Linux之C++毫秒级计时方法

Posted 2022-05-21 ZONG_XP

C++11 提供的标准的”最佳计时方法“的代码

参考：std::chrono::duration_cast - cppreference.com

#include <iostream>
#include <chrono>

 
void f()

    std::this_thread::sleep_for(std::chrono::seconds(1));

 
int main()

    auto t1 = std::chrono::high_resolution_clock::now();
    f();
    auto t2 = std::chrono::high_resolution_clock::now();
 
    // 浮点持续时间：不需要 duration_cast
    std::chrono::duration<double, std::milli> fp_ms = t2 - t1;
 
    // 整数持续时间：需要 duration_cast
    auto int_ms = std::chrono::duration_cast<std::chrono::milliseconds>(t2 - t1);
 
    // 将整数持续时间转换为更短时间单位的整数持续时间：
    // 不需要 duration_cast 
    std::chrono::duration<long, std::micro> int_usec = int_ms;
 
    std::cout << "f() took " << fp_ms.count() << " ms, "
              << "or " << int_ms.count() << " whole milliseconds "
              << "(which is " << int_usec.count() << " whole microseconds)" << std::endl;