1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/dom/base/nsWrapperCache.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,119 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* vim: set ts=8 sts=2 et sw=2 tw=80: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#include "nsWrapperCacheInlines.h"
1.11 +
1.12 +#include "jsproxy.h"
1.13 +#include "mozilla/dom/DOMJSProxyHandler.h"
1.14 +#include "mozilla/HoldDropJSObjects.h"
1.15 +#include "nsCycleCollectionTraversalCallback.h"
1.16 +#include "nsCycleCollector.h"
1.17 +
1.18 +using namespace mozilla;
1.19 +using namespace mozilla::dom;
1.20 +
1.21 +/* static */ void
1.22 +nsWrapperCache::HoldJSObjects(void* aScriptObjectHolder,
1.23 + nsScriptObjectTracer* aTracer)
1.24 +{
1.25 + cyclecollector::HoldJSObjectsImpl(aScriptObjectHolder, aTracer);
1.26 +}
1.27 +
1.28 +void
1.29 +nsWrapperCache::ReleaseWrapper(void* aScriptObjectHolder)
1.30 +{
1.31 + if (PreservingWrapper()) {
1.32 + // PreserveWrapper puts new DOM bindings in the JS holders hash, but they
1.33 + // can also be in the DOM expando hash, so we need to try to remove them
1.34 + // from both here.
1.35 + JSObject* obj = GetWrapperPreserveColor();
1.36 + if (IsDOMBinding() && obj && js::IsProxy(obj)) {
1.37 + DOMProxyHandler::GetAndClearExpandoObject(obj);
1.38 + }
1.39 + SetPreservingWrapper(false);
1.40 + cyclecollector::DropJSObjectsImpl(aScriptObjectHolder);
1.41 + }
1.42 +}
1.43 +
1.44 +#ifdef DEBUG
1.45 +
1.46 +class DebugWrapperTraversalCallback : public nsCycleCollectionTraversalCallback
1.47 +{
1.48 +public:
1.49 + DebugWrapperTraversalCallback(void* aWrapper)
1.50 + : mFound(false)
1.51 + , mWrapper(aWrapper)
1.52 + {
1.53 + mFlags = WANT_ALL_TRACES;
1.54 + }
1.55 +
1.56 + NS_IMETHOD_(void) DescribeRefCountedNode(nsrefcnt aRefCount,
1.57 + const char* aObjName)
1.58 + {
1.59 + }
1.60 + NS_IMETHOD_(void) DescribeGCedNode(bool aIsMarked,
1.61 + const char* aObjName,
1.62 + uint64_t aCompartmentAddress)
1.63 + {
1.64 + }
1.65 +
1.66 + NS_IMETHOD_(void) NoteJSChild(void* aChild)
1.67 + {
1.68 + if (aChild == mWrapper) {
1.69 + mFound = true;
1.70 + }
1.71 + }
1.72 + NS_IMETHOD_(void) NoteXPCOMChild(nsISupports* aChild)
1.73 + {
1.74 + }
1.75 + NS_IMETHOD_(void) NoteNativeChild(void* aChild,
1.76 + nsCycleCollectionParticipant* aHelper)
1.77 + {
1.78 + }
1.79 +
1.80 + NS_IMETHOD_(void) NoteNextEdgeName(const char* aName)
1.81 + {
1.82 + }
1.83 +
1.84 + bool mFound;
1.85 +
1.86 +private:
1.87 + void* mWrapper;
1.88 +};
1.89 +
1.90 +static void
1.91 +DebugWrapperTraceCallback(void* aP, const char* aName, void* aClosure)
1.92 +{
1.93 + DebugWrapperTraversalCallback* callback =
1.94 + static_cast<DebugWrapperTraversalCallback*>(aClosure);
1.95 + callback->NoteJSChild(aP);
1.96 +}
1.97 +
1.98 +void
1.99 +nsWrapperCache::CheckCCWrapperTraversal(void* aScriptObjectHolder,
1.100 + nsScriptObjectTracer* aTracer)
1.101 +{
1.102 + JSObject* wrapper = GetWrapper();
1.103 + if (!wrapper) {
1.104 + return;
1.105 + }
1.106 +
1.107 + DebugWrapperTraversalCallback callback(wrapper);
1.108 +
1.109 + aTracer->Traverse(aScriptObjectHolder, callback);
1.110 + MOZ_ASSERT(callback.mFound,
1.111 + "Cycle collection participant didn't traverse to preserved "
1.112 + "wrapper! This will probably crash.");
1.113 +
1.114 + callback.mFound = false;
1.115 + aTracer->Trace(aScriptObjectHolder,
1.116 + TraceCallbackFunc(DebugWrapperTraceCallback), &callback);
1.117 + MOZ_ASSERT(callback.mFound,
1.118 + "Cycle collection participant didn't trace preserved wrapper! "
1.119 + "This will probably crash.");
1.120 +}
1.121 +
1.122 +#endif // DEBUG
