// Copyright 2021 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. #ifndef V8_SNAPSHOT_SHARED_HEAP_SERIALIZER_H_ #define V8_SNAPSHOT_SHARED_HEAP_SERIALIZER_H_ #include "src/snapshot/roots-serializer.h" namespace v8 { namespace internal { class HeapObject; class ReadOnlySerializer; // SharedHeapSerializer serializes objects that should be in the shared heap in // the shared Isolate during startup. Currently the shared heap is only in use // behind flags (e.g. --shared-string-table). When it is not in use, its // contents are deserialized into each Isolate. class V8_EXPORT_PRIVATE SharedHeapSerializer : public RootsSerializer { public: SharedHeapSerializer(Isolate* isolate, Snapshot::SerializerFlags flags, ReadOnlySerializer* read_only_serializer); ~SharedHeapSerializer() override; SharedHeapSerializer(const SharedHeapSerializer&) = delete; SharedHeapSerializer& operator=(const SharedHeapSerializer&) = delete; // Terminate the shared heap object cache with an undefined value and // serialize the string table.. void FinalizeSerialization(); // If |obj| can be serialized in the read-only snapshot then add it to the // read-only object cache if not already present and emit a // ReadOnlyObjectCache bytecode into |sink|. Returns whether this was // successful. bool SerializeUsingReadOnlyObjectCache(SnapshotByteSink* sink, Handle<HeapObject> obj); // If |obj| can be serialized in the shared heap snapshot then add it to the // shared heap object cache if not already present and emit a // SharedHeapObjectCache bytecode into |sink|. Returns whether this was // successful. bool SerializeUsingSharedHeapObjectCache(SnapshotByteSink* sink, Handle<HeapObject> obj); static bool CanBeInSharedOldSpace(HeapObject obj); static bool ShouldBeInSharedHeapObjectCache(HeapObject obj); private: bool ShouldReconstructSharedHeapObjectCacheForTesting() const; void ReconstructSharedHeapObjectCacheForTesting(); void SerializeStringTable(StringTable* string_table); void SerializeObjectImpl(Handle<HeapObject> obj) override; ReadOnlySerializer* read_only_serializer_; #ifdef DEBUG IdentityMap<int, base::DefaultAllocationPolicy> serialized_objects_; #endif }; } // namespace internal } // namespace v8 #endif // V8_SNAPSHOT_SHARED_HEAP_SERIALIZER_H_