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| 1 // Copyright 2012 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_SERIALIZE_H_ | |
| 6 #define V8_SNAPSHOT_SERIALIZE_H_ | |
| 7 | |
| 8 #include "src/address-map.h" | |
| 9 #include "src/heap/heap.h" | |
| 10 #include "src/objects.h" | |
| 11 #include "src/snapshot/snapshot-source-sink.h" | |
| 12 | |
| 13 namespace v8 { | |
| 14 namespace internal { | |
| 15 | |
| 16 class Isolate; | |
| 17 class ScriptData; | |
| 18 | |
| 19 static const int kDeoptTableSerializeEntryCount = 64; | |
| 20 | |
| 21 // ExternalReferenceTable is a helper class that defines the relationship | |
| 22 // between external references and their encodings. It is used to build | |
| 23 // hashmaps in ExternalReferenceEncoder and ExternalReferenceDecoder. | |
| 24 class ExternalReferenceTable { | |
| 25 public: | |
| 26 static ExternalReferenceTable* instance(Isolate* isolate); | |
| 27 | |
| 28 int size() const { return refs_.length(); } | |
| 29 Address address(int i) { return refs_[i].address; } | |
| 30 const char* name(int i) { return refs_[i].name; } | |
| 31 | |
| 32 inline static Address NotAvailable() { return NULL; } | |
| 33 | |
| 34 private: | |
| 35 struct ExternalReferenceEntry { | |
| 36 Address address; | |
| 37 const char* name; | |
| 38 }; | |
| 39 | |
| 40 explicit ExternalReferenceTable(Isolate* isolate); | |
| 41 | |
| 42 void Add(Address address, const char* name) { | |
| 43 ExternalReferenceEntry entry = {address, name}; | |
| 44 refs_.Add(entry); | |
| 45 } | |
| 46 | |
| 47 List<ExternalReferenceEntry> refs_; | |
| 48 | |
| 49 DISALLOW_COPY_AND_ASSIGN(ExternalReferenceTable); | |
| 50 }; | |
| 51 | |
| 52 | |
| 53 class ExternalReferenceEncoder { | |
| 54 public: | |
| 55 explicit ExternalReferenceEncoder(Isolate* isolate); | |
| 56 | |
| 57 uint32_t Encode(Address key) const; | |
| 58 | |
| 59 const char* NameOfAddress(Isolate* isolate, Address address) const; | |
| 60 | |
| 61 private: | |
| 62 static uint32_t Hash(Address key) { | |
| 63 return static_cast<uint32_t>(reinterpret_cast<uintptr_t>(key) >> | |
| 64 kPointerSizeLog2); | |
| 65 } | |
| 66 | |
| 67 HashMap* map_; | |
| 68 | |
| 69 DISALLOW_COPY_AND_ASSIGN(ExternalReferenceEncoder); | |
| 70 }; | |
| 71 | |
| 72 | |
| 73 class PartialCacheIndexMap : public AddressMapBase { | |
| 74 public: | |
| 75 PartialCacheIndexMap() : map_(HashMap::PointersMatch) {} | |
| 76 | |
| 77 static const int kInvalidIndex = -1; | |
| 78 | |
| 79 // Lookup object in the map. Return its index if found, or create | |
| 80 // a new entry with new_index as value, and return kInvalidIndex. | |
| 81 int LookupOrInsert(HeapObject* obj, int new_index) { | |
| 82 HashMap::Entry* entry = LookupEntry(&map_, obj, false); | |
| 83 if (entry != NULL) return GetValue(entry); | |
| 84 SetValue(LookupEntry(&map_, obj, true), static_cast<uint32_t>(new_index)); | |
| 85 return kInvalidIndex; | |
| 86 } | |
| 87 | |
| 88 private: | |
| 89 HashMap map_; | |
| 90 | |
| 91 DISALLOW_COPY_AND_ASSIGN(PartialCacheIndexMap); | |
| 92 }; | |
| 93 | |
| 94 | |
| 95 class HotObjectsList { | |
| 96 public: | |
| 97 HotObjectsList() : index_(0) { | |
| 98 for (int i = 0; i < kSize; i++) circular_queue_[i] = NULL; | |
| 99 } | |
| 100 | |
| 101 void Add(HeapObject* object) { | |
| 102 circular_queue_[index_] = object; | |
| 103 index_ = (index_ + 1) & kSizeMask; | |
| 104 } | |
| 105 | |
| 106 HeapObject* Get(int index) { | |
| 107 DCHECK_NOT_NULL(circular_queue_[index]); | |
| 108 return circular_queue_[index]; | |
| 109 } | |
| 110 | |
| 111 static const int kNotFound = -1; | |
| 112 | |
| 113 int Find(HeapObject* object) { | |
| 114 for (int i = 0; i < kSize; i++) { | |
| 115 if (circular_queue_[i] == object) return i; | |
| 116 } | |
| 117 return kNotFound; | |
| 118 } | |
| 119 | |
| 120 static const int kSize = 8; | |
| 121 | |
| 122 private: | |
| 123 STATIC_ASSERT(IS_POWER_OF_TWO(kSize)); | |
| 124 static const int kSizeMask = kSize - 1; | |
| 125 HeapObject* circular_queue_[kSize]; | |
| 126 int index_; | |
| 127 | |
