//----------------------------------------------------
// flag3.cc: versión ttas y con uso de bloqueo de flag.cc
//----------------------------------------------------

#include <atomic>
#include <iostream>
#include <thread>

//----------------------------------------------------

using namespace std::literals;

//----------------------------------------------------

const size_t N = 16;
std::atomic<bool> start = false, stop = false;

//----------------------------------------------------

class cerrojo
{
public:
    void adquirir()
    {
        while (cerrado.test(std::memory_order_relaxed) ||
               cerrado.test_and_set(std::memory_order_acq_rel))
            cerrado.wait(true);
    }

    void liberar()
    {
        cerrado.clear(std::memory_order_release);
        cerrado.notify_one();
    }

private:
    std::atomic_flag cerrado;
} c;

//----------------------------------------------------

void seccion_critica()
{
    std::cout << "[" << std::this_thread::get_id() << "]: ";
    for (size_t i = 0; i < 10; ++i) std::cout << i;
    std::cout << std::endl;
}

//----------------------------------------------------

void hebra()
{
    while (!start) std::this_thread::yield();
    while (!stop)
    {
        c.adquirir();
        if (!stop) seccion_critica();
        c.liberar();
    }
}

//----------------------------------------------------

int main()
{
    std::thread threads[N];

    for (auto &t : threads) t = std::thread(hebra);

    start = true;
    std::this_thread::sleep_for(100ms);
    stop = true;

    for (auto &t : threads) t.join();
}

//----------------------------------------------------