epoll reactor model code

libevent library core idea

/***
epoll_loop.c
***/
#include<stdio.h>
#include<sys/epoll.h>
#include<sys/socket.h>
#include<arpa/inet.h>
#include<fcntl.h>
#include<unistd.h>
#include<errno.h>
#include<string.h>
#include<stdlib.h>
#include<time.h>

#define MAX_EVENTS 2014
#define BUFLEN 4096
#define SERV_PORT 8080

void recvdata(int fd,int events,void *arg);
void senddata(int fd,int events,void *arg);

struct myevent_s
{
    int fd;
    int events;
    void *arg;
    void (*call_back)(int fd,int events,void *arg);
    int status;
    char buf[BUFLEN];
    int len;
    long last_active;
};

int g_efd;
struct myevent_s g_events[MAX_EVENTS + 1];

void eventset(struct 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;
    ev->last_active = time(NULL);
    return;
}

void eventadd(int efd,int events,struct 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(efd,op,ev->fd,&epv) < 0)
    {
        printf("event add failed [fd=%d],evens[%d]\n",ev->fd,events) ;
    }
    else
    {
        printf("event add OK[fd=%d],op = %d,evens[%0X]\n",ev->fd,op,events) ;
         
    }
    return;
}

void eventdel(int efd,struct myevent_s *ev)
{
    struct epoll_event epv = {0,{0}};

    if(ev->status != 1)
    {
        return; 
    }

    epv.data.ptr = ev;
    ev->status = 0;
    epoll_ctl(efd,EPOLL_CTL_DEL,ev->fd,&epv);

    return;
}


void acceptconn(int lfd,int events,void *arg)
{
    struct sockaddr_in cin;
    socklen_t len = sizeof(cin);
    int cfd,i;

    if((cfd = accept(lfd,(struct sockaddr *)&cin,&len)) == -1)
    {
        if(errno != EAGAIN && errno != EINTR) 
        {
        
        }
        printf("%s : accept,%s \n",__func__,strerror(errno));
        return ;
    }

    do
    {
        for(i = 0; i < MAX_EVENTS; i++) 
        {
            if(g_events[i].status == 0) 
            {
                break; 
            }
        }
            
            if(i == MAX_EVENTS)
            {
                printf("%s: max connect limit[%d]\n]",__func__,MAX_EVENTS) ;
                return;
            }

            int flag = 0;
            if((flag = fcntl(cfd,F_SETFL,O_NONBLOCK)) < 0)
            {
                 printf("%s : accept,%s \n",__func__,strerror(errno));
                 break;
            }

            eventset(&g_events[i],cfd,recvdata,&g_events[i]);
            eventadd(g_efd,EPOLLIN,&g_events[i]);
    }while(0);

    printf("new connect [%s:%d][time:%ld],pos[%d]\n",
            inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),g_events[i].last_active,i);
    return;
}

void recvdata(int fd,int events,void *arg)
{
    struct myevent_s *ev = (struct myevent_s *)arg;
    int len;

    len = recv(fd,ev->buf,sizeof(ev->buf),0);

    eventdel(g_efd,ev);

    if(len > 0)
    {
        ev->len = len;
        ev->buf[len]  = 0;
        printf("C[%d]:%s\n",fd,ev->buf);
        
        eventset(ev,fd,senddata,ev);
        eventadd(g_efd,EPOLLOUT,ev);
    }
    else if(len == 0)
    {
        close(ev->fd) ;
        printf("[fd = %d] pos[%ld],close\n",fd,ev-g_events);
    }
    else
    {
        close(ev->fd) ;
        printf("recv[fd=%d] error[%d]:%s\n",fd,errno,strerror(errno));
    }
    return;
}

void senddata(int fd,int events,void *arg)
{
    struct myevent_s *ev = (struct myevent_s *)arg;
    int len;

    len = send(fd,ev->buf,ev->len,0);

    if(len > 0)
    {
        printf("send[fd=%d],[%d]%s\n",fd,len,ev->buf) ;
        eventdel(g_efd,ev);
        eventset(ev,fd,recvdata,ev);
        eventadd(g_efd,EPOLLIN,ev);
    }
    else
    {
        close(ev->fd) ;
        eventdel(g_efd,ev);
        printf("send[fd=%d] error %s\n",fd,strerror(errno));
    }
    return;
}

void initlistensocket(int efd,short port)
{
    int lfd = socket(AF_INET,SOCK_STREAM,0);
    fcntl(lfd,F_SETFL,O_NONBLOCK);

    eventset(&g_events[MAX_EVENTS],lfd,acceptconn,&g_events[MAX_EVENTS]);
    eventadd(efd,EPOLLIN,&g_events[MAX_EVENTS]);

    struct sockaddr_in sin;
    memset(&sin,0,sizeof(sin));
    sin.sin_addr.s_addr = INADDR_ANY;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(port);

    bind(lfd,(struct sockaddr*)&sin,sizeof(sin));
    listen(lfd,20);
    return ;
}


int main(int argc, char *argv[])
{
    unsigned short port = SERV_PORT;

    if(argc == 2)
    {
        port = atoi(argv[1]) ;
    }

    g_efd = epoll_create(MAX_EVENTS+1);
    if(g_efd <= 0)
    {
        printf("Create efd in %s error %s\n",
                __func__,strerror(errno)) ;
    }
    initlistensocket(g_efd,port);

    struct epoll_event events[MAX_EVENTS+1];
    printf("server running:port[%d]\n",port);

    int checkpos = 0,i;
    while(1)
    {
        long now = time(NULL) ;
        for(i = 0 ; i < 100; i++,checkpos++)
        {
            if(checkpos == MAX_EVENTS) 
                checkpos = 0;
            if(g_events[checkpos].status != 1)
            {
                continue; 
            }

            long duration = now - g_events[checkpos].last_active;

            if(duration >= 60)
            {
                close(g_events[checkpos].fd) ;
                printf("[fd=%d] timeout\n",g_events[checkpos].fd);
                eventdel(g_efd,&g_events[checkpos]);
            }
        }

        int nfd = epoll_wait(g_efd,events,MAX_EVENTS+1,1000);
        if(nfd < 0)
        {
            printf("epoll_wait error, exit\n") ;
            break;
        }

        for(i = 0; i < nfd; i++)
        {
            struct myevent_s *ev = (struct myevent_s *)events[i].data.ptr;

            if((events[i].events & EPOLLIN) && (ev->events & EPOLLIN))
            {
                ev->call_back(ev->fd,events[i].events,ev->arg) ;
            }
            if((events[i].events & EPOLLOUT) && (ev->events & EPOLLOUT))
            {
                ev->call_back(ev->fd,events[i].events,ev->arg);
            }
        }
    }
    return 0;
}