关于C/C++获取事件，计算时间差方式

关于C++获取事件，计算时间差方式

方案1：clock_t

方案2：gettimeofday

方案3：high_resolution_clock

代码如下：

 1 #include <iostream>
 2 #include <memory>
 3 #include <sys/time.h> //for gettimeofday
 4 #include <unistd.h>
 5 #include <thread>
 6 #include <time.h>  //for clock_t
 7 #include <chrono>  //for high_resolution_clock
 8 
 9 using std::chrono::high_resolution_clock;
10 using std::chrono::milliseconds;
11 
12 using namespace std;
13 
14 
15 int main(int argc, char *argv[])
16 {
17     int64_t sleeptime = 3;
18     cout << "sleeptime: "<< sleeptime << " ms" << endl;
19     //////clock_t//////
20     clock_t start;
21     clock_t end;
22     start = clock();
23 
24     this_thread::sleep_for(chrono::milliseconds(sleeptime));
25 
26     end = clock();
27     cout << "the clock_t start: "<< start << " ms, end: " << end << " ms" << endl;
28     cout << "the clock_t func time span: "<< end - start << " ms" << endl;
29     //////gettimeofday//////
30     struct timeval start_time;
31     struct timeval stop_time;
32 
33     gettimeofday(&start_time, NULL);
34     this_thread::sleep_for(chrono::milliseconds(sleeptime));
35     gettimeofday(&stop_time, NULL);
36 
37     cout << "the gettimeofday start: "<< (start_time.tv_sec*1000 + start_time.tv_usec/1000) << " ms, end: " << (stop_time.tv_sec*1000 + stop_time.tv_usec/1000) << " ms"<< endl;
38     long start_1 = (start_time.tv_sec*1000 + start_time.tv_usec/1000);
39     long stop_1 = (stop_time.tv_sec*1000 + stop_time.tv_usec/1000);
40 
41     cout << "the gettimeofday time span: "<< stop_1 - start_1 << " ms" << endl;
42 
43     //////high_resolution_clock//////
44     high_resolution_clock::time_point beginTime = high_resolution_clock::now();
45 
46     //sleep(3);  //延时
47     this_thread::sleep_for(chrono::milliseconds(sleeptime));
48 
49     high_resolution_clock::time_point endTime = high_resolution_clock::now();
50 
51     milliseconds timeInterval = std::chrono::duration_cast<milliseconds>(endTime - beginTime);
52 
53     cout << "the high_resolution_clock time span: "<< timeInterval.count() << " ms\n";
54 
55     return 0;
56 }
 

运行结果如下：

sleeptime: 3 ms

the clock_t start: 2751 ms, end: 2781 ms

the clock_t func time span: 30 ms

the gettimeofday start: 1597892088378 ms, end: 1597892088382 ms

the gettimeofday time span: 4 ms

the high_resolution_clock time span: 3 ms


运行多次，结论如下：

　　精确度：high_resolution_clock > gettimeofday > clock_t
posted @ 2020-09-04 14:59  danny_gao_1024  阅读(456)  评论(0)    收藏  举报