【并发服务器系列】3 epoll模型

chat_server.cpp

 

#include "chat.h"





extern int sock_server_init(int &listenfd , uint16_t server_port);



void err_quit(const char *error_string)

{

    printf("%s\n", error_string);    

    exit(1);

}

void err_sys(const char *error_string)

{

    printf("%s\n", error_string);    

}



extern ssize_t p_read_from_p(int clientfd);

extern ssize_t p_write_to_p(int clientfd, const char *msg);



int do_use_fd(int fd)

{

    p_read_from_p(fd);

//     sleep(2);

    p_write_to_p(fd, "Hi this is server");

    

    

}

//#define WAIT_TIME_OUT

void sig_chld(int signo)

{

    pid_t pid;

    int stat;

    while( (pid = waitpid(-1, &stat, WNOHANG)) > 0 )

    {

        printf("client %d terminated \n", pid);

    }

    return;

}

int setnonblocking(int fd)

{

    return fcntl(fd, F_SETFL, O_NONBLOCK) ;        

}



#include <sys/epoll.h>



#define MAX_EVENTS 1000

void chat_server()

{

    int listenfd, connfd, nfds, epollfd;

    struct epoll_event ev, events[MAX_EVENTS];

    

    struct sockaddr_in cliaddr;

    socklen_t clilen;

    char buf[200] = {0};

    

    sock_server_init(listenfd, SERVER_PORT);

    

    epollfd = epoll_create(MAX_EVENTS);

    if(epollfd == -1)

    {

        perror("epoll_create");

        exit(EXIT_FAILURE);        

    }

    ev.events = EPOLLIN;

    ev.data.fd = listenfd;

    if(epoll_ctl(epollfd, EPOLL_CTL_ADD, listenfd, &ev) == -1)

    {

        perror("epoll_ctl listenfd");

        exit(EXIT_FAILURE);

    }

//     sleep(10);

    int i_have_server_client_counter = 0;

    for(;;)

    {

        nfds = epoll_wait(epollfd, events, MAX_EVENTS, -1);

        if(nfds == -1)

        {

            perror("epoll_wait");

            exit(EXIT_FAILURE);

        }

        

        for(int n = 0; n < nfds; ++n)

        {

            printf("got client counts %d handling fd: %d\n", nfds, events[n].data.fd );

            if(events[n].data.fd == listenfd)

            {

                clilen = sizeof(cliaddr);

                connfd = accept(listenfd, (struct sockaddr *)&cliaddr , &clilen);

                if(connfd == -1)

                {

                    perror("accept");

                    exit(EXIT_FAILURE);

                }

                printf("incoming connection from IP: %s Port: %d\n",

                            inet_ntop(AF_INET, &cliaddr.sin_addr, buf, sizeof(buf)),

                             ntohs(cliaddr.sin_port));

                

                setnonblocking(connfd);

                ev.events = EPOLLIN|EPOLLET;

                ev.data.fd = connfd;

                if(epoll_ctl(epollfd,EPOLL_CTL_ADD, connfd, &ev) == -1)

                {

                    perror("epoll_ctl: connfd");

                    exit(EXIT_FAILURE);

                }                

            }//if

            else

            {

                do_use_fd(events[n].data.fd);

                i_have_server_client_counter++;

                printf("server count %d\n", i_have_server_client_counter);

                if(epoll_ctl(epollfd,EPOLL_CTL_DEL, events[n].data.fd, &ev) == -1)

                {

                    perror("epoll_ctl: EPOLL_CTL_DEL events[n].data.fd");

                    exit(EXIT_FAILURE);

                }    

                close(events[n].data.fd);

            }

        }//for

        

    }//for

 

Performance：Testing Machine: Local test ,OS: Fedora 14(Linux 2.6.35) 2 Cores:E3200@2.4GHz， Memory： 2GiB
Result: Handles about 300~400 clients per sec
not so many as I expected