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背景

有时候为了C++测试程序在cpu资源紧张情况下是否正常，需要人为创造cpu资源紧张

编译方法

g++ -o dummp_worker dummp_worker.cpp -std=c++11 -pthread

使用方法

./dummp_worker 4 0.2

占用4个cpu核的20%比例的cpu资源

源码

// dummp_worker.cpp
#include <cassert>
#include <chrono>
#include <iostream>
#include <thread>
#include <vector>using namespace std;
using namespace chrono;void busy_wait(size_t nanosec) {auto t0 = high_resolution_clock::now();while (duration_cast<nanoseconds>(high_resolution_clock::now() - t0).count() < nanosec) {}
}[[noreturn]] void work(float percentage) {assert(percentage >= 0.f && percentage <= 1.f);constexpr float period = 1000000.0f;while (true) {// busy_wait(900000);// this_thread::sleep_for(100000ns);busy_wait(static_cast<size_t>(period * percentage));this_thread::sleep_for(nanoseconds(static_cast<size_t>(period * (1.f - percentage))));}
}int main(int argc, char* argv[]) {if (argc < 3) {cout << "Args: worker_num occupation_rate.\n";return 0;}const int num = stoi(argv[1]);const float percentage = stof(argv[2]);if (num < 1) {cout << "Error: num of workers less than 1.\n";return 0;}if (percentage < 0.f || percentage > 1.f) {cout << "Error: occupation rate should be between [0.0, 1.0].\n";return 0;}cout << "num of workers: " << num << "\n"<< "occupation rate: " << percentage << "\n";// do the workvector<thread> tds;for (size_t i = 0; i < num; ++i) {tds.emplace_back(work, percentage);}tds[0].join();
}

参考

https://github.com/mightbxg/DummyWorker