//-----------------------------------------------------
// rwlock.cc: cerrojo de lectura/escritura de pthread
//-----------------------------------------------------

#include <atomic>
#include <chrono>
#include <iostream>
#include <latch>
#include <pthread.h>
#include <thread>

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

using namespace std::literals;

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

const size_t N = 24; // número de hebras

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

std::latch latch(N);
pthread_rwlock_t rwlock; // cerrojo de lectura/escritura

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

void seccion_critica(char c)
{
    for (char i = 0; i < 10; ++i)
        std::cout << c;
    std::cout << '\n';
}

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

void lector(char c)
{
    latch.arrive_and_wait();
    while (true)
    {
        pthread_rwlock_rdlock(&rwlock);
        seccion_critica(c);
        pthread_rwlock_unlock(&rwlock);
    }
}

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

void escritor(char c)
{
    latch.arrive_and_wait();
    while (true)
    {
        pthread_rwlock_wrlock(&rwlock);
        seccion_critica(c);
        pthread_rwlock_unlock(&rwlock);
    }
}

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

int main()
{
    pthread_rwlock_init(&rwlock, NULL);

    for (size_t i = 0; i < N / 2; ++i)
    {
        std::thread(lector, '0' + i).detach();
        std::thread(escritor, 'a' + i).detach();
    }

    std::this_thread::sleep_for(12ms);
}

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