自从在C中执行以来获取已用时间的最简洁方法

What is the simplest and cleanest way to get the time since execution of the program (with milliseconds precision) in C++ ?

我正在制作一个波浪干涉模拟器,用C生产Lissajous curves.它需要自执行程序(精度至少为毫秒)起的时间才能运行.经过一些研究后,我似乎无法找到任何干净简单的方法.
全部< chrono>功能对我来说似乎很混乱. Stack Overflow上的类似问题似乎是无关的,令我感到困惑(对我而言)或不适用于我的情况.我尝试使用< time.h>中的函数,却发现它们的精度只有秒.
我正在运行Windows 7 x64.该程序不需要独立于平台,因为它是供个人使用的.
任何帮助是极大的赞赏.
谢谢！

解决方法:

新的< chrono>函数需要一点点习惯,但是当你了解它们的工作方式时,它们会让事情变得相当简单.

您的问题可以像这样解决,例如：

#include <chrono>
#include <thread>
#include <iostream>

// for readability
using hr_clock = std::chrono::high_resolution_clock;
using hr_time_point = hr_clock::time_point;
using hr_duration = hr_clock::duration;
using milliseconds = std::chrono::milliseconds;

int main()
{
    // note the program start time
    hr_time_point prog_start = hr_clock::now();

    // do stuff
    std::this_thread::sleep_for(milliseconds(1000));

    // find the duration
    hr_duration d = hr_clock::now() - prog_start;

    // cast the duration to milliseconds
    milliseconds ms = std::chrono::duration_cast<milliseconds>(d);

    // print out the number of milliseconds
    std::cout << "time passed: " << ms.count() << " milliseconds.\n";
}

为方便起见,您可以创建一个函数来返回自上次调用该函数以来的时间：

milliseconds since_last_call()
{
    // retain time between calls (static)
    static hr_time_point previous = hr_clock::now();

    // get current time
    hr_time_point current = hr_clock::now();

    // get the time difference between now and previous call to the function
    milliseconds ms = std::chrono::duration_cast<milliseconds>(current - previous);

    // store current time for next call
    previous = current;

    // return elapsed time in milliseconds
    return ms;
}

int main()
{
    since_last_call(); // initialize functions internal static time_point

    // do stuff
    std::this_thread::sleep_for(milliseconds(1000));

    milliseconds ms = since_last_call();

    // print out the number of milliseconds
    std::cout << "time passed: " << ms.count() << " milliseconds.\n";
}

标签：c,time,execution-time,elapsedtime
来源： https://codeday.me/bug/20190824/1711308.html