зеркало из https://github.com/mozilla/pjs.git
125 строки
3.1 KiB
C++
125 строки
3.1 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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*
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* The contents of this file are subject to the Mozilla Public
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* License Version 1.1 (the "License"); you may not use this file
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* except in compliance with the License. You may obtain a copy of
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* the License at http://www.mozilla.org/MPL/
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*
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* Software distributed under the License is distributed on an "AS
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* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
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* implied. See the License for the specific language governing
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* rights and limitations under the License.
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*
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* The Original Code is the Mozilla browser.
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*
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* The Initial Developer of the Original Code is Netscape
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* Communications, Inc. Portions created by Netscape are
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* Copyright (C) 1999, Mozilla. All Rights Reserved.
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*
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* Contributor(s):
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* Scott Collins <scc@netscape.com>
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*/
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#ifndef nsWeakReference_h__
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#define nsWeakReference_h__
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// nsWeakReference.h
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#include "nsIWeakReference.h"
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class NS_COM nsSupportsWeakReference : public nsISupportsWeakReference
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{
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public:
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nsSupportsWeakReference()
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: mProxy(0)
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{
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// nothing else to do here
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}
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inline virtual ~nsSupportsWeakReference();
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NS_DECL_NSISUPPORTSWEAKREFERENCE
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private:
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friend class nsWeakReference;
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void
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NoticeProxyDestruction()
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// ...called (only) by an |nsWeakReference| from _its_ dtor.
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{
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mProxy = 0;
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}
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nsWeakReference* mProxy;
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protected:
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inline void ClearWeakReferences();
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PRBool HasWeakReferences() const {return mProxy != 0;}
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};
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class NS_COM nsWeakReference : public nsIWeakReference
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{
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public:
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// nsISupports...
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NS_IMETHOD_(nsrefcnt) AddRef();
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NS_IMETHOD_(nsrefcnt) Release();
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NS_IMETHOD QueryInterface( const nsIID&, void** );
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// nsIWeakReference...
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NS_DECL_NSIWEAKREFERENCE
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private:
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friend class nsSupportsWeakReference;
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nsWeakReference( nsSupportsWeakReference* referent )
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: mRefCount(0),
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mReferent(referent)
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// ...I can only be constructed by an |nsSupportsWeakReference|
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{
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// nothing else to do here
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}
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virtual ~nsWeakReference()
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// ...I will only be destroyed by calling |delete| myself.
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{
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if ( mReferent )
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mReferent->NoticeProxyDestruction();
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}
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void
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NoticeReferentDestruction()
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// ...called (only) by an |nsSupportsWeakReference| from _its_ dtor.
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{
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mReferent = 0;
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}
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nsrefcnt mRefCount;
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nsSupportsWeakReference* mReferent;
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};
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inline
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void
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nsSupportsWeakReference::ClearWeakReferences()
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/*
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Usually being called from |nsSupportsWeakReference::~nsSupportsWeakReference|
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will be good enough, but you may have a case where you need to call disconnect
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your weak references in an outer destructor (to prevent some client holding a
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weak reference from re-entering your destructor).
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*/
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{
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if ( mProxy )
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{
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mProxy->NoticeReferentDestruction();
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mProxy = 0;
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}
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}
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inline
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nsSupportsWeakReference::~nsSupportsWeakReference()
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{
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ClearWeakReferences();
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}
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#endif
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