c++ - C/C++ time_t(以微秒为单位)

Question

该程序返回以秒为单位的时间。我需要在微秒内返回它。

time_t timeStart = time(0);
usleep(2.5e6);
time_t timeEnd = time(0);

float R = (timeEnd - timeStart);
std::cout << R << std::endl;

Answer 1

如果您正在寻找更高分辨率，可以使用std::chrono::high_resolution_clock从 C++11 开始。

#include <chrono>

using namespace std::chrono;

high_resolution_clock::time_point t1 = high_resolution_clock::now();

/* some extensive action... */
usleep(2.5e6);

high_resolution_clock::time_point t2 = high_resolution_clock::now();

duration<double> time_span = duration_cast<duration<double>>(t2 - t1);

std::cout << "It took me " << time_span.count() << " seconds.";
std::cout << std::endl;

输出类似

It took me 0.091001 seconds.

示例来自 http://www.cplusplus.com/reference/chrono/high_resolution_clock/now/