main.cpp

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/epoll.h>
#include "locker.h"
#include "threadpool.h"
#include "http_conn.h"
#include "lst_timer.h"

#define MAX_FD 65536           // max num of fd
#define MAX_EVENT_NUMBER 10000 // max num of listened events
#define TIMESLOT 5

static int pipefd[2];
static sort_timer_lst timer_lst;
static int epoll_fd = 0;

extern void addfd(int epollfd, int fd, bool one_shot);
extern void removefd(int epollfd, int fd);
extern int setnonblocking(int fd);

void addfd(int epollfd, int fd)
{
    epoll_event event;
    event.data.fd = fd;
    event.events = EPOLLIN | EPOLLET;
    epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &event);
    setnonblocking(fd);
}

void sig_handler(int sig)
{
    int save_errno = errno;
    int msg = sig;
    send(pipefd[1], (char *)&msg, 1, 0);
    errno = save_errno;
}

void addsig(int sig)
{
    printf("addsig\n");
    struct sigaction sa;
    memset(&sa, '\0', sizeof(sa));
    sa.sa_handler = sig_handler;
    sa.sa_flags |= SA_RESTART;
    sigfillset(&sa.sa_mask);
    assert(sigaction(sig, &sa, NULL) != -1);
}

void timer_handler()
{
    // 定时处理任务，实际上就是调用tick()函数
    timer_lst.tick_();
    // 因为一次 alarm 调用只会引起一次SIGALARM 信号，所以我们要重新定时，以不断触发 SIGALARM信号。
    alarm(TIMESLOT);
}

// 定时器回调函数，它删除非活动连接socket上的注册事件，并关闭之。
void cb_func(client_data *user_data)
{
    epoll_ctl(epoll_fd, EPOLL_CTL_DEL, user_data->sockfd, 0);
    assert(user_data);
    close(user_data->sockfd);
    printf("close fd %d\n", user_data->sockfd);
}

void addsig(int sig, void(handler)(int))
{
    struct sigaction sa;
    memset(&sa, '\0', sizeof(sa));
    sa.sa_handler = handler;
    sigfillset(&sa.sa_mask);
    assert(sigaction(sig, &sa, NULL) != -1);
}

int main(int argc, char *argv[])
{
    if (argc <= 1)
    {
        printf("port number need to be provided");
        return 1;
    }

    int port = atoi(argv[1]);
    addsig(SIGPIPE, SIG_IGN);

    threadpool<http_conn> *pool = NULL;
    try
    {
        pool = new threadpool<http_conn>;
    }
    catch (...)
    {
        return 1;
    }

    http_conn *users = new http_conn[MAX_FD];

    int ret = 0;
    struct sockaddr_in address;
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(port);

    int listenfd = socket(PF_INET, SOCK_STREAM, 0);
    assert(listen >= 0);

    // 端口复用
    int reuse = 1;
    setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse));

    ret = bind(listenfd, (struct sockaddr *)&address, sizeof(address));
    assert(ret != -1);

    ret = listen(listenfd, 5);
    assert(ret != -1);

    epoll_event events[MAX_EVENT_NUMBER];
    int epollfd = epoll_create(5);
    assert(epollfd != -1);

    addfd(epollfd, listenfd, false);
    http_conn::m_epollfd = epollfd;

    // 创建管道
    ret = socketpair(PF_UNIX, SOCK_STREAM, 0, pipefd);
    assert(ret != -1);
    setnonblocking(pipefd[1]);
    addfd(epollfd, pipefd[0]);

