基于c++11设计一个定时器timer

来源：互联网发布：家庭网限制80端口吗编辑：程序博客网时间：2024/06/09 21:35
这里设计了一个异步定时器，在windows下定时器通常是基于消息队列实现的，也是同步的。c++11提供了一系列方便我写一个跨平台定时器的标准函数和类。以下是一个简单的但是完备的定时器的实现。
#pragma once#include <limits>#include <condition_variable>    // std::condition_variable#include <chrono>#include <thread>#include <mutex>#include <memory>#include <functional>#include <atomic>#include "min_max_heap.hpp"//仿照消息队列queue，添加了几个函数，他是最小堆。代码就不上传了#if defined(_WIN32)#define TRACE(...)  _CrtDbgReport( _CRT_WARN, __FILE__, __LINE__, "min_max_heap",__VA_ARGS__  );#else#define TRACE(...) printf(__VA_ARGS__);#endifnamespace prudens{    uint64_t now()    {        return duration_cast<milliseconds>(            system_clock::now() - time_point<system_clock>() ).count();    }    typedef  std::function<void( uint32_t, void* ) > timer_callback;    struct timer_msg    {#define MAX_MACRO_COMPILE_SUPPORT        uint32_t timer_id;        uint32_t elapsed;        uint64_t expired;        bool repeat;        void* userdata;        timer_callback action;        timer_msg() :timer_id( 0 ),            elapsed( 0 ),            expired( std::numeric_limits<uint64_t>::max MAX_MACRO_COMPILE_SUPPORT() ),            repeat( false ),            userdata( nullptr ) {}        bool operator < ( const timer_msg& other )const        {            return this->elapsed < other.elapsed;        }    };    class timer    {    public:        class TimerQueue        {        public:            TimerQueue() {                _stop.store( false );                _flag.store( false );            }            void run()            {                while ( true )                {                    while ( true )                    {                        if (_stop)                        {                            return;                        }                        timer_msg msg;                        uint64_t t = now();                        {                            std::lock_guard<std::mutex> guard( _mutex );                            if ( !_timers.empty() )                            {                                msg = _timers.top();                            }                        }                        if ( msg.expired >= t )                        {                            break;                        }                        if ( msg.action )                        {                            msg.action( msg.timer_id, msg.userdata );                        }                        {                            std::lock_guard<std::mutex> guard( _mutex );                            if ( !_timers.empty() )                            {                                _timers.pop();                                if ( msg.repeat )                                {                                    msg.expired = msg.elapsed + now();                                    _timers.push( msg );                                }                            }                        }                    }                    int32_t sleep_time = std::numeric_limits<int32_t>::max MAX_MACRO_COMPILE_SUPPORT ();//列表为空的时候就睡眠30ms                    {                        std::lock_guard<std::mutex> guard( _mutex );                        if ( !_timers.empty() )                        {                            sleep_time = static_cast<int32_t>(_timers.top().expired - now());                            if (sleep_time<0)                            {                                continue;                            }                        }                    }                    if (_stop)                    {                        return;                    }                    std::unique_lock <std::mutex> lck( _mutex );                    if ( _flag.load() == false )                    {                        if ( _cv.wait_for( lck, milliseconds( sleep_time ), [this] ()->bool { return this->_flag.load(); } ) )                        {                            TRACE( "cv is time out:%d\n", sleep_time );                        }                        else                        {                            TRACE( "cv flag is true\n" );                        }                    }                    _flag.store( false );                }            }            void push( timer_msg& msg )            {                std::unique_lock <std::mutex> lck( _mutex );                _timers.push( msg );                _flag.store( true );                _cv.notify_all();                            }            void clear()            {                std::lock_guard<std::mutex> guard( _mutex );                while ( !_timers.empty() )                {                    _timers.pop();                }            }            void remove( uint32_t time_id )            {                std::lock_guard<std::mutex> guard( _mutex );                _timers.remove_if( [&] ( const timer_msg& msg )                {                    return msg.timer_id == time_id;                } );            }        private:            std::atomic_bool _stop;            prudens::max_min_heap<timer_msg> _timers;            std::mutex _mutex;            std::condition_variable _cv;            std::atomic_bool _flag;        };        timer()        {            _queue = std::make_shared<TimerQueue>();            std::thread( [] ( std::shared_ptr<TimerQueue> queue )            {                queue->run();            },_queue ).detach();        }        ~timer()        {            _queue->clear();        }        uint32_t start( int elapsed_ms, bool repeat, timer_callback action,void* userdata )        {            timer_msg msg;            msg.elapsed = elapsed_ms ;            msg.expired = elapsed_ms + now();            msg.repeat = repeat;            msg.userdata = userdata;            msg.timer_id = s_timer_id++;            msg.action = action;            _queue->push( msg );            return msg.timer_id;        }        void remove( uint32_t time_id )        {            _queue->remove( time_id );        }    private:        std::shared_ptr<TimerQueue> _queue;        static uint32_t s_timer_id;    };    uint32_t timer::s_timer_id = 1;}
0 0