main.cpp

#include <iostream>
#include <random>
#include "thread_pool.h"

std::random_device rd; //真实随机数产生器

std::mt19937 mt(rd()); //生成计算随机数mt;

std::uniform_int_distribution<int> dist(-1000, 1000);//生成-1000到1000之间的离散均匀分部数

auto rnd = std::bind(dist, mt);

//设置线程睡眠时间
void simulate_hard_computation() {
    int nWaitTime = 1000 + rnd();
    auto tBegin = std::chrono::steady_clock::now();
    while (true) {
        auto tNow = std::chrono::steady_clock::now();
        if (std::chrono::duration<double,std::milli>(tNow - tBegin).count() >= nWaitTime) break;
    }
}

// 添加两个数字的简单函数并打印结果
void multiply(const int a, const int b) {
    simulate_hard_computation();
    const int res = a * b;
    //std::cout << a << " * " << b << " = " << res << std::endl;
}

//添加并输出结果
void multiply_output(int & out, const int a, const int b) {
    simulate_hard_computation();
    out = a * b;
    //std::cout << a << " * " << b << " = " << out << std::endl;
}

// 结果返回
int multiply_return(const int a, const int b) {
    simulate_hard_computation();
    const int res = a * b;
    //std::cout << a << " * " << b << " = " << res << std::endl;
    return res;
}

void example() {
    // 创建3个线程的线程池
    // ThreadPool pool(3);
    ThreadPool pool(std::chrono::milliseconds(10000));

    std::cout << "Machine Threads: " << ThreadPool::MachineThreadNum << std::endl;

    auto t1 = std::chrono::steady_clock::now();
    // 提交乘法操作，总共30个
    for (int i = 1; i <= 5; ++i) {
        for (int j = 1; j <= 100; ++j) {
            pool.submit(multiply, i, j);
        }
    }
    auto t2 = std::chrono::steady_clock::now();

    // 使用ref传递的输出参数提交函数
    int output_ref;
    auto future1 = pool.submit(multiply_output, std::ref(output_ref), 5, 6);

    // 等待乘法输出完成
    future1.get();
    std::cout << "Last operation result is equals to " << output_ref << std::endl;

    // 使用return参数提交函数
    auto future2 = pool.submit(multiply_return, 5, 3);

    // 等待乘法输出完成
    int res = future2.get();
    std::cout << "Last operation result is equals to " << res << std::endl;

    //微妙级
    double dr_us = std::chrono::duration<double,std::micro>(t2-t1).count();
    std::cout << "submit 500 * multiply: "<< dr_us << " microsecond" << std::endl;
}

int main() {
    example();
    return 0;
}