| 128 DISALLOW_COPY_AND_ASSIGN(HotObjectsList); | |
| 129 }; | |
| 130 | |
| 131 | |
| 132 // The Serializer/Deserializer class is a common superclass for Serializer and | |
| 133 // Deserializer which is used to store common constants and methods used by | |
| 134 // both. | |
| 135 class SerializerDeserializer: public ObjectVisitor { | |
| 136 public: | |
| 137 static void Iterate(Isolate* isolate, ObjectVisitor* visitor); | |
| 138 | |
| 139 // No reservation for large object space necessary. | |
| 140 static const int kNumberOfPreallocatedSpaces = LAST_PAGED_SPACE + 1; | |
| 141 static const int kNumberOfSpaces = LAST_SPACE + 1; | |
| 142 | |
| 143 protected: | |
| 144 static bool CanBeDeferred(HeapObject* o); | |
| 145 | |
| 146 // ---------- byte code range 0x00..0x7f ---------- | |
| 147 // Byte codes in this range represent Where, HowToCode and WhereToPoint. | |
| 148 // Where the pointed-to object can be found: | |
| 149 // The static assert below will trigger when the number of preallocated spaces | |
| 150 // changed. If that happens, update the bytecode ranges in the comments below. | |
| 151 STATIC_ASSERT(5 == kNumberOfSpaces); | |
| 152 enum Where { | |
| 153 // 0x00..0x04 Allocate new object, in specified space. | |
| 154 kNewObject = 0, | |
| 155 // 0x05 Unused (including 0x25, 0x45, 0x65). | |
| 156 // 0x06 Unused (including 0x26, 0x46, 0x66). | |
| 157 // 0x07 Unused (including 0x27, 0x47, 0x67). | |
| 158 // 0x08..0x0c Reference to previous object from space. | |
| 159 kBackref = 0x08, | |
| 160 // 0x0d Unused (including 0x2d, 0x4d, 0x6d). | |
| 161 // 0x0e Unused (including 0x2e, 0x4e, 0x6e). | |
| 162 // 0x0f Unused (including 0x2f, 0x4f, 0x6f). | |
| 163 // 0x10..0x14 Reference to previous object from space after skip. | |
| 164 kBackrefWithSkip = 0x10, | |
| 165 // 0x15 Unused (including 0x35, 0x55, 0x75). | |
| 166 // 0x16 Unused (including 0x36, 0x56, 0x76). | |
| 167 // 0x17 Misc (including 0x37, 0x57, 0x77). | |
| 168 // 0x18 Root array item. | |
| 169 kRootArray = 0x18, | |
| 170 // 0x19 Object in the partial snapshot cache. | |
| 171 kPartialSnapshotCache = 0x19, | |
| 172 // 0x1a External reference referenced by id. | |
| 173 kExternalReference = 0x1a, | |
| 174 // 0x1b Object provided in the attached list. | |
| 175 kAttachedReference = 0x1b, | |
| 176 // 0x1c Builtin code referenced by index. | |
| 177 kBuiltin = 0x1c | |
| 178 // 0x1d..0x1f Misc (including 0x3d..0x3f, 0x5d..0x5f, 0x7d..0x7f) | |
| 179 }; | |
| 180 | |
| 181 static const int kWhereMask = 0x1f; | |
| 182 static const int kSpaceMask = 7; | |
| 183 STATIC_ASSERT(kNumberOfSpaces <= kSpaceMask + 1); | |
| 184 | |
| 185 // How to code the pointer to the object. | |
| 186 enum HowToCode { | |
| 187 // Straight pointer. | |
| 188 kPlain = 0, | |
| 189 // A pointer inlined in code. What this means depends on the architecture. | |
| 190 kFromCode = 0x20 | |
| 191 }; | |
| 192 | |
| 193 static const int kHowToCodeMask = 0x20; | |
| 194 | |
| 195 // Where to point within the object. | |
| 196 enum WhereToPoint { | |
| 197 // Points to start of object | |
| 198 kStartOfObject = 0, | |
| 199 // Points to instruction in code object or payload of cell. | |
| 200 kInnerPointer = 0x40 | |
| 201 }; | |
| 202 | |
| 203 static const int kWhereToPointMask = 0x40; | |
| 204 | |
| 205 // ---------- Misc ---------- | |
| 206 // Skip. | |
| 207 static const int kSkip = 0x1d; | |
| 208 // Internal reference encoded as offsets of pc and target from code entry. | |
| 209 static const int kInternalReference = 0x1e; | |
| 210 static const int kInternalReferenceEncoded = 0x1f; | |
| 211 // Do nothing, used for padding. | |
| 212 static const int kNop = 0x3d; | |
| 213 // Move to next reserved chunk. | |
| 214 static const int kNextChunk = 0x3e; | |
| 215 // Deferring object content. | |
| 216 static const int kDeferred = 0x3f; | |
| 217 // Used for the source code of the natives, which is in the executable, but | |
| 218 // is referred to from external strings in the snapshot. | |
| 219 static const int kNativesStringResource = 0x5d; | |
