#pragma once

#include <condition_variable.hpp>

#include <cstddef>
#include <mutex>

namespace tpcc {
namespace solutions {

class CyclicBarrier {
 public:
  explicit CyclicBarrier(const size_t num_threads)
      : num_threads_(num_threads), counts{0, 0}, index_(0) {
  }

  void PassThrough() {

    std::unique_lock<std::mutex> lock{mutex_};

    size_t current_index = index_;
    ++counts[current_index];
    if (counts[current_index] < num_threads_) {
      while (counts[current_index] < num_threads_) {
        cv_.wait(lock);
      }
    } else {
      index_ ^= 1;
      counts[index_] = 0;
      cv_.notify_all();
    }
  }

 private:
  std::mutex mutex_;
  tpcc::condition_variable cv_;
  size_t num_threads_;
  size_t counts[2];
  size_t index_;
};

} // namespace solutions
} // namespace tpcc