#pragma once

#include <rwlock_traits.hpp>

#include <tpcc/stdlike/condition_variable.hpp>

#include <mutex>

namespace tpcc {
namespace solutions {

class ReaderWriterLock {
 public:

  // Reader section
  void ReaderLock() {
    std::unique_lock<std::mutex> lock(mutex);
    while (writer)
      unlocked.wait(lock);
    readers++;
  }

  void ReaderUnlock() {
    std::unique_lock<std::mutex> lock(mutex);
    readers--;
    if (readers == 0)
      unlocked.notify_all();
  }

  // Writer section
  void WriterLock() {
    std::unique_lock<std::mutex> lock(mutex);
    while (writer || (readers > 0))
      unlocked.wait(lock);
    writer = true;
  }

  void WriterUnlock() {
     std::unique_lock<std::mutex> lock(mutex);
     writer = false;
     unlocked.notify_all();
  }

  private:
    bool writer{false};
    std::mutex mutex;
    tpcc::condition_variable unlocked;
    int readers{0};
};

} // namespace solutions
} // namespace tpcc