C++ windows 精确延时简单实现

C++ 线程在进入sleep 之后唤醒会导致延时不准确，测试达到最大38ms 延时，采用组合睡眠方式，最后延时判断阶段能逼近延时情况。

 

#include <iostream>
#include <thread>
#include <string>
#include <ctime>

using namespace std;

bool pass_flg = false;

void Pt1()
{
    cout << "Pt1线程运行" << endl;
    clock_t curr_st = clock();
    clock_t last_st = clock();

    while (true)
    {
        curr_st = clock();
        if ((curr_st - last_st) > 1000)
        {
            last_st = curr_st;
            pass_flg = true;
        }
        std::this_thread::sleep_for(std::chrono::milliseconds(10)); //线程睡眠 避免cpu 占用过大
    }
}
void Pt2()
{
    cout << "Pt2线程运行" << endl;
    clock_t curr_st = clock();
    clock_t last_st = clock();

    while (true)
    {
        if (pass_flg)
        {
            pass_flg = false;

            clock_t tmp_val = 0;

            curr_st = clock();
            last_st = curr_st;
            while (tmp_val < 1000)
            {
                curr_st = clock();
                tmp_val = (curr_st - last_st);
                if ((1000 - tmp_val) > 50)
                {
                    std::this_thread::sleep_for(std::chrono::milliseconds(10));
                }
            }

            cout << "Pt2 print: " << tmp_val << endl;

        }
        std::this_thread::sleep_for(std::chrono::milliseconds(10)); //线程睡眠 避免cpu 占用过大
    }
}

//#include<Windows.h>
//
//void ShowWindow()
//{
//    cout << "show ..." << endl;
//}
//
//void  CALLBACK HideWnd(HWND   hwnd, UINT   uMsg, UINT   idEvent, DWORD   dwTime);//回调函数声明
//
//void  CALLBACK HideWnd(HWND   hwnd, UINT   uMsg, UINT   idEvent, DWORD   dwTime)//回调函数
//{
//    ShowWindow();
//    KillTimer(hwnd, 1);
//}

int main()
{
    std::thread t1(Pt1);
    std::thread t2(Pt2);

    //HWND thand;
    //SetTimer(thand, 1, 1000, HideWnd);

    std::string tmp;
    std::cin >> tmp;
}