//----------------------------------------------------
// dekker.cc
//----------------------------------------------------

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

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

using namespace std::literals;

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

std::atomic<bool> start = false, stop = false;

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

class dekker
{
public:
    void lock(const size_t id)
    {
        flags[id] = true;
        while (flags[1 - id] == true)
        {
            flags[id] = false;
            while (turn != id);
            flags[id] = true;
        }
    }

    void unlock(const size_t id)
    {
        turn = 1 - id;
        flags[id] = false;
    }

private:
    std::atomic<bool> flags[2] = {false, false};
    size_t turn = 0;
} l;

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

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(size_t id)
{
    while (!start) std::this_thread::yield();
    while (!stop)
    {
        l.lock(id);
        seccion_critica();
        l.unlock(id);
    }
}

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

int main()
{
    std::thread threads[2];

    for (size_t i = 0; i < 2; ++i) threads[i] = std::thread(hebra, i);

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

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

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