epoll+socket的简单测试例子

server：

#include <sys/socket.h>    
#include <sys/epoll.h>    
#include <netinet/in.h>    
#include <arpa/inet.h>    
#include <fcntl.h>    
#include <unistd.h>    
#include <stdio.h>    
#include <errno.h>    
#include <iostream>    
#include <string.h>
#include <stdlib.h>
using namespace std;    
#define MAX_EVENTS 500    
struct myevent_s    
{    
    int fd;    
    void (*call_back)(int fd, int events, void *arg);    
    int events;    
    void *arg;    
    int status; // 1: in epoll wait list, 0 not in    
    char buff[128]; // recv data buffer    
    int len, s_offset;    
    long last_active; // last active time    
};    
// set event    
void EventSet(myevent_s *ev, int fd, void (*call_back)(int, int, void*), void *arg)    
{    
    ev->fd = fd;    
    ev->call_back = call_back;    
    ev->events = 0;    
    ev->arg = arg;    
    ev->status = 0;  
    bzero(ev->buff, sizeof(ev->buff));  
    ev->s_offset = 0;    
    ev->len = 0;  
    ev->last_active = time(NULL);    
}    
// add/mod an event to epoll    
void EventAdd(int epollFd, int events, myevent_s *ev)    
{    
    struct epoll_event epv = {0, {0}};    
    int op;    
    epv.data.ptr = ev;    
    epv.events = ev->events = events;    
    if(ev->status == 1){    
        op = EPOLL_CTL_MOD;    
    }    
    else{    
        op = EPOLL_CTL_ADD;    
        ev->status = 1;    
    }    
    if(epoll_ctl(epollFd, op, ev->fd, &epv) < 0)    
        printf("Event Add failed[fd=%d], evnets[%d]\n", ev->fd, events);    
    else    
        printf("Event Add OK[fd=%d], op=%d, evnets[%0X]\n", ev->fd, op, events);    
}    
// delete an event from epoll    
void EventDel(int epollFd, myevent_s *ev)    
{    
    struct epoll_event epv = {0, {0}};    
    if(ev->status != 1) return;    
    epv.data.ptr = ev;    
    ev->status = 0;  
    epoll_ctl(epollFd, EPOLL_CTL_DEL, ev->fd, &epv);    
}    
int g_epollFd;    
myevent_s g_Events[MAX_EVENTS+1]; // g_Events[MAX_EVENTS] is used by listen fd    
void RecvData(int fd, int events, void *arg);    
void SendData(int fd, int events, void *arg);    
// accept new connections from clients    
void AcceptConn(int fd, int events, void *arg)    
{    
    struct sockaddr_in sin;    
    socklen_t len = sizeof(struct sockaddr_in);    
    int nfd, i;    
    // accept    
    if((nfd = accept(fd, (struct sockaddr*)&sin, &len)) == -1)    
    {    
        if(errno != EAGAIN && errno != EINTR)    
        {    
        }  
        printf("%s: accept, %d", __func__, errno);    
        return;    
    }    
    do    
    {    
        for(i = 0; i < MAX_EVENTS; i++)    
        {    
            if(g_Events[i].status == 0)    
            {    
                break;    
            }    
        }    
        if(i == MAX_EVENTS)    
        {    
            printf("%s:max connection limit[%d].", __func__, MAX_EVENTS);    
            break;    
        }    
        // set nonblocking  
        int iret = 0;  
        if((iret = fcntl(nfd, F_SETFL, O_NONBLOCK)) < 0)  
        {  
            printf("%s: fcntl nonblocking failed:%d", __func__, iret);  
            break;  
        }  
        // add a read event for receive data    
        EventSet(&g_Events[i], nfd, RecvData, &g_Events[i]);    
        EventAdd(g_epollFd, EPOLLIN, &g_Events[i]);    
    }while(0);    
    printf("new conn[%s:%d][time:%d], pos[%d]\n", inet_ntoa(sin.sin_addr),   
            ntohs(sin.sin_port), g_Events[i].last_active, i);    
}    
// receive data    
void RecvData(int fd, int events, void *arg)    
{    
    struct myevent_s *ev = (struct myevent_s*)arg;    
    int len;    
    // receive data  
    len = recv(fd, ev->buff+ev->len, sizeof(ev->buff)-1-ev->len, 0);      
    EventDel(g_epollFd, ev);  
    if(len > 0)  
    {  
        ev->len += len;  
        ev->buff[ev->len] = '\0';    
        printf("C[%d]:%s\n", fd, ev->buff);    
        // change to send event    
        EventSet(ev, fd, SendData, ev);    
        EventAdd(g_epollFd, EPOLLOUT, ev);    
    }    
    else if(len == 0)    
    {    
        close(ev->fd);    
        printf("[fd=%d] pos[%d], closed gracefully.\n", fd, ev-g_Events);    
    }    
    else    
    {    
        close(ev->fd);    
        printf("recv[fd=%d] error[%d]:%s\n", fd, errno, strerror(errno));    
    }    
}    
// send data    
void SendData(int fd, int events, void *arg)    
{    
    struct myevent_s *ev = (struct myevent_s*)arg;    
    int len;    
    // send data    
    sprintf(ev->buff, "callback");
    ev->len = strlen(ev->buff);
    len = send(fd, ev->buff + ev->s_offset, ev->len - ev->s_offset, 0);  
    if(len > 0)    
    {  
        printf("send[fd=%d], [%d<->%d]%s\n", fd, len, ev->len, ev->buff);  
        ev->s_offset += len;  
        if(ev->s_offset == ev->len)  
        {  
            // change to receive event  
            EventDel(g_epollFd, ev);    
            EventSet(ev, fd, RecvData, ev);    
            EventAdd(g_epollFd, EPOLLIN, ev);    
        }  
    }    
    else    
    {    
        close(ev->fd);    
        EventDel(g_epollFd, ev);    
        printf("send[fd=%d] error[%d]:%s\n", fd, errno, strerror(errno));    
    }    
}    
void InitListenSocket(int epollFd, short port)    
{    
    int listenFd = socket(AF_INET, SOCK_STREAM, 0);    
    fcntl(listenFd, F_SETFL, O_NONBLOCK); // set non-blocking    
    printf("server listen fd=%d\n", listenFd);    
    EventSet(&g_Events[MAX_EVENTS], listenFd, AcceptConn, &g_Events[MAX_EVENTS]);    
    // add listen socket    
    EventAdd(epollFd, EPOLLIN, &g_Events[MAX_EVENTS]);    
    // bind & listen    
    sockaddr_in sin;    
    bzero(&sin, sizeof(sin));    
    sin.sin_family = AF_INET;    
    sin.sin_addr.s_addr = INADDR_ANY;    
    sin.sin_port = htons(port);    
    bind(listenFd, (const sockaddr*)&sin, sizeof(sin));    
    listen(listenFd, 5);    
}    
int main(int argc, char **argv)    
{    
    unsigned short port = 12345; // default port    
    if(argc == 2){    
        port = atoi(argv[1]);    
    }    
    // create epoll    
    g_epollFd = epoll_create(MAX_EVENTS);    
    if(g_epollFd <= 0) printf("create epoll failed.%d\n", g_epollFd);    
    // create & bind listen socket, and add to epoll, set non-blocking    
    InitListenSocket(g_epollFd, port);    
    // event loop    
    struct epoll_event events[MAX_EVENTS];    
    printf("server running:port[%d]\n", port);    
    int checkPos = 0;    
    while(1){    
        // a simple timeout check here, every time 100, better to use a mini-heap, and add timer event    
        long now = time(NULL);    
        for(int i = 0; i < 100; i++, checkPos++) // doesn't check listen fd    
        {    
            if(checkPos == MAX_EVENTS) checkPos = 0; // recycle    
            if(g_Events[checkPos].status != 1) continue;    
            long duration = now - g_Events[checkPos].last_active;    
            if(duration >= 60) // 60s timeout    
            {    
                close(g_Events[checkPos].fd);    
                printf("[fd=%d] timeout[%d--%d].\n", g_Events[checkPos].fd, g_Events[checkPos].last_active, now);    
                EventDel(g_epollFd, &g_Events[checkPos]);    
            }    
        }    
        // wait for events to happen    
        int fds = epoll_wait(g_epollFd, events, MAX_EVENTS, 1000);    
        if(fds < 0){    
            printf("epoll_wait error, exit\n");    
            break;    
        }    
        for(int i = 0; i < fds; i++){    
            myevent_s *ev = (struct myevent_s*)events[i].data.ptr;    
            if((events[i].events&EPOLLIN)&&(ev->events&EPOLLIN)) // read event    
            {    
                ev->call_back(ev->fd, events[i].events, ev->arg);    
            }    
            if((events[i].events&EPOLLOUT)&&(ev->events&EPOLLOUT)) // write event    
            {    
                ev->call_back(ev->fd, events[i].events, ev->arg);    
            }    
        }    
    }    
    // free resource    
    return 0;    
} 

