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      1 // Copyright 2017 the V8 project authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "src/snapshot/object-deserializer.h"
      6 
      7 #include "src/assembler-inl.h"
      8 #include "src/code-stubs.h"
      9 #include "src/isolate.h"
     10 #include "src/objects.h"
     11 #include "src/snapshot/code-serializer.h"
     12 
     13 namespace v8 {
     14 namespace internal {
     15 
     16 MaybeHandle<SharedFunctionInfo>
     17 ObjectDeserializer::DeserializeSharedFunctionInfo(
     18     Isolate* isolate, const SerializedCodeData* data, Handle<String> source) {
     19   ObjectDeserializer d(data);
     20 
     21   d.AddAttachedObject(source);
     22 
     23   Vector<const uint32_t> code_stub_keys = data->CodeStubKeys();
     24   for (int i = 0; i < code_stub_keys.length(); i++) {
     25     d.AddAttachedObject(
     26         CodeStub::GetCode(isolate, code_stub_keys[i]).ToHandleChecked());
     27   }
     28 
     29   Handle<HeapObject> result;
     30   return d.Deserialize(isolate).ToHandle(&result)
     31              ? Handle<SharedFunctionInfo>::cast(result)
     32              : MaybeHandle<SharedFunctionInfo>();
     33 }
     34 
     35 MaybeHandle<HeapObject> ObjectDeserializer::Deserialize(Isolate* isolate) {
     36   Initialize(isolate);
     37 
     38   if (!allocator()->ReserveSpace()) return MaybeHandle<HeapObject>();
     39 
     40   DCHECK(deserializing_user_code());
     41   HandleScope scope(isolate);
     42   Handle<HeapObject> result;
     43   {
     44     DisallowHeapAllocation no_gc;
     45     Object* root;
     46     VisitRootPointer(Root::kPartialSnapshotCache, nullptr, &root);
     47     DeserializeDeferredObjects();
     48     FlushICacheForNewCodeObjectsAndRecordEmbeddedObjects();
     49     result = handle(HeapObject::cast(root), isolate);
     50     Rehash();
     51     allocator()->RegisterDeserializedObjectsForBlackAllocation();
     52   }
     53   CommitPostProcessedObjects();
     54   return scope.CloseAndEscape(result);
     55 }
     56 
     57 void ObjectDeserializer::
     58     FlushICacheForNewCodeObjectsAndRecordEmbeddedObjects() {
     59   DCHECK(deserializing_user_code());
     60   for (Code* code : new_code_objects()) {
     61     // Record all references to embedded objects in the new code object.
     62     WriteBarrierForCode(code);
     63     Assembler::FlushICache(code->raw_instruction_start(),
     64                            code->raw_instruction_size());
     65   }
     66 }
     67 
     68 void ObjectDeserializer::CommitPostProcessedObjects() {
     69   CHECK_LE(new_internalized_strings().size(), kMaxInt);
     70   StringTable::EnsureCapacityForDeserialization(
     71       isolate(), static_cast<int>(new_internalized_strings().size()));
     72   for (Handle<String> string : new_internalized_strings()) {
     73     DisallowHeapAllocation no_gc;
     74     StringTableInsertionKey key(*string);
     75     DCHECK_NULL(StringTable::ForwardStringIfExists(isolate(), &key, *string));
     76     StringTable::AddKeyNoResize(isolate(), &key);
     77   }
     78 
     79   Heap* heap = isolate()->heap();
     80   Factory* factory = isolate()->factory();
     81   for (Handle<Script> script : new_scripts()) {
     82     // Assign a new script id to avoid collision.
     83     script->set_id(isolate()->heap()->NextScriptId());
     84     LOG(isolate(),
     85         ScriptEvent(Logger::ScriptEventType::kDeserialize, script->id()));
     86     LOG(isolate(), ScriptDetails(*script));
     87     // Add script to list.
     88     Handle<WeakArrayList> list = factory->script_list();
     89     list = WeakArrayList::AddToEnd(isolate(), list,
     90                                    MaybeObjectHandle::Weak(script));
     91     heap->SetRootScriptList(*list);
     92   }
     93 }
     94 
     95 }  // namespace internal
     96 }  // namespace v8
     97