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。

 

 1 #include <iostream>
 2 #include <thread>
 3 #include <string>
 4 #include <ctime>
 5 
 6 using namespace std;
 7 
 8 bool pass_flg = false;
 9 
10 void Pt1()
11 {
12     cout << "Pt1线程运行" << endl;
13     clock_t curr_st = clock();
14     clock_t last_st = clock();
15 
16     while (true)
17     {
18         curr_st = clock();
19         if ((curr_st - last_st) > 1000)
20         {
21             last_st = curr_st;
22             pass_flg = true;
23         }
24         std::this_thread::sleep_for(std::chrono::milliseconds(10)); //线程睡眠 避免cpu 占用过大
25     }
26 }
27 void Pt2()
28 {
29     cout << "Pt2线程运行" << endl;
30     clock_t curr_st = clock();
31     clock_t last_st = clock();
32 
33     while (true)
34     {
35         if (pass_flg)
36         {
37             pass_flg = false;
38 
39             clock_t tmp_val = 0;
40 
41             curr_st = clock();
42             last_st = curr_st;
43             while (tmp_val < 1000)
44             {
45                 curr_st = clock();
46                 tmp_val = (curr_st - last_st);
47                 if ((1000 - tmp_val) > 50)
48                 {
49                     std::this_thread::sleep_for(std::chrono::milliseconds(10));
50                 }
51             }
52 
53             cout << "Pt2 print: " << tmp_val << endl;
54 
55         }
56         std::this_thread::sleep_for(std::chrono::milliseconds(10)); //线程睡眠 避免cpu 占用过大
57     }
58 }
59 
60 //#include<Windows.h>
61 //
62 //void ShowWindow()
63 //{
64 //    cout << "show ..." << endl;
65 //}
66 //
67 //void  CALLBACK HideWnd(HWND   hwnd, UINT   uMsg, UINT   idEvent, DWORD   dwTime);//回调函数声明
68 //
69 //void  CALLBACK HideWnd(HWND   hwnd, UINT   uMsg, UINT   idEvent, DWORD   dwTime)//回调函数
70 //{
71 //    ShowWindow();
72 //    KillTimer(hwnd, 1);
73 //}
74 
75 int main()
76 {
77     std::thread t1(Pt1);
78     std::thread t2(Pt2);
79 
80     //HWND thand;
81     //SetTimer(thand, 1, 1000, HideWnd);
82 
83     std::string tmp;
84     std::cin >> tmp;
85 }