Initial implementation of dedicated FixedArray processing.

src/profiler/heap-snapshot-generator.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/profiler/heap-snapshot-generator.h"
 
 #include "src/code-stubs.h"
 #include "src/conversions.h"
 #include "src/debug/debug.h"
 #include "src/objects-body-descriptors.h"
@@ skipping 1175 matching lines @@
                        Symbol::kNameOffset);
 }
 
 
 void V8HeapExplorer::ExtractJSCollectionReferences(int entry,
                                                    JSCollection* collection) {
   SetInternalReference(collection, entry, "table", collection->table(),
                        JSCollection::kTableOffset);
 }
 
-
-void V8HeapExplorer::ExtractJSWeakCollectionReferences(
-    int entry, JSWeakCollection* collection) {
-  MarkAsWeakContainer(collection->table());
-  SetInternalReference(collection, entry,
-                       "table", collection->table(),
+void V8HeapExplorer::ExtractJSWeakCollectionReferences(int entry,
+                                                       JSWeakCollection* obj) {
+  if (obj->table()->IsHashTable()) {
+    ObjectHashTable* table = ObjectHashTable::cast(obj->table());
+    TagFixedArraySubType(table, JS_WEAK_COLLECTION_SUB_TYPE);
+  }
+  SetInternalReference(obj, entry, "table", obj->table(),
                        JSWeakCollection::kTableOffset);
 }
 
-
 void V8HeapExplorer::ExtractContextReferences(int entry, Context* context) {
   if (context == context->declaration_context()) {
     ScopeInfo* scope_info = context->closure()->shared()->scope_info();
     // Add context allocated locals.
     int context_locals = scope_info->ContextLocalCount();
     for (int i = 0; i < context_locals; ++i) {
       String* local_name = scope_info->ContextLocalName(i);
       int idx = Context::MIN_CONTEXT_SLOTS + i;
       SetContextReference(context, entry, local_name, context->get(idx),
                           Context::OffsetOfElementAt(idx));
@@ skipping 306 matching lines @@
   if (!buffer->backing_store())
     return;
   size_t data_size = NumberToSize(heap_->isolate(), buffer->byte_length());
   JSArrayBufferDataEntryAllocator allocator(data_size, this);
   HeapEntry* data_entry =
       filler_->FindOrAddEntry(buffer->backing_store(), &allocator);
   filler_->SetNamedReference(HeapGraphEdge::kInternal,
                              entry, "backing_store", data_entry);
 }
 
+void V8HeapExplorer::ExtractFixedArrayReferences(int entry, FixedArray* array) {
+  auto it = array_types_.find(array);
+  if (it == array_types_.end()) {
+    for (int i = 0, l = array->length(); i < l; ++i) {
+      SetInternalReference(array, entry, i, array->get(i),
+                           array->OffsetOfElementAt(i));
+    }
+    return;
+  }
+  switch (it->second) {
+    case JS_WEAK_COLLECTION_SUB_TYPE:
+      for (int i = 0, l = array->length(); i < l; ++i) {
+        SetWeakReference(array, entry, i, array->get(i),
+                         array->OffsetOfElementAt(i));
+      }
+      break;
 
-void V8HeapExplorer::ExtractFixedArrayReferences(int entry, FixedArray* array) {
-  bool is_weak = weak_containers_.Contains(array);
-  for (int i = 0, l = array->length(); i < l; ++i) {
-    if (is_weak) {
-      SetWeakReference(array, entry,
-                       i, array->get(i), array->OffsetOfElementAt(i));
-    } else {
-      SetInternalReference(array, entry,
-                           i, array->get(i), array->OffsetOfElementAt(i));
-    }
+    // TODO(alph): Add special processing for other types of FixedArrays.
+
+    default:
+      for (int i = 0, l = array->length(); i < l; ++i) {
+        SetInternalReference(array, entry, i, array->get(i),
+                             array->OffsetOfElementAt(i));
+      }
+      break;
   }
 }
 
-
 void V8HeapExplorer::ExtractPropertyReferences(JSObject* js_obj, int entry) {
   Isolate* isolate = js_obj->GetIsolate();
   if (js_obj->HasFastProperties()) {
     DescriptorArray* descs = js_obj->map()->instance_descriptors();
     int real_size = js_obj->map()->NumberOfOwnDescriptors();
     for (int i = 0; i < real_size; i++) {
       PropertyDetails details = descs->GetDetails(i);
       switch (details.location()) {
         case kField: {
           Representation r = details.representation();
@@ skipping 564 matching lines @@
 
 void V8HeapExplorer::TagObject(Object* obj, const char* tag) {
   if (IsEssentialObject(obj)) {
     HeapEntry* entry = GetEntry(obj);
     if (entry->name()[0] == '\0') {
       entry->set_name(tag);
     }
   }
 }
 
-
-void V8HeapExplorer::MarkAsWeakContainer(Object* object) {
-  if (IsEssentialObject(object) && object->IsFixedArray()) {
-    weak_containers_.Insert(object);
-  }
+void V8HeapExplorer::TagFixedArraySubType(const FixedArray* array,
+                                          FixedArraySubInstanceType type) {
+  DCHECK(array_types_.find(array) == array_types_.end());
+  array_types_[array] = type;
 }
 
-
 class GlobalObjectsEnumerator : public ObjectVisitor {
  public:
   void VisitPointers(Object** start, Object** end) override {
     for (Object** p = start; p < end; p++) {
       if ((*p)->IsNativeContext()) {
         Context* context = Context::cast(*p);
         JSObject* proxy = context->global_proxy();
         if (proxy->IsJSGlobalProxy()) {
           Object* global = proxy->map()->prototype();
           if (global->IsJSGlobalObject()) {
@@ skipping 964 matching lines @@
   for (int i = 1; i < sorted_strings.length(); ++i) {
     writer_->AddCharacter(',');
     SerializeString(sorted_strings[i]);
     if (writer_->aborted()) return;
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8