使用libevent：echo server

来源：互联网发布：java编写游戏编辑：程序博客网时间：2024/06/05 02:05

原文： https://www.felix021.com/blog/read.php?2068

echo server

// gcc echo_server.c -levent -o es#include <stdio.h>#include <stdlib.h>#include <errno.h>#include <assert.h>#include <event2/event.h>#include <event2/bufferevent.h>#define LISTEN_PORT 9999#define LISTEN_BACKLOG 32void do_accept(evutil_socket_t listener, short event, void *arg);void read_cb(struct bufferevent *bev, void *arg);void error_cb(struct bufferevent *bev, short event, void *arg);void write_cb(struct bufferevent *bev, void *arg);int main(int argc, char *argv[]){    int ret;    evutil_socket_t listener;    listener = socket(AF_INET, SOCK_STREAM, 0);    assert(listener > 0);    evutil_make_listen_socket_reuseable(listener);    struct sockaddr_in sin;    sin.sin_family = AF_INET;    sin.sin_addr.s_addr = 0;    sin.sin_port = htons(LISTEN_PORT);    if (bind(listener, (struct sockaddr *)&sin, sizeof(sin)) < 0) {        perror("bind");        return 1;    }    if (listen(listener, LISTEN_BACKLOG) < 0) {        perror("listen");        return 1;    }    printf ("Listening...\n");    evutil_make_socket_nonblocking(listener);    struct event_base *base = event_base_new();    assert(base != NULL);    struct event *listen_event;    listen_event = event_new(base, listener, EV_READ|EV_PERSIST, do_accept, (void*)base);    event_add(listen_event, NULL);    event_base_dispatch(base);    printf("The End.");    return 0;}void do_accept(evutil_socket_t listener, short event, void *arg){    struct event_base *base = (struct event_base *)arg;    evutil_socket_t fd;    struct sockaddr_in sin;    socklen_t slen = sizeof(sin);    fd = accept(listener, (struct sockaddr *)&sin, &slen);    if (fd < 0) {        perror("accept");        return;    }    if (fd > FD_SETSIZE) { //这个if是参考了那个ROT13的例子，貌似是官方的疏漏，从select-based例子里抄过来忘了改        perror("fd > FD_SETSIZE\n");        return;    }    printf("ACCEPT: fd = %u\n", fd);    struct bufferevent *bev = bufferevent_socket_new(base, fd, BEV_OPT_CLOSE_ON_FREE);    bufferevent_setcb(bev, read_cb, NULL, error_cb, arg);    bufferevent_enable(bev, EV_READ|EV_WRITE|EV_PERSIST);}void read_cb(struct bufferevent *bev, void *arg){#define MAX_LINE    256    char line[MAX_LINE+1];    int n;    evutil_socket_t fd = bufferevent_getfd(bev);    while (n = bufferevent_read(bev, line, MAX_LINE), n > 0) {        line[n] = '\0';        printf("fd=%u, read line: %s\n", fd, line);        bufferevent_write(bev, line, n);    }}void write_cb(struct bufferevent *bev, void *arg) {}void error_cb(struct bufferevent *bev, short event, void *arg){    evutil_socket_t fd = bufferevent_getfd(bev);    printf("fd = %u, ", fd);    if (event & BEV_EVENT_TIMEOUT) {        printf("Timed out\n"); //if bufferevent_set_timeouts() called    }    else if (event & BEV_EVENT_EOF) {        printf("connection closed\n");    }    else if (event & BEV_EVENT_ERROR) {        printf("some other error\n");    }    bufferevent_free(bev);}

简单的压测工具

#include <stdlib.h>#include <stdio.h>#include <assert.h>#include <unistd.h>#include <sys/types.h>#include <sys/epoll.h>#include <fcntl.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <string.h>static const char* request = "GET http://localhost/index.html HTTP/1.1\r\nConnection: keep-alive\r\n\r\nxxxxxxxxxxxx";int setnonblocking( int fd ){    int old_option = fcntl( fd, F_GETFL );    int new_option = old_option | O_NONBLOCK;    fcntl( fd, F_SETFL, new_option );    return old_option;}void addfd( int epoll_fd, int fd ){    epoll_event event;    event.data.fd = fd;    event.events = EPOLLOUT | EPOLLET | EPOLLERR;    epoll_ctl( epoll_fd, EPOLL_CTL_ADD, fd, &event );    setnonblocking( fd );}bool write_nbytes( int sockfd, const char* buffer, int len ){    int bytes_write = 0;    printf( "write out %d bytes to socket %d\n", len, sockfd );    while( 1 )     {           bytes_write = send( sockfd, buffer, len, 0 );        if ( bytes_write == -1 )        {               return false;        }           else if ( bytes_write == 0 )         {               return false;        }           len -= bytes_write;        buffer = buffer + bytes_write;        if ( len <= 0 )         {               return true;        }       }   }bool read_once( int sockfd, char* buffer, int len ){    int bytes_read = 0;    memset( buffer, '\0', len );    bytes_read = recv( sockfd, buffer, len, 0 );    if ( bytes_read == -1 )    {        return false;    }    else if ( bytes_read == 0 )    {        return false;    }    printf( "read in %d bytes from socket %d with content: %s\n", bytes_read, sockfd, buffer );    return true;}void start_conn( int epoll_fd, int num, const char* ip, int port ){    int ret = 0;    struct sockaddr_in address;    bzero( &address, sizeof( address ) );    address.sin_family = AF_INET;    inet_pton( AF_INET, ip, &address.sin_addr );    address.sin_port = htons( port );    for ( int i = 0; i < num; ++i )    {        sleep( 1 );        int sockfd = socket( PF_INET, SOCK_STREAM, 0 );        printf( "create 1 sock\n" );        if( sockfd < 0 )        {            continue;        }        if (  connect( sockfd, ( struct sockaddr* )&address, sizeof( address ) ) == 0  )        {            printf( "build connection %d\n", i );            addfd( epoll_fd, sockfd );        }    }}void close_conn( int epoll_fd, int sockfd ){    epoll_ctl( epoll_fd, EPOLL_CTL_DEL, sockfd, 0 );    close( sockfd );}int main( int argc, char* argv[] ){    assert( argc == 4 );    int epoll_fd = epoll_create( 100 );    start_conn( epoll_fd, atoi( argv[ 3 ] ), argv[1], atoi( argv[2] ) );    epoll_event events[ 10000 ];    char buffer[ 2048 ];    while ( 1 )    {        int fds = epoll_wait( epoll_fd, events, 10000, 2000 );        for ( int i = 0; i < fds; i++ )        {               int sockfd = events[i].data.fd;            if ( events[i].events & EPOLLIN )            {                   if ( ! read_once( sockfd, buffer, 2048 ) )                {                    close_conn( epoll_fd, sockfd );                }                struct epoll_event event;                event.events = EPOLLOUT | EPOLLET | EPOLLERR;                event.data.fd = sockfd;                epoll_ctl( epoll_fd, EPOLL_CTL_MOD, sockfd, &event );            }            else if( events[i].events & EPOLLOUT )             {                if ( ! write_nbytes( sockfd, request, strlen( request ) ) )                {                    close_conn( epoll_fd, sockfd );                }                struct epoll_event event;                event.events = EPOLLIN | EPOLLET | EPOLLERR;                event.data.fd = sockfd;                epoll_ctl( epoll_fd, EPOLL_CTL_MOD, sockfd, &event );            }            else if( events[i].events & EPOLLERR )            {                close_conn( epoll_fd, sockfd );            }        }    }}

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