| // Copyright 2016 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/snapshot/partial-serializer.h" |
| #include "src/snapshot/startup-serializer.h" |
| |
| #include "src/objects-inl.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| PartialSerializer::PartialSerializer(Isolate* isolate, |
| StartupSerializer* startup_serializer) |
| : Serializer(isolate), startup_serializer_(startup_serializer) { |
| InitializeCodeAddressMap(); |
| } |
| |
| PartialSerializer::~PartialSerializer() { |
| OutputStatistics("PartialSerializer"); |
| } |
| |
| void PartialSerializer::Serialize(Object** o) { |
| if ((*o)->IsContext()) { |
| Context* context = Context::cast(*o); |
| reference_map()->AddAttachedReference(context->global_proxy()); |
| // The bootstrap snapshot has a code-stub context. When serializing the |
| // partial snapshot, it is chained into the weak context list on the isolate |
| // and it's next context pointer may point to the code-stub context. Clear |
| // it before serializing, it will get re-added to the context list |
| // explicitly when it's loaded. |
| if (context->IsNativeContext()) { |
| context->set(Context::NEXT_CONTEXT_LINK, |
| isolate_->heap()->undefined_value()); |
| DCHECK(!context->global_object()->IsUndefined(context->GetIsolate())); |
| // Reset math random cache to get fresh random numbers. |
| context->set_math_random_index(Smi::kZero); |
| context->set_math_random_cache(isolate_->heap()->undefined_value()); |
| } |
| } |
| VisitPointer(o); |
| SerializeDeferredObjects(); |
| Pad(); |
| } |
| |
| void PartialSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code, |
| WhereToPoint where_to_point, int skip) { |
| if (obj->IsMap()) { |
| // The code-caches link to context-specific code objects, which |
| // the startup and context serializes cannot currently handle. |
| DCHECK(Map::cast(obj)->code_cache() == obj->GetHeap()->empty_fixed_array()); |
| } |
| |
| // Replace typed arrays by undefined. |
| if (obj->IsJSTypedArray()) obj = isolate_->heap()->undefined_value(); |
| |
| if (SerializeHotObject(obj, how_to_code, where_to_point, skip)) return; |
| |
| int root_index = root_index_map_.Lookup(obj); |
| if (root_index != RootIndexMap::kInvalidRootIndex) { |
| PutRoot(root_index, obj, how_to_code, where_to_point, skip); |
| return; |
| } |
| |
| if (SerializeBackReference(obj, how_to_code, where_to_point, skip)) return; |
| |
| if (ShouldBeInThePartialSnapshotCache(obj)) { |
| FlushSkip(skip); |
| |
| int cache_index = startup_serializer_->PartialSnapshotCacheIndex(obj); |
| sink_.Put(kPartialSnapshotCache + how_to_code + where_to_point, |
| "PartialSnapshotCache"); |
| sink_.PutInt(cache_index, "partial_snapshot_cache_index"); |
| return; |
| } |
| |
| // Pointers from the partial snapshot to the objects in the startup snapshot |
| // should go through the root array or through the partial snapshot cache. |
| // If this is not the case you may have to add something to the root array. |
| DCHECK(!startup_serializer_->reference_map()->Lookup(obj).is_valid()); |
| // All the internalized strings that the partial snapshot needs should be |
| // either in the root table or in the partial snapshot cache. |
| DCHECK(!obj->IsInternalizedString()); |
| // Function and object templates are not context specific. |
| DCHECK(!obj->IsTemplateInfo()); |
| |
| FlushSkip(skip); |
| |
| // Clear literal boilerplates. |
| if (obj->IsJSFunction()) { |
| JSFunction* function = JSFunction::cast(obj); |
| LiteralsArray* literals = function->literals(); |
| for (int i = 0; i < literals->literals_count(); i++) { |
| literals->set_literal_undefined(i); |
| } |
| function->ClearTypeFeedbackInfo(); |
| } |
| |
| // Object has not yet been serialized. Serialize it here. |
| ObjectSerializer serializer(this, obj, &sink_, how_to_code, where_to_point); |
| serializer.Serialize(); |
| } |
| |
| bool PartialSerializer::ShouldBeInThePartialSnapshotCache(HeapObject* o) { |
| // Scripts should be referred only through shared function infos. We can't |
| // allow them to be part of the partial snapshot because they contain a |
| // unique ID, and deserializing several partial snapshots containing script |
| // would cause dupes. |
| DCHECK(!o->IsScript()); |
| return o->IsName() || o->IsSharedFunctionInfo() || o->IsHeapNumber() || |
| o->IsCode() || o->IsScopeInfo() || o->IsAccessorInfo() || |
| o->map() == |
| startup_serializer_->isolate()->heap()->fixed_cow_array_map(); |
| } |
| |
| } // namespace internal |
| } // namespace v8 |