| 220 // Used for the source code for compiled stubs, which is in the executable, | |
| 221 // but is referred to from external strings in the snapshot. | |
| 222 static const int kExtraNativesStringResource = 0x5e; | |
| 223 // A tag emitted at strategic points in the snapshot to delineate sections. | |
| 224 // If the deserializer does not find these at the expected moments then it | |
| 225 // is an indication that the snapshot and the VM do not fit together. | |
| 226 // Examine the build process for architecture, version or configuration | |
| 227 // mismatches. | |
| 228 static const int kSynchronize = 0x17; | |
| 229 // Repeats of variable length. | |
| 230 static const int kVariableRepeat = 0x37; | |
| 231 // Raw data of variable length. | |
| 232 static const int kVariableRawData = 0x57; | |
| 233 // Alignment prefixes 0x7d..0x7f | |
| 234 static const int kAlignmentPrefix = 0x7d; | |
| 235 | |
| 236 // 0x77 unused | |
| 237 | |
| 238 // ---------- byte code range 0x80..0xff ---------- | |
| 239 // First 32 root array items. | |
| 240 static const int kNumberOfRootArrayConstants = 0x20; | |
| 241 // 0x80..0x9f | |
| 242 static const int kRootArrayConstants = 0x80; | |
| 243 // 0xa0..0xbf | |
| 244 static const int kRootArrayConstantsWithSkip = 0xa0; | |
| 245 static const int kRootArrayConstantsMask = 0x1f; | |
| 246 | |
| 247 // 8 hot (recently seen or back-referenced) objects with optional skip. | |
| 248 static const int kNumberOfHotObjects = 0x08; | |
| 249 // 0xc0..0xc7 | |
| 250 static const int kHotObject = 0xc0; | |
| 251 // 0xc8..0xcf | |
| 252 static const int kHotObjectWithSkip = 0xc8; | |
| 253 static const int kHotObjectMask = 0x07; | |
| 254 | |
| 255 // 32 common raw data lengths. | |
| 256 static const int kNumberOfFixedRawData = 0x20; | |
| 257 // 0xd0..0xef | |
| 258 static const int kFixedRawData = 0xd0; | |
| 259 static const int kOnePointerRawData = kFixedRawData; | |
| 260 static const int kFixedRawDataStart = kFixedRawData - 1; | |
| 261 | |
| 262 // 16 repeats lengths. | |
| 263 static const int kNumberOfFixedRepeat = 0x10; | |
| 264 // 0xf0..0xff | |
| 265 static const int kFixedRepeat = 0xf0; | |
| 266 static const int kFixedRepeatStart = kFixedRepeat - 1; | |
| 267 | |
| 268 // ---------- special values ---------- | |
| 269 static const int kAnyOldSpace = -1; | |
| 270 | |
| 271 // Sentinel after a new object to indicate that double alignment is needed. | |
| 272 static const int kDoubleAlignmentSentinel = 0; | |
| 273 | |
| 274 // Used as index for the attached reference representing the source object. | |
| 275 static const int kSourceObjectReference = 0; | |
| 276 | |
| 277 // Used as index for the attached reference representing the global proxy. | |
| 278 static const int kGlobalProxyReference = 0; | |
| 279 | |
| 280 // ---------- member variable ---------- | |
| 281 HotObjectsList hot_objects_; | |
| 282 }; | |
| 283 | |
| 284 | |
| 285 class SerializedData { | |
| 286 public: | |
| 287 class Reservation { | |
| 288 public: | |
| 289 explicit Reservation(uint32_t size) | |
| 290 : reservation_(ChunkSizeBits::encode(size)) {} | |
| 291 | |
| 292 uint32_t chunk_size() const { return ChunkSizeBits::decode(reservation_); } | |
| 293 bool is_last() const { return IsLastChunkBits::decode(reservation_); } | |
| 294 | |
| 295 void mark_as_last() { reservation_ |= IsLastChunkBits::encode(true); } | |
| 296 | |
| 297 private: | |
| 298 uint32_t reservation_; | |
| 299 }; | |
| 300 | |
| 301 SerializedData(byte* data, int size) | |
| 302 : data_(data), size_(size), owns_data_(false) {} | |
| 303 SerializedData() : data_(NULL), size_(0), owns_data_(false) {} | |
| 304 | |
| 305 ~SerializedData() { | |
| 306 if (owns_data_) DeleteArray<byte>(data_); | |
| 307 } | |
| 308 | |
| 309 uint32_t GetMagicNumber() const { return GetHeaderValue(kMagicNumberOffset); } | |
| 310 | |
| 311 class ChunkSizeBits : public BitField<uint32_t, 0, 31> {}; | |
| 312 class IsLastChunkBits : public BitField<bool, 31, 1> {}; | |
| 313 | |
| 314 static uint32_t ComputeMagicNumber(ExternalReferenceTable* table) { | |
