// Copyright 2012 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/v8.h" #include "src/accessors.h" #include "src/api.h" #include "src/base/platform/platform.h" #include "src/bootstrapper.h" #include "src/code-stubs.h" #include "src/compiler.h" #include "src/deoptimizer.h" #include "src/execution.h" #include "src/global-handles.h" #include "src/ic/ic.h" #include "src/ic/stub-cache.h" #include "src/natives.h" #include "src/objects.h" #include "src/runtime/runtime.h" #include "src/serialize.h" #include "src/snapshot.h" #include "src/snapshot-source-sink.h" #include "src/v8threads.h" #include "src/version.h" namespace v8 { namespace internal { // ----------------------------------------------------------------------------- // Coding of external references. // The encoding of an external reference. The type is in the high word. // The id is in the low word. static uint32_t EncodeExternal(TypeCode type, uint16_t id) { return static_cast(type) << 16 | id; } static int* GetInternalPointer(StatsCounter* counter) { // All counters refer to dummy_counter, if deserializing happens without // setting up counters. static int dummy_counter = 0; return counter->Enabled() ? counter->GetInternalPointer() : &dummy_counter; } ExternalReferenceTable* ExternalReferenceTable::instance(Isolate* isolate) { ExternalReferenceTable* external_reference_table = isolate->external_reference_table(); if (external_reference_table == NULL) { external_reference_table = new ExternalReferenceTable(isolate); isolate->set_external_reference_table(external_reference_table); } return external_reference_table; } void ExternalReferenceTable::AddFromId(TypeCode type, uint16_t id, const char* name, Isolate* isolate) { Address address; switch (type) { case C_BUILTIN: { ExternalReference ref(static_cast(id), isolate); address = ref.address(); break; } case BUILTIN: { ExternalReference ref(static_cast(id), isolate); address = ref.address(); break; } case RUNTIME_FUNCTION: { ExternalReference ref(static_cast(id), isolate); address = ref.address(); break; } case IC_UTILITY: { ExternalReference ref(IC_Utility(static_cast(id)), isolate); address = ref.address(); break; } default: UNREACHABLE(); return; } Add(address, type, id, name); } void ExternalReferenceTable::Add(Address address, TypeCode type, uint16_t id, const char* name) { DCHECK_NOT_NULL(address); ExternalReferenceEntry entry; entry.address = address; entry.code = EncodeExternal(type, id); entry.name = name; DCHECK_NE(0u, entry.code); // Assert that the code is added in ascending order to rule out duplicates. DCHECK((size() == 0) || (code(size() - 1) < entry.code)); refs_.Add(entry); if (id > max_id_[type]) max_id_[type] = id; } void ExternalReferenceTable::PopulateTable(Isolate* isolate) { for (int type_code = 0; type_code < kTypeCodeCount; type_code++) { max_id_[type_code] = 0; } // Miscellaneous Add(ExternalReference::roots_array_start(isolate).address(), "Heap::roots_array_start()"); Add(ExternalReference::address_of_stack_limit(isolate).address(), "StackGuard::address_of_jslimit()"); Add(ExternalReference::address_of_real_stack_limit(isolate).address(), "StackGuard::address_of_real_jslimit()"); Add(ExternalReference::new_space_start(isolate).address(), "Heap::NewSpaceStart()"); Add(ExternalReference::new_space_mask(isolate).address(), "Heap::NewSpaceMask()"); Add(ExternalReference::new_space_allocation_limit_address(isolate).address(), "Heap::NewSpaceAllocationLimitAddress()"); Add(ExternalReference::new_space_allocation_top_address(isolate).address(), "Heap::NewSpaceAllocationTopAddress()"); Add(ExternalReference::debug_break(isolate).address(), "Debug::Break()"); Add(ExternalReference::debug_step_in_fp_address(isolate).address(), "Debug::step_in_fp_addr()"); Add(ExternalReference::mod_two_doubles_operation(isolate).address(), "mod_two_doubles"); // Keyed lookup cache. Add(ExternalReference::keyed_lookup_cache_keys(isolate).address(), "KeyedLookupCache::keys()"); Add(ExternalReference::keyed_lookup_cache_field_offsets(isolate).address(), "KeyedLookupCache::field_offsets()"); Add(ExternalReference::handle_scope_next_address(isolate).address(), "HandleScope::next"); Add(ExternalReference::handle_scope_limit_address(isolate).address(), "HandleScope::limit"); Add(ExternalReference::handle_scope_level_address(isolate).address(), "HandleScope::level"); Add(ExternalReference::new_deoptimizer_function(isolate).address(), "Deoptimizer::New()"); Add(ExternalReference::compute_output_frames_function(isolate).address(), "Deoptimizer::ComputeOutputFrames()"); Add(ExternalReference::address_of_min_int().address(), "LDoubleConstant::min_int"); Add(ExternalReference::address_of_one_half().address(), "LDoubleConstant::one_half"); Add(ExternalReference::isolate_address(isolate).address(), "isolate"); Add(ExternalReference::address_of_negative_infinity().address(), "LDoubleConstant::negative_infinity"); Add(ExternalReference::power_double_double_function(isolate).address(), "power_double_double_function"); Add(ExternalReference::power_double_int_function(isolate).address(), "power_double_int_function"); Add(ExternalReference::math_log_double_function(isolate).address(), "std::log"); Add(ExternalReference::store_buffer_top(isolate).address(), "store_buffer_top"); Add(ExternalReference::address_of_the_hole_nan().address(), "the_hole_nan"); Add(ExternalReference::get_date_field_function(isolate).address(), "JSDate::GetField"); Add(ExternalReference::date_cache_stamp(isolate).address(), "date_cache_stamp"); Add(ExternalReference::address_of_pending_message_obj(isolate).address(), "address_of_pending_message_obj"); Add(ExternalReference::address_of_has_pending_message(isolate).address(), "address_of_has_pending_message"); Add(ExternalReference::address_of_pending_message_script(isolate).address(), "pending_message_script"); Add(ExternalReference::get_make_code_young_function(isolate).address(), "Code::MakeCodeYoung"); Add(ExternalReference::cpu_features().address(), "cpu_features"); Add(ExternalReference(Runtime::kAllocateInNewSpace, isolate).address(), "Runtime::AllocateInNewSpace"); Add(ExternalReference(Runtime::kAllocateInTargetSpace, isolate).address(), "Runtime::AllocateInTargetSpace"); Add(ExternalReference::old_pointer_space_allocation_top_address(isolate) .address(), "Heap::OldPointerSpaceAllocationTopAddress"); Add(ExternalReference::old_pointer_space_allocation_limit_address(isolate) .address(), "Heap::OldPointerSpaceAllocationLimitAddress"); Add(ExternalReference::old_data_space_allocation_top_address(isolate) .address(), "Heap::OldDataSpaceAllocationTopAddress"); Add(ExternalReference::old_data_space_allocation_limit_address(isolate) .address(), "Heap::OldDataSpaceAllocationLimitAddress"); Add(ExternalReference::allocation_sites_list_address(isolate).address(), "Heap::allocation_sites_list_address()"); Add(ExternalReference::address_of_uint32_bias().address(), "uint32_bias"); Add(ExternalReference::get_mark_code_as_executed_function(isolate).address(), "Code::MarkCodeAsExecuted"); Add(ExternalReference::is_profiling_address(isolate).address(), "CpuProfiler::is_profiling"); Add(ExternalReference::scheduled_exception_address(isolate).address(), "Isolate::scheduled_exception"); Add(ExternalReference::invoke_function_callback(isolate).address(), "InvokeFunctionCallback"); Add(ExternalReference::invoke_accessor_getter_callback(isolate).address(), "InvokeAccessorGetterCallback"); Add(ExternalReference::flush_icache_function(isolate).address(), "CpuFeatures::FlushICache"); Add(ExternalReference::log_enter_external_function(isolate).address(), "Logger::EnterExternal"); Add(ExternalReference::log_leave_external_function(isolate).address(), "Logger::LeaveExternal"); Add(ExternalReference::address_of_minus_one_half().address(), "double_constants.minus_one_half"); Add(ExternalReference::stress_deopt_count(isolate).address(), "Isolate::stress_deopt_count_address()"); Add(ExternalReference::incremental_marking_record_write_function(isolate) .address(), "IncrementalMarking::RecordWriteFromCode"); // Debug addresses Add(ExternalReference::debug_after_break_target_address(isolate).address(), "Debug::after_break_target_address()"); Add(ExternalReference::debug_restarter_frame_function_pointer_address(isolate) .address(), "Debug::restarter_frame_function_pointer_address()"); Add(ExternalReference::debug_is_active_address(isolate).address(), "Debug::is_active_address()"); #ifndef V8_INTERPRETED_REGEXP Add(ExternalReference::re_case_insensitive_compare_uc16(isolate).address(), "NativeRegExpMacroAssembler::CaseInsensitiveCompareUC16()"); Add(ExternalReference::re_check_stack_guard_state(isolate).address(), "RegExpMacroAssembler*::CheckStackGuardState()"); Add(ExternalReference::re_grow_stack(isolate).address(), "NativeRegExpMacroAssembler::GrowStack()"); Add(ExternalReference::re_word_character_map().address(), "NativeRegExpMacroAssembler::word_character_map"); Add(ExternalReference::address_of_regexp_stack_limit(isolate).address(), "RegExpStack::limit_address()"); Add(ExternalReference::address_of_regexp_stack_memory_address(isolate) .address(), "RegExpStack::memory_address()"); Add(ExternalReference::address_of_regexp_stack_memory_size(isolate).address(), "RegExpStack::memory_size()"); Add(ExternalReference::address_of_static_offsets_vector(isolate).address(), "OffsetsVector::static_offsets_vector"); #endif // V8_INTERPRETED_REGEXP // The following populates all of the different type of external references // into the ExternalReferenceTable. // // NOTE: This function was originally 100k of code. It has since been // rewritten to be mostly table driven, as the callback macro style tends to // very easily cause code bloat. Please be careful in the future when adding // new references. struct RefTableEntry { TypeCode type; uint16_t id; const char* name; }; static const RefTableEntry ref_table[] = { // Builtins #define DEF_ENTRY_C(name, ignored) \ { C_BUILTIN, \ Builtins::c_##name, \ "Builtins::" #name }, BUILTIN_LIST_C(DEF_ENTRY_C) #undef DEF_ENTRY_C #define DEF_ENTRY_C(name, ignored) \ { BUILTIN, \ Builtins::k##name, \ "Builtins::" #name }, #define DEF_ENTRY_A(name, kind, state, extra) DEF_ENTRY_C(name, ignored) BUILTIN_LIST_C(DEF_ENTRY_C) BUILTIN_LIST_A(DEF_ENTRY_A) BUILTIN_LIST_DEBUG_A(DEF_ENTRY_A) #undef DEF_ENTRY_C #undef DEF_ENTRY_A // Runtime functions #define RUNTIME_ENTRY(name, nargs, ressize) \ { RUNTIME_FUNCTION, \ Runtime::k##name, \ "Runtime::" #name }, RUNTIME_FUNCTION_LIST(RUNTIME_ENTRY) INLINE_OPTIMIZED_FUNCTION_LIST(RUNTIME_ENTRY) #undef RUNTIME_ENTRY #define INLINE_OPTIMIZED_ENTRY(name, nargs, ressize) \ { RUNTIME_FUNCTION, \ Runtime::kInlineOptimized##name, \ "Runtime::" #name }, INLINE_OPTIMIZED_FUNCTION_LIST(INLINE_OPTIMIZED_ENTRY) #undef INLINE_OPTIMIZED_ENTRY // IC utilities #define IC_ENTRY(name) \ { IC_UTILITY, \ IC::k##name, \ "IC::" #name }, IC_UTIL_LIST(IC_ENTRY) #undef IC_ENTRY }; // end of ref_table[]. for (size_t i = 0; i < arraysize(ref_table); ++i) { AddFromId(ref_table[i].type, ref_table[i].id, ref_table[i].name, isolate); } // Stat counters struct StatsRefTableEntry { StatsCounter* (Counters::*counter)(); uint16_t id; const char* name; }; const StatsRefTableEntry stats_ref_table[] = { #define COUNTER_ENTRY(name, caption) \ { &Counters::name, \ Counters::k_##name, \ "Counters::" #name }, STATS_COUNTER_LIST_1(COUNTER_ENTRY) STATS_COUNTER_LIST_2(COUNTER_ENTRY) #undef COUNTER_ENTRY }; // end of stats_ref_table[]. Counters* counters = isolate->counters(); for (size_t i = 0; i < arraysize(stats_ref_table); ++i) { Add(reinterpret_cast
