Remove unused V8 integration code in Sky

sky/engine/bindings/core/v8/V8GCController.cpp

Index: sky/engine/bindings/core/v8/V8GCController.cpp
diff --git a/sky/engine/bindings/core/v8/V8GCController.cpp b/sky/engine/bindings/core/v8/V8GCController.cpp
deleted file mode 100644
index 7903cc3c4522c421e2a1e535b67758a156ac825c..0000000000000000000000000000000000000000
--- a/sky/engine/bindings/core/v8/V8GCController.cpp
+++ /dev/null
@@ -1,403 +0,0 @@
-/*
- * Copyright (C) 2009 Google Inc. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "sky/engine/config.h"
-#include "sky/engine/bindings/core/v8/V8GCController.h"
-
-#include <algorithm>
-#include "bindings/core/v8/V8MutationObserver.h"
-#include "bindings/core/v8/V8Node.h"
-#include "sky/engine/bindings/core/v8/RetainedDOMInfo.h"
-#include "sky/engine/bindings/core/v8/V8AbstractEventListener.h"
-#include "sky/engine/bindings/core/v8/V8Binding.h"
-#include "sky/engine/bindings/core/v8/V8ScriptRunner.h"
-#include "sky/engine/bindings/core/v8/WrapperTypeInfo.h"
-#include "sky/engine/core/dom/Attr.h"
-#include "sky/engine/core/dom/Document.h"
-#include "sky/engine/core/dom/NodeTraversal.h"
-#include "sky/engine/core/dom/TemplateContentDocumentFragment.h"
-#include "sky/engine/core/dom/shadow/ElementShadow.h"
-#include "sky/engine/core/dom/shadow/ShadowRoot.h"
-#include "sky/engine/core/html/HTMLImageElement.h"
-#include "sky/engine/core/html/HTMLTemplateElement.h"
-#include "sky/engine/core/html/imports/HTMLImportsController.h"
-#include "sky/engine/platform/Partitions.h"
-#include "sky/engine/platform/TraceEvent.h"
-#include "sky/engine/wtf/Vector.h"
-
-namespace blink {
-
-// FIXME: This should use opaque GC roots.
-static void addReferencesForNodeWithEventListeners(v8::Isolate* isolate, Node* node, const v8::Persistent<v8::Object>& wrapper)
-{
-    ASSERT(node->hasEventListeners());
-
-    EventListenerIterator iterator(node);
-    while (EventListener* listener = iterator.nextListener()) {
-        V8AbstractEventListener* v8listener = static_cast<V8AbstractEventListener*>(listener);
-        if (!v8listener->hasExistingListenerObject())
-            continue;
-
-        isolate->SetReference(wrapper, v8::Persistent<v8::Value>::Cast(v8listener->existingListenerObjectPersistentHandle()));
-    }
-}
-
-Node* V8GCController::opaqueRootForGC(Node* node, v8::Isolate*)
-{
-    ASSERT(node);
-    // FIXME: Remove the special handling for image elements.
-    // The same special handling is in V8GCController::gcTree().
-    // Maybe should image elements be active DOM nodes?
-    // See https://code.google.com/p/chromium/issues/detail?id=164882
-    if (node->inDocument() || (isHTMLImageElement(*node) && toHTMLImageElement(*node).hasPendingActivity())) {
-        Document& document = node->document();
-        if (HTMLImportsController* controller = document.importsController())
-            return controller->master();
-        return &document;
-    }
-
-    while (Node* parent = node->parentOrShadowHostOrTemplateHostNode())
-        node = parent;
-
-    return node;
-}
-
-// Regarding a minor GC algorithm for DOM nodes, see this document:
-// https://docs.google.com/a/google.com/presentation/d/1uifwVYGNYTZDoGLyCb7sXa7g49mWNMW2gaWvMN5NLk8/edit#slide=id.p
-class MinorGCWrapperVisitor : public v8::PersistentHandleVisitor {
-public:
-    explicit MinorGCWrapperVisitor(v8::Isolate* isolate)
-        : m_isolate(isolate)
-    { }
-
-    virtual void VisitPersistentHandle(v8::Persistent<v8::Value>* value, uint16_t classId) override
-    {
-        // A minor DOM GC can collect only Nodes.
-        if (classId != WrapperTypeInfo::NodeClassId)
-            return;
-
-        // To make minor GC cycle time bounded, we limit the number of wrappers handled
-        // by each minor GC cycle to 10000. This value was selected so that the minor
-        // GC cycle time is bounded to 20 ms in a case where the new space size
-        // is 16 MB and it is full of wrappers (which is almost the worst case).