    // 设置信号处理函数
    addsig(SIGALRM);
    addsig(SIGTERM);
    bool stop_server = false;

    client_data *users_timer = new client_data[MAX_FD];
    bool timeout = false;
    alarm(TIMESLOT); // 定时,5秒后产生SIGALARM信号

    while (!stop_server)
    {
        int number = epoll_wait(epollfd, events, MAX_EVENT_NUMBER, -1);
        if (number < 0 && errno != EINTR)
        {
            printf("epoll failure\n");
            break;
        }

        for (int i = 0; i < number; i++)
        {
            int socketfd = events[i].data.fd;
            if (socketfd == listenfd)
            {

                struct sockaddr_in client_address;
                socklen_t client_addrlength = sizeof(client_address);

                int connfd = accept(socketfd, (struct sockaddr *)&client_address, &client_addrlength);
                if (connfd < 0)
                {
                    printf("errno is: %d\n", errno);
                    continue;
                }

                if (http_conn::m_user_count >= MAX_FD)
                {
                    close(connfd);
                    continue;
                }
                users[connfd].init(connfd, client_address);

                users_timer[connfd].address = client_address;
                users_timer[connfd].sockfd = connfd;

                // 创建定时器，设置其回调函数与超时时间，然后绑定定时器与用户数据，最后将定时器添加到链表timer_lst中
                util_timer *timer = new util_timer;
                timer->user_data = &users_timer[connfd];
                timer->cb_func = cb_func;
                time_t cur = time(NULL);
                timer->expire = cur + 3 * TIMESLOT;
                users_timer[connfd].timer = timer;
                timer_lst.add_timer(timer);
            }
            else if ((socketfd == pipefd[0]) && (events[i].events & EPOLLIN))
            {
                // 处理信号
                printf("sig\n");
                int sig;
                char signals[1024];
                ret = recv(pipefd[0], signals, sizeof(signals), 0);
                if (ret == -1)
                {
                    continue;
                }
                else if (ret == 0)
                {
                    continue;
                }
                else
                {
                    for (int i = 0; i < ret; ++i)
                    {
                        switch (signals[i])
                        {
                        case SIGALRM:
                        {
                            // 用timeout变量标记有定时任务需要处理，但不立即处理定时任务
                            // 这是因为定时任务的优先级不是很高，我们优先处理其他更重要的任务。
                            timeout = true;
                            break;
                        }
                        case SIGTERM:
                        {
                            stop_server = true;
                        }
                        }
                    }
                }
            }
            else if (events[i].events & (EPOLLRDHUP | EPOLLHUP | EPOLLERR))
            {
                util_timer *timer = users_timer[socketfd].timer;
                users[socketfd].close_conn();
                if (timer)
                {
                    timer_lst.del_timer(timer);
                }
            }
            else if (events[i].events & EPOLLIN)
            {
                util_timer *timer = users_timer[socketfd].timer;
                if (users[socketfd].read())
                {
                    pool->append(users + socketfd);
                    if (timer)
                    {
                        time_t cur = time(NULL);
                        timer->expire = cur + 3 * TIMESLOT;
                        printf("adjust timer once\n");
                        timer_lst.adjust_timer(timer);
                    }
                }
                else
                {
                    users[socketfd].close_conn();
                    if (timer)
                    {
                        timer_lst.del_timer(timer);
                    }
                }
            }
            else if (events[i].events & EPOLLOUT)
            {
                util_timer *timer = users_timer[socketfd].timer;
                if (!users[socketfd].write())
                {
                    users[socketfd].close_conn();
                    if (timer)
                    {
                        timer_lst.del_timer(timer);
                    }
                }
            }
        }
        // 最后处理定时事件，因为I/O事件有更高的优先级。当然，这样做将导致定时任务不能精准的按照预定的时间执行。
        if (timeout)
        {
            printf("timeout\n");
            // 定时处理任务，实际上就是调用tick()函数
            timer_lst.tick_();
            // 因为一次 alarm 调用只会引起一次SIGALARM 信号，所以我们要重新定时，以不断触发 SIGALARM信号。
            alarm(TIMESLOT);
            timeout = false;
        }
    }
    close(epollfd);
    close(listenfd);
    close(pipefd[1]);
    close(pipefd[0]);
    delete[] users;
    delete[] users_timer;
    delete pool;
    return 0;
}