1、直接上TCP Server源码，这种方法没有使用向muduo那样的活塞式buffer，可谓简单粗暴：
#include <stdio.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include <sys/socket.h> #include <sys/epoll.h> #include <sys/types.h> #include <sys/resource.h> /*setrlimit */ #include <unistd.h> #include <string.h> #include <fcntl.h> #include <netinet/in.h> #include <arpa/inet.h> #include <assert.h> #include <signal.h> #include <pthread.h> #define IPADDRESS "127.0.0.1" #define PORT 8011 #define MAXSIZE 1024 #define LISTENQ 5 #define FDSIZE 50000 #define EPOLLEVENTS 100 int stop_server = 0; //函数声明 //创建套接字并进行绑定 static int socket_bind(const char* ip,int port); //IO多路复用epoll static void do_epoll(int listenfd); //事件处理函数 static void handle_events(int epollfd,struct epoll_event *events,int num,int listenfd,char *buf); //处理接收到的连接 static void handle_accpet(int epollfd,int listenfd); //读处理 static void do_read(int epollfd,int fd,char *buf); //写处理 static void do_write(int epollfd,int fd,char *buf); //添加事件 static void add_event(int epollfd,int fd,int state); //修改事件 static void modify_event(int epollfd,int fd,int state); //删除事件 static void delete_event(int epollfd,int fd,int state); //other static int do_error(int fd, int *error); static int setnonblocking(int fd); static void daemonize(void); static int set_fdlimit(); static void signal_exit_handler(); static void signal_exit_func(int signo); int main(int argc,char *argv[]) { //设置每个进程允许打开的最大文件数,socket if (set_fdlimit() < 0) { return -1; } int background = 0; if (background) { daemonize(); } //设置信号处理,SIG_IGN表示忽略信号,SIG_DFL表示使用信号的默认处理方式 //signal(SIGHUP, SIG_IGN); //开启的话，就捕获不到终端窗口关闭的信号了。即窗口关闭，进程仍然进行。 signal(SIGPIPE, SIG_IGN); /* if (argc != 2) { fprintf(stderr, "Usage: %s port\n", argv[0]); return 1; } int port = atoi(argv[1]);*/ int listenfd; listenfd = socket_bind(IPADDRESS,PORT); listen(listenfd,LISTENQ); printf("start listening...\n"); signal_exit_handler(); do_epoll(listenfd); return 0; } static int socket_bind(const char* ip,int port) { int listenfd; struct sockaddr_in servaddr; listenfd = socket(AF_INET,SOCK_STREAM,0); if (listenfd == -1) { perror("socket error:"); exit(1); } bzero(&servaddr,sizeof(servaddr)); servaddr.sin_family = AF_INET; //inet_pton(AF_INET,ip,&servaddr.sin_addr); servaddr.sin_port = htons(port); servaddr.sin_addr.s_addr = htonl(INADDR_ANY); int error; int reuse = 1; int ret = setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse)); if (ret == -1) { return do_error(listenfd, &error); } if (bind(listenfd,(struct sockaddr*)&servaddr,sizeof(servaddr)) == -1) { perror("bind error: "); exit(1); } return listenfd; } static void do_epoll(int listenfd) { int epollfd; struct epoll_event events[EPOLLEVENTS]; int ret; char buf[MAXSIZE]; memset(buf,0,MAXSIZE); //创建一个描述符 int error; epollfd = epoll_create(1024);//1024 is just a hint for the kernel if (epollfd == -1) { return do_error(epollfd, &error); } //添加监听描述符事件 add_event(epollfd,listenfd,EPOLLIN); while ( stop_server == 0 ) { //获取已经准备好的描述符事件 ret = epoll_wait(epollfd,events,EPOLLEVENTS,-1); handle_events(epollfd,events,ret,listenfd,buf); } close(epollfd); } static void handle_events(int epollfd,struct epoll_event *events,int num,int listenfd,char *buf) { int i; int fd; //进行选好遍历 for (i = 0;i < num;i++) { fd = events[i].data.fd; //根据描述符的类型和事件类型进行处理 if ((fd == listenfd) &&(events[i].events & EPOLLIN)) handle_accpet(epollfd,listenfd); else if (events[i].events & EPOLLIN) do_read(epollfd,fd,buf); else if (events[i].events & EPOLLOUT) do_write(epollfd,fd,buf); } } static void handle_accpet(int epollfd,int listenfd) { int clifd; struct sockaddr_in cliaddr; socklen_t cliaddrlen = sizeof(cliaddr); clifd = accept(listenfd,(struct sockaddr*)&cliaddr,&cliaddrlen); if (clifd == -1) perror("accpet error:"); else { printf("accept a new client: %s:%d\n",inet_ntoa(cliaddr.sin_addr),cliaddr.sin_port); //添加一个客户描述符和事件 add_event(epollfd,clifd,EPOLLIN); } } static void do_read(int epollfd,int fd,char *buf) { int nread; nread = read(fd,buf,MAXSIZE); if (nread == -1) { perror("read error:"); close(fd); delete_event(epollfd,fd,EPOLLIN); } else if (nread == 0) { fprintf(stderr,"client close,fd=%d\n",fd); close(fd); delete_event(epollfd,fd,EPOLLIN); } else { printf("read message is: %s,fd=%d\n",buf,fd); //修改描述符对应的事件，由读改为写 modify_event(epollfd,fd,EPOLLOUT); } } static void do_write(int epollfd,int fd,char *buf) { int nwrite; nwrite = write(fd,buf,strlen(buf)); if (nwrite == -1) { perror("write error:"); close(fd); delete_event(epollfd,fd,EPOLLOUT); } else modify_event(epollfd,fd,EPOLLIN); memset(buf,0,MAXSIZE); } static void add_event(int epollfd,int fd,int state) { struct epoll_event ev; ev.events = state; ev.data.fd = fd; epoll_ctl(epollfd,EPOLL_CTL_ADD,fd,&ev); setnonblocking(fd); } static void delete_event(int epollfd,int fd,int state) { struct epoll_event ev; ev.events = state; ev.data.fd = fd; epoll_ctl(epollfd,EPOLL_CTL_DEL,fd,&ev); } static void modify_event(int epollfd,int fd,int state) { struct epoll_event ev; ev.events = state; ev.data.fd = fd; epoll_ctl(epollfd,EPOLL_CTL_MOD,fd,&ev); } static int do_error(int fd, int *error) { fprintf(stderr, "error: %s\n", strerror(errno)); *error = errno; while ((close(fd) == -1) && (errno == EINTR)); errno = *error; return 1; } static 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; } static void daemonize(void) { //come from /redis/server.c/daemonize() int fd; if (fork() != 0) exit(0); /* parent exits */ setsid(); /* create a new session */ /* Every output goes to /dev/null. If Redis is daemonized but * the 'logfile' is set to 'stdout' in the configuration file * it will not log at all. */ if ((fd = open("/dev/null", O_RDWR, 0)) != -1) { dup2(fd, STDIN_FILENO); dup2(fd, STDOUT_FILENO); dup2(fd, STDERR_FILENO); if (fd > STDERR_FILENO) close(fd); } } static int set_fdlimit() { //设置每个进程允许打开的最大文件数 //这项功能等价于linux终端命令 "ulimit -n 102400" struct rlimit rt; rt.rlim_max = rt.rlim_cur = FDSIZE; if (setrlimit(RLIMIT_NOFILE, &rt) == -1) { perror("setrlimit error"); return -1; } return 0; } static void signal_exit_handler() { struct sigaction sa; memset(&sa, 0, sizeof(sa)); sa.sa_handler = signal_exit_func; sigaction(SIGINT, &sa, NULL);//当按下ctrl+c时，它的效果就是发送SIGINT信号 sigaction(SIGTERM, &sa, NULL);//kill pid sigaction(SIGQUIT, &sa, NULL);//ctrl+\代表退出SIGQUIT //SIGSTOP和SIGKILL信号是不可捕获的,所以下面两句话写了等于没有写 sigaction(SIGKILL, &sa, NULL);//kill -9 pid sigaction(SIGSTOP, &sa, NULL);//ctrl+z代表停止 //#define SIGTERM 15 //#define SIGKILL 9 //kill和kill -9，两个命令在linux中都有杀死进程的效果，然而两命令的执行过程却大有不同，在程序中如果用错了，可能会造成莫名其妙的现象。 //执行kill pid命令，系统会发送一个SIGTERM信号给对应的程序。 //执行kill -9 pid命令，系统给对应程序发送的信号是SIGKILL，即exit。exit信号不会被系统阻塞，所以kill -9能顺利杀掉进程。 } static void signal_exit_func(int signo) { printf("exit signo is %d\n", signo); stop_server = 1; }
2、添加buffer和最小堆定时器的完整版本，请参见：