-        // Practically speaking, as far as I crawled real web applications,
-        // the number of wrappers handled by each minor GC cycle is at most 3000.
-        // So this limit is mainly for pathological micro benchmarks.
-        const unsigned wrappersHandledByEachMinorGC = 10000;
-        if (m_nodesInNewSpace.size() >= wrappersHandledByEachMinorGC)
-            return;
-
-        // Casting to a Handle is safe here, since the Persistent doesn't get GCd
-        // during the GC prologue.
-        ASSERT((*reinterpret_cast<v8::Handle<v8::Value>*>(value))->IsObject());
-        v8::Handle<v8::Object>* wrapper = reinterpret_cast<v8::Handle<v8::Object>*>(value);
-        ASSERT(V8DOMWrapper::isDOMWrapper(*wrapper));
-        ASSERT(V8Node::hasInstance(*wrapper, m_isolate));
-        Node* node = V8Node::toNative(*wrapper);
-        // A minor DOM GC can handle only node wrappers in the main world.
-        // Note that node->wrapper().IsEmpty() returns true for nodes that
-        // do not have wrappers in the main world.
-        if (node->containsWrapper()) {
-            const WrapperTypeInfo* type = toWrapperTypeInfo(*wrapper);
-            ActiveDOMObject* activeDOMObject = type->toActiveDOMObject(*wrapper);
-            if (activeDOMObject && activeDOMObject->hasPendingActivity())
-                return;
-            // FIXME: Remove the special handling for image elements.
-            // The same special handling is in V8GCController::opaqueRootForGC().
-            // Maybe should image elements be active DOM nodes?
-            // See https://code.google.com/p/chromium/issues/detail?id=164882
-            if (isHTMLImageElement(*node) && toHTMLImageElement(*node).hasPendingActivity())
-                return;
-
-            m_nodesInNewSpace.append(node);
-            node->markV8CollectableDuringMinorGC();
-        }
-    }
-
-    void notifyFinished()
-    {
-        for (size_t i = 0; i < m_nodesInNewSpace.size(); i++) {
-            Node* node = m_nodesInNewSpace[i];
-            ASSERT(node->containsWrapper());
-            if (node->isV8CollectableDuringMinorGC()) { // This branch is just for performance.
-                gcTree(m_isolate, node);
-                node->clearV8CollectableDuringMinorGC();
-            }
-        }
-    }
-
-private:
-    bool traverseTree(Node* rootNode, Vector<RawPtr<Node>, initialNodeVectorSize>* partiallyDependentNodes)
-    {
-        // To make each minor GC time bounded, we might need to give up
-        // traversing at some point for a large DOM tree. That being said,
-        // I could not observe the need even in pathological test cases.
-        for (Node* node = rootNode; node; node = NodeTraversal::next(*node)) {
-            if (node->containsWrapper()) {
-                if (!node->isV8CollectableDuringMinorGC()) {
-                    // This node is not in the new space of V8. This indicates that
-                    // the minor GC cannot anyway judge reachability of this DOM tree.
-                    // Thus we give up traversing the DOM tree.
-                    return false;
-                }
-                node->clearV8CollectableDuringMinorGC();
-                partiallyDependentNodes->append(node);
-            }
-            if (ShadowRoot* shadowRoot = node->shadowRoot()) {
-                if (!traverseTree(shadowRoot, partiallyDependentNodes))
-                    return false;
-            }
-            // <template> has a |content| property holding a DOM fragment which we must traverse,
-            // just like we do for the shadow trees above.
-            if (isHTMLTemplateElement(*node)) {
-                if (!traverseTree(toHTMLTemplateElement(*node).content(), partiallyDependentNodes))
-                    return false;
-            }
-
-            // Document maintains the list of imported documents through HTMLImportsController.
-            if (node->isDocumentNode()) {
-                Document* document = toDocument(node);
-                HTMLImportsController* controller = document->importsController();
-                if (controller && document == controller->master()) {
-                    for (unsigned i = 0; i < controller->loaderCount(); ++i) {
-                        if (!traverseTree(controller->loaderDocumentAt(i), partiallyDependentNodes))
-                            return false;
-                    }
-                }
-            }
-        }
-        return true;
-    }
-
-    void gcTree(v8::Isolate* isolate, Node* startNode)
-    {
-        Vector<RawPtr<Node>, initialNodeVectorSize> partiallyDependentNodes;
-
-        Node* node = startNode;
-        while (Node* parent = node->parentOrShadowHostOrTemplateHostNode())
-            node = parent;
-
-        if (!traverseTree(node, &partiallyDependentNodes))
-            return;
-
-        // We completed the DOM tree traversal. All wrappers in the DOM tree are
-        // stored in partiallyDependentNodes and are expected to exist in the new space of V8.
