Map::Normalize() introduced as single entry point for map normalization and Map::NotifyLeafMapLayou…

src/objects.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 "v8.h"
 
 #include "accessors.h"
 #include "allocation-site-scopes.h"
 #include "api.h"
 #include "arguments.h"
@@ skipping 4640 matching lines @@
     // We need to follow the spec and simulate a call to [[GetOwnProperty]].
     return JSProxy::GetElementAttributeWithHandler(
         Handle<JSProxy>::cast(proto), receiver, index);
   }
   if (proto->IsNull()) return ABSENT;
   return GetElementAttributeWithReceiver(
       Handle<JSObject>::cast(proto), receiver, index, true);
 }
 
 
-Handle<Map> NormalizedMapCache::Get(Handle<NormalizedMapCache> cache,
-                                    Handle<Map> fast_map,
-                                    PropertyNormalizationMode mode) {
-  int index = fast_map->Hash() % kEntries;
-  Handle<Object> result = handle(cache->get(index), cache->GetIsolate());
-  if (result->IsMap() &&
-      Handle<Map>::cast(result)->EquivalentToForNormalization(
-          *fast_map, mode)) {
-#ifdef VERIFY_HEAP
-    if (FLAG_verify_heap) {
-      Handle<Map>::cast(result)->SharedMapVerify();
-    }
-#endif
-#ifdef ENABLE_SLOW_ASSERTS
-    if (FLAG_enable_slow_asserts) {
-      // The cached map should match newly created normalized map bit-by-bit,
-      // except for the code cache, which can contain some ics which can be
-      // applied to the shared map.
-      Handle<Map> fresh = Map::CopyNormalized(
-          fast_map, mode, SHARED_NORMALIZED_MAP);
-
-      ASSERT(memcmp(fresh->address(),
-                    Handle<Map>::cast(result)->address(),
-                    Map::kCodeCacheOffset) == 0);
-      STATIC_ASSERT(Map::kDependentCodeOffset ==
-                    Map::kCodeCacheOffset + kPointerSize);
-      int offset = Map::kDependentCodeOffset + kPointerSize;
-      ASSERT(memcmp(fresh->address() + offset,
-                    Handle<Map>::cast(result)->address() + offset,
-                    Map::kSize - offset) == 0);
-    }
-#endif
-    return Handle<Map>::cast(result);
-  }
-
-  Isolate* isolate = cache->GetIsolate();
-  Handle<Map> map = Map::CopyNormalized(fast_map, mode, SHARED_NORMALIZED_MAP);
-  ASSERT(map->is_dictionary_map());
-  cache->set(index, *map);
-  isolate->counters()->normalized_maps()->Increment();
-
-  return map;
+Handle<NormalizedMapCache> NormalizedMapCache::New(Isolate* isolate) {
+  Handle<FixedArray> array(
+      isolate->factory()->NewFixedArray(kEntries, TENURED));
+  return Handle<NormalizedMapCache>::cast(array);
 }
 
 
+MaybeHandle<Map> NormalizedMapCache::Get(Handle<Map> fast_map) {
+  DisallowHeapAllocation no_gc;
+  Object* value = FixedArray::get(GetIndex(fast_map));
+  if (!value->IsMap()) return MaybeHandle<Map>();
+  return handle(Map::cast(value));
+}
+
+
+void NormalizedMapCache::Set(Handle<Map> fast_map,
+                             Handle<Map> normalized_map) {
+  DisallowHeapAllocation no_gc;
+  ASSERT(normalized_map->is_dictionary_map());
+  FixedArray::set(GetIndex(fast_map), *normalized_map);
+}
+
+
 void NormalizedMapCache::Clear() {
   int entries = length();
   for (int i = 0; i != entries; i++) {
     set_undefined(i);
   }
 }
 
 
 void HeapObject::UpdateMapCodeCache(Handle<HeapObject> object,
                                     Handle<Name> name,
                                     Handle<Code> code) {
   Handle<Map> map(object->map());
   Map::UpdateCodeCache(map, name, code);
 }
 
 
 void JSObject::NormalizeProperties(Handle<JSObject> object,
                                    PropertyNormalizationMode mode,
                                    int expected_additional_properties) {
   if (!object->HasFastProperties()) return;
 
   // The global object is always normalized.
   ASSERT(!object->IsGlobalObject());
   // JSGlobalProxy must never be normalized
   ASSERT(!object->IsJSGlobalProxy());
 
   Isolate* isolate = object->GetIsolate();
   HandleScope scope(isolate);
   Handle<Map> map(object->map());
+  Handle<Map> new_map = Map::Normalize(map, mode);
 
   // Allocate new content.
   int real_size = map->NumberOfOwnDescriptors();
   int property_count = real_size;
   if (expected_additional_properties > 0) {
     property_count += expected_additional_properties;
   } else {
     property_count += 2;  // Make space for two more properties.
   }
   Handle<NameDictionary> dictionary =
@@ skipping 34 matching lines @@
       case NORMAL:
       case NONEXISTENT:
         UNREACHABLE();
         break;
     }
   }
 
