/* -*- 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/. */

#include "mozilla/RWLock.h"

#ifdef XP_WIN

#include <windows.h>

static_assert(sizeof(SRWLOCK) <= sizeof(void*), "SRWLOCK is too big!");

#define NativeHandle(m) (reinterpret_cast<SRWLOCK*>(&m))

#else

#define NativeHandle(m) (&m)

#endif

namespace mozilla {

RWLock::RWLock(const char* aName)

  : BlockingResourceBase(aName, eMutex)

#ifdef DEBUG

  , mOwningThread(nullptr)

#endif

{

#ifdef XP_WIN

  InitializeSRWLock(NativeHandle(mRWLock));

#else

  MOZ_RELEASE_ASSERT(pthread_rwlock_init(NativeHandle(mRWLock), nullptr) == 0,

                     "pthread_rwlock_init failed");

#endif

}

#ifdef DEBUG

bool

RWLock::LockedForWritingByCurrentThread()

{

  return mOwningThread == PR_GetCurrentThread();

}

#endif

#ifndef XP_WIN

RWLock::~RWLock()

{

  MOZ_RELEASE_ASSERT(pthread_rwlock_destroy(NativeHandle(mRWLock)) == 0,

                     "pthread_rwlock_destroy failed");

}

#endif

void

RWLock::ReadLockInternal()

{

#ifdef XP_WIN

  AcquireSRWLockShared(NativeHandle(mRWLock));

#else

  MOZ_RELEASE_ASSERT(pthread_rwlock_rdlock(NativeHandle(mRWLock)) == 0,

                     "pthread_rwlock_rdlock failed");

#endif

}

void

RWLock::ReadUnlockInternal()

{

#ifdef XP_WIN

  ReleaseSRWLockShared(NativeHandle(mRWLock));

#else

  MOZ_RELEASE_ASSERT(pthread_rwlock_unlock(NativeHandle(mRWLock)) == 0,

                     "pthread_rwlock_unlock failed");

#endif

}

void

RWLock::WriteLockInternal()

{

#ifdef XP_WIN

  AcquireSRWLockExclusive(NativeHandle(mRWLock));

#else

  MOZ_RELEASE_ASSERT(pthread_rwlock_wrlock(NativeHandle(mRWLock)) == 0,

                     "pthread_rwlock_wrlock failed");

#endif

}

void

RWLock::WriteUnlockInternal()

{

#ifdef XP_WIN

  ReleaseSRWLockExclusive(NativeHandle(mRWLock));

#else

  MOZ_RELEASE_ASSERT(pthread_rwlock_unlock(NativeHandle(mRWLock)) == 0,

                     "pthread_rwlock_unlock failed");

#endif

}

}

#undef NativeHandle