michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim: set ts=8 sts=2 et sw=2 tw=80: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef mozilla_HoldDropJSObjects_h
michael@0: #define mozilla_HoldDropJSObjects_h
michael@0: 
michael@0: #include "mozilla/TypeTraits.h"
michael@0: #include "nsCycleCollectionParticipant.h"
michael@0: 
michael@0: class nsISupports;
michael@0: class nsScriptObjectTracer;
michael@0: 
michael@0: // Only HoldJSObjects and DropJSObjects should be called directly.
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace cyclecollector {
michael@0: 
michael@0: // These methods are defined in nsCycleCollector.cpp
michael@0: void HoldJSObjectsImpl(void* aHolder, nsScriptObjectTracer* aTracer);
michael@0: void HoldJSObjectsImpl(nsISupports* aHolder);
michael@0: void DropJSObjectsImpl(void* aHolder);
michael@0: void DropJSObjectsImpl(nsISupports* aHolder);
michael@0: 
michael@0: } // namespace cyclecollector
michael@0: 
michael@0: 
michael@0: template<class T, bool isISupports=IsBaseOf<nsISupports, T>::value>
michael@0: struct HoldDropJSObjectsHelper
michael@0: {
michael@0:   static void Hold(T* aHolder)
michael@0:   {
michael@0:     cyclecollector::HoldJSObjectsImpl(aHolder, NS_CYCLE_COLLECTION_PARTICIPANT(T));
michael@0:   }
michael@0:   static void Drop(T* aHolder)
michael@0:   {
michael@0:     cyclecollector::DropJSObjectsImpl(aHolder);
michael@0:   }
michael@0: };
michael@0: 
michael@0: template<class T>
michael@0: struct HoldDropJSObjectsHelper<T, true>
michael@0: {
michael@0:   static void Hold(T* aHolder)
michael@0:   {
michael@0:     cyclecollector::HoldJSObjectsImpl(ToSupports(aHolder));
michael@0:   }
michael@0:   static void Drop(T* aHolder)
michael@0:   {
michael@0:     cyclecollector::DropJSObjectsImpl(ToSupports(aHolder));
michael@0:   }
michael@0: };
michael@0: 
michael@0: 
michael@0: template<class T>
michael@0: void HoldJSObjects(T* aHolder)
michael@0: {
michael@0:   HoldDropJSObjectsHelper<T>::Hold(aHolder);
michael@0: }
michael@0: 
michael@0: template<class T>
michael@0: void DropJSObjects(T* aHolder)
michael@0: {
michael@0:   HoldDropJSObjectsHelper<T>::Drop(aHolder);
michael@0: }
michael@0: 
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif // mozilla_HoldDropJSObjects_h