client：

/*************************************************************************
    > File Name: epoll_echo_client.cpp
    > Author: 
    > Mail: 
    > Created Time: Tue 05 Dec 2017 04:53:44 PM CST
 ************************************************************************/

#include<iostream>
using namespace std;

#include<stdio.h>  
#include<stdlib.h>  
#include<string.h>  
#include<errno.h>  
#include<sys/types.h>  
#include<sys/socket.h>  
#include<netinet/in.h>  
#include<arpa/inet.h>
#include<unistd.h>
  
#define MAXLINE 4096  


int main(int argc, char** argv)  
{  
    int    sockfd, n,rec_len;  
    char    recvline[4096], sendline[4096];  
    char    buf[MAXLINE];  
    struct sockaddr_in    servaddr;  
    char* ip = "127.0.0.1";
    int port = 12345;
  
    if( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0 ){  
        printf("create socket error: %s(errno: %d)\n", strerror(errno),errno);  
        exit(0);  
        }  
  
  
    memset(&servaddr, 0, sizeof(servaddr));  
    servaddr.sin_family = AF_INET;  
    servaddr.sin_port = htons(port);  
    if( inet_pton(AF_INET, ip, &servaddr.sin_addr) <= 0 ){  
        printf("inet_pton error for %s\n",ip);  
        exit(0);  
        }  
  
  
    if( connect(sockfd, (struct sockaddr*)&servaddr, sizeof(servaddr)) < 0 ){  
        printf("connect error: %s(errno: %d)\n",strerror(errno),errno);  
        exit(0);  
        }  
  
  
    printf("send msg to server: \n");  
    fgets(sendline, 4096, stdin);  
    if( send(sockfd, sendline, strlen(sendline), 0) < 0 )  
    {  
        printf("send msg error: %s(errno: %d)\n", strerror(errno), errno);  
        exit(0);  
        }  
    if((rec_len = recv(sockfd, buf, MAXLINE,0)) == -1) {  
           perror("recv error");  
           exit(1);  
        }  
    buf[rec_len]  = '\0';  
    printf("Received : %s ",buf);  
    close(sockfd);  
    exit(0);  
}