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    利用linux的timerfd_create实现计时器示例分享

    作者:admin 时间:2021-02-15 15:02

    timer_poll.h

    复制代码 代码如下:

    /*
     * File:   timer_poll.h
     * Author: Administrator
     */

    #ifndef TIMER_POLL_H
    #define TIMER_POLL_H
    #include <sys/types.h>
    #include <fcntl.h>
    #include <signal.h>
    #include <sys/epoll.h>
    #include <stdlib.h>
    #include <string.h>
    #include <stdlib.h>
    #include <stdio.h>
    #include <sys/time.h>
    #include <sys/resource.h>
    #include <sys/timerfd.h>
    #include <unistd.h>
    #include <pthread.h>
    #include <map>

    #define MAXFDS 128
    #define EVENTS 100
    class timer;
    typedef int(*timer_callback)(timer &);//user callback

    class timer
    {
    public:

        timer() : timer_internal(0.0), cb(0), timer_id(0), repeat(0), userdata(0){}
        timer(double internal_value, int  (*callback)(timer &ptimer), void *data, int rep) : timer_internal(internal_value), cb(callback), userdata(data), repeat(rep)
        {
            timer_id = timerfd_create(CLOCK_REALTIME, 0);
            setNonBlock(timer_id);
        }

        timer(const timer &ptimer);
        timer & operator=(const timer &ptimer);
        int timer_start();
        int timer_stop();
        int timer_modify_internal(double timer_internal);

        int timer_get_id()
        {
            return timer_id;
        }

        void *timer_get_userdata()
        {
            return userdata;
        }

        timer_callback get_user_callback()
        {
            return cb;
        }

        ~timer()
        {
            timer_stop();
        }

    private:

        bool setNonBlock (int fd)
        {
            int flags = fcntl (fd, F_GETFL, 0);
            flags |= O_NONBLOCK;
            if (-1 == fcntl (fd, F_SETFL, flags))
            {
                return false;
            }
            return true;
        }
        int     timer_id;
        double  timer_internal;
        void    *userdata;
        bool    repeat;//will the timer repeat or only once
        timer_callback cb;
    } ;
    class timers_poll
    {
    public:
        timers_poll(int max_num=128)
        {
            active = 1;
            epfd = epoll_create(max_num);
        }

        int timers_poll_add_timer(timer &ptimer);
        int timers_poll_del_timer(timer &ptimer);
        int run();

        int timers_poll_deactive()
        {
            active = 0;
        }

        ~ timers_poll()
        {

        }
    private:
        int epfd;
        int active;
        std::map<int, timer> timers_map;
        /* data */
    } ;
    #endif /* TIMER_POLL_H */

    timer_poll.cpp

    复制代码 代码如下:

    /*
     * File:   timer_poll.cpp
     * Author: Administrator
     */

    #include <cstdlib>
    #include "timer_poll.h"

    using namespace std;

    timer::timer(const timer& ptimer)
    {
        timer_internal = ptimer.timer_internal;
        cb = ptimer.cb;
        timer_id = ptimer.timer_id;
        repeat = ptimer.repeat;
        userdata = ptimer.userdata;
    }

    timer & timer::operator =(const timer& ptimer)
    {
        if (this == &ptimer)
        {
            return *this;
        }

        timer_internal = ptimer.timer_internal;
        cb = ptimer.cb;
        timer_id = ptimer.timer_id;
        repeat = ptimer.repeat;
        userdata = ptimer.userdata;
        return *this;
    }

    int timer::timer_start()
    {
        struct itimerspec ptime_internal = {0};
        ptime_internal.it_value.tv_sec = (int) timer_internal;
        ptime_internal.it_value.tv_nsec = (timer_internal - (int) timer_internal)*1000000;
        if(repeat)
        {
            ptime_internal.it_interval.tv_sec = ptime_internal.it_value.tv_sec;
            ptime_internal.it_interval.tv_nsec = ptime_internal.it_value.tv_nsec;
        }

        timerfd_settime(timer_id, 0, &ptime_internal, NULL);
        return 0;
    }

    int timer::timer_stop()
    {
        close(timer_id);
        return 0;
    }

    int timer::timer_modify_internal(double timer_internal)
    {
        this->timer_internal = timer_internal;
        timer_start();
    }

    int timers_poll::timers_poll_add_timer(timer& ptimer)
    {
        int timer_id = ptimer.timer_get_id();
        struct epoll_event ev;
        ev.data.fd = timer_id;
        ev.events = EPOLLIN | EPOLLET;
        timers_map[timer_id] = ptimer; //add or modify
        epoll_ctl (epfd, EPOLL_CTL_ADD, timer_id, &ev);
        ptimer.timer_start();

        return 0;
    }

    int timers_poll::timers_poll_del_timer(timer& ptimer)
    {
        int timer_id = ptimer.timer_get_id();
        struct epoll_event ev;
        ev.data.fd = timer_id;
        ev.events = EPOLLIN | EPOLLET;
        epoll_ctl (epfd, EPOLL_CTL_DEL, timer_id, &ev);
        timers_map.erase(timer_id);

        return 0;
    }

    int timers_poll::run()
    {
        char buf[128] ={0};
        for (; active ; )
        {
            struct epoll_event events[MAXFDS] ={0};
            int nfds = epoll_wait (epfd, events, MAXFDS, -1);
            for (int i = 0; i < nfds; ++i)
            {
                std::map<int, timer>::iterator itmp = timers_map.find(events[i].data.fd);
                if (itmp != timers_map.end())
                {
                    //timer ptimer = itmp->second;
                    while (read(events[i].data.fd, buf, 128) > 0);
                    itmp->second.get_user_callback()(itmp->second);
                }
            }
        }
    }

    main.cpp

    复制代码 代码如下:

    /*
     * File:   main.cpp
     * Author: Administrator
     */

    #include <cstdlib>
    #include <iostream>

    #include "timer_poll.h"

    using namespace std;

    int callback(timer &ptimer)
    {
        printf("timer id=%d:%s\n", ptimer.timer_get_id(), (char *) ptimer.timer_get_userdata());
        return 0;
    }

    void *thread_fun(void *data)
    {
        timers_poll *my_timers = (timers_poll *)data;
        my_timers->run();
    }

    /*
     *
     */
    int main(int argc, char** argv)
    {
        timers_poll my_timers(128);
        pthread_t thread_id = 0;
        pthread_create(&thread_id, NULL, thread_fun, &my_timers);

       
        timer timer1(1.05, callback, (void *) "hello 1",0);
        timer timer2(1.10, callback, (void *) "hello 2",0);

       // timer1.timer_start();
       // timer2.timer_start();

        my_timers.timers_poll_add_timer(timer1);
        my_timers.timers_poll_add_timer(timer2);

        sleep(5);
        my_timers.timers_poll_del_timer(timer2);
        cout<<"del complete"<<endl;
        timer1.timer_modify_internal(5.1);
        //timer2.timer_modify_internal(10.1);
        cout<<"modify complete"<<endl;
        sleep(4);
        //my_timers.timers_poll_del_timer(timer2);

        //sleep(5);

        //my_timers.timers_poll_deactive();

        pthread_join(thread_id,NULL);
        return 0;
    }

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