(GetInternalPointer( (counters->*(stats_ref_table[i].counter))())), STATS_COUNTER, stats_ref_table[i].id, stats_ref_table[i].name); } // Top addresses const char* AddressNames[] = { #define BUILD_NAME_LITERAL(CamelName, hacker_name) \ "Isolate::" #hacker_name "_address", FOR_EACH_ISOLATE_ADDRESS_NAME(BUILD_NAME_LITERAL) NULL #undef BUILD_NAME_LITERAL }; for (uint16_t i = 0; i < Isolate::kIsolateAddressCount; ++i) { Add(isolate->get_address_from_id((Isolate::AddressId)i), TOP_ADDRESS, i, AddressNames[i]); } // Accessors #define ACCESSOR_INFO_DECLARATION(name) \ Add(FUNCTION_ADDR(&Accessors::name##Getter), ACCESSOR_CODE, \ Accessors::k##name##Getter, "Accessors::" #name "Getter"); \ Add(FUNCTION_ADDR(&Accessors::name##Setter), ACCESSOR_CODE, \ Accessors::k##name##Setter, "Accessors::" #name "Setter"); ACCESSOR_INFO_LIST(ACCESSOR_INFO_DECLARATION) #undef ACCESSOR_INFO_DECLARATION StubCache* stub_cache = isolate->stub_cache(); // Stub cache tables Add(stub_cache->key_reference(StubCache::kPrimary).address(), STUB_CACHE_TABLE, 1, "StubCache::primary_->key"); Add(stub_cache->value_reference(StubCache::kPrimary).address(), STUB_CACHE_TABLE, 2, "StubCache::primary_->value"); Add(stub_cache->map_reference(StubCache::kPrimary).address(), STUB_CACHE_TABLE, 3, "StubCache::primary_->map"); Add(stub_cache->key_reference(StubCache::kSecondary).address(), STUB_CACHE_TABLE, 4, "StubCache::secondary_->key"); Add(stub_cache->value_reference(StubCache::kSecondary).address(), STUB_CACHE_TABLE, 5, "StubCache::secondary_->value"); Add(stub_cache->map_reference(StubCache::kSecondary).address(), STUB_CACHE_TABLE, 6, "StubCache::secondary_->map"); // Runtime entries Add(ExternalReference::delete_handle_scope_extensions(isolate).address(), RUNTIME_ENTRY, 1, "HandleScope::DeleteExtensions"); Add(ExternalReference::incremental_marking_record_write_function(isolate) .address(), RUNTIME_ENTRY, 2, "IncrementalMarking::RecordWrite"); Add(ExternalReference::store_buffer_overflow_function(isolate).address(), RUNTIME_ENTRY, 3, "StoreBuffer::StoreBufferOverflow"); // Add a small set of deopt entry addresses to encoder without generating the // deopt table code, which isn't possible at deserialization time. HandleScope scope(isolate); for (int entry = 0; entry < kDeoptTableSerializeEntryCount; ++entry) { Address address = Deoptimizer::GetDeoptimizationEntry( isolate, entry, Deoptimizer::LAZY, Deoptimizer::CALCULATE_ENTRY_ADDRESS); Add(address, LAZY_DEOPTIMIZATION, entry, "lazy_deopt"); } } ExternalReferenceEncoder::ExternalReferenceEncoder(Isolate* isolate) : encodings_(HashMap::PointersMatch), isolate_(isolate) { ExternalReferenceTable* external_references = ExternalReferenceTable::instance(isolate_); for (int i = 0; i < external_references->size(); ++i) { Put(external_references->address(i), i); } } uint32_t ExternalReferenceEncoder::Encode(Address key) const { int index = IndexOf(key); DCHECK(key == NULL || index >= 0); return index >= 0 ? ExternalReferenceTable::instance(isolate_)->code(index) : 0; } const char* ExternalReferenceEncoder::NameOfAddress(Address key) const { int index = IndexOf(key); return index >= 0 ? ExternalReferenceTable::instance(isolate_)->name(index) : ""; } int ExternalReferenceEncoder::IndexOf(Address key) const { if (key == NULL) return -1; HashMap::Entry* entry = const_cast(encodings_).Lookup(key, Hash(key), false); return entry == NULL ? -1 : static_cast(reinterpret_cast(entry->value)); } void ExternalReferenceEncoder::Put(Address key, int index) { HashMap::Entry* entry = encodings_.Lookup(key, Hash(key), true); entry->value = reinterpret_cast(index); } ExternalReferenceDecoder::ExternalReferenceDecoder(Isolate* isolate) : encodings_(NewArray(kTypeCodeCount)), isolate_(isolate) { ExternalReferenceTable* external_references = ExternalReferenceTable::instance(isolate_); for (int type = kFirstTypeCode; type < kTypeCodeCount; ++type) { int max = external_references->max_id(type) + 1; encodings_[type] = NewArray
(max + 1); } for (int i = 0; i < external_references->size(); ++i) { Put(external_references->code(i), external_references->address(i)); } } ExternalReferenceDecoder::~ExternalReferenceDecoder() { for (int type = kFirstTypeCode; type < kTypeCodeCount; ++type) { DeleteArray(encodings_[type]); } DeleteArray(encodings_); } RootIndexMap::RootIndexMap(Isolate* isolate) { map_ = new HashMap(HashMap::PointersMatch); Object** root_array = isolate->heap()->roots_array_start(); for (int i = 0; i < Heap::kStrongRootListLength; i++) { Object* root = root_array[i]; if (root->IsHeapObject() && !isolate->heap()->InNewSpace(root)) { HeapObject* heap_object = HeapObject::cast(root); if (LookupEntry(map_, heap_object, false) != NULL) { // Some root values are initialized to the empty FixedArray(); // Do not add them to the map. // TODO(yangguo): This assert is not true. Some roots like // instanceof_cache_answer can be e.g. null. // DCHECK_EQ(isolate->heap()->empty_fixed_array(), heap_object); } else { SetValue(LookupEntry(map_, heap_object, true), i); } } } } class CodeAddressMap: public CodeEventLogger { public: explicit CodeAddressMap(Isolate* isolate) : isolate_(isolate) { isolate->logger()->addCodeEventListener(this); } virtual ~CodeAddressMap() { isolate_->logger()->removeCodeEventListener(this); } virtual void CodeMoveEvent(Address from, Address to) { address_to_name_map_.Move(from, to); } virtual void CodeDisableOptEvent(Code* code, SharedFunctionInfo* shared) { } virtual void CodeDeleteEvent(Address from) { address_to_name_map_.Remove(from); } const char* Lookup(Address address) { return address_to_name_map_.Lookup(address); } private: class NameMap { public: NameMap() : impl_(HashMap::PointersMatch) {} ~NameMap() { for (HashMap::Entry* p = impl_.Start(); p != NULL; p = impl_.Next(p)) { DeleteArray(static_cast(p->value)); } } void Insert(Address code_address, const char* name, int name_size) { HashMap::Entry* entry = FindOrCreateEntry(code_address); if (entry->value == NULL) { entry->value = CopyName(name, name_size); } } const char* Lookup(Address code_address) { HashMap::Entry* entry = FindEntry(code_address); return (entry != NULL) ? static_cast(entry->value) : NULL; } void Remove(Address code_address) { HashMap::Entry* entry = FindEntry(code_address); if (entry != NULL) { DeleteArray(static_cast(entry->value)); RemoveEntry(entry); } } void Move(Address from, Address to) { if (from == to) return; HashMap::Entry* from_entry = FindEntry(from); DCHECK(from_entry != NULL); void* value = from_entry->value; RemoveEntry(from_entry); HashMap::Entry* to_entry = FindOrCreateEntry(to); DCHECK(to_entry->value == NULL); to_entry->value = value; } private: static char* CopyName(const char* name, int name_size) { char* result = NewArray(name_size + 1); for (int i = 0; i < name_size; ++i) { char c = name[i]; if (c == '\0') c = ' '; result[i] = c; } result[name_size] = '\0'; return result; } HashMap::Entry* FindOrCreateEntry(Address code_address) { return impl_.Lookup(code_address, ComputePointerHash(code_address), true); } HashMap::Entry* FindEntry(Address code_address) { return impl_.Lookup(code_address, ComputePointerHash(code_address), false); } void RemoveEntry(HashMap::Entry* entry) { impl_.Remove(entry->key, entry->hash); } HashMap impl_; DISALLOW_COPY_AND_ASSIGN(NameMap); }; virtual void LogRecordedBuffer(Code* code, SharedFunctionInfo*, const char* name, int length) { address_to_name_map_.Insert(code->address(), name, length); } NameMap address_to_name_map_; Isolate* isolate_; }; void Deserializer::DecodeReservation( Vector res) { DCHECK_EQ(0, reservations_[NEW_SPACE].length()); STATIC_ASSERT(NEW_SPACE == 0); int current_space = NEW_SPACE; for (int i = 0; i < res.length(); i++) { SerializedData::Reservation r(0); memcpy(&r, res.start() + i, sizeof(r)); reservations_[current_space].Add({r.chunk_size(), NULL, NULL}); if (r.is_last()) current_space++; } DCHECK_EQ(kNumberOfSpaces, current_space); for (int i = 0; i < kNumberOfPreallocatedSpaces; i++) current_chunk_[i] = 0; } void Deserializer::FlushICacheForNewCodeObjects() { PageIterator it(isolate_->heap()->code_space()); while (it.has_next()) { Page* p = it.next(); CpuFeatures::FlushICache(p->area_start(), p->area_end() - p->area_start()); } } bool Deserializer::ReserveSpace() { #ifdef DEBUG for (int i = NEW_SPACE; i < kNumberOfSpaces; ++i) { CHECK(reservations_[i].length() > 0); } #endif // DEBUG if (!isolate_->heap()->ReserveSpace(reservations_)) return false; for (int i = 0; i < kNumberOfPreallocatedSpaces; i++) { high_water_[i] = reservations_[i][0].start; } return true; } void Deserializer::Initialize(Isolate* isolate) { DCHECK_NULL(isolate_); DCHECK_NOT_NULL(isolate); isolate_ = isolate; DCHECK_NULL(external_reference_decoder_); external_reference_decoder_ = new ExternalReferenceDecoder(isolate); } void Deserializer::Deserialize(Isolate* isolate) { Initialize(isolate); if (!ReserveSpace()) V8::FatalProcessOutOfMemory("deserializing context"); // No active threads. DCHECK_NULL(isolate_->thread_manager()->FirstThreadStateInUse()); // No active handles. DCHECK(isolate_->handle_scope_implementer()->blocks()->is_empty()); isolate_->heap()->IterateSmiRoots(this); isolate_->heap()->IterateStrongRoots(this, VISIT_ONLY_STRONG); isolate_->heap()->RepairFreeListsAfterDeserialization(); isolate_->heap()->IterateWeakRoots(this, VISIT_ALL); isolate_->heap()->set_native_contexts_list( isolate_->heap()->undefined_value()); isolate_->heap()->set_array_buffers_list( isolate_->heap()->undefined_value()); // The allocation site list is build during root iteration, but if no sites // were encountered then it needs to be initialized to undefined. if (isolate_->heap()->allocation_sites_list() == Smi::FromInt(0)) { isolate_->heap()->set_allocation_sites_list( isolate_->heap()->undefined_value()); } // Update data pointers to the external strings containing natives sources. for (int i = 0; i < Natives::GetBuiltinsCount(); i++) { Object* source = isolate_->heap()->natives_source_cache()->get(i); if (!source->IsUndefined()) { ExternalOneByteString::cast(source)->update_data_cache(); } } FlushICacheForNewCodeObjects(); // Issue code events for newly deserialized code objects. LOG_CODE_EVENT(isolate_, LogCodeObjects()); LOG_CODE_EVENT(isolate_, LogCompiledFunctions()); } MaybeHandle