| 315 uint32_t external_refs = table->size(); | |
| 316 return 0xC0DE0000 ^ external_refs; | |
| 317 } | |
| 318 | |
| 319 protected: | |
| 320 void SetHeaderValue(int offset, uint32_t value) { | |
| 321 uint32_t* address = reinterpret_cast<uint32_t*>(data_ + offset); | |
| 322 memcpy(reinterpret_cast<uint32_t*>(address), &value, sizeof(value)); | |
| 323 } | |
| 324 | |
| 325 uint32_t GetHeaderValue(int offset) const { | |
| 326 uint32_t value; | |
| 327 memcpy(&value, reinterpret_cast<int*>(data_ + offset), sizeof(value)); | |
| 328 return value; | |
| 329 } | |
| 330 | |
| 331 void AllocateData(int size); | |
| 332 | |
| 333 static uint32_t ComputeMagicNumber(Isolate* isolate) { | |
| 334 return ComputeMagicNumber(ExternalReferenceTable::instance(isolate)); | |
| 335 } | |
| 336 | |
| 337 void SetMagicNumber(Isolate* isolate) { | |
| 338 SetHeaderValue(kMagicNumberOffset, ComputeMagicNumber(isolate)); | |
| 339 } | |
| 340 | |
| 341 static const int kMagicNumberOffset = 0; | |
| 342 | |
| 343 byte* data_; | |
| 344 int size_; | |
| 345 bool owns_data_; | |
| 346 }; | |
| 347 | |
| 348 | |
| 349 // A Deserializer reads a snapshot and reconstructs the Object graph it defines. | |
| 350 class Deserializer: public SerializerDeserializer { | |
| 351 public: | |
| 352 // Create a deserializer from a snapshot byte source. | |
| 353 template <class Data> | |
| 354 explicit Deserializer(Data* data) | |
| 355 : isolate_(NULL), | |
| 356 source_(data->Payload()), | |
| 357 magic_number_(data->GetMagicNumber()), | |
| 358 external_reference_table_(NULL), | |
| 359 deserialized_large_objects_(0), | |
| 360 deserializing_user_code_(false), | |
| 361 next_alignment_(kWordAligned) { | |
| 362 DecodeReservation(data->Reservations()); | |
| 363 } | |
| 364 | |
| 365 ~Deserializer() override; | |
| 366 | |
| 367 // Deserialize the snapshot into an empty heap. | |
| 368 void Deserialize(Isolate* isolate); | |
| 369 | |
| 370 // Deserialize a single object and the objects reachable from it. | |
| 371 MaybeHandle<Object> DeserializePartial(Isolate* isolate, | |
| 372 Handle<JSGlobalProxy> global_proxy); | |
| 373 | |
| 374 // Deserialize a shared function info. Fail gracefully. | |
| 375 MaybeHandle<SharedFunctionInfo> DeserializeCode(Isolate* isolate); | |
| 376 | |
| 377 // Pass a vector of externally-provided objects referenced by the snapshot. | |
| 378 // The ownership to its backing store is handed over as well. | |
| 379 void SetAttachedObjects(Vector<Handle<Object> > attached_objects) { | |
| 380 attached_objects_ = attached_objects; | |
| 381 } | |
| 382 | |
| 383 private: | |
| 384 void VisitPointers(Object** start, Object** end) override; | |
| 385 | |
| 386 void Synchronize(VisitorSynchronization::SyncTag tag) override; | |
| 387 | |
| 388 void VisitRuntimeEntry(RelocInfo* rinfo) override { UNREACHABLE(); } | |
| 389 | |
| 390 void Initialize(Isolate* isolate); | |
| 391 | |
| 392 bool deserializing_user_code() { return deserializing_user_code_; } | |
| 393 | |
| 394 void DecodeReservation(Vector<const SerializedData::Reservation> res); | |
| 395 | |
| 396 bool ReserveSpace(); | |
| 397 | |
| 398 void UnalignedCopy(Object** dest, Object** src) { | |
| 399 memcpy(dest, src, sizeof(*src)); | |
| 400 } | |
| 401 | |
| 402 void SetAlignment(byte data) { | |
| 403 DCHECK_EQ(kWordAligned, next_alignment_); | |
| 404 int alignment = data - (kAlignmentPrefix - 1); | |
| 405 DCHECK_LE(kWordAligned, alignment); | |
| 406 DCHECK_LE(alignment, kSimd128Unaligned); | |
| 407 next_alignment_ = static_cast<AllocationAlignment>(alignment); | |
| 408 } | |
| 409 | |
| 410 void DeserializeDeferredObjects(); | |
| 411 | |
| 412 void FlushICacheForNewIsolate(); | |
| 413 void FlushICacheForNewCodeObjects(); | |
| 414 | |
| 415 void CommitPostProcessedObjects(Isolate* isolate); | |
| 416 | |
| 417 // Fills in some heap data in an area from start to end (non-inclusive). The | |
| 418 // space id is used for the write barrier. The object_address is the address | |
| 419 // of the object we are writing into, or NULL if we are not writing into an | |