-        // We report those wrappers to V8 as an object group.
-        if (!partiallyDependentNodes.size())
-            return;
-        Node* groupRoot = partiallyDependentNodes[0];
-        for (size_t i = 0; i < partiallyDependentNodes.size(); i++) {
-            partiallyDependentNodes[i]->markAsDependentGroup(groupRoot, isolate);
-        }
-    }
-
-    Vector<RawPtr<Node> > m_nodesInNewSpace;
-    v8::Isolate* m_isolate;
-};
-
-class MajorGCWrapperVisitor : public v8::PersistentHandleVisitor {
-public:
-    explicit MajorGCWrapperVisitor(v8::Isolate* isolate, bool constructRetainedObjectInfos)
-        : m_isolate(isolate)
-        , m_liveRootGroupIdSet(false)
-        , m_constructRetainedObjectInfos(constructRetainedObjectInfos)
-    {
-    }
-
-    virtual void VisitPersistentHandle(v8::Persistent<v8::Value>* value, uint16_t classId) override
-    {
-        if (classId != WrapperTypeInfo::NodeClassId && classId != WrapperTypeInfo::ObjectClassId)
-            return;
-
-        // Casting to a Handle is safe here, since the Persistent doesn't get GCd
-        // during the GC prologue.
-        ASSERT((*reinterpret_cast<v8::Handle<v8::Value>*>(value))->IsObject());
-        v8::Handle<v8::Object>* wrapper = reinterpret_cast<v8::Handle<v8::Object>*>(value);
-        ASSERT(V8DOMWrapper::isDOMWrapper(*wrapper));
-
-        if (value->IsIndependent())
-            return;
-
-        const WrapperTypeInfo* type = toWrapperTypeInfo(*wrapper);
-
-        ActiveDOMObject* activeDOMObject = type->toActiveDOMObject(*wrapper);
-        if (activeDOMObject && activeDOMObject->hasPendingActivity())
-            m_isolate->SetObjectGroupId(*value, liveRootId());
-
-        if (classId == WrapperTypeInfo::NodeClassId) {
-            ASSERT(V8Node::hasInstance(*wrapper, m_isolate));
-            Node* node = V8Node::toNative(*wrapper);
-            if (node->hasEventListeners())
-                addReferencesForNodeWithEventListeners(m_isolate, node, v8::Persistent<v8::Object>::Cast(*value));
-            Node* root = V8GCController::opaqueRootForGC(node, m_isolate);
-            m_isolate->SetObjectGroupId(*value, v8::UniqueId(reinterpret_cast<intptr_t>(root)));
-            if (m_constructRetainedObjectInfos)
-                m_groupsWhichNeedRetainerInfo.append(root);
-        } else if (classId == WrapperTypeInfo::ObjectClassId) {
-            type->visitDOMWrapper(toScriptWrappableBase(*wrapper), v8::Persistent<v8::Object>::Cast(*value), m_isolate);
-        } else {
-            ASSERT_NOT_REACHED();
-        }
-    }
-
-    void notifyFinished()
-    {
-        if (!m_constructRetainedObjectInfos)
-            return;
-        std::sort(m_groupsWhichNeedRetainerInfo.begin(), m_groupsWhichNeedRetainerInfo.end());
-        Node* alreadyAdded = 0;
-        v8::HeapProfiler* profiler = m_isolate->GetHeapProfiler();
-        for (size_t i = 0; i < m_groupsWhichNeedRetainerInfo.size(); ++i) {
-            Node* root = m_groupsWhichNeedRetainerInfo[i];
-            if (root != alreadyAdded) {
-                profiler->SetRetainedObjectInfo(v8::UniqueId(reinterpret_cast<intptr_t>(root)), new RetainedDOMInfo(root));
-                alreadyAdded = root;
-            }
-        }
-    }
-
-private:
-    v8::UniqueId liveRootId()
-    {
-        const v8::Persistent<v8::Value>& liveRoot = V8PerIsolateData::from(m_isolate)->ensureLiveRoot();
-        const intptr_t* idPointer = reinterpret_cast<const intptr_t*>(&liveRoot);
-        v8::UniqueId id(*idPointer);
-        if (!m_liveRootGroupIdSet) {
-            m_isolate->SetObjectGroupId(liveRoot, id);
-            m_liveRootGroupIdSet = true;
-        }
-        return id;
-    }
-
-    v8::Isolate* m_isolate;
-    Vector<RawPtr<Node> > m_groupsWhichNeedRetainerInfo;
-    bool m_liveRootGroupIdSet;
-    bool m_constructRetainedObjectInfos;
-};
-
-void V8GCController::gcPrologue(v8::GCType type, v8::GCCallbackFlags flags)
-{
-    // FIXME: It would be nice if the GC callbacks passed the Isolate directly....