Deserializer::DeserializePartial( Isolate* isolate, Handle global_proxy, Handle* outdated_contexts_out) { Initialize(isolate); if (!ReserveSpace()) { V8::FatalProcessOutOfMemory("deserialize context"); return MaybeHandle(); } Vector > attached_objects = Vector >::New(1); attached_objects[kGlobalProxyReference] = global_proxy; SetAttachedObjects(attached_objects); DisallowHeapAllocation no_gc; // Keep track of the code space start and end pointers in case new // code objects were unserialized OldSpace* code_space = isolate_->heap()->code_space(); Address start_address = code_space->top(); Object* root; Object* outdated_contexts; VisitPointer(&root); VisitPointer(&outdated_contexts); // There's no code deserialized here. If this assert fires // then that's changed and logging should be added to notify // the profiler et al of the new code. CHECK_EQ(start_address, code_space->top()); CHECK(outdated_contexts->IsFixedArray()); *outdated_contexts_out = Handle(FixedArray::cast(outdated_contexts), isolate); return Handle(root, isolate); } MaybeHandle Deserializer::DeserializeCode( Isolate* isolate) { Initialize(isolate); if (!ReserveSpace()) { return Handle(); } else { deserializing_user_code_ = true; DisallowHeapAllocation no_gc; Object* root; VisitPointer(&root); return Handle(SharedFunctionInfo::cast(root)); } } Deserializer::~Deserializer() { // TODO(svenpanne) Re-enable this assertion when v8 initialization is fixed. // DCHECK(source_.AtEOF()); if (external_reference_decoder_) { delete external_reference_decoder_; external_reference_decoder_ = NULL; } attached_objects_.Dispose(); } // This is called on the roots. It is the driver of the deserialization // process. It is also called on the body of each function. void Deserializer::VisitPointers(Object** start, Object** end) { // The space must be new space. Any other space would cause ReadChunk to try // to update the remembered using NULL as the address. ReadData(start, end, NEW_SPACE, NULL); } void Deserializer::RelinkAllocationSite(AllocationSite* site) { if (isolate_->heap()->allocation_sites_list() == Smi::FromInt(0)) { site->set_weak_next(isolate_->heap()->undefined_value()); } else { site->set_weak_next(isolate_->heap()->allocation_sites_list()); } isolate_->heap()->set_allocation_sites_list(site); } // Used to insert a deserialized internalized string into the string table. class StringTableInsertionKey : public HashTableKey { public: explicit StringTableInsertionKey(String* string) : string_(string), hash_(HashForObject(string)) { DCHECK(string->IsInternalizedString()); } bool IsMatch(Object* string) OVERRIDE { // We know that all entries in a hash table had their hash keys created. // Use that knowledge to have fast failure. if (hash_ != HashForObject(string)) return false; // We want to compare the content of two internalized strings here. return string_->SlowEquals(String::cast(string)); } uint32_t Hash() OVERRIDE { return hash_; } uint32_t HashForObject(Object* key) OVERRIDE { return String::cast(key)->Hash(); } MUST_USE_RESULT virtual Handle AsHandle(Isolate* isolate) OVERRIDE { return handle(string_, isolate); } String* string_; uint32_t hash_; }; HeapObject* Deserializer::ProcessNewObjectFromSerializedCode(HeapObject* obj) { if (obj->IsString()) { String* string = String::cast(obj); // Uninitialize hash field as the hash seed may have changed. string->set_hash_field(String::kEmptyHashField); if (string->IsInternalizedString()) { DisallowHeapAllocation no_gc; HandleScope scope(isolate_); StringTableInsertionKey key(string); String* canonical = *StringTable::LookupKey(isolate_, &key); string->SetForwardedInternalizedString(canonical); return canonical; } } return obj; } HeapObject* Deserializer::GetBackReferencedObject(int space) { HeapObject* obj; BackReference back_reference(source_.GetInt()); if (space == LO_SPACE) { CHECK(back_reference.chunk_index() == 0); uint32_t index = back_reference.large_object_index(); obj = deserialized_large_objects_[index]; } else { DCHECK(space < kNumberOfPreallocatedSpaces); uint32_t chunk_index = back_reference.chunk_index(); DCHECK_LE(chunk_index, current_chunk_[space]); uint32_t chunk_offset = back_reference.chunk_offset(); obj = HeapObject::FromAddress(reservations_[space][chunk_index].start + chunk_offset); } if (deserializing_user_code() && obj->IsInternalizedString()) { obj = String::cast(obj)->GetForwardedInternalizedString(); } hot_objects_.Add(obj); return obj; } // This routine writes the new object into the pointer provided and then // returns true if the new object was in young space and false otherwise. // The reason for this strange interface is that otherwise the object is // written very late, which means the FreeSpace map is not set up by the // time we need to use it to mark the space at the end of a page free. void Deserializer::ReadObject(int space_number, Object** write_back) { Address address; HeapObject* obj; int next_int = source_.GetInt(); bool double_align = false; #ifndef V8_HOST_ARCH_64_BIT double_align = next_int == kDoubleAlignmentSentinel; if (double_align) next_int = source_.GetInt(); #endif DCHECK_NE(kDoubleAlignmentSentinel, next_int); int size = next_int << kObjectAlignmentBits; int reserved_size = size + (double_align ? kPointerSize : 0); address = Allocate(space_number, reserved_size); obj = HeapObject::FromAddress(address); if (double_align) { obj = isolate_->heap()->DoubleAlignForDeserialization(obj, reserved_size); address = obj->address(); } isolate_->heap()->OnAllocationEvent(obj, size); Object** current = reinterpret_cast(address); Object** limit = current + (size >> kPointerSizeLog2); if (FLAG_log_snapshot_positions) { LOG(isolate_, SnapshotPositionEvent(address, source_.position())); } ReadData(current, limit, space_number, address); // TODO(mvstanton): consider treating the heap()->allocation_sites_list() // as a (weak) root. If this root is relocated correctly, // RelinkAllocationSite() isn't necessary. if (obj->IsAllocationSite()) RelinkAllocationSite(AllocationSite::cast(obj)); // Fix up strings from serialized user code. if (deserializing_user_code()) obj = ProcessNewObjectFromSerializedCode(obj); Object* write_back_obj = obj; UnalignedCopy(write_back, &write_back_obj); #ifdef DEBUG if (obj->IsCode()) { DCHECK(space_number == CODE_SPACE || space_number == LO_SPACE); } else { DCHECK(space_number != CODE_SPACE); } #endif #if V8_TARGET_ARCH_PPC && \ (ABI_USES_FUNCTION_DESCRIPTORS || V8_OOL_CONSTANT_POOL) // If we're on a platform that uses function descriptors // these jump tables make use of RelocInfo::INTERNAL_REFERENCE. // As the V8 serialization code doesn't handle that relocation type // we use this to fix up code that has function descriptors. if (space_number == CODE_SPACE) { Code* code = reinterpret_cast(HeapObject::FromAddress(address)); for (RelocIterator it(code); !it.done(); it.next()) { RelocInfo::Mode rmode = it.rinfo()->rmode(); if (rmode == RelocInfo::INTERNAL_REFERENCE) { Assembler::RelocateInternalReference(it.rinfo()->pc(), 0, code->instruction_start()); } } } #endif } // We know the space requirements before deserialization and can // pre-allocate that reserved space. During deserialization, all we need // to do is to bump up the pointer for each space in the reserved // space. This is also used for fixing back references. // We may have to split up the pre-allocation into several chunks // because it would not fit onto a single page. We do not have to keep // track of when to move to the next chunk. An opcode will signal this. // Since multiple large objects cannot be folded into one large object // space allocation, we have to do an actual allocation when deserializing // each large object. Instead of tracking offset for back references, we // reference large objects by index. Address Deserializer::Allocate(int space_index, int size) { if (space_index == LO_SPACE) { AlwaysAllocateScope scope(isolate_); LargeObjectSpace* lo_space = isolate_->heap()->lo_space(); Executability exec = static_cast(source_.Get()); AllocationResult result = lo_space->AllocateRaw(size, exec); HeapObject* obj = HeapObject::cast(result.ToObjectChecked()); deserialized_large_objects_.Add(obj); return obj->address(); } else { DCHECK(space_index < kNumberOfPreallocatedSpaces); Address address = high_water_[space_index]; DCHECK_NOT_NULL(address); high_water_[space_index] += size; #ifdef DEBUG // Assert that the current reserved chunk is still big enough. const Heap::Reservation& reservation = reservations_[space_index]; int chunk_index = current_chunk_[space_index]; CHECK_LE(high_water_[space_index], reservation[chunk_index].end); #endif return address; } } void Deserializer::ReadData(Object** current, Object** limit, int source_space, Address current_object_address) { Isolate* const isolate = isolate_; // Write barrier support costs around 1% in startup time. In fact there // are no new space objects in current boot snapshots, so it's not needed, // but that may change. bool write_barrier_needed = (current_object_address != NULL && source_space != NEW_SPACE && source_space != CELL_SPACE && source_space != PROPERTY_CELL_SPACE && source_space != CODE_SPACE && source_space != OLD_DATA_SPACE); while (current < limit) { byte data = source_.Get(); switch (data) { #define CASE_STATEMENT(where, how, within, space_number) \ case where + how + within + space_number: \ STATIC_ASSERT((where & ~kPointedToMask) == 0); \ STATIC_ASSERT((how & ~kHowToCodeMask) == 0); \ STATIC_ASSERT((within & ~kWhereToPointMask) == 0); \ STATIC_ASSERT((space_number & ~kSpaceMask) == 0); #define CASE_BODY(where, how, within, space_number_if_any) \ { \ bool emit_write_barrier = false; \ bool current_was_incremented = false; \ int space_number = space_number_if_any == kAnyOldSpace \ ? (data & kSpaceMask) \ : space_number_if_any; \ if (where == kNewObject && how == kPlain && within == kStartOfObject) { \ ReadObject(space_number, current); \ emit_write_barrier = (space_number == NEW_SPACE); \ } else { \ Object* new_object = NULL; /* May not be a real Object pointer. */ \ if (where == kNewObject) { \ ReadObject(space_number, &new_object); \ } else if (where == kRootArray) { \ int root_id = source_.GetInt(); \ new_object = isolate->heap()->roots_array_start()[root_id]; \ emit_write_barrier = isolate->heap()->InNewSpace(new_object); \ } else if (where == kPartialSnapshotCache) { \ int cache_index = source_.GetInt(); \ new_object = isolate->serialize_partial_snapshot_cache()[cache_index]; \ emit_write_barrier = isolate->heap()->InNewSpace(new_object); \ } else if (where == kExternalReference) { \ int skip = source_.GetInt(); \ current = reinterpret_cast( \ reinterpret_cast
