/**
 * PANDA 3D SOFTWARE
 * Copyright (c) Carnegie Mellon University.  All rights reserved.
 *
 * All use of this software is subject to the terms of the revised BSD
 * license.  You should have received a copy of this license along
 * with this source code in a file named "LICENSE."
 *
 * @file mutexSimpleImpl.h
 * @author drose
 * @date 2007-06-19
 */

#ifndef MUTEXSIMPLEIMPL_H
#define MUTEXSIMPLEIMPL_H

#include "pandabase.h"
#include "selectThreadImpl.h"

#ifdef THREAD_SIMPLE_IMPL

#include "blockerSimple.h"
#include "threadSimpleImpl.h"

/**
 * This is the mutex implementation for the simple, simulated threads case.
 * It's designed to be as lightweight as possible, of course.  This
 * implementation simply yields the thread when the mutex would block.
 *
 * We can't define this class in dtoolbase along with the other mutex
 * implementations, because this implementation requires knowing about the
 * SimpleThreadManager.  This complicates the MutexDirect and MutexDebug
 * definitions (we have to define a MutexImpl, for code before pipeline to use
 * --which maps to MutexDummyImpl--and a MutexTrueImpl, for code after
 * pipeline to use--which maps to this class, MutexSimpleImpl).
 */
class EXPCL_PANDA_PIPELINE MutexSimpleImpl : public BlockerSimple {
public:
  constexpr MutexSimpleImpl() = default;

  INLINE void lock();
  INLINE bool try_lock();
  INLINE void unlock();
  INLINE void unlock_quietly();

private:
  void do_lock();
  void do_unlock();
  void do_unlock_quietly();

  friend class ThreadSimpleManager;
};

#include "mutexSimpleImpl.I"

#endif  // THREAD_SIMPLE_IMPL

#endif