зеркало из https://github.com/mozilla/pjs.git
93 строки
3.5 KiB
C++
93 строки
3.5 KiB
C++
/* ***** BEGIN LICENSE BLOCK *****
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* Version: MPL 1.1/GPL 2.0/LGPL 2.1
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*
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* The contents of this file are subject to the Mozilla Public License Version
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* 1.1 (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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* http://www.mozilla.org/MPL/
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*
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* Software distributed under the License is distributed on an "AS IS" basis,
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* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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* for the specific language governing rights and limitations under the
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* License.
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*
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* The Original Code is Java XPCOM Bindings.
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*
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* The Initial Developer of the Original Code is
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* IBM Corporation.
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* Portions created by the Initial Developer are Copyright (C) 2005
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* IBM Corporation. All Rights Reserved.
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*
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* Contributor(s):
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* Javier Pedemonte (jhpedemonte@gmail.com)
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*
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* Alternatively, the contents of this file may be used under the terms of
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* either the GNU General Public License Version 2 or later (the "GPL"), or
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* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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* in which case the provisions of the GPL or the LGPL are applicable instead
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* of those above. If you wish to allow use of your version of this file only
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* under the terms of either the GPL or the LGPL, and not to allow others to
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* use your version of this file under the terms of the MPL, indicate your
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* decision by deleting the provisions above and replace them with the notice
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* and other provisions required by the GPL or the LGPL. If you do not delete
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* the provisions above, a recipient may use your version of this file under
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* the terms of any one of the MPL, the GPL or the LGPL.
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*
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* ***** END LICENSE BLOCK ***** */
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#include "jni.h"
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#include "nsJavaXPTCStubWeakRef.h"
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#include "nsJavaXPTCStub.h"
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#include "nsJavaXPCOMBindingUtils.h"
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#include "nsIInterfaceInfoManager.h"
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/**
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* How we handle XPCOM weak references to a Java object:
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*
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* If XPCOM requires or asks for a weak reference of a Java object, we first
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* find (or create) an nsJavaXPTCStub for that Java object. That way, there is
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* always an nsJavaXPTCStub for any nsJavaXPTCStubWeakRef. However, the
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* XPTCStub may not always be 'valid'; that is, its refcount may be zero if
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* is not currently referenced by any XPCOM class.
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* When an XPCOM method queries the referent from the weak reference, the
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* weak ref checks first whether the Java object is still valid. If so, we can
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* immediately return an addref'd nsJavaXPTCStub. The XPTCStub takes care of
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* finding an XPTCStub for the required IID.
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*/
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nsJavaXPTCStubWeakRef::nsJavaXPTCStubWeakRef(jobject aJavaObject,
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nsJavaXPTCStub* aXPTCStub)
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: mXPTCStub(aXPTCStub)
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{
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mWeakRef = GetJNIEnv()->NewWeakGlobalRef(aJavaObject);
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}
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nsJavaXPTCStubWeakRef::~nsJavaXPTCStubWeakRef()
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{
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GetJNIEnv()->DeleteWeakGlobalRef(mWeakRef);
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mXPTCStub->ReleaseWeakRef();
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}
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NS_IMPL_ADDREF(nsJavaXPTCStubWeakRef)
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NS_IMPL_RELEASE(nsJavaXPTCStubWeakRef)
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NS_IMPL_QUERY_INTERFACE1(nsJavaXPTCStubWeakRef, nsIWeakReference)
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NS_IMETHODIMP
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nsJavaXPTCStubWeakRef::QueryReferent(const nsIID& aIID, void** aInstancePtr)
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{
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LOG(("nsJavaXPTCStubWeakRef::QueryReferent()\n"));
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// Is weak ref still valid?
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// We create a strong local ref to make sure Java object isn't garbage
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// collected during this call.
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jobject javaObject = GetJNIEnv()->NewLocalRef(mWeakRef);
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if (!javaObject)
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return NS_ERROR_NULL_POINTER;
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// Java object has not been garbage collected, so return QI from XPTCStub.
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return mXPTCStub->QueryInterface(aIID, aInstancePtr);
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}
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