(current) + skip); \ int reference_id = source_.GetInt(); \ Address address = external_reference_decoder_->Decode(reference_id); \ new_object = reinterpret_cast(address); \ } else if (where == kBackref) { \ emit_write_barrier = (space_number == NEW_SPACE); \ new_object = GetBackReferencedObject(data & kSpaceMask); \ } else if (where == kBuiltin) { \ DCHECK(deserializing_user_code()); \ int builtin_id = source_.GetInt(); \ DCHECK_LE(0, builtin_id); \ DCHECK_LT(builtin_id, Builtins::builtin_count); \ Builtins::Name name = static_cast(builtin_id); \ new_object = isolate->builtins()->builtin(name); \ emit_write_barrier = false; \ } else if (where == kAttachedReference) { \ int index = source_.GetInt(); \ DCHECK(deserializing_user_code() || index == kGlobalProxyReference); \ new_object = *attached_objects_[index]; \ emit_write_barrier = isolate->heap()->InNewSpace(new_object); \ } else { \ DCHECK(where == kBackrefWithSkip); \ int skip = source_.GetInt(); \ current = reinterpret_cast( \ reinterpret_cast
(current) + skip); \ emit_write_barrier = (space_number == NEW_SPACE); \ new_object = GetBackReferencedObject(data & kSpaceMask); \ } \ if (within == kInnerPointer) { \ if (space_number != CODE_SPACE || new_object->IsCode()) { \ Code* new_code_object = reinterpret_cast(new_object); \ new_object = \ reinterpret_cast(new_code_object->instruction_start()); \ } else { \ DCHECK(space_number == CODE_SPACE); \ Cell* cell = Cell::cast(new_object); \ new_object = reinterpret_cast(cell->ValueAddress()); \ } \ } \ if (how == kFromCode) { \ Address location_of_branch_data = reinterpret_cast
(current); \ Assembler::deserialization_set_special_target_at( \ location_of_branch_data, \ Code::cast(HeapObject::FromAddress(current_object_address)), \ reinterpret_cast
(new_object)); \ location_of_branch_data += Assembler::kSpecialTargetSize; \ current = reinterpret_cast(location_of_branch_data); \ current_was_incremented = true; \ } else { \ UnalignedCopy(current, &new_object); \ } \ } \ if (emit_write_barrier && write_barrier_needed) { \ Address current_address = reinterpret_cast
(current); \ isolate->heap()->RecordWrite( \ current_object_address, \ static_cast(current_address - current_object_address)); \ } \ if (!current_was_incremented) { \ current++; \ } \ break; \ } // This generates a case and a body for the new space (which has to do extra // write barrier handling) and handles the other spaces with 8 fall-through // cases and one body. #define ALL_SPACES(where, how, within) \ CASE_STATEMENT(where, how, within, NEW_SPACE) \ CASE_BODY(where, how, within, NEW_SPACE) \ CASE_STATEMENT(where, how, within, OLD_DATA_SPACE) \ CASE_STATEMENT(where, how, within, OLD_POINTER_SPACE) \ CASE_STATEMENT(where, how, within, CODE_SPACE) \ CASE_STATEMENT(where, how, within, MAP_SPACE) \ CASE_STATEMENT(where, how, within, CELL_SPACE) \ CASE_STATEMENT(where, how, within, PROPERTY_CELL_SPACE) \ CASE_STATEMENT(where, how, within, LO_SPACE) \ CASE_BODY(where, how, within, kAnyOldSpace) #define FOUR_CASES(byte_code) \ case byte_code: \ case byte_code + 1: \ case byte_code + 2: \ case byte_code + 3: #define SIXTEEN_CASES(byte_code) \ FOUR_CASES(byte_code) \ FOUR_CASES(byte_code + 4) \ FOUR_CASES(byte_code + 8) \ FOUR_CASES(byte_code + 12) #define COMMON_RAW_LENGTHS(f) \ f(1) \ f(2) \ f(3) \ f(4) \ f(5) \ f(6) \ f(7) \ f(8) \ f(9) \ f(10) \ f(11) \ f(12) \ f(13) \ f(14) \ f(15) \ f(16) \ f(17) \ f(18) \ f(19) \ f(20) \ f(21) \ f(22) \ f(23) \ f(24) \ f(25) \ f(26) \ f(27) \ f(28) \ f(29) \ f(30) \ f(31) // We generate 15 cases and bodies that process special tags that combine // the raw data tag and the length into one byte. #define RAW_CASE(index) \ case kRawData + index: { \ byte* raw_data_out = reinterpret_cast(current); \ source_.CopyRaw(raw_data_out, index* kPointerSize); \ current = reinterpret_cast(raw_data_out + index * kPointerSize); \ break; \ } COMMON_RAW_LENGTHS(RAW_CASE) #undef RAW_CASE // Deserialize a chunk of raw data that doesn't have one of the popular // lengths. case kRawData: { int size = source_.GetInt(); byte* raw_data_out = reinterpret_cast(current); source_.CopyRaw(raw_data_out, size); break; } SIXTEEN_CASES(kRootArrayConstants + kNoSkipDistance) SIXTEEN_CASES(kRootArrayConstants + kNoSkipDistance + 16) { int root_id = RootArrayConstantFromByteCode(data); Object* object = isolate->heap()->roots_array_start()[root_id]; DCHECK(!isolate->heap()->InNewSpace(object)); UnalignedCopy(current++, &object); break; } SIXTEEN_CASES(kRootArrayConstants + kHasSkipDistance) SIXTEEN_CASES(kRootArrayConstants + kHasSkipDistance + 16) { int root_id = RootArrayConstantFromByteCode(data); int skip = source_.GetInt(); current = reinterpret_cast( reinterpret_cast(current) + skip); Object* object = isolate->heap()->roots_array_start()[root_id]; DCHECK(!isolate->heap()->InNewSpace(object)); UnalignedCopy(current++, &object); break; } case kVariableRepeat: { int repeats = source_.GetInt(); Object* object = current[-1]; DCHECK(!isolate->heap()->InNewSpace(object)); for (int i = 0; i < repeats; i++) UnalignedCopy(current++, &object); break; } STATIC_ASSERT(kRootArrayNumberOfConstantEncodings == Heap::kOldSpaceRoots); STATIC_ASSERT(kMaxFixedRepeats == 15); FOUR_CASES(kFixedRepeat) FOUR_CASES(kFixedRepeat + 4) FOUR_CASES(kFixedRepeat + 8) case kFixedRepeat + 12: case kFixedRepeat + 13: case kFixedRepeat + 14: { int repeats = RepeatsForCode(data); Object* object; UnalignedCopy(&object, current - 1); DCHECK(!isolate->heap()->InNewSpace(object)); for (int i = 0; i < repeats; i++) UnalignedCopy(current++, &object); break; } // Deserialize a new object and write a pointer to it to the current // object. ALL_SPACES(kNewObject, kPlain, kStartOfObject) // Support for direct instruction pointers in functions. It's an inner // pointer because it points at the entry point, not at the start of the // code object. CASE_STATEMENT(kNewObject, kPlain, kInnerPointer, CODE_SPACE) CASE_BODY(kNewObject, kPlain, kInnerPointer, CODE_SPACE) // Deserialize a new code object and write a pointer to its first // instruction to the current code object. ALL_SPACES(kNewObject, kFromCode, kInnerPointer) // Find a recently deserialized object using its offset from the current // allocation point and write a pointer to it to the current object. ALL_SPACES(kBackref, kPlain, kStartOfObject) ALL_SPACES(kBackrefWithSkip, kPlain, kStartOfObject) #if defined(V8_TARGET_ARCH_MIPS) || defined(V8_TARGET_ARCH_MIPS64) || \ defined(V8_TARGET_ARCH_PPC) || V8_OOL_CONSTANT_POOL // Deserialize a new object from pointer found in code and write // a pointer to it to the current object. Required only for MIPS, PPC or // ARM with ool constant pool, and omitted on the other architectures // because it is fully unrolled and would cause bloat. ALL_SPACES(kNewObject, kFromCode, kStartOfObject) // Find a recently deserialized code object using its offset from the // current allocation point and write a pointer to it to the current // object. Required only for MIPS, PPC or ARM with ool constant pool. ALL_SPACES(kBackref, kFromCode, kStartOfObject) ALL_SPACES(kBackrefWithSkip, kFromCode, kStartOfObject) #endif // Find a recently deserialized code object using its offset from the // current allocation point and write a pointer to its first instruction // to the current code object or the instruction pointer in a function // object. ALL_SPACES(kBackref, kFromCode, kInnerPointer) ALL_SPACES(kBackrefWithSkip, kFromCode, kInnerPointer) ALL_SPACES(kBackref, kPlain, kInnerPointer) ALL_SPACES(kBackrefWithSkip, kPlain, kInnerPointer) // Find an object in the roots array and write a pointer to it to the // current object. CASE_STATEMENT(kRootArray, kPlain, kStartOfObject, 0) CASE_BODY(kRootArray, kPlain, kStartOfObject, 0) #if defined(V8_TARGET_ARCH_MIPS) || V8_OOL_CONSTANT_POOL || \ defined(V8_TARGET_ARCH_MIPS64) || defined(V8_TARGET_ARCH_PPC) // Find an object in the roots array and write a pointer to it to in code. CASE_STATEMENT(kRootArray, kFromCode, kStartOfObject, 0) CASE_BODY(kRootArray, kFromCode, kStartOfObject, 0) #endif // Find an object in the partial snapshots cache and write a pointer to it // to the current object. CASE_STATEMENT(kPartialSnapshotCache, kPlain, kStartOfObject, 0) CASE_BODY(kPartialSnapshotCache, kPlain, kStartOfObject, 0) // Find an code entry in the partial snapshots cache and // write a pointer to it to the current object. CASE_STATEMENT(kPartialSnapshotCache, kPlain, kInnerPointer, 0) CASE_BODY(kPartialSnapshotCache, kPlain, kInnerPointer, 0) // Find an external reference and write a pointer to it to the current // object. CASE_STATEMENT(kExternalReference, kPlain, kStartOfObject, 0) CASE_BODY(kExternalReference, kPlain, kStartOfObject, 0) // Find an external reference and write a pointer to it in the current // code object. CASE_STATEMENT(kExternalReference, kFromCode, kStartOfObject, 0) CASE_BODY(kExternalReference, kFromCode, kStartOfObject, 0) // Find a builtin and write a pointer to it to the current object. CASE_STATEMENT(kBuiltin, kPlain, kStartOfObject, 0) CASE_BODY(kBuiltin, kPlain, kStartOfObject, 0) CASE_STATEMENT(kBuiltin, kPlain, kInnerPointer, 0) CASE_BODY(kBuiltin, kPlain, kInnerPointer, 0) CASE_STATEMENT(kBuiltin, kFromCode, kInnerPointer, 0) CASE_BODY(kBuiltin, kFromCode, kInnerPointer, 0) // Find an object in the attached references and write a pointer to it to // the current object. CASE_STATEMENT(kAttachedReference, kPlain, kStartOfObject, 0) CASE_BODY(kAttachedReference, kPlain, kStartOfObject, 0) CASE_STATEMENT(kAttachedReference, kPlain, kInnerPointer, 0) CASE_BODY(kAttachedReference, kPlain, kInnerPointer, 0) CASE_STATEMENT(kAttachedReference, kFromCode, kInnerPointer, 0) CASE_BODY(kAttachedReference, kFromCode, kInnerPointer, 0) #undef CASE_STATEMENT #undef CASE_BODY #undef ALL_SPACES case kSkip: { int size = source_.GetInt(); current = reinterpret_cast( reinterpret_cast(current) + size); break; } case kNativesStringResource: { DCHECK(!isolate_->heap()->deserialization_complete()); int index = source_.Get(); Vector source_vector = Natives::GetScriptSource(index); NativesExternalStringResource* resource = new NativesExternalStringResource(source_vector.start(), source_vector.length()); Object* resource_obj = reinterpret_cast(resource); UnalignedCopy(current++, &resource_obj); break; } case kNextChunk: { int space = source_.Get(); DCHECK(space < kNumberOfPreallocatedSpaces); int chunk_index = current_chunk_[space]; const Heap::Reservation& reservation = reservations_[space]; // Make sure the current chunk is indeed exhausted. CHECK_EQ(reservation[chunk_index].end, high_water_[space]); // Move to next reserved chunk. chunk_index = ++current_chunk_[space]; CHECK_LT(chunk_index, reservation.length()); high_water_[space] = reservation[chunk_index].start; break; } FOUR_CASES(kHotObjectWithSkip) FOUR_CASES(kHotObjectWithSkip + 4) { int skip = source_.GetInt(); current = reinterpret_cast( reinterpret_cast
(current) + skip); // Fall through. } FOUR_CASES(kHotObject) FOUR_CASES(kHotObject + 4) { int index = data & kHotObjectIndexMask; Object* hot_object = hot_objects_.Get(index); UnalignedCopy(current, &hot_object); if (write_barrier_needed && isolate->heap()->InNewSpace(hot_object)) { Address current_address = reinterpret_cast