| 420 // object, i.e. if we are writing a series of tagged values that are not on | |
| 421 // the heap. Return false if the object content has been deferred. | |
| 422 bool ReadData(Object** start, Object** end, int space, | |
| 423 Address object_address); | |
| 424 void ReadObject(int space_number, Object** write_back); | |
| 425 Address Allocate(int space_index, int size); | |
| 426 | |
| 427 // Special handling for serialized code like hooking up internalized strings. | |
| 428 HeapObject* PostProcessNewObject(HeapObject* obj, int space); | |
| 429 | |
| 430 // This returns the address of an object that has been described in the | |
| 431 // snapshot by chunk index and offset. | |
| 432 HeapObject* GetBackReferencedObject(int space); | |
| 433 | |
| 434 Object** CopyInNativesSource(Vector<const char> source_vector, | |
| 435 Object** current); | |
| 436 | |
| 437 // Cached current isolate. | |
| 438 Isolate* isolate_; | |
| 439 | |
| 440 // Objects from the attached object descriptions in the serialized user code. | |
| 441 Vector<Handle<Object> > attached_objects_; | |
| 442 | |
| 443 SnapshotByteSource source_; | |
| 444 uint32_t magic_number_; | |
| 445 | |
| 446 // The address of the next object that will be allocated in each space. | |
| 447 // Each space has a number of chunks reserved by the GC, with each chunk | |
| 448 // fitting into a page. Deserialized objects are allocated into the | |
| 449 // current chunk of the target space by bumping up high water mark. | |
| 450 Heap::Reservation reservations_[kNumberOfSpaces]; | |
| 451 uint32_t current_chunk_[kNumberOfPreallocatedSpaces]; | |
| 452 Address high_water_[kNumberOfPreallocatedSpaces]; | |
| 453 | |
| 454 ExternalReferenceTable* external_reference_table_; | |
| 455 | |
| 456 List<HeapObject*> deserialized_large_objects_; | |
| 457 List<Code*> new_code_objects_; | |
| 458 List<Handle<String> > new_internalized_strings_; | |
| 459 List<Handle<Script> > new_scripts_; | |
| 460 | |
| 461 bool deserializing_user_code_; | |
| 462 | |
| 463 AllocationAlignment next_alignment_; | |
| 464 | |
| 465 DISALLOW_COPY_AND_ASSIGN(Deserializer); | |
| 466 }; | |
| 467 | |
| 468 | |
| 469 class CodeAddressMap; | |
| 470 | |
| 471 // There can be only one serializer per V8 process. | |
| 472 class Serializer : public SerializerDeserializer { | |
| 473 public: | |
| 474 Serializer(Isolate* isolate, SnapshotByteSink* sink); | |
| 475 ~Serializer() override; | |
| 476 | |
| 477 void EncodeReservations(List<SerializedData::Reservation>* out) const; | |
| 478 | |
| 479 void SerializeDeferredObjects(); | |
| 480 | |
| 481 Isolate* isolate() const { return isolate_; } | |
| 482 | |
| 483 BackReferenceMap* back_reference_map() { return &back_reference_map_; } | |
| 484 RootIndexMap* root_index_map() { return &root_index_map_; } | |
| 485 | |
| 486 #ifdef OBJECT_PRINT | |
| 487 void CountInstanceType(Map* map, int size); | |
| 488 #endif // OBJECT_PRINT | |
| 489 | |
| 490 protected: | |
| 491 class ObjectSerializer; | |
| 492 class RecursionScope { | |
| 493 public: | |
| 494 explicit RecursionScope(Serializer* serializer) : serializer_(serializer) { | |
| 495 serializer_->recursion_depth_++; | |
| 496 } | |
| 497 ~RecursionScope() { serializer_->recursion_depth_--; } | |
| 498 bool ExceedsMaximum() { | |
| 499 return serializer_->recursion_depth_ >= kMaxRecursionDepth; | |
| 500 } | |
| 501 | |
| 502 private: | |
| 503 static const int kMaxRecursionDepth = 32; | |
| 504 Serializer* serializer_; | |
| 505 }; | |
| 506 | |
| 507 virtual void SerializeObject(HeapObject* o, HowToCode how_to_code, | |
| 508 WhereToPoint where_to_point, int skip) = 0; | |
| 509 | |
| 510 void PutRoot(int index, HeapObject* object, HowToCode how, WhereToPoint where, | |
| 511 int skip); | |
| 512 | |
| 513 void PutBackReference(HeapObject* object, BackReference reference); | |
| 514 | |
| 515 // Emit alignment prefix if necessary, return required padding space in bytes. | |
| 516 int PutAlignmentPrefix(HeapObject* object); | |
| 517 | |
| 518 // Returns true if the object was successfully serialized. | |
