c++ - 用 C++ 测量程序的 CPU 时间和挂钟时间

Question

std::clock() 测量程序持续时间内的时钟滴答数。在下面的代码中，它计算的是 CPU 时间还是挂钟时间？

std::clock_t 开始； 双倍持续时间；

start = std::clock();

/* Your algorithm here */

duration = ( std::clock() - start ) / (double) CLOCKS_PER_SEC;

另一种场景，代码如下:

std::clock_t start;
double time;
start = std::clock();
time = start  / (double) CLOCKS_PER_SEC;

时间的值(value)是多少？

Answer 1

来自 the documentation :

std::clock time may advance faster or slower than the wall clock, depending on the execution resources given to the program by the operating system.