1.移植移植libevent
到官网下载https://libevent.org/ libevent-2.1.12-stable.tar.gz 或 libevent-2.1.10-stable.tar.gz
解压tar -zxvf libevent-2.1.12-stable.tar.gz
进入解压目录:cd libevent-2.1.12-stable/
配置编译工具链: ./configure --prefix=/home/jest/libevent --host=arm-linux-gnueabihf CC=/xxx/xxx/xxx/arm-linux-gnueabihf-gcc CXX=/xxx/xxx/xxx/arm-linux-gnueabihf-g++ ("/xxx/xxx/xxx/"为存放工具链的目录)
执行后出现错误:
没有找到openssl,那么可以disable openssl功能(如果使用是libevent-2.1.10-stable.tar.gz以下版本是没有这个错误)
这样配置编译工具链:./configure --prefix=/home/jest/libevent --host=arm-linux-gnueabihf CC=/xxx/xxx/xxx/arm-linux-gnueabihf-gcc CXX=/xxx/xxx/xxx/arm-linux-gnueabihf-g++ --disable-openssl,执行成功
make -j4 (4核编译)
make install
2.测试libevent(server是一个echo服务器)
服务端代码:server.c
#include<netinet/in.h> #include<sys/socket.h> #include<unistd.h> #include<stdio.h> #include<string.h> #include<event.h> #include<event2/listener.h> #include<event2/bufferevent.h> #include<event2/thread.h> void listener_cb(struct evconnlistener *listener, evutil_socket_t fd, struct sockaddr*sock, int socklen, void*arg); void socket_read_cb(struct bufferevent*bev, void*arg); void socket_event_cb(struct bufferevent*bev, short events, void*arg); int main() { //evthread_use_pthreads();//enable threads struct sockaddr_in sin; memset(&sin, 0, sizeof(struct sockaddr_in)); sin.sin_family = AF_INET; sin.sin_port = htons(9999); struct event_base*base = event_base_new(); struct evconnlistener *listener = evconnlistener_new_bind(base, listener_cb, base, LEV_OPT_REUSEABLE | LEV_OPT_CLOSE_ON_FREE, 10, (struct sockaddr*) &sin, sizeof(struct sockaddr_in)); //事件循环开始 event_base_dispatch(base); evconnlistener_free(listener); event_base_free(base); return 0; } /* * 当新客户端连接上服务器,此函数被调用,libevent已经帮助accept了此客户端,该客户端的文件描述符位fd */ void listener_cb(struct evconnlistener*listener, evutil_socket_t fd, struct sockaddr*sock, int socklen, void*arg) { printf("accept a client %d\n", fd); struct event_base*base = (struct event_base*) arg; //为此客户端分配一个bufferevent struct bufferevent *bev = bufferevent_socket_new(base, fd, BEV_OPT_CLOSE_ON_FREE); bufferevent_setcb(bev, socket_read_cb, NULL, socket_event_cb, NULL); bufferevent_enable(bev, EV_READ | EV_PERSIST); } void socket_read_cb(struct bufferevent*bev, void*arg) { char msg[4096]; size_t len = bufferevent_read(bev, msg, sizeof(msg) - 1); msg[len] = '\0'; printf("server read the data %s\n", msg); char reply[] = "I have read your data"; bufferevent_write(bev, reply, strlen(reply)); } void socket_event_cb(struct bufferevent*bev, short events, void*arg) { if (events & BEV_EVENT_EOF) { printf("connection closed\n"); } else if (events & BEV_EVENT_ERROR) { printf("some other error\n"); } //自动关闭套接字和释放读写缓冲区 bufferevent_free(bev); }
客户端代码:client.c
#include<sys/types.h> #include<sys/socket.h> #include<netinet/in.h> #include<arpa/inet.h> #include<errno.h> #include<unistd.h> #include<stdio.h> #include<string.h> #include<stdlib.h> #include<event.h> #include<event2/bufferevent.h> #include<event2/buffer.h> #include<event2/util.h> int tcp_connect_server(const char*server_ip, int port); void cmd_msg_cb(int fd, short events, void*arg); void server_msg_cb(struct bufferevent*bev, void*arg); void event_cb(struct bufferevent*bev, short event, void*arg); int main(int argc, char**argv) { if (argc < 3) { //2param printf("please input 2 parameter:ip_addr port\n"); return -1; } struct event_base*base = event_base_new(); struct bufferevent*bev = bufferevent_socket_new(base, -1, BEV_OPT_CLOSE_ON_FREE); //监听终端输入事件 struct event*ev_cmd = event_new(base, STDIN_FILENO, EV_READ | EV_PERSIST, cmd_msg_cb, (void*) bev); event_add(ev_cmd, NULL); struct sockaddr_in server_addr; memset(&server_addr, 0, sizeof(server_addr)); server_addr.sin_family = AF_INET; server_addr.sin_port = htons(atoi(argv[2])); inet_aton(argv[1], &server_addr.sin_addr); bufferevent_socket_connect(bev, (struct sockaddr*) &server_addr, sizeof(server_addr)); bufferevent_setcb(bev, server_msg_cb, NULL, event_cb, (void*) ev_cmd); bufferevent_enable(bev, EV_READ | EV_PERSIST); event_base_dispatch(base); printf("finished \n"); return 0; } void cmd_msg_cb(int fd, short events, void*arg) { char msg[1024]; int ret = read(fd, msg, sizeof(msg)); if (ret < 0) { perror("read fail "); exit(1); } struct bufferevent*bev = (struct bufferevent*) arg; //把终端的消息发送给服务器端 bufferevent_write(bev, msg, ret); } void server_msg_cb(struct bufferevent*bev, void*arg) { char msg[1024]; size_t len = bufferevent_read(bev, msg, sizeof(msg)); msg[len] = '\0'; printf("recv %s from server \n", msg); } void event_cb(struct bufferevent* bev, short event, void*arg) { if (event & BEV_EVENT_EOF) { printf("connection closed\n"); } else if (event & BEV_EVENT_ERROR) { printf("some other error\n"); } else if (event & BEV_EVENT_CONNECTED) { printf("the client has connected to server\n"); return; } //自动关闭套接字和清空缓冲区 bufferevent_free(bev); struct event*ev = (struct event*) arg; event_free(ev); }
编译脚本:
将/home/jest/libevent目录的lib与include拷贝到测试源码的libevent2.1.12-arm目录,编写编译脚本build.sh如下
arm-linux-gnueabihf-gcc ./server.c -o server.out -I./ -I./libevent2.1.12-arm/include/event2 -I./libevent2.1.12-arm/include ./libevent2.1.12-arm/lib/libevent.a -lrt -lpthread arm-linux-gnueabihf-gcc ./client.c -o client.out -I./ -I./libevent2.1.12-arm/include/event2 -I./libevent2.1.12-arm/include ./libevent2.1.12-arm/lib/libevent.a -lpthread
更改为可执行权限后执行build.sh,将server.out client.out放入板子后验证
server:
client1:
client2: