/* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
 *
 * Copyright (C) 2010 Brian Aker
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 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
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 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
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 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 */

#include <boost/thread/mutex.hpp>
#include <boost/thread/condition_variable.hpp>
#include <boost/shared_ptr.hpp>

#pragma once

namespace user_locks {

class Observer {
public:
  typedef boost::shared_ptr<Observer> shared_ptr;
  typedef std::list <shared_ptr> list;

  Observer(int64_t wait_until_arg) :
    woken(false),
    waiting_for(wait_until_arg)
  { 
    _mutex.lock();
  }

  void sleep()
  {
    while (not woken)
    {
      cond.wait(_mutex);
    }
    _mutex.unlock();
  }

  void wake()
  {
    {
      boost::mutex::scoped_lock mutex;
      woken= true;
    }
    cond.notify_all();
  }

  ~Observer()
  {
  }

  int64_t getLimit() const
  {
    return waiting_for;
  }

private:
  bool woken;
  const int64_t waiting_for;
  boost::mutex _mutex;
  boost::condition_variable_any cond;
};

} // namespace user_locks