85 lines
2.5 KiB
C++
85 lines
2.5 KiB
C++
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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/*
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* The contents of this file are subject to the Netscape 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/NPL/
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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 Mozilla Communicator client code,
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* released March 31, 1998.
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*
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* The Initial Developer of the Original Code is Netscape Communications
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* Corporation. Portions created by Netscape are
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* Copyright (C) 1998 Netscape Communications Corporation. All
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* Rights Reserved.
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*
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* Contributor(s):
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*/
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/* A set of support classes for defining weak references, rather like
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nsIWeakReference, but for use with non-COM objects
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*/
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#include "nsCWeakReference.h"
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/************ a thing supporting weak references to itself ***********/
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nsCWeakReferent::nsCWeakReferent(void *aRealThing) :
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mRealThing(aRealThing),
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mProxy(0) {
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}
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nsCWeakReferent::~nsCWeakReferent() {
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if (mProxy)
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mProxy->RealThingDeleted();
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}
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void nsCWeakReferent::SetReferent(void *aRealThing) {
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NS_ASSERTION(!mRealThing && !mProxy, "weak referent set twice");
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mRealThing = aRealThing;
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mProxy = 0;
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}
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nsCWeakProxy *nsCWeakReferent::GetProxy() {
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if (!mProxy)
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mProxy = new nsCWeakProxy(mRealThing, this);
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return mProxy;
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}
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/************ a reference proxy whose lifetime we control ***********/
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/* the nsCWeakProxy object is an object whose creation and lifetime is
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under our control, unlike the nsCWeakReferent and its family of
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nsCWeakReferences. An nsCWeakProxy is created by the nsCWeakReferent
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when the first weak reference is necessary, and refcounted for each
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additional reference. It knows about the lifetime of the nsCWeakReferent,
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and deletes itself once all weak references have been broken.
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*/
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nsCWeakProxy::nsCWeakProxy(void *aRealThing, nsCWeakReferent *aReferent) :
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mRealPointer(aRealThing),
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mReferent(aReferent),
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mRefCount(0) {
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NS_ASSERTION(aRealThing && aReferent, "weak proxy constructed with null ptr");
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}
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nsCWeakProxy::~nsCWeakProxy() {
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if (mReferent)
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mReferent->ProxyDeleted();
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}
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void nsCWeakProxy::ReleaseReference() {
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if (--mRefCount == 0) {
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delete this;
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}
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}
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