| 519 bool SerializeKnownObject(HeapObject* obj, HowToCode how_to_code, | |
| 520 WhereToPoint where_to_point, int skip); | |
| 521 | |
| 522 inline void FlushSkip(int skip) { | |
| 523 if (skip != 0) { | |
| 524 sink_->Put(kSkip, "SkipFromSerializeObject"); | |
| 525 sink_->PutInt(skip, "SkipDistanceFromSerializeObject"); | |
| 526 } | |
| 527 } | |
| 528 | |
| 529 bool BackReferenceIsAlreadyAllocated(BackReference back_reference); | |
| 530 | |
| 531 // This will return the space for an object. | |
| 532 BackReference AllocateLargeObject(int size); | |
| 533 BackReference Allocate(AllocationSpace space, int size); | |
| 534 int EncodeExternalReference(Address addr) { | |
| 535 return external_reference_encoder_.Encode(addr); | |
| 536 } | |
| 537 | |
| 538 // GetInt reads 4 bytes at once, requiring padding at the end. | |
| 539 void Pad(); | |
| 540 | |
| 541 // Some roots should not be serialized, because their actual value depends on | |
| 542 // absolute addresses and they are reset after deserialization, anyway. | |
| 543 bool ShouldBeSkipped(Object** current); | |
| 544 | |
| 545 // We may not need the code address map for logging for every instance | |
| 546 // of the serializer. Initialize it on demand. | |
| 547 void InitializeCodeAddressMap(); | |
| 548 | |
| 549 Code* CopyCode(Code* code); | |
| 550 | |
| 551 inline uint32_t max_chunk_size(int space) const { | |
| 552 DCHECK_LE(0, space); | |
| 553 DCHECK_LT(space, kNumberOfSpaces); | |
| 554 return max_chunk_size_[space]; | |
| 555 } | |
| 556 | |
| 557 SnapshotByteSink* sink() const { return sink_; } | |
| 558 | |
| 559 void QueueDeferredObject(HeapObject* obj) { | |
| 560 DCHECK(back_reference_map_.Lookup(obj).is_valid()); | |
| 561 deferred_objects_.Add(obj); | |
| 562 } | |
| 563 | |
| 564 void OutputStatistics(const char* name); | |
| 565 | |
| 566 Isolate* isolate_; | |
| 567 | |
| 568 SnapshotByteSink* sink_; | |
| 569 ExternalReferenceEncoder external_reference_encoder_; | |
| 570 | |
| 571 BackReferenceMap back_reference_map_; | |
| 572 RootIndexMap root_index_map_; | |
| 573 | |
| 574 int recursion_depth_; | |
| 575 | |
| 576 friend class Deserializer; | |
| 577 friend class ObjectSerializer; | |
| 578 friend class RecursionScope; | |
| 579 friend class SnapshotData; | |
| 580 | |
| 581 private: | |
| 582 void VisitPointers(Object** start, Object** end) override; | |
| 583 | |
| 584 CodeAddressMap* code_address_map_; | |
| 585 // Objects from the same space are put into chunks for bulk-allocation | |
| 586 // when deserializing. We have to make sure that each chunk fits into a | |
| 587 // page. So we track the chunk size in pending_chunk_ of a space, but | |
| 588 // when it exceeds a page, we complete the current chunk and start a new one. | |
| 589 uint32_t pending_chunk_[kNumberOfPreallocatedSpaces]; | |
| 590 List<uint32_t> completed_chunks_[kNumberOfPreallocatedSpaces]; | |
| 591 uint32_t max_chunk_size_[kNumberOfPreallocatedSpaces]; | |
| 592 | |
| 593 // We map serialized large objects to indexes for back-referencing. | |
| 594 uint32_t large_objects_total_size_; | |
| 595 uint32_t seen_large_objects_index_; | |
| 596 | |
| 597 List<byte> code_buffer_; | |
| 598 | |
| 599 // To handle stack overflow. | |
| 600 List<HeapObject*> deferred_objects_; | |
| 601 | |
| 602 #ifdef OBJECT_PRINT | |
| 603 static const int kInstanceTypes = 256; | |
| 604 int* instance_type_count_; | |
| 605 size_t* instance_type_size_; | |
| 606 #endif // OBJECT_PRINT | |
| 607 | |
| 608 DISALLOW_COPY_AND_ASSIGN(Serializer); | |
| 609 }; | |
| 610 | |
| 611 | |
| 612 class PartialSerializer : public Serializer { | |
| 613 public: | |
| 614 PartialSerializer(Isolate* isolate, Serializer* startup_snapshot_serializer, | |
| 615 SnapshotByteSink* sink) | |
| 616 : Serializer(isolate, sink), | |
| 617 startup_serializer_(startup_snapshot_serializer), | |
| 618 global_object_(NULL) { | |
| 619 InitializeCodeAddressMap(); | |
| 620 } | |
| 621 | |
| 622 ~PartialSerializer() override { OutputStatistics("PartialSerializer"); } | |
| 623 | |
