gecko-dev/xpcom/threads/RecursiveMutex.h

121 строка
3.4 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/ThreadSafety.h"
#include "mozilla/BlockingResourceBase.h"
#ifndef XP_WIN
# include <pthread.h>
#endif
namespace mozilla {
class MOZ_CAPABILITY("recursive mutex") RecursiveMutex
: public BlockingResourceBase {
public:
explicit RecursiveMutex(const char* aName);
~RecursiveMutex();
#ifdef DEBUG
void Lock() MOZ_CAPABILITY_ACQUIRE();
void Unlock() MOZ_CAPABILITY_RELEASE();
#else
void Lock() MOZ_CAPABILITY_ACQUIRE() { LockInternal(); }
void Unlock() MOZ_CAPABILITY_RELEASE() { UnlockInternal(); }
#endif
#ifdef DEBUG
/**
* AssertCurrentThreadIn
**/
void AssertCurrentThreadIn() const MOZ_ASSERT_CAPABILITY(this);
/**
* AssertNotCurrentThreadIn
**/
void AssertNotCurrentThreadIn() const MOZ_EXCLUDES(this) {
// Not currently implemented. See bug 476536 for discussion.
}
#else
void AssertCurrentThreadIn() const MOZ_ASSERT_CAPABILITY(this) {}
void AssertNotCurrentThreadIn() const MOZ_EXCLUDES(this) {}
#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
};
class MOZ_RAII MOZ_SCOPED_CAPABILITY RecursiveMutexAutoLock {
public:
explicit RecursiveMutexAutoLock(RecursiveMutex& aRecursiveMutex)
MOZ_CAPABILITY_ACQUIRE(aRecursiveMutex)
: mRecursiveMutex(&aRecursiveMutex) {
NS_ASSERTION(mRecursiveMutex, "null mutex");
mRecursiveMutex->Lock();
}
~RecursiveMutexAutoLock(void) MOZ_CAPABILITY_RELEASE() {
mRecursiveMutex->Unlock();
}
private:
RecursiveMutexAutoLock() = delete;
RecursiveMutexAutoLock(const RecursiveMutexAutoLock&) = delete;
RecursiveMutexAutoLock& operator=(const RecursiveMutexAutoLock&) = delete;
static void* operator new(size_t) noexcept(true);
mozilla::RecursiveMutex* mRecursiveMutex;
};
class MOZ_RAII MOZ_SCOPED_CAPABILITY RecursiveMutexAutoUnlock {
public:
explicit RecursiveMutexAutoUnlock(RecursiveMutex& aRecursiveMutex)
MOZ_SCOPED_UNLOCK_RELEASE(aRecursiveMutex)
: mRecursiveMutex(&aRecursiveMutex) {
NS_ASSERTION(mRecursiveMutex, "null mutex");
mRecursiveMutex->Unlock();
}
~RecursiveMutexAutoUnlock(void) MOZ_SCOPED_UNLOCK_REACQUIRE() {
mRecursiveMutex->Lock();
}
private:
RecursiveMutexAutoUnlock() = delete;
RecursiveMutexAutoUnlock(const RecursiveMutexAutoUnlock&) = delete;
RecursiveMutexAutoUnlock& operator=(const RecursiveMutexAutoUnlock&) = delete;
static void* operator new(size_t) noexcept(true);
mozilla::RecursiveMutex* mRecursiveMutex;
};
} // namespace mozilla
#endif // mozilla_RecursiveMutex_h