我个人的Linux TCP server和client测试源码，C语言（2）（★firecat推荐★）

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 
#include 
#include 
#include 

#include 
#include 
#include 
#include     /*setrlimit */

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

#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：

把libevent 2.1.8源码的最小堆提取出来，自己封装成定时器使用（2）（★firecat推荐★）

把libevent 2.1.8源码的最小堆提取出来，自己封装成定时器使用（3）（★firecat推荐★）

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参考文章：

我个人的Linux TCP server和client测试源码，C语言（1）（★firecat推荐★）

IO多路复用之epoll总结 --- 注意源码有一处错误，需要修正为：

static void handle_accpet(int epollfd,int listenfd)
{
    int clifd;
    struct sockaddr_in cliaddr;
    socklen_t  cliaddrlen = sizeof(cliaddr);