在我的昨天的博文《[原]我在Windows环境下的首个Libevent测试实例》中介绍了在Windows环境下如何编译一个echo server例子。今天我又试了一下在Linux环境中编译这个例子,遇到了一些问题,学习到了很多知识。这里也顺便记一下,增强一下理解。直接上代码:
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1 #include <iostream> 2 #include <sys/socket.h> 3 #include <event2/event.h> 4 #include <event2/bufferevent.h> 5 using namespace std; 6 7 void do_accept(evutil_socket_t listener, short event, void *arg); 8 void read_cb(struct bufferevent *bev, void *arg); 9 void error_cb(struct bufferevent *bev, short event, void *arg); 10 void write_cb(struct bufferevent *bev, void *arg); 11 12 int main() 13 { 14 int ret = 0; 15 evutil_socket_t listener; 16 listener = socket(AF_INET, SOCK_STREAM, 0); 17 evutil_make_listen_socket_reuseable(listener); 18 19 struct sockaddr_in sin; 20 sin.sin_family = AF_INET; 21 sin.sin_addr.s_addr = 0; 22 sin.sin_port = htons(6789); 23 if (bind(listener, (struct sockaddr *)&sin, sizeof(sin)) < 0) 24 { 25 cout << "bind error" << endl; 26 return -1; 27 } 28 if (listen(listener, 32) < 0) 29 { 30 cout << "listen error" << endl; 31 return -1; 32 } 33 cout << "Listening..." << endl; 34 35 evutil_make_socket_nonblocking(listener); 36 struct event_base* base = event_base_new(); 37 if (NULL == base) 38 { 39 cout << "event_base_new error" << endl; 40 return -1; 41 } 42 43 struct event* listen_event = event_new(base, listener, EV_READ | EV_PERSIST, do_accept, (void*)base); 44 event_add(listen_event, NULL); 45 event_base_dispatch(base); 46 event_base_free(base); 47 48 cout << "Done!" << endl; 49 return 0; 50 } 51 52 void do_accept(evutil_socket_t listener, short event, void *arg) 53 { 54 struct event_base* base = (struct event_base *)arg; 55 struct sockaddr_in sin; 56 socklen_t slen = sizeof sin; 57 evutil_socket_t fd = accept(listener, (struct sockaddr *)&sin, &slen); 58 if (fd < 0) 59 { 60 cout << "accept error" << endl; 61 return; 62 } 63 //if (fd > FD_SETSIZE) 64 //{ 65 // cout << "accept����fd����FD_SETSIZE����" << endl; 66 // return; 67 //} 68 cout << "accept:fd=" << fd << endl; 69 70 struct bufferevent *bev = bufferevent_socket_new(base, fd, BEV_OPT_CLOSE_ON_FREE); 71 bufferevent_setcb(bev, read_cb, NULL, error_cb, arg); 72 bufferevent_enable(bev, EV_READ | EV_WRITE | EV_PERSIST); 73 } 74 75 void read_cb(struct bufferevent *bev, void *arg) 76 { 77 #define MAX_LINE 256 78 char szLine[MAX_LINE + 1]; 79 evutil_socket_t fd = bufferevent_getfd(bev); 80 81 int n = 0; 82 while (n = bufferevent_read(bev, szLine, MAX_LINE), n > 0) 83 { 84 szLine[n] = '