gecko-dev/xpcom/threads/RecursiveMutex.h
2017-10-26 14:39:00 -04:00

133 lines
3.3 KiB
C++

/* -*- 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