std::this_thread::yield/sleep_for

 

std::this_thread::yield()：　當前線程放棄執行，操作系統調度另一線程繼續執行。。

std::this_thread::sleep_for()：　表示當前線程休眠一段時間，休眠期間不與其他線程競爭CPU，根據線程需求，等待若干時間。

 

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

void little_sleep(std::chrono::microseconds us)
{
    auto start = std::chrono::high_resolution_clock::now();
    auto end = start + us;
    do {
        std::this_thread::yield();
    } while (std::chrono::high_resolution_clock::now() < end);
}

int main()
{
    auto start = std::chrono::high_resolution_clock::now();

    little_sleep(std::chrono::microseconds(100));

    auto elapsed = std::chrono::high_resolution_clock::now() - start;
    std::cout << "waited for "
        << std::chrono::duration_cast<std::chrono::microseconds>(elapsed).count()
        << " microseconds\n";

    system("pause");
}