1 // Copyright 2016 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 #ifndef V8_SNAPSHOT_STARTUP_SERIALIZER_H_ 6 #define V8_SNAPSHOT_STARTUP_SERIALIZER_H_ 7 8 #include <bitset> 9 #include "include/v8.h" 10 #include "src/snapshot/serializer.h" 11 12 namespace v8 { 13 namespace internal { 14 15 class StartupSerializer : public Serializer<> { 16 public: 17 explicit StartupSerializer(Isolate* isolate); 18 ~StartupSerializer() override; 19 20 // Serialize the current state of the heap. The order is: 21 // 1) Strong roots 22 // 2) Builtins and bytecode handlers 23 // 3) Partial snapshot cache 24 // 4) Weak references (e.g. the string table) 25 void SerializeStrongReferences(); 26 void SerializeWeakReferencesAndDeferred(); 27 28 int PartialSnapshotCacheIndex(HeapObject* o); 29 30 bool can_be_rehashed() const { return can_be_rehashed_; } 31 bool root_has_been_serialized(int root_index) const { 32 return root_has_been_serialized_.test(root_index); 33 } 34 35 private: 36 class PartialCacheIndexMap { 37 public: 38 PartialCacheIndexMap() : map_(), next_index_(0) {} 39 40 // Lookup object in the map. Return its index if found, or create 41 // a new entry with new_index as value, and return kInvalidIndex. 42 bool LookupOrInsert(HeapObject* obj, int* index_out) { 43 Maybe<uint32_t> maybe_index = map_.Get(obj); 44 if (maybe_index.IsJust()) { 45 *index_out = maybe_index.FromJust(); 46 return true; 47 } 48 *index_out = next_index_; 49 map_.Set(obj, next_index_++); 50 return false; 51 } 52 53 private: 54 DisallowHeapAllocation no_allocation_; 55 HeapObjectToIndexHashMap map_; 56 int next_index_; 57 58 DISALLOW_COPY_AND_ASSIGN(PartialCacheIndexMap); 59 }; 60 61 // The StartupSerializer has to serialize the root array, which is slightly 62 // different. 63 void VisitRootPointers(Root root, const char* description, Object** start, 64 Object** end) override; 65 void SerializeObject(HeapObject* o, HowToCode how_to_code, 66 WhereToPoint where_to_point, int skip) override; 67 void Synchronize(VisitorSynchronization::SyncTag tag) override; 68 bool MustBeDeferred(HeapObject* object) override; 69 70 void CheckRehashability(HeapObject* obj); 71 72 std::bitset<Heap::kStrongRootListLength> root_has_been_serialized_; 73 PartialCacheIndexMap partial_cache_index_map_; 74 std::vector<AccessorInfo*> accessor_infos_; 75 std::vector<CallHandlerInfo*> call_handler_infos_; 76 // Indicates whether we only serialized hash tables that we can rehash. 77 // TODO(yangguo): generalize rehashing, and remove this flag. 78 bool can_be_rehashed_; 79 80 DISALLOW_COPY_AND_ASSIGN(StartupSerializer); 81 }; 82 83 class SerializedHandleChecker : public RootVisitor { 84 public: 85 SerializedHandleChecker(Isolate* isolate, std::vector<Context*>* contexts); 86 virtual void VisitRootPointers(Root root, const char* description, 87 Object** start, Object** end); 88 bool CheckGlobalAndEternalHandles(); 89 90 private: 91 void AddToSet(FixedArray* serialized); 92 93 Isolate* isolate_; 94 std::unordered_set<Object*> serialized_; 95 bool ok_ = true; 96 }; 97 98 } // namespace internal 99 } // namespace v8 100 101 #endif // V8_SNAPSHOT_STARTUP_SERIALIZER_H_ 102