| 624 // Serialize the objects reachable from a single object pointer. | |
| 625 void Serialize(Object** o); | |
| 626 | |
| 627 private: | |
| 628 void SerializeObject(HeapObject* o, HowToCode how_to_code, | |
| 629 WhereToPoint where_to_point, int skip) override; | |
| 630 | |
| 631 int PartialSnapshotCacheIndex(HeapObject* o); | |
| 632 bool ShouldBeInThePartialSnapshotCache(HeapObject* o); | |
| 633 | |
| 634 Serializer* startup_serializer_; | |
| 635 Object* global_object_; | |
| 636 PartialCacheIndexMap partial_cache_index_map_; | |
| 637 DISALLOW_COPY_AND_ASSIGN(PartialSerializer); | |
| 638 }; | |
| 639 | |
| 640 | |
| 641 class StartupSerializer : public Serializer { | |
| 642 public: | |
| 643 StartupSerializer(Isolate* isolate, SnapshotByteSink* sink); | |
| 644 ~StartupSerializer() override { OutputStatistics("StartupSerializer"); } | |
| 645 | |
| 646 // Serialize the current state of the heap. The order is: | |
| 647 // 1) Strong references. | |
| 648 // 2) Partial snapshot cache. | |
| 649 // 3) Weak references (e.g. the string table). | |
| 650 void SerializeStrongReferences(); | |
| 651 void SerializeWeakReferencesAndDeferred(); | |
| 652 | |
| 653 private: | |
| 654 // The StartupSerializer has to serialize the root array, which is slightly | |
| 655 // different. | |
| 656 void VisitPointers(Object** start, Object** end) override; | |
| 657 void SerializeObject(HeapObject* o, HowToCode how_to_code, | |
| 658 WhereToPoint where_to_point, int skip) override; | |
| 659 void Synchronize(VisitorSynchronization::SyncTag tag) override; | |
| 660 | |
| 661 intptr_t root_index_wave_front_; | |
| 662 bool serializing_builtins_; | |
| 663 DISALLOW_COPY_AND_ASSIGN(StartupSerializer); | |
| 664 }; | |
| 665 | |
| 666 | |
| 667 class CodeSerializer : public Serializer { | |
| 668 public: | |
| 669 static ScriptData* Serialize(Isolate* isolate, | |
| 670 Handle<SharedFunctionInfo> info, | |
| 671 Handle<String> source); | |
| 672 | |
| 673 MUST_USE_RESULT static MaybeHandle<SharedFunctionInfo> Deserialize( | |
| 674 Isolate* isolate, ScriptData* cached_data, Handle<String> source); | |
| 675 | |
| 676 static const int kSourceObjectIndex = 0; | |
| 677 STATIC_ASSERT(kSourceObjectReference == kSourceObjectIndex); | |
| 678 | |
| 679 static const int kCodeStubsBaseIndex = 1; | |
| 680 | |
| 681 String* source() const { | |
| 682 DCHECK(!AllowHeapAllocation::IsAllowed()); | |
| 683 return source_; | |
| 684 } | |
| 685 | |
| 686 const List<uint32_t>* stub_keys() const { return &stub_keys_; } | |
| 687 | |
| 688 private: | |
| 689 CodeSerializer(Isolate* isolate, SnapshotByteSink* sink, String* source) | |
| 690 : Serializer(isolate, sink), source_(source) { | |
| 691 back_reference_map_.AddSourceString(source); | |
| 692 } | |
| 693 | |
| 694 ~CodeSerializer() override { OutputStatistics("CodeSerializer"); } | |
| 695 | |
| 696 void SerializeObject(HeapObject* o, HowToCode how_to_code, | |
| 697 WhereToPoint where_to_point, int skip) override; | |
| 698 | |
| 699 void SerializeBuiltin(int builtin_index, HowToCode how_to_code, | |
| 700 WhereToPoint where_to_point); | |
| 701 void SerializeIC(Code* ic, HowToCode how_to_code, | |
| 702 WhereToPoint where_to_point); | |
| 703 void SerializeCodeStub(uint32_t stub_key, HowToCode how_to_code, | |
| 704 WhereToPoint where_to_point); | |
| 705 void SerializeGeneric(HeapObject* heap_object, HowToCode how_to_code, | |
| 706 WhereToPoint where_to_point); | |
| 707 int AddCodeStubKey(uint32_t stub_key); | |
| 708 | |
| 709 DisallowHeapAllocation no_gc_; | |
| 710 String* source_; | |
| 711 List<uint32_t> stub_keys_; | |
| 712 DISALLOW_COPY_AND_ASSIGN(CodeSerializer); | |
| 713 }; | |
| 714 | |
| 715 | |
| 716 // Wrapper around reservation sizes and the serialization payload. | |
| 717 class SnapshotData : public SerializedData { | |
| 718 public: | |
| 719 // Used when producing. | |
| 720 explicit SnapshotData(const Serializer& ser); | |
| 721 | |
| 722 // Used when consuming. | |
| 723 explicit SnapshotData(const Vector<const byte> snapshot) | |
