/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

// A lock that can be acquired multiple times on the same thread.

#ifndef mozilla_RecursiveMutex_h

#define mozilla_RecursiveMutex_h

#include "mozilla/BlockingResourceBase.h"

#include "mozilla/GuardObjects.h"

#ifndef XP_WIN

#include <pthread.h>

#endif

namespace mozilla {

class RecursiveMutex : public BlockingResourceBase

{

public:

  explicit RecursiveMutex(const char* aName MOZ_GUARD_OBJECT_NOTIFIER_PARAM);

  ~RecursiveMutex();

#ifdef DEBUG

  void Lock();

  void Unlock();

#else

  void Lock() { LockInternal(); }

  void Unlock() { UnlockInternal(); }

#endif

#ifdef DEBUG

  /**

   * AssertCurrentThreadIn

   **/

  void AssertCurrentThreadIn();

  /**

   * AssertNotCurrentThreadIn

   **/

  void AssertNotCurrentThreadIn()

  {

    //Not currently implemented. See bug 476536 for discussion.

  }

#else

  void AssertCurrentThreadIn() {}

  void AssertNotCurrentThreadIn() {}

#endif

private:

  RecursiveMutex() = delete;

  RecursiveMutex(const RecursiveMutex&) = delete;

  RecursiveMutex& operator=(const RecursiveMutex&) = delete;

  void LockInternal();

  void UnlockInternal();

#ifdef DEBUG

  PRThread* mOwningThread;

  size_t mEntryCount;

#endif

#if !defined(XP_WIN)

  pthread_mutex_t mMutex;

#else

  // We eschew including windows.h and using CRITICAL_SECTION here so that files

  // including us don't also pull in windows.h.  Just use a type that's big

  // enough for CRITICAL_SECTION, and we'll fix it up later.

  void* mMutex[6];

#endif

  MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER

};

class MOZ_RAII RecursiveMutexAutoLock

{

public:

  explicit RecursiveMutexAutoLock(RecursiveMutex& aRecursiveMutex

                                  MOZ_GUARD_OBJECT_NOTIFIER_PARAM)

    : mRecursiveMutex(&aRecursiveMutex)

  {

    MOZ_GUARD_OBJECT_NOTIFIER_INIT;

    NS_ASSERTION(mRecursiveMutex, "null mutex");

    mRecursiveMutex->Lock();

  }

  ~RecursiveMutexAutoLock(void)

  {

    mRecursiveMutex->Unlock();

  }

private:

  RecursiveMutexAutoLock() = delete;

  RecursiveMutexAutoLock(const RecursiveMutexAutoLock&) = delete;

  RecursiveMutexAutoLock& operator=(const RecursiveMutexAutoLock&) = delete;

  static void* operator new(size_t) CPP_THROW_NEW;

  mozilla::RecursiveMutex* mRecursiveMutex;

  MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER

};

class MOZ_RAII RecursiveMutexAutoUnlock

{

public:

  explicit RecursiveMutexAutoUnlock(RecursiveMutex& aRecursiveMutex

                                    MOZ_GUARD_OBJECT_NOTIFIER_PARAM)

    : mRecursiveMutex(&aRecursiveMutex)

  {

    MOZ_GUARD_OBJECT_NOTIFIER_INIT;

    NS_ASSERTION(mRecursiveMutex, "null mutex");

    mRecursiveMutex->Unlock();

  }

  ~RecursiveMutexAutoUnlock(void)

  {

    mRecursiveMutex->Lock();

  }

private:

  RecursiveMutexAutoUnlock() = delete;

  RecursiveMutexAutoUnlock(const RecursiveMutexAutoUnlock&) = delete;

  RecursiveMutexAutoUnlock& operator=(const RecursiveMutexAutoUnlock&) = delete;

  static void* operator new(size_t) CPP_THROW_NEW;

  mozilla::RecursiveMutex* mRecursiveMutex;

  MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER

};

} // namespace mozilla

#endif // mozilla_RecursiveMutex_h