EPOLL_CTL_ADD, iSockFd, &oEvent) < )
     {
         cerr << "fail to add listen fd to epoll, err: " << strerror(errno) << endl;
         return -;
     }

     epoll_event aoEvents[];
     uint8_t acRecvBuf[ * ];
     while (true)
     {
         int iFdCnt = epoll_wait(iEpollFd, aoEvents, , -);
         if (iFdCnt < )
         {
             cerr << "epoll wait error, err: " << strerror(errno) << endl;
             return -;
         }

         for (int i = ; i < iFdCnt; i++)
         {
             if (aoEvents[i].data.fd == iSockFd)
             {
                 sockaddr_in oClientAddr;
                 socklen_t iAddrLen = sizeof(oClientAddr);
                 int iAcceptFd = accept(iSockFd, (sockaddr *)&oClientAddr, &iAddrLen);
                 if (iAcceptFd < )
                 {
                     cerr << "fail to accpet, err: " << strerror(errno) << endl;
                     continue;
                 }
                 cout << "recv connection from " << inet_ntoa(oClientAddr.sin_addr) << ":" << ntohs(oClientAddr.sin_port) << endl;

                 oEvent.events = EPOLLIN;
                 oEvent.data.fd = iAcceptFd;
                 if (epoll_ctl(iEpollFd, EPOLL_CTL_ADD, iAcceptFd, &oEvent) < )
                 {
                     close(iAcceptFd);
                     cerr << "fail to add fd to epoll, err: " << strerror(errno) << endl;
                     continue;
                 }
             }
             else
             {
                 int iCurFd = aoEvents[i].data.fd;
                 ssize_t iRecvLen = recv(iCurFd, acRecvBuf, sizeof(acRecvBuf), );
                 if (iRecvLen < )
                 {
                     cerr << "fail to recv, close connection, err: " << strerror(errno) << endl;
                     if (epoll_ctl(iEpollFd, EPOLL_CTL_DEL, iCurFd, NULL) < )
                     {
                         cerr << "fail to del fd from epoll, err: " << strerror(errno) << endl;
                     }
                     close(iCurFd);
                     continue;
                 }
                 if (iRecvLen == )
                 {
                     cout << "connection closed by client" << endl;
                     if (epoll_ctl(iEpollFd, EPOLL_CTL_DEL, iCurFd, NULL) < )
                     {
                         cerr << "fail to del fd from epoll, err: " << strerror(errno) << endl;
                     }
                     close(iCurFd);
                     continue;
                 }
                 cout << "recv data len: " << iRecvLen << endl;

                 ssize_t iSendLen = send(iCurFd, acRecvBuf, iRecvLen, );
                 if (iSendLen < )
                 {
                     cerr << "fail to send, err: " << strerror(errno) << endl;
                     if (epoll_ctl(iEpollFd, EPOLL_CTL_DEL, iCurFd, NULL) < )
                     {
                         cerr << "fail to del fd from epoll, err: " << strerror(errno) << endl;
                     }
                     close(iCurFd);
                     break;
                 }
                 cout << "echo to client, len: " << iSendLen << endl;
             }
         }
     }
 }