(current); isolate->heap()->RecordWrite( current_object_address, static_cast(current_address - current_object_address)); } current++; break; } case kSynchronize: { // If we get here then that indicates that you have a mismatch between // the number of GC roots when serializing and deserializing. CHECK(false); } default: CHECK(false); } } CHECK_EQ(limit, current); } Serializer::Serializer(Isolate* isolate, SnapshotByteSink* sink) : isolate_(isolate), sink_(sink), external_reference_encoder_(new ExternalReferenceEncoder(isolate)), root_index_map_(isolate), code_address_map_(NULL), large_objects_total_size_(0), seen_large_objects_index_(0) { // The serializer is meant to be used only to generate initial heap images // from a context in which there is only one isolate. for (int i = 0; i < kNumberOfPreallocatedSpaces; i++) { pending_chunk_[i] = 0; max_chunk_size_[i] = static_cast( MemoryAllocator::PageAreaSize(static_cast(i))); } } Serializer::~Serializer() { delete external_reference_encoder_; if (code_address_map_ != NULL) delete code_address_map_; } void StartupSerializer::SerializeStrongReferences() { Isolate* isolate = this->isolate(); // No active threads. CHECK_NULL(isolate->thread_manager()->FirstThreadStateInUse()); // No active or weak handles. CHECK(isolate->handle_scope_implementer()->blocks()->is_empty()); CHECK_EQ(0, isolate->global_handles()->NumberOfWeakHandles()); CHECK_EQ(0, isolate->eternal_handles()->NumberOfHandles()); // We don't support serializing installed extensions. CHECK(!isolate->has_installed_extensions()); isolate->heap()->IterateSmiRoots(this); isolate->heap()->IterateStrongRoots(this, VISIT_ONLY_STRONG); } void StartupSerializer::VisitPointers(Object** start, Object** end) { for (Object** current = start; current < end; current++) { if (start == isolate()->heap()->roots_array_start()) { root_index_wave_front_ = Max(root_index_wave_front_, static_cast(current - start)); } if (ShouldBeSkipped(current)) { sink_->Put(kSkip, "Skip"); sink_->PutInt(kPointerSize, "SkipOneWord"); } else if ((*current)->IsSmi()) { sink_->Put(kOnePointerRawData, "Smi"); for (int i = 0; i < kPointerSize; i++) { sink_->Put(reinterpret_cast(current)[i], "Byte"); } } else { SerializeObject(HeapObject::cast(*current), kPlain, kStartOfObject, 0); } } } void PartialSerializer::Serialize(Object** o) { if ((*o)->IsContext()) { Context* context = Context::cast(*o); global_object_ = context->global_object(); back_reference_map()->AddGlobalProxy(context->global_proxy()); } VisitPointer(o); SerializeOutdatedContextsAsFixedArray(); Pad(); } void PartialSerializer::SerializeOutdatedContextsAsFixedArray() { int length = outdated_contexts_.length(); if (length == 0) { FixedArray* empty = isolate_->heap()->empty_fixed_array(); SerializeObject(empty, kPlain, kStartOfObject, 0); } else { // Serialize an imaginary fixed array containing outdated contexts. int size = FixedArray::SizeFor(length); Allocate(NEW_SPACE, size); sink_->Put(kNewObject + NEW_SPACE, "emulated FixedArray"); sink_->PutInt(size >> kObjectAlignmentBits, "FixedArray size in words"); Map* map = isolate_->heap()->fixed_array_map(); SerializeObject(map, kPlain, kStartOfObject, 0); Smi* length_smi = Smi::FromInt(length); sink_->Put(kOnePointerRawData, "Smi"); for (int i = 0; i < kPointerSize; i++) { sink_->Put(reinterpret_cast(&length_smi)[i], "Byte"); } for (int i = 0; i < length; i++) { BackReference back_ref = outdated_contexts_[i]; DCHECK(BackReferenceIsAlreadyAllocated(back_ref)); sink_->Put(kBackref + back_ref.space(), "BackRef"); sink_->PutInt(back_ref.reference(), "BackRefValue"); } } } bool Serializer::ShouldBeSkipped(Object** current) { Object** roots = isolate()->heap()->roots_array_start(); return current == &roots[Heap::kStoreBufferTopRootIndex] || current == &roots[Heap::kStackLimitRootIndex] || current == &roots[Heap::kRealStackLimitRootIndex]; } void Serializer::VisitPointers(Object** start, Object** end) { for (Object** current = start; current < end; current++) { if ((*current)->IsSmi()) { sink_->Put(kOnePointerRawData, "Smi"); for (int i = 0; i < kPointerSize; i++) { sink_->Put(reinterpret_cast(current)[i], "Byte"); } } else { SerializeObject(HeapObject::cast(*current), kPlain, kStartOfObject, 0); } } } void Serializer::EncodeReservations( List* out) const { for (int i = 0; i < kNumberOfPreallocatedSpaces; i++) { for (int j = 0; j < completed_chunks_[i].length(); j++) { out->Add(SerializedData::Reservation(completed_chunks_[i][j])); } if (pending_chunk_[i] > 0 || completed_chunks_[i].length() == 0) { out->Add(SerializedData::Reservation(pending_chunk_[i])); } out->last().mark_as_last(); } out->Add(SerializedData::Reservation(large_objects_total_size_)); out->last().mark_as_last(); } // This ensures that the partial snapshot cache keeps things alive during GC and // tracks their movement. When it is called during serialization of the startup // snapshot nothing happens. When the partial (context) snapshot is created, // this array is populated with the pointers that the partial snapshot will // need. As that happens we emit serialized objects to the startup snapshot // that correspond to the elements of this cache array. On deserialization we // therefore need to visit the cache array. This fills it up with pointers to // deserialized objects. void SerializerDeserializer::Iterate(Isolate* isolate, ObjectVisitor* visitor) { if (isolate->serializer_enabled()) return; for (int i = 0; ; i++) { if (isolate->serialize_partial_snapshot_cache_length() <= i) { // Extend the array ready to get a value from the visitor when // deserializing. isolate->PushToPartialSnapshotCache(Smi::FromInt(0)); } Object** cache = isolate->serialize_partial_snapshot_cache(); visitor->VisitPointers(&cache[i], &cache[i + 1]); // Sentinel is the undefined object, which is a root so it will not normally // be found in the cache. if (cache[i] == isolate->heap()->undefined_value()) { break; } } } int PartialSerializer::PartialSnapshotCacheIndex(HeapObject* heap_object) { Isolate* isolate = this->isolate(); for (int i = 0; i < isolate->serialize_partial_snapshot_cache_length(); i++) { Object* entry = isolate->serialize_partial_snapshot_cache()[i]; if (entry == heap_object) return i; } // We didn't find the object in the cache. So we add it to the cache and // then visit the pointer so that it becomes part of the startup snapshot // and we can refer to it from the partial snapshot. int length = isolate->serialize_partial_snapshot_cache_length(); isolate->PushToPartialSnapshotCache(heap_object); startup_serializer_->VisitPointer(reinterpret_cast(&heap_object)); // We don't recurse from the startup snapshot generator into the partial // snapshot generator. DCHECK(length == isolate->serialize_partial_snapshot_cache_length() - 1); return length; } #ifdef DEBUG bool Serializer::BackReferenceIsAlreadyAllocated(BackReference reference) { DCHECK(reference.is_valid()); DCHECK(!reference.is_source()); DCHECK(!reference.is_global_proxy()); AllocationSpace space = reference.space(); int chunk_index = reference.chunk_index(); if (space == LO_SPACE) { return chunk_index == 0 && reference.large_object_index() < seen_large_objects_index_; } else if (chunk_index == completed_chunks_[space].length()) { return reference.chunk_offset() < pending_chunk_[space]; } else { return chunk_index < completed_chunks_[space].length() && reference.chunk_offset() < completed_chunks_[space][chunk_index]; } } #endif // DEBUG bool Serializer::SerializeKnownObject(HeapObject* obj, HowToCode how_to_code, WhereToPoint where_to_point, int skip) { if (how_to_code == kPlain && where_to_point == kStartOfObject) { // Encode a reference to a hot object by its index in the working set. int index = hot_objects_.Find(obj); if (index != HotObjectsList::kNotFound) { DCHECK(index >= 0 && index <= kMaxHotObjectIndex); if (FLAG_trace_serializer) { PrintF(" Encoding hot object %d:", index); obj->ShortPrint(); PrintF("\n"); } if (skip != 0) { sink_->Put(kHotObjectWithSkip + index, "HotObjectWithSkip"); sink_->PutInt(skip, "HotObjectSkipDistance"); } else { sink_->Put(kHotObject + index, "HotObject"); } return true; } } BackReference back_reference = back_reference_map_.Lookup(obj); if (back_reference.is_valid()) { // Encode the location of an already deserialized object in order to write // its location into a later object. We can encode the location as an // offset fromthe start of the deserialized objects or as an offset // backwards from thecurrent allocation pointer. if (back_reference.is_source()) { FlushSkip(skip); if (FLAG_trace_serializer) PrintF(" Encoding source object\n"); DCHECK(how_to_code == kPlain && where_to_point == kStartOfObject); sink_->Put(kAttachedReference + kPlain + kStartOfObject, "Source"); sink_->PutInt(kSourceObjectReference, "kSourceObjectReference"); } else if (back_reference.is_global_proxy()) { FlushSkip(skip); if (FLAG_trace_serializer) PrintF(" Encoding global proxy\n"); DCHECK(how_to_code == kPlain && where_to_point == kStartOfObject); sink_->Put(kAttachedReference + kPlain + kStartOfObject, "Global Proxy"); sink_->PutInt(kGlobalProxyReference, "kGlobalProxyReference"); } else { if (FLAG_trace_serializer) { PrintF(" Encoding back reference to: "); obj->ShortPrint(); PrintF("\n"); } AllocationSpace space = back_reference.space(); if (skip == 0) { sink_->Put(kBackref + how_to_code + where_to_point + space, "BackRef"); } else { sink_->Put(kBackrefWithSkip + how_to_code + where_to_point + space, "BackRefWithSkip"); sink_->PutInt(skip, "BackRefSkipDistance"); } DCHECK(BackReferenceIsAlreadyAllocated(back_reference)); sink_->PutInt(back_reference.reference(), "BackRefValue"); hot_objects_.Add(obj); } return true; } return false; } void StartupSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code, WhereToPoint where_to_point, int skip) { DCHECK(!obj->IsJSFunction()); int root_index = root_index_map_.Lookup(obj); // We can only encode roots as such if it has already been serialized. // That applies to root indices below the wave front. if (root_index != RootIndexMap::kInvalidRootIndex && root_index < root_index_wave_front_) { PutRoot(root_index, obj, how_to_code, where_to_point, skip); return; } if (SerializeKnownObject(obj, how_to_code, where_to_point, skip)) return; FlushSkip(skip); // Object has not yet been serialized. Serialize it here. ObjectSerializer object_serializer(this, obj, sink_, how_to_code, where_to_point); object_serializer.Serialize(); } void StartupSerializer::SerializeWeakReferences() { // This phase comes right after the serialization (of the snapshot). // After we have done the partial serialization the partial snapshot cache // will contain some references needed to decode the partial snapshot. We // add one entry with 'undefined' which is the sentinel that the deserializer // uses to know it is done deserializing the array. Object* undefined = isolate()->heap()->undefined_value(); VisitPointer(&undefined); isolate()->heap()->IterateWeakRoots(this, VISIT_ALL); Pad(); } void Serializer::PutRoot(int root_index, HeapObject* object, SerializerDeserializer::HowToCode how_to_code, SerializerDeserializer::WhereToPoint where_to_point, int skip) { if (FLAG_trace_serializer) { PrintF(" Encoding root %d:", root_index); object->ShortPrint(); PrintF("\n"); } if (how_to_code == kPlain && where_to_point == kStartOfObject && root_index < kRootArrayNumberOfConstantEncodings && !isolate()->heap()->InNewSpace(object)) { if (skip == 0) { sink_->Put(kRootArrayConstants + kNoSkipDistance + root_index, "RootConstant"); } else { sink_->Put(kRootArrayConstants + kHasSkipDistance + root_index, "RootConstant"); sink_->PutInt(skip, "SkipInPutRoot"); } } else { FlushSkip(skip); sink_->Put(kRootArray + how_to_code + where_to_point, "RootSerialization"); sink_->PutInt(root_index, "root_index"); } } 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(); 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 (ShouldBeInThePartialSnapshotCache(obj)) { FlushSkip(skip); int cache_index = 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_->back_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()); if (SerializeKnownObject(obj, how_to_code, where_to_point, skip)) return; FlushSkip(skip); // Object has not yet been serialized. Serialize it here. ObjectSerializer serializer(this, obj, sink_, how_to_code, where_to_point); serializer.Serialize(); if (obj->IsContext() && Context::cast(obj)->global_object() == global_object_) { // Context refers to the current global object. This reference will // become outdated after deserialization. BackReference back_reference = back_reference_map_.Lookup(obj); DCHECK(back_reference.is_valid()); outdated_contexts_.Add(back_reference); } } void Serializer::ObjectSerializer::SerializePrologue(AllocationSpace space, int size, Map* map) { if (serializer_->code_address_map_) { const char* code_name = serializer_->code_address_map_->Lookup(object_->address()); LOG(serializer_->isolate_, CodeNameEvent(object_->address(), sink_->Position(), code_name)); LOG(serializer_->isolate_, SnapshotPositionEvent(object_->address(), sink_->Position())); } BackReference back_reference; if (space == LO_SPACE) { sink_->Put(kNewObject + reference_representation_ + space, "NewLargeObject"); sink_->PutInt(size >> kObjectAlignmentBits, "ObjectSizeInWords"); if (object_->IsCode()) { sink_->Put(EXECUTABLE, "executable large object"); } else { sink_->Put(NOT_EXECUTABLE, "not executable large object"); } back_reference = serializer_->AllocateLargeObject(size); } else { bool needs_double_align = false; if (object_->NeedsToEnsureDoubleAlignment()) { // Add wriggle room for double alignment padding. back_reference = serializer_->Allocate(space, size + kPointerSize); needs_double_align = true; } else { back_reference = serializer_->Allocate(space, size); } sink_->Put(kNewObject + reference_representation_ + space, "NewObject"); if (needs_double_align) sink_->PutInt(kDoubleAlignmentSentinel, "DoubleAlignSentinel"); int encoded_size = size >> kObjectAlignmentBits; DCHECK_NE(kDoubleAlignmentSentinel, encoded_size); sink_->PutInt(encoded_size, "ObjectSizeInWords"); } // Mark this object as already serialized. serializer_->back_reference_map()->Add(object_, back_reference); // Serialize the map (first word of the object). serializer_->SerializeObject(map, kPlain, kStartOfObject, 0); } void Serializer::ObjectSerializer::SerializeExternalString() { // Instead of serializing this as an external string, we serialize // an imaginary sequential string with the same content. Isolate* isolate = serializer_->isolate(); DCHECK(object_->IsExternalString()); DCHECK(object_->map() != isolate->heap()->native_source_string_map()); ExternalString* string = ExternalString::cast(object_); int length = string->length(); Map* map; int content_size; int allocation_size; const byte* resource; // Find the map and size for the imaginary sequential string. bool internalized = object_->IsInternalizedString(); if (object_->IsExternalOneByteString()) { map = internalized ? isolate->heap()->one_byte_internalized_string_map() : isolate->heap()->one_byte_string_map(); allocation_size = SeqOneByteString::SizeFor(length); content_size = length * kCharSize; resource = reinterpret_cast( ExternalOneByteString::cast(string)->resource()->data()); } else { map = internalized ? isolate->heap()->internalized_string_map() : isolate->heap()->string_map(); allocation_size = SeqTwoByteString::SizeFor(length); content_size = length * kShortSize; resource = reinterpret_cast( ExternalTwoByteString::cast(string)->resource()->data()); } AllocationSpace space = (allocation_size > Page::kMaxRegularHeapObjectSize) ? LO_SPACE : OLD_DATA_SPACE; SerializePrologue(space, allocation_size, map); // Output the rest of the imaginary string. int bytes_to_output = allocation_size - HeapObject::kHeaderSize; // Output raw data header. Do not bother with common raw length cases here. sink_->Put(kRawData, "RawDataForString"); sink_->PutInt(bytes_to_output, "length"); // Serialize string header (except for map). Address string_start = string->address(); for (int i = HeapObject::kHeaderSize; i < SeqString::kHeaderSize; i++) { sink_->PutSection(string_start[i], "StringHeader"); } // Serialize string content. sink_->PutRaw(resource, content_size, "StringContent"); // Since the allocation size is rounded up to object alignment, there // maybe left-over bytes that need to be padded. int padding_size = allocation_size - SeqString::kHeaderSize - content_size; DCHECK(0 <= padding_size && padding_size < kObjectAlignment); for (int i = 0; i < padding_size; i++) sink_->PutSection(0, "StringPadding"); sink_->Put(kSkip, "SkipAfterString"); sink_->PutInt(bytes_to_output, "SkipDistance"); } void Serializer::ObjectSerializer::Serialize() { if (FLAG_trace_serializer) { PrintF(" Encoding heap object: "); object_->ShortPrint(); PrintF("\n"); } // We cannot serialize typed array objects correctly. DCHECK(!object_->IsJSTypedArray()); if (object_->IsScript()) { // Clear cached line ends. Object* undefined = serializer_->isolate()->heap()->undefined_value(); Script::cast(object_)->set_line_ends(undefined); } if (object_->IsExternalString()) { Heap* heap = serializer_->isolate()->heap(); if (object_->map() != heap->native_source_string_map()) { // Usually we cannot recreate resources for external strings. To work // around this, external strings are serialized to look like ordinary // sequential strings. // The exception are native source code strings, since we can recreate // their resources. In that case we fall through and leave it to // VisitExternalOneByteString further down. SerializeExternalString(); return; } } int size = object_->Size(); Map* map = object_->map(); SerializePrologue(Serializer::SpaceOfObject(object_), size, map); // Serialize the rest of the object. CHECK_EQ(0, bytes_processed_so_far_); bytes_processed_so_far_ = kPointerSize; object_->IterateBody(map->instance_type(), size, this); OutputRawData(object_->address() + size); } void Serializer::ObjectSerializer::VisitPointers(Object** start, Object** end) { Object** current = start; while (current < end) { while (current < end && (*current)->IsSmi()) current++; if (current < end) OutputRawData(reinterpret_cast
(current)); while (current < end && !(*current)->IsSmi()) { HeapObject* current_contents = HeapObject::cast(*current); int root_index = serializer_->root_index_map()->Lookup(current_contents); // Repeats are not subject to the write barrier so we can only use // immortal immovable root members. They are never in new space. if (current != start && root_index != RootIndexMap::kInvalidRootIndex && Heap::RootIsImmortalImmovable(root_index) && current_contents == current[-1]) { DCHECK(!serializer_->isolate()->heap()->InNewSpace(current_contents)); int repeat_count = 1; while (¤t[repeat_count] < end - 1 && current[repeat_count] == current_contents) { repeat_count++; } current += repeat_count; bytes_processed_so_far_ += repeat_count * kPointerSize; if (repeat_count > kMaxFixedRepeats) { sink_->Put(kVariableRepeat, "SerializeRepeats"); sink_->PutInt(repeat_count, "SerializeRepeats"); } else { sink_->Put(CodeForRepeats(repeat_count), "SerializeRepeats"); } } else { serializer_->SerializeObject( current_contents, kPlain, kStartOfObject, 0); bytes_processed_so_far_ += kPointerSize; current++; } } } } void Serializer::ObjectSerializer::VisitEmbeddedPointer(RelocInfo* rinfo) { // Out-of-line constant pool entries will be visited by the ConstantPoolArray. if (FLAG_enable_ool_constant_pool && rinfo->IsInConstantPool()) return; int skip = OutputRawData(rinfo->target_address_address(), kCanReturnSkipInsteadOfSkipping); HowToCode how_to_code = rinfo->IsCodedSpecially() ? kFromCode : kPlain; Object* object = rinfo->target_object(); serializer_->SerializeObject(HeapObject::cast(object), how_to_code, kStartOfObject, skip); bytes_processed_so_far_ += rinfo->target_address_size(); } void Serializer::ObjectSerializer::VisitExternalReference(Address* p) { int skip = OutputRawData(reinterpret_cast
(p), kCanReturnSkipInsteadOfSkipping); sink_->Put(kExternalReference + kPlain + kStartOfObject, "ExternalRef"); sink_->PutInt(skip, "SkipB4ExternalRef"); Address target = *p; sink_->PutInt(serializer_->EncodeExternalReference(target), "reference id"); bytes_processed_so_far_ += kPointerSize; } void Serializer::ObjectSerializer::VisitExternalReference(RelocInfo* rinfo) { int skip = OutputRawData(rinfo->target_address_address(), kCanReturnSkipInsteadOfSkipping); HowToCode how_to_code = rinfo->IsCodedSpecially() ? kFromCode : kPlain; sink_->Put(kExternalReference + how_to_code + kStartOfObject, "ExternalRef"); sink_->PutInt(skip, "SkipB4ExternalRef"); Address target = rinfo->target_reference(); sink_->PutInt(serializer_->EncodeExternalReference(target), "reference id"); bytes_processed_so_far_ += rinfo->target_address_size(); } void Serializer::ObjectSerializer::VisitRuntimeEntry(RelocInfo* rinfo) { int skip = OutputRawData(rinfo->target_address_address(), kCanReturnSkipInsteadOfSkipping); HowToCode how_to_code = rinfo->IsCodedSpecially() ? kFromCode : kPlain; sink_->Put(kExternalReference + how_to_code + kStartOfObject, "ExternalRef"); sink_->PutInt(skip, "SkipB4ExternalRef"); Address target = rinfo->target_address(); sink_->PutInt(serializer_->EncodeExternalReference(target), "reference id"); bytes_processed_so_far_ += rinfo->target_address_size(); } void Serializer::ObjectSerializer::VisitCodeTarget(RelocInfo* rinfo) { // Out-of-line constant pool entries will be visited by the ConstantPoolArray. if (FLAG_enable_ool_constant_pool && rinfo->IsInConstantPool()) return; int skip = OutputRawData(rinfo->target_address_address(), kCanReturnSkipInsteadOfSkipping); Code* object = Code::GetCodeFromTargetAddress(rinfo->target_address()); serializer_->SerializeObject(object, kFromCode, kInnerPointer, skip); bytes_processed_so_far_ += rinfo->target_address_size(); } void Serializer::ObjectSerializer::VisitCodeEntry(Address entry_address) { int skip = OutputRawData(entry_address, kCanReturnSkipInsteadOfSkipping); Code* object = Code::cast(Code::GetObjectFromEntryAddress(entry_address)); serializer_->SerializeObject(object, kPlain, kInnerPointer, skip); bytes_processed_so_far_ += kPointerSize; } void Serializer::ObjectSerializer::VisitCell(RelocInfo* rinfo) { // Out-of-line constant pool entries will be visited by the ConstantPoolArray. if (FLAG_enable_ool_constant_pool && rinfo->IsInConstantPool()) return; int skip = OutputRawData(rinfo->pc(), kCanReturnSkipInsteadOfSkipping); Cell* object = Cell::cast(rinfo->target_cell()); serializer_->SerializeObject(object, kPlain, kInnerPointer, skip); bytes_processed_so_far_ += kPointerSize; } void Serializer::ObjectSerializer::VisitExternalOneByteString( v8::String::ExternalOneByteStringResource** resource_pointer) { Address references_start = reinterpret_cast
