gecko-dev/xpcom/base/nsWeakReference.h
2020-02-25 19:44:27 +00:00

69 lines
2.3 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/. */
#ifndef nsWeakReference_h__
#define nsWeakReference_h__
// nsWeakReference.h
// See mfbt/WeakPtr.h for a more typesafe C++ implementation of weak references
#include "nsIWeakReferenceUtils.h"
class nsWeakReference;
class nsSupportsWeakReference : public nsISupportsWeakReference {
public:
nsSupportsWeakReference() : mProxy(0) {}
NS_DECL_NSISUPPORTSWEAKREFERENCE
protected:
inline ~nsSupportsWeakReference();
private:
friend class nsWeakReference;
// Called (only) by an |nsWeakReference| from _its_ dtor.
// The thread safety check is made by the caller.
void NoticeProxyDestruction() { mProxy = nullptr; }
nsWeakReference* MOZ_NON_OWNING_REF mProxy;
protected:
void ClearWeakReferences();
bool HasWeakReferences() const { return !!mProxy; }
};
inline nsSupportsWeakReference::~nsSupportsWeakReference() {
ClearWeakReferences();
}
#define NS_IMPL_CYCLE_COLLECTION_UNLINK_WEAK_REFERENCE \
tmp->ClearWeakReferences();
#define NS_IMPL_CYCLE_COLLECTION_WEAK(class_, ...) \
NS_IMPL_CYCLE_COLLECTION_CLASS(class_) \
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(class_) \
NS_IMPL_CYCLE_COLLECTION_UNLINK(__VA_ARGS__) \
NS_IMPL_CYCLE_COLLECTION_UNLINK_WEAK_REFERENCE \
NS_IMPL_CYCLE_COLLECTION_UNLINK_END \
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(class_) \
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(__VA_ARGS__) \
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
#define NS_IMPL_CYCLE_COLLECTION_WEAK_INHERITED(class_, super_, ...) \
NS_IMPL_CYCLE_COLLECTION_CLASS(class_) \
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(class_, super_) \
NS_IMPL_CYCLE_COLLECTION_UNLINK(__VA_ARGS__) \
NS_IMPL_CYCLE_COLLECTION_UNLINK_WEAK_REFERENCE \
NS_IMPL_CYCLE_COLLECTION_UNLINK_END \
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(class_, super_) \
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(__VA_ARGS__) \
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
#endif