-    v8::Isolate* isolate = v8::Isolate::GetCurrent();
-    if (type == v8::kGCTypeScavenge)
-        minorGCPrologue(isolate);
-    else if (type == v8::kGCTypeMarkSweepCompact)
-        majorGCPrologue(flags & v8::kGCCallbackFlagConstructRetainedObjectInfos, isolate);
-}
-
-void V8GCController::minorGCPrologue(v8::Isolate* isolate)
-{
-    TRACE_EVENT_BEGIN0("v8", "minorGC");
-    if (isMainThread()) {
-        ScriptForbiddenScope::enter();
-        {
-            TRACE_EVENT_SCOPED_SAMPLING_STATE("blink", "DOMMinorGC");
-            v8::HandleScope scope(isolate);
-            MinorGCWrapperVisitor visitor(isolate);
-            v8::V8::VisitHandlesForPartialDependence(isolate, &visitor);
-            visitor.notifyFinished();
-        }
-        V8PerIsolateData::from(isolate)->setPreviousSamplingState(TRACE_EVENT_GET_SAMPLING_STATE());
-        TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8MinorGC");
-    }
-}
-
-// Create object groups for DOM tree nodes.
-void V8GCController::majorGCPrologue(bool constructRetainedObjectInfos, v8::Isolate* isolate)
-{
-    v8::HandleScope scope(isolate);
-    TRACE_EVENT_BEGIN0("v8", "majorGC");
-    if (isMainThread()) {
-        ScriptForbiddenScope::enter();
-        {
-            TRACE_EVENT_SCOPED_SAMPLING_STATE("blink", "DOMMajorGC");
-            MajorGCWrapperVisitor visitor(isolate, constructRetainedObjectInfos);
-            v8::V8::VisitHandlesWithClassIds(&visitor);
-            visitor.notifyFinished();
-        }
-        V8PerIsolateData::from(isolate)->setPreviousSamplingState(TRACE_EVENT_GET_SAMPLING_STATE());
-        TRACE_EVENT_SET_SAMPLING_STATE("v8", "V8MajorGC");
-    } else {
-        MajorGCWrapperVisitor visitor(isolate, constructRetainedObjectInfos);
-        v8::V8::VisitHandlesWithClassIds(&visitor);
-        visitor.notifyFinished();
-    }
-}
-
-void V8GCController::gcEpilogue(v8::GCType type, v8::GCCallbackFlags flags)
-{
-    // FIXME: It would be nice if the GC callbacks passed the Isolate directly....
-    v8::Isolate* isolate = v8::Isolate::GetCurrent();
-    if (type == v8::kGCTypeScavenge)
-        minorGCEpilogue(isolate);
-    else if (type == v8::kGCTypeMarkSweepCompact)
-        majorGCEpilogue(isolate);
-}
-
-void V8GCController::minorGCEpilogue(v8::Isolate* isolate)
-{
-    TRACE_EVENT_END0("v8", "minorGC");
-    if (isMainThread())
-        ScriptForbiddenScope::exit();
-}
-
-void V8GCController::majorGCEpilogue(v8::Isolate* isolate)
-{
-    v8::HandleScope scope(isolate);
-
-    TRACE_EVENT_END0("v8", "majorGC");
-    if (isMainThread())
-        ScriptForbiddenScope::exit();
-}
-
-void V8GCController::collectGarbage(v8::Isolate* isolate)
-{
-    v8::HandleScope handleScope(isolate);
-    RefPtr<ScriptState> scriptState = ScriptState::create(v8::Context::New(isolate), DOMWrapperWorld::create(FakeWorld));
-    ScriptState::Scope scope(scriptState.get());
-    V8ScriptRunner::compileAndRunInternalScript(v8String(isolate, "if (gc) gc();"), isolate);
-    scriptState->disposePerContextData();
-}
-
-void V8GCController::reportDOMMemoryUsageToV8(v8::Isolate* isolate)
-{
-    if (!isMainThread())
-        return;
-
-    static size_t lastUsageReportedToV8 = 0;
-
-    size_t currentUsage = Partitions::currentDOMMemoryUsage();
-    int64_t diff = static_cast<int64_t>(currentUsage) - static_cast<int64_t>(lastUsageReportedToV8);
-    isolate->AdjustAmountOfExternalAllocatedMemory(diff);
-
-    lastUsageReportedToV8 = currentUsage;
-}
-
-} // namespace blink