(resource_pointer); OutputRawData(references_start); for (int i = 0; i < Natives::GetBuiltinsCount(); i++) { Object* source = serializer_->isolate()->heap()->natives_source_cache()->get(i); if (!source->IsUndefined()) { ExternalOneByteString* string = ExternalOneByteString::cast(source); typedef v8::String::ExternalOneByteStringResource Resource; const Resource* resource = string->resource(); if (resource == *resource_pointer) { sink_->Put(kNativesStringResource, "NativesStringResource"); sink_->PutSection(i, "NativesStringResourceEnd"); bytes_processed_so_far_ += sizeof(resource); return; } } } // One of the strings in the natives cache should match the resource. We // don't expect any other kinds of external strings here. UNREACHABLE(); } static Code* CloneCodeObject(HeapObject* code) { Address copy = new byte[code->Size()]; MemCopy(copy, code->address(), code->Size()); return Code::cast(HeapObject::FromAddress(copy)); } static void WipeOutRelocations(Code* code) { int mode_mask = RelocInfo::kCodeTargetMask | RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) | RelocInfo::ModeMask(RelocInfo::EXTERNAL_REFERENCE) | RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY); for (RelocIterator it(code, mode_mask); !it.done(); it.next()) { if (!(FLAG_enable_ool_constant_pool && it.rinfo()->IsInConstantPool())) { it.rinfo()->WipeOut(); } } } int Serializer::ObjectSerializer::OutputRawData( Address up_to, Serializer::ObjectSerializer::ReturnSkip return_skip) { Address object_start = object_->address(); int base = bytes_processed_so_far_; int up_to_offset = static_cast(up_to - object_start); int to_skip = up_to_offset - bytes_processed_so_far_; int bytes_to_output = to_skip; bytes_processed_so_far_ += to_skip; // This assert will fail if the reloc info gives us the target_address_address // locations in a non-ascending order. Luckily that doesn't happen. DCHECK(to_skip >= 0); bool outputting_code = false; if (to_skip != 0 && code_object_ && !code_has_been_output_) { // Output the code all at once and fix later. bytes_to_output = object_->Size() + to_skip - bytes_processed_so_far_; outputting_code = true; code_has_been_output_ = true; } if (bytes_to_output != 0 && (!code_object_ || outputting_code)) { #define RAW_CASE(index) \ if (!outputting_code && bytes_to_output == index * kPointerSize && \ index * kPointerSize == to_skip) { \ sink_->PutSection(kRawData + index, "RawDataFixed"); \ to_skip = 0; /* This insn already skips. */ \ } else /* NOLINT */ COMMON_RAW_LENGTHS(RAW_CASE) #undef RAW_CASE { /* NOLINT */ // We always end up here if we are outputting the code of a code object. sink_->Put(kRawData, "RawData"); sink_->PutInt(bytes_to_output, "length"); } // To make snapshots reproducible, we need to wipe out all pointers in code. if (code_object_) { Code* code = CloneCodeObject(object_); // Code age headers are not serializable. code->MakeYoung(serializer_->isolate()); WipeOutRelocations(code); // We need to wipe out the header fields *after* wiping out the // relocations, because some of these fields are needed for the latter. code->WipeOutHeader(); object_start = code->address(); } const char* description = code_object_ ? "Code" : "Byte"; #ifdef MEMORY_SANITIZER // Object sizes are usually rounded up with uninitialized padding space. MSAN_MEMORY_IS_INITIALIZED(object_start + base, bytes_to_output); #endif // MEMORY_SANITIZER sink_->PutRaw(object_start + base, bytes_to_output, description); if (code_object_) delete[] object_start; } if (to_skip != 0 && return_skip == kIgnoringReturn) { sink_->Put(kSkip, "Skip"); sink_->PutInt(to_skip, "SkipDistance"); to_skip = 0; } return to_skip; } AllocationSpace Serializer::SpaceOfObject(HeapObject* object) { for (int i = FIRST_SPACE; i <= LAST_SPACE; i++) { AllocationSpace s = static_cast(i); if (object->GetHeap()->InSpace(object, s)) { DCHECK(i < kNumberOfSpaces); return s; } } UNREACHABLE(); return FIRST_SPACE; } BackReference Serializer::AllocateLargeObject(int size) { // Large objects are allocated one-by-one when deserializing. We do not // have to keep track of multiple chunks. large_objects_total_size_ += size; return BackReference::LargeObjectReference(seen_large_objects_index_++); } BackReference Serializer::Allocate(AllocationSpace space, int size) { DCHECK(space >= 0 && space < kNumberOfPreallocatedSpaces); DCHECK(size > 0 && size <= static_cast(max_chunk_size(space))); uint32_t new_chunk_size = pending_chunk_[space] + size; if (new_chunk_size > max_chunk_size(space)) { // The new chunk size would not fit onto a single page. Complete the // current chunk and start a new one. sink_->Put(kNextChunk, "NextChunk"); sink_->Put(space, "NextChunkSpace"); completed_chunks_[space].Add(pending_chunk_[space]); DCHECK_LE(completed_chunks_[space].length(), BackReference::kMaxChunkIndex); pending_chunk_[space] = 0; new_chunk_size = size; } uint32_t offset = pending_chunk_[space]; pending_chunk_[space] = new_chunk_size; return BackReference::Reference(space, completed_chunks_[space].length(), offset); } void Serializer::Pad() { // The non-branching GetInt will read up to 3 bytes too far, so we need // to pad the snapshot to make sure we don't read over the end. for (unsigned i = 0; i < sizeof(int32_t) - 1; i++) { sink_->Put(kNop, "Padding"); } // Pad up to pointer size for checksum. while (!IsAligned(sink_->Position(), kPointerAlignment)) { sink_->Put(kNop, "Padding"); } } void Serializer::InitializeCodeAddressMap() { isolate_->InitializeLoggingAndCounters(); code_address_map_ = new CodeAddressMap(isolate_); } ScriptData* CodeSerializer::Serialize(Isolate* isolate, Handle info, Handle source) { base::ElapsedTimer timer; if (FLAG_profile_deserialization) timer.Start(); if (FLAG_trace_serializer) { PrintF("[Serializing from"); Object* script = info->script(); if (script->IsScript()) Script::cast(script)->name()->ShortPrint(); PrintF("]\n"); } // Serialize code object. SnapshotByteSink sink(info->code()->CodeSize() * 2); CodeSerializer cs(isolate, &sink, *source, info->code()); DisallowHeapAllocation no_gc; Object** location = Handle::cast(info).location(); cs.VisitPointer(location); cs.Pad(); SerializedCodeData data(sink.data(), cs); ScriptData* script_data = data.GetScriptData(); if (FLAG_profile_deserialization) { double ms = timer.Elapsed().InMillisecondsF(); int length = script_data->length(); PrintF("[Serializing to %d bytes took %0.3f ms]\n", length, ms); } return script_data; } void CodeSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code, WhereToPoint where_to_point, int skip) { 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 (SerializeKnownObject(obj, how_to_code, where_to_point, skip)) return; FlushSkip(skip); if (obj->IsCode()) { Code* code_object = Code::cast(obj); switch (code_object->kind()) { case Code::OPTIMIZED_FUNCTION: // No optimized code compiled yet. case Code::HANDLER: // No handlers patched in yet. case Code::REGEXP: // No regexp literals initialized yet. case Code::NUMBER_OF_KINDS: // Pseudo enum value. CHECK(false); case Code::BUILTIN: SerializeBuiltin(code_object->builtin_index(), how_to_code, where_to_point); return; case Code::STUB: SerializeCodeStub(code_object->stub_key(), how_to_code, where_to_point); return; #define IC_KIND_CASE(KIND) case Code::KIND: IC_KIND_LIST(IC_KIND_CASE) #undef IC_KIND_CASE SerializeIC(code_object, how_to_code, where_to_point); return; case Code::FUNCTION: DCHECK(code_object->has_reloc_info_for_serialization()); // Only serialize the code for the toplevel function unless specified // by flag. Replace code of inner functions by the lazy compile builtin. // This is safe, as checked in Compiler::BuildFunctionInfo. if (code_object != main_code_ && !FLAG_serialize_inner) { SerializeBuiltin(Builtins::kCompileLazy, how_to_code, where_to_point); } else { SerializeGeneric(code_object, how_to_code, where_to_point); } return; } UNREACHABLE(); } // Past this point we should not see any (context-specific) maps anymore. CHECK(!obj->IsMap()); // There should be no references to the global object embedded. CHECK(!obj->IsJSGlobalProxy() && !obj->IsGlobalObject()); // There should be no hash table embedded. They would require rehashing. CHECK(!obj->IsHashTable()); // We expect no instantiated function objects or contexts. CHECK(!obj->IsJSFunction() && !obj->IsContext()); SerializeGeneric(obj, how_to_code, where_to_point); } void CodeSerializer::SerializeGeneric(HeapObject* heap_object, HowToCode how_to_code, WhereToPoint where_to_point) { if (heap_object->IsInternalizedString()) num_internalized_strings_++; // Object has not yet been serialized. Serialize it here. ObjectSerializer serializer(this, heap_object, sink_, how_to_code, where_to_point); serializer.Serialize(); } void CodeSerializer::SerializeBuiltin(int builtin_index, HowToCode how_to_code, WhereToPoint where_to_point) { DCHECK((how_to_code == kPlain && where_to_point == kStartOfObject) || (how_to_code == kPlain && where_to_point == kInnerPointer) || (how_to_code == kFromCode && where_to_point == kInnerPointer)); DCHECK_LT(builtin_index, Builtins::builtin_count); DCHECK_LE(0, builtin_index); if (FLAG_trace_serializer) { PrintF(" Encoding builtin: %s\n", isolate()->builtins()->name(builtin_index)); } sink_->Put(kBuiltin + how_to_code + where_to_point, "Builtin"); sink_->PutInt(builtin_index, "builtin_index"); } void CodeSerializer::SerializeCodeStub(uint32_t stub_key, HowToCode how_to_code, WhereToPoint where_to_point) { DCHECK((how_to_code == kPlain && where_to_point == kStartOfObject) || (how_to_code == kPlain && where_to_point == kInnerPointer) || (how_to_code == kFromCode && where_to_point == kInnerPointer)); DCHECK(CodeStub::MajorKeyFromKey(stub_key) != CodeStub::NoCache); DCHECK(!CodeStub::GetCode(isolate(), stub_key).is_null()); int index = AddCodeStubKey(stub_key) + kCodeStubsBaseIndex; if (FLAG_trace_serializer) { PrintF(" Encoding code