[原]我在Windows环境下的首个Libevent测试实例

  1 #include <iostream>
  2 #include <WinSock2.h>    // Windows环境下的网络通信
  3 #include "event.h"        // 使用libevent函数库
  4 using namespace std;
  5 
  6 // 加载所有相关的静态链接库，也可以在工程参数中指定
  7 #pragma comment(lib, "ws2_32.lib")
  8 #pragma comment(lib, "libevent.lib")
  9 #pragma comment(lib, "libevent_core.lib")
 10 #pragma comment(lib, "libevent_extras.lib")
 11 
 12 // 回调函数声明
 13 void do_accept(evutil_socket_t listener, short event, void *arg);
 14 void read_cb(struct bufferevent *bev, void *arg);
 15 void error_cb(struct bufferevent *bev, short event, void *arg);
 16 void write_cb(struct bufferevent *bev, void *arg);
 17 
 18 int main()
 19 {
 20     // 创建SOCKET
 21     WSAData wsaData;
 22     WSAStartup(MAKEWORD(2, 1), &wsaData);    // Windows环境下网络编程必备
 23     int ret = 0;
 24     evutil_socket_t listener;
 25     listener = socket(AF_INET, SOCK_STREAM, 0);
 26     evutil_make_listen_socket_reuseable(listener);    // 通用函数：设置SOCKET复用
 27 
 28     // 绑定本地地址
 29     SOCKADDR_IN sin;
 30     sin.sin_family = AF_INET;
 31     sin.sin_addr.s_addr = ADDR_ANY;
 32     sin.sin_port = htons(6789);
 33     if (bind(listener, (SOCKADDR *)&sin, sizeof(sin)) < 0)
 34     {
 35         cout << "bind出错！" << endl;
 36         return -1;
 37     }
 38     if (listen(listener, 32) < 0)
 39     {
 40         cout << "listen出错！" << endl;
 41         return -1;
 42     }
 43     cout << "正在监听……" << endl;
 44 
 45     // <A>设置SOCKET无阻塞模式
 46     evutil_make_socket_nonblocking(listener);
 47 
 48     // （1）创建“事件管理器”
 49     struct event_base* base = event_base_new();    
 50     if (NULL == base)
 51     {
 52         cout << "event_base_new出错！" << endl;
 53         return -1;
 54     }
 55     
 56     // （2）创建事件
 57     struct event* listen_event = event_new(base, listener, EV_READ | EV_PERSIST, do_accept, (void*)base);
 58     
 59     // （3）添加事件
 60     event_add(listen_event, NULL);
 61 
 62     // （4）启动事件管理循环
 63     event_base_dispatch(base);
 64 
 65     cout << "Done!" << endl;
 66     return 0;
 67 }
 68 
 69 void do_accept(evutil_socket_t listener, short event, void *arg)
 70 {
 71     struct event_base* base = (struct event_base *)arg;
 72     SOCKADDR_IN sin;
 73     int slen = sizeof sin;
 74     evutil_socket_t fd = accept(listener, (SOCKADDR *)&sin, &slen);
 75     if (fd < 0)
 76     {
 77         cout << "accept出错！" << endl;
 78         return;
 79     }
 80     //if (fd > FD_SETSIZE)
 81     //{
 82     //    cout << "accept返回fd超出FD_SETSIZE限制" << endl;
 83     //    return;
 84     //}
 85     cout << "accept:fd=" << fd << endl;
 86 
 87     // <B>创建“读写事件管理器”，自libevent2之后才有的
 88     struct bufferevent *bev = bufferevent_socket_new(base, fd, BEV_OPT_CLOSE_ON_FREE);
 89 
 90     // <C>设置“读写事件管理器”的回调函数
 91     bufferevent_setcb(bev, read_cb, NULL, error_cb, arg);
 92 
 93     // <D>启动“读写事件管理器”
 94     bufferevent_enable(bev, EV_READ | EV_WRITE | EV_PERSIST);
 95 }
 96 
 97 void read_cb(struct bufferevent *bev, void *arg)
 98 {
 99 #define MAX_LINE    256
100     char szLine[MAX_LINE + 1];
101     evutil_socket_t fd = bufferevent_getfd(bev);
102 
103     int n = 0;
104     while (n = bufferevent_read(bev, szLine, MAX_LINE), n > 0)
105     {
106         szLine[n] = ‘\0‘;
107         cout << "Read Line:" << szLine << endl;
108         bufferevent_write(bev, szLine, n);
109     }
110 }
111 
112 void write_cb(struct bufferevent *bev, void *arg)
113 {
114 
115 }
116 
117 void error_cb(struct bufferevent *bev, short event, void *arg)
118 {
119     evutil_socket_t fd = bufferevent_getfd(bev);
120     cout << "error:fd=" << fd << endl;
121     if (event & BEV_EVENT_TIMEOUT)
122     {
123         cout << "Time out!" << endl;
124     }
125     else if (event & BEV_EVENT_EOF)
126     {
127         cout << "EOF!" << endl;
128     }
129     else if    (event & BEV_EVENT_ERROR)
130     {
131         cout << "Error!" << endl;
132     }
133     bufferevent_free(bev);
134 }