| 724 : SerializedData(const_cast<byte*>(snapshot.begin()), snapshot.length()) { | |
| 725 CHECK(IsSane()); | |
| 726 } | |
| 727 | |
| 728 Vector<const Reservation> Reservations() const; | |
| 729 Vector<const byte> Payload() const; | |
| 730 | |
| 731 Vector<const byte> RawData() const { | |
| 732 return Vector<const byte>(data_, size_); | |
| 733 } | |
| 734 | |
| 735 private: | |
| 736 bool IsSane(); | |
| 737 | |
| 738 // The data header consists of uint32_t-sized entries: | |
| 739 // [0] magic number and external reference count | |
| 740 // [1] version hash | |
| 741 // [2] number of reservation size entries | |
| 742 // [3] payload length | |
| 743 // ... reservations | |
| 744 // ... serialized payload | |
| 745 static const int kCheckSumOffset = kMagicNumberOffset + kInt32Size; | |
| 746 static const int kNumReservationsOffset = kCheckSumOffset + kInt32Size; | |
| 747 static const int kPayloadLengthOffset = kNumReservationsOffset + kInt32Size; | |
| 748 static const int kHeaderSize = kPayloadLengthOffset + kInt32Size; | |
| 749 }; | |
| 750 | |
| 751 | |
| 752 // Wrapper around ScriptData to provide code-serializer-specific functionality. | |
| 753 class SerializedCodeData : public SerializedData { | |
| 754 public: | |
| 755 // Used when consuming. | |
| 756 static SerializedCodeData* FromCachedData(Isolate* isolate, | |
| 757 ScriptData* cached_data, | |
| 758 String* source); | |
| 759 | |
| 760 // Used when producing. | |
| 761 SerializedCodeData(const List<byte>& payload, const CodeSerializer& cs); | |
| 762 | |
| 763 // Return ScriptData object and relinquish ownership over it to the caller. | |
| 764 ScriptData* GetScriptData(); | |
| 765 | |
| 766 Vector<const Reservation> Reservations() const; | |
| 767 Vector<const byte> Payload() const; | |
| 768 | |
| 769 Vector<const uint32_t> CodeStubKeys() const; | |
| 770 | |
| 771 private: | |
| 772 explicit SerializedCodeData(ScriptData* data); | |
| 773 | |
| 774 enum SanityCheckResult { | |
| 775 CHECK_SUCCESS = 0, | |
| 776 MAGIC_NUMBER_MISMATCH = 1, | |
| 777 VERSION_MISMATCH = 2, | |
| 778 SOURCE_MISMATCH = 3, | |
| 779 CPU_FEATURES_MISMATCH = 4, | |
| 780 FLAGS_MISMATCH = 5, | |
| 781 CHECKSUM_MISMATCH = 6 | |
| 782 }; | |
| 783 | |
| 784 SanityCheckResult SanityCheck(Isolate* isolate, String* source) const; | |
| 785 | |
| 786 uint32_t SourceHash(String* source) const; | |
| 787 | |
| 788 // The data header consists of uint32_t-sized entries: | |
| 789 // [0] magic number and external reference count | |
| 790 // [1] version hash | |
| 791 // [2] source hash | |
| 792 // [3] cpu features | |
| 793 // [4] flag hash | |
| 794 // [5] number of code stub keys | |
| 795 // [6] number of reservation size entries | |
| 796 // [7] payload length | |
| 797 // [8] payload checksum part 1 | |
| 798 // [9] payload checksum part 2 | |
| 799 // ... reservations | |
| 800 // ... code stub keys | |
| 801 // ... serialized payload | |
| 802 static const int kVersionHashOffset = kMagicNumberOffset + kInt32Size; | |
| 803 static const int kSourceHashOffset = kVersionHashOffset + kInt32Size; | |
| 804 static const int kCpuFeaturesOffset = kSourceHashOffset + kInt32Size; | |
| 805 static const int kFlagHashOffset = kCpuFeaturesOffset + kInt32Size; | |
| 806 static const int kNumReservationsOffset = kFlagHashOffset + kInt32Size; | |
| 807 static const int kNumCodeStubKeysOffset = kNumReservationsOffset + kInt32Size; | |
| 808 static const int kPayloadLengthOffset = kNumCodeStubKeysOffset + kInt32Size; | |
| 809 static const int kChecksum1Offset = kPayloadLengthOffset + kInt32Size; | |
| 810 static const int kChecksum2Offset = kChecksum1Offset + kInt32Size; | |
| 811 static const int kHeaderSize = kChecksum2Offset + kInt32Size; | |
| 812 }; | |
| 813 } // namespace internal | |
| 814 } // namespace v8 | |
| 815 | |
| 816 #endif // V8_SNAPSHOT_SERIALIZE_H_ | |
| OLD | NEW |
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Chromium Code Reviews
Issue 1751863002:
[serializer] split up src/snapshot/serialize.* (Closed)
Base URL: https://chromium.googlesource.com/v8/v8.git@master