stub %s as %d\n", CodeStub::MajorName(CodeStub::MajorKeyFromKey(stub_key), false), index); } sink_->Put(kAttachedReference + how_to_code + where_to_point, "CodeStub"); sink_->PutInt(index, "CodeStub key"); } void CodeSerializer::SerializeIC(Code* ic, HowToCode how_to_code, WhereToPoint where_to_point) { // The IC may be implemented as a stub. uint32_t stub_key = ic->stub_key(); if (stub_key != CodeStub::NoCacheKey()) { if (FLAG_trace_serializer) { PrintF(" %s is a code stub\n", Code::Kind2String(ic->kind())); } SerializeCodeStub(stub_key, how_to_code, where_to_point); return; } // The IC may be implemented as builtin. Only real builtins have an // actual builtin_index value attached (otherwise it's just garbage). // Compare to make sure we are really dealing with a builtin. int builtin_index = ic->builtin_index(); if (builtin_index < Builtins::builtin_count) { Builtins::Name name = static_cast(builtin_index); Code* builtin = isolate()->builtins()->builtin(name); if (builtin == ic) { if (FLAG_trace_serializer) { PrintF(" %s is a builtin\n", Code::Kind2String(ic->kind())); } DCHECK(ic->kind() == Code::KEYED_LOAD_IC || ic->kind() == Code::KEYED_STORE_IC); SerializeBuiltin(builtin_index, how_to_code, where_to_point); return; } } // The IC may also just be a piece of code kept in the non_monomorphic_cache. // In that case, just serialize as a normal code object. if (FLAG_trace_serializer) { PrintF(" %s has no special handling\n", Code::Kind2String(ic->kind())); } DCHECK(ic->kind() == Code::LOAD_IC || ic->kind() == Code::STORE_IC); SerializeGeneric(ic, how_to_code, where_to_point); } int CodeSerializer::AddCodeStubKey(uint32_t stub_key) { // TODO(yangguo) Maybe we need a hash table for a faster lookup than O(n^2). int index = 0; while (index < stub_keys_.length()) { if (stub_keys_[index] == stub_key) return index; index++; } stub_keys_.Add(stub_key); return index; } MaybeHandle CodeSerializer::Deserialize( Isolate* isolate, ScriptData* cached_data, Handle source) { base::ElapsedTimer timer; if (FLAG_profile_deserialization) timer.Start(); HandleScope scope(isolate); SmartPointer scd( SerializedCodeData::FromCachedData(cached_data, *source)); if (scd.is_empty()) { if (FLAG_profile_deserialization) PrintF("[Cached code failed check]\n"); DCHECK(cached_data->rejected()); return MaybeHandle(); } // Eagerly expand string table to avoid allocations during deserialization. StringTable::EnsureCapacityForDeserialization(isolate, scd->NumInternalizedStrings()); // Prepare and register list of attached objects. Vector code_stub_keys = scd->CodeStubKeys(); Vector > attached_objects = Vector >::New( code_stub_keys.length() + kCodeStubsBaseIndex); attached_objects[kSourceObjectIndex] = source; for (int i = 0; i < code_stub_keys.length(); i++) { attached_objects[i + kCodeStubsBaseIndex] = CodeStub::GetCode(isolate, code_stub_keys[i]).ToHandleChecked(); } Deserializer deserializer(scd.get()); deserializer.SetAttachedObjects(attached_objects); // Deserialize. Handle result; if (!deserializer.DeserializeCode(isolate).ToHandle(&result)) { // Deserializing may fail if the reservations cannot be fulfilled. if (FLAG_profile_deserialization) PrintF("[Deserializing failed]\n"); return MaybeHandle(); } deserializer.FlushICacheForNewCodeObjects(); if (FLAG_profile_deserialization) { double ms = timer.Elapsed().InMillisecondsF(); int length = cached_data->length(); PrintF("[Deserializing from %d bytes took %0.3f ms]\n", length, ms); } result->set_deserialized(true); if (isolate->logger()->is_logging_code_events() || isolate->cpu_profiler()->is_profiling()) { String* name = isolate->heap()->empty_string(); if (result->script()->IsScript()) { Script* script = Script::cast(result->script()); if (script->name()->IsString()) name = String::cast(script->name()); } isolate->logger()->CodeCreateEvent(Logger::SCRIPT_TAG, result->code(), *result, NULL, name); } return scope.CloseAndEscape(result); } void SerializedData::AllocateData(int size) { DCHECK(!owns_data_); data_ = NewArray(size); size_ = size; owns_data_ = true; DCHECK(IsAligned(reinterpret_cast(data_), kPointerAlignment)); } SnapshotData::SnapshotData(const SnapshotByteSink& sink, const Serializer& ser) { DisallowHeapAllocation no_gc; List reservations; ser.EncodeReservations(&reservations); const List& payload = sink.data(); // Calculate sizes. int reservation_size = reservations.length() * kInt32Size; int size = kHeaderSize + reservation_size + payload.length(); // Allocate backing store and create result data. AllocateData(size); // Set header values. SetHeaderValue(kCheckSumOffset, Version::Hash()); SetHeaderValue(kNumReservationsOffset, reservations.length()); SetHeaderValue(kPayloadLengthOffset, payload.length()); // Copy reservation chunk sizes. CopyBytes(data_ + kHeaderSize, reinterpret_cast(reservations.begin()), reservation_size); // Copy serialized data. CopyBytes(data_ + kHeaderSize + reservation_size, payload.begin(), static_cast(payload.length())); } bool SnapshotData::IsSane() { return GetHeaderValue(kCheckSumOffset) == Version::Hash(); } Vector SnapshotData::Reservations() const { return Vector( reinterpret_cast(data_ + kHeaderSize), GetHeaderValue(kNumReservationsOffset)); } Vector SnapshotData::Payload() const { int reservations_size = GetHeaderValue(kNumReservationsOffset) * kInt32Size; const byte* payload = data_ + kHeaderSize + reservations_size; int length = GetHeaderValue(kPayloadLengthOffset); DCHECK_EQ(data_ + size_, payload + length); return Vector(payload, length); } class Checksum { public: explicit Checksum(Vector payload) { // Fletcher's checksum. Modified to reduce 64-bit sums to 32-bit. uintptr_t a = 1; uintptr_t b = 0; const uintptr_t* cur = reinterpret_cast(payload.start()); DCHECK(IsAligned(payload.length(), kIntptrSize)); const uintptr_t* end = cur + payload.length() / kIntptrSize; while (cur < end) { // Unsigned overflow expected and intended. a += *cur++; b += a; } #if V8_HOST_ARCH_64_BIT a ^= a >> 32; b ^= b >> 32; #endif // V8_HOST_ARCH_64_BIT a_ = static_cast(a); b_ = static_cast(b); } bool Check(uint32_t a, uint32_t b) const { return a == a_ && b == b_; } uint32_t a() const { return a_; } uint32_t b() const { return b_; } private: uint32_t a_; uint32_t b_; DISALLOW_COPY_AND_ASSIGN(Checksum); }; SerializedCodeData::SerializedCodeData(const List& payload, const CodeSerializer& cs) { DisallowHeapAllocation no_gc; const List* stub_keys = cs.stub_keys(); List reservations; cs.EncodeReservations(&reservations); // Calculate sizes. int reservation_size = reservations.length() * kInt32Size; int num_stub_keys = stub_keys->length(); int stub_keys_size = stub_keys->length() * kInt32Size; int payload_offset = kHeaderSize + reservation_size + stub_keys_size; int padded_payload_offset = POINTER_SIZE_ALIGN(payload_offset); int size = padded_payload_offset + payload.length(); // Allocate backing store and create result data. AllocateData(size); // Set header values. SetHeaderValue(kMagicNumberOffset, kMagicNumber); SetHeaderValue(kVersionHashOffset, Version::Hash()); SetHeaderValue(kSourceHashOffset, SourceHash(cs.source())); SetHeaderValue(kCpuFeaturesOffset, static_cast(CpuFeatures::SupportedFeatures())); SetHeaderValue(kFlagHashOffset, FlagList::Hash()); SetHeaderValue(kNumInternalizedStringsOffset, cs.num_internalized_strings()); SetHeaderValue(kNumReservationsOffset, reservations.length()); SetHeaderValue(kNumCodeStubKeysOffset, num_stub_keys); SetHeaderValue(kPayloadLengthOffset, payload.length()); Checksum checksum(payload.ToConstVector()); SetHeaderValue(kChecksum1Offset, checksum.a()); SetHeaderValue(kChecksum2Offset, checksum.b()); // Copy reservation chunk sizes. CopyBytes(data_ + kHeaderSize, reinterpret_cast(reservations.begin()), reservation_size); // Copy code stub keys. CopyBytes(data_ + kHeaderSize + reservation_size, reinterpret_cast(stub_keys->begin()), stub_keys_size); memset(data_ + payload_offset, 0, padded_payload_offset - payload_offset); // Copy serialized data. CopyBytes(data_ + padded_payload_offset, payload.begin(), static_cast(payload.length())); } SerializedCodeData::SanityCheckResult SerializedCodeData::SanityCheck( String* source) const { uint32_t magic_number = GetHeaderValue(kMagicNumberOffset); uint32_t version_hash = GetHeaderValue(kVersionHashOffset); uint32_t source_hash = GetHeaderValue(kSourceHashOffset); uint32_t cpu_features = GetHeaderValue(kCpuFeaturesOffset); uint32_t flags_hash = GetHeaderValue(kFlagHashOffset); uint32_t c1 = GetHeaderValue(kChecksum1Offset); uint32_t c2 = GetHeaderValue(kChecksum2Offset); if (magic_number != kMagicNumber) return MAGIC_NUMBER_MISMATCH; if (version_hash != Version::Hash()) return VERSION_MISMATCH; if (source_hash != SourceHash(source)) return SOURCE_MISMATCH; if (cpu_features != static_cast(CpuFeatures::SupportedFeatures())) { return CPU_FEATURES_MISMATCH; } if (flags_hash != FlagList::Hash()) return FLAGS_MISMATCH; if (!Checksum(Payload()).Check(c1, c2)) return CHECKSUM_MISMATCH; return CHECK_SUCCESS; } // Return ScriptData object and relinquish ownership over it to the caller. ScriptData* SerializedCodeData::GetScriptData() { DCHECK(owns_data_); ScriptData* result = new ScriptData(data_, size_); result->AcquireDataOwnership(); owns_data_ = false; data_ = NULL; return result; } Vector SerializedCodeData::Reservations() const { return Vector( reinterpret_cast(data_ + kHeaderSize), GetHeaderValue(kNumReservationsOffset)); } Vector SerializedCodeData::Payload() const { int reservations_size = GetHeaderValue(kNumReservationsOffset) * kInt32Size; int code_stubs_size = GetHeaderValue(kNumCodeStubKeysOffset) * kInt32Size; int payload_offset = kHeaderSize + reservations_size + code_stubs_size; int padded_payload_offset = POINTER_SIZE_ALIGN(payload_offset); const byte* payload = data_ + padded_payload_offset; DCHECK(IsAligned(reinterpret_cast(payload), kPointerAlignment)); int length = GetHeaderValue(kPayloadLengthOffset); DCHECK_EQ(data_ + size_, payload + length); return Vector(payload, length); } int SerializedCodeData::NumInternalizedStrings() const { return GetHeaderValue(kNumInternalizedStringsOffset); } Vector SerializedCodeData::CodeStubKeys() const { int reservations_size = GetHeaderValue(kNumReservationsOffset) * kInt32Size; const byte* start = data_ + kHeaderSize + reservations_size; return Vector(reinterpret_cast(start), GetHeaderValue(kNumCodeStubKeysOffset)); } SerializedCodeData::SerializedCodeData(ScriptData* data) : SerializedData(const_cast(data->data()), data->length()) {} SerializedCodeData* SerializedCodeData::FromCachedData(ScriptData* cached_data, String* source) { DisallowHeapAllocation no_gc; SerializedCodeData* scd = new SerializedCodeData(cached_data); SanityCheckResult r = scd->SanityCheck(source); if (r == CHECK_SUCCESS) return scd; cached_data->Reject(); source->GetIsolate()->counters()->code_cache_reject_reason()->AddSample(r); delete scd; return NULL; } } } // namespace v8::internal