   // Copy the next enumeration index from instance descriptor.
   dictionary->SetNextEnumerationIndex(real_size + 1);
 
-  Handle<NormalizedMapCache> cache(
-      isolate->context()->native_context()->normalized_map_cache());
-  Handle<Map> new_map = NormalizedMapCache::Get(
-      cache, handle(object->map()), mode);
-  ASSERT(new_map->is_dictionary_map());
-
   // From here on we cannot fail and we shouldn't GC anymore.
   DisallowHeapAllocation no_allocation;
 
   // Resize the object in the heap if necessary.
   int new_instance_size = new_map->instance_size();
   int instance_size_delta = map->instance_size() - new_instance_size;
   ASSERT(instance_size_delta >= 0);
   Heap* heap = isolate->heap();
   heap->CreateFillerObjectAt(object->address() + new_instance_size,
                              instance_size_delta);
   heap->AdjustLiveBytes(object->address(),
                         -instance_size_delta,
                         Heap::FROM_MUTATOR);
 
   // We are storing the new map using release store after creating a filler for
   // the left-over space to avoid races with the sweeper thread.
   object->synchronized_set_map(*new_map);
 
-  map->NotifyLeafMapLayoutChange();
-
   object->set_properties(*dictionary);
 
   isolate->counters()->props_to_dictionary()->Increment();
 
 #ifdef DEBUG
   if (FLAG_trace_normalization) {
     PrintF("Object properties have been normalized:\n");
     object->Print();
   }
 #endif
@@ skipping 2406 matching lines @@
                                           kInvalidEnumCacheSentinel);
   new_bit_field3 = Deprecated::update(new_bit_field3, false);
   if (!map->is_dictionary_map()) {
     new_bit_field3 = IsUnstable::update(new_bit_field3, false);
   }
   result->set_bit_field3(new_bit_field3);
   return result;
 }
 
 
+Handle<Map> Map::Normalize(Handle<Map> fast_map,
+                           PropertyNormalizationMode mode) {
+  ASSERT(!fast_map->is_dictionary_map());
+
+  Isolate* isolate = fast_map->GetIsolate();
+  Handle<NormalizedMapCache> cache(
+      isolate->context()->native_context()->normalized_map_cache());
+
+  Handle<Map> new_map;
+  if (cache->Get(fast_map).ToHandle(&new_map) &&
+      new_map->EquivalentToForNormalization(*fast_map, mode)) {

[Toon Verwaest, 2014/05/01 11:24:34]

Seems like EquivalentToForNormalization should be moved into
cache->Get(fast_map, mode), since hash collisions are an internal property of
the cache.

[Igor Sheludko, 2014/05/02 09:47:38]

Done.

+#ifdef VERIFY_HEAP
+    if (FLAG_verify_heap) {
+      new_map->SharedMapVerify();
+    }
+#endif
+#ifdef ENABLE_SLOW_ASSERTS
+    if (FLAG_enable_slow_asserts) {
+      // The cached map should match newly created normalized map bit-by-bit,
+      // except for the code cache, which can contain some ics which can be
+      // applied to the shared map.
+      Handle<Map> fresh = Map::CopyNormalized(
+          fast_map, mode, SHARED_NORMALIZED_MAP);
+
+      ASSERT(memcmp(fresh->address(),
+                    new_map->address(),
+                    Map::kCodeCacheOffset) == 0);
+      STATIC_ASSERT(Map::kDependentCodeOffset ==
+                    Map::kCodeCacheOffset + kPointerSize);
+      int offset = Map::kDependentCodeOffset + kPointerSize;
+      ASSERT(memcmp(fresh->address() + offset,
+                    new_map->address() + offset,
+                    Map::kSize - offset) == 0);
+    }
+#endif
+  } else {
+    new_map = Map::CopyNormalized(fast_map, mode, SHARED_NORMALIZED_MAP);
+    cache->Set(fast_map, new_map);
+    isolate->counters()->normalized_maps()->Increment();
+  }
+  fast_map->NotifyLeafMapLayoutChange();
+  return new_map;
+}
+
+
 Handle<Map> Map::CopyNormalized(Handle<Map> map,
                                 PropertyNormalizationMode mode,
                                 NormalizedMapSharingMode sharing) {
   int new_instance_size = map->instance_size();
   if (mode == CLEAR_INOBJECT_PROPERTIES) {
     new_instance_size -= map->inobject_properties() * kPointerSize;
   }
 
   Handle<Map> result = RawCopy(map, new_instance_size);
 
@@ skipping 9959 matching lines @@
 #define ERROR_MESSAGES_TEXTS(C, T) T,
   static const char* error_messages_[] = {
       ERROR_MESSAGES_LIST(ERROR_MESSAGES_TEXTS)
   };
 #undef ERROR_MESSAGES_TEXTS
   return error_messages_[reason];
 }
 
 
 } }  // namespace v8::internal