gecko/content/base/public/nsIDOMGCParticipant.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998-1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
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*
* ***** END LICENSE BLOCK ***** */
#ifndef nsIDOMGCParticipant_h_
#define nsIDOMGCParticipant_h_
#include "nsISupports.h"
template<class E> class nsCOMArray;
// 0e2a5a8d-28fd-4a5c-8bf1-5b0067ff3286
#define NS_IDOMGCPARTICIPANT_IID \
{ 0x0e2a5a8d, 0x28fd, 0x4a5c, \
{0x8b, 0xf1, 0x5b, 0x00, 0x67, 0xff, 0x32, 0x86} }
/**
* DOM GC Participants are objects that expose information about
* reachability in the native object graphs to help prevent script ->
* native -> script cyclical reference from causing leaks due to the
* creation of garbage collection roots and native/script boundaries.
*
* Some implementations of nsIDOMGCParticipant may be responsible for
* enforcing the requirement that callers of
* |nsDOMClassInfo::PreserveWrapper| must call
* |nsDOMClassInfo::ReleaseWrapper| before the nsIDOMGCParticipant
* argument to the former is destroyed.
*/
class nsIDOMGCParticipant : public nsISupports
{
public:
NS_DECLARE_STATIC_IID_ACCESSOR(NS_IDOMGCPARTICIPANT_IID)
/**
* Get a reference node for what is known to be a strongly connected
* component of nsIDOMGCParticipants. For example, DOM trees are
* strongly connected, so can return the root node to greatly reduce
* the number of nodes on which we need to run graph algorithms.
*
* Note that it's acceptable for nodes in a single strongly connected
* component to return different values for GetSCCIndex, as long as
* those two values claim that they're reachable from each other in
* AppendReachableList.
*/
virtual nsIDOMGCParticipant* GetSCCIndex() = 0;
/**
* Append the list of nsIDOMGCPartipants reachable from this one via
* C++ getters exposed to script that return a different result from
* |GetSCCIndex|. The caller is responsible for taking the transitive
* closure of |AppendReachableList|.
*
* This will only be called on objects that are returned by GetSCCIndex.
*
* null pointers may be appended; they will be ignored by the caller.
*/
virtual void AppendReachableList(nsCOMArray<nsIDOMGCParticipant>& aArray) = 0;
};
NS_DEFINE_STATIC_IID_ACCESSOR(nsIDOMGCParticipant, NS_IDOMGCPARTICIPANT_IID)
#endif // !defined(nsIDOMGCParticipant_h_)