#pragma once
#include "./std_headers.h"

#include <condition_variable>
#include <mutex>
#include <thread>

struct ParEngine {

  explicit ParEngine(size_t _threadsAvail = 0, size_t _memAvail = 0);
  ~ParEngine();
  ParEngine(ParEngine const &) = delete;
  ParEngine(ParEngine &&) = delete;
  ParEngine operator=(ParEngine const &) = delete;
  ParEngine operator=(ParEngine &&) = delete;

  void push(thread &&it);
  void finish();

  mutex mtx;
  condition_variable readyCv;
  size_t threadsUsed{0};
  size_t threadsAvail{0};
  size_t memUsed{0};
  size_t memAvail{0};
  bool verbose{false};

  deque<thread> pending;
};

struct ParEngineRsv {
  explicit ParEngineRsv(ParEngine *_owner, size_t _memNeeded);
  ~ParEngineRsv();
  ParEngineRsv(ParEngineRsv const &) = delete;
  ParEngineRsv(ParEngineRsv &&) = delete;
  ParEngineRsv operator=(ParEngineRsv const &) = delete;
  ParEngineRsv operator=(ParEngineRsv &&) = delete;

  ParEngine *owner;
  size_t memNeeded;
};