tests/manual/clients/parallel.cpp


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// SPDX-License-Identifier: LGPL-2.1-or-later

#include <cmath>
#include <complex>
#include <future>
#include <iostream>
#include <mutex>
#include <random>
#include <thread>
#include <vector>

using namespace std;

double worker()
{
    uniform_real_distribution<double> uniform(-1E5, 1E5);
    default_random_engine engine;
    double s = 0;
    for (int i = 0; i < 10000; ++i) {
        s += norm(complex<double>(uniform(engine), uniform(engine)));
    }
    cout << s << endl;
    return s;
}

int main(int argc, char** argv)
{
    const int numTasks = argc > 1 ? stoi(argv[1]) : std::thread::hardware_concurrency();
    vector<std::future<double>> results;
    for (int i = 0; i < numTasks; ++i) {
        results.push_back(async(launch::async, [i]() {
            return worker() * i;
        }));
    }
    return 0;
}