// 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. #ifndef V8_HEAP_HEAP_H_ #define V8_HEAP_HEAP_H_ #include #include // Clients of this interface shouldn't depend on lots of heap internals. // Do not include anything from src/heap here! #include "src/allocation.h" #include "src/assert-scope.h" #include "src/atomic-utils.h" #include "src/globals.h" // TODO(mstarzinger): Two more includes to kill! #include "src/heap/spaces.h" #include "src/heap/store-buffer.h" #include "src/list.h" namespace v8 { namespace internal { // Defines all the roots in Heap. #define STRONG_ROOT_LIST(V) \ V(Map, byte_array_map, ByteArrayMap) \ V(Map, free_space_map, FreeSpaceMap) \ V(Map, one_pointer_filler_map, OnePointerFillerMap) \ V(Map, two_pointer_filler_map, TwoPointerFillerMap) \ /* Cluster the most popular ones in a few cache lines here at the top. */ \ V(Smi, store_buffer_top, StoreBufferTop) \ V(Oddball, undefined_value, UndefinedValue) \ V(Oddball, the_hole_value, TheHoleValue) \ V(Oddball, null_value, NullValue) \ V(Oddball, true_value, TrueValue) \ V(Oddball, false_value, FalseValue) \ V(String, empty_string, empty_string) \ V(String, hidden_string, hidden_string) \ V(Oddball, uninitialized_value, UninitializedValue) \ V(Map, cell_map, CellMap) \ V(Map, global_property_cell_map, GlobalPropertyCellMap) \ V(Map, shared_function_info_map, SharedFunctionInfoMap) \ V(Map, meta_map, MetaMap) \ V(Map, heap_number_map, HeapNumberMap) \ V(Map, mutable_heap_number_map, MutableHeapNumberMap) \ V(Map, float32x4_map, Float32x4Map) \ V(Map, int32x4_map, Int32x4Map) \ V(Map, uint32x4_map, Uint32x4Map) \ V(Map, bool32x4_map, Bool32x4Map) \ V(Map, int16x8_map, Int16x8Map) \ V(Map, uint16x8_map, Uint16x8Map) \ V(Map, bool16x8_map, Bool16x8Map) \ V(Map, int8x16_map, Int8x16Map) \ V(Map, uint8x16_map, Uint8x16Map) \ V(Map, bool8x16_map, Bool8x16Map) \ V(Map, native_context_map, NativeContextMap) \ V(Map, fixed_array_map, FixedArrayMap) \ V(Map, code_map, CodeMap) \ V(Map, scope_info_map, ScopeInfoMap) \ V(Map, fixed_cow_array_map, FixedCOWArrayMap) \ V(Map, fixed_double_array_map, FixedDoubleArrayMap) \ V(Map, weak_cell_map, WeakCellMap) \ V(Map, one_byte_string_map, OneByteStringMap) \ V(Map, one_byte_internalized_string_map, OneByteInternalizedStringMap) \ V(Map, function_context_map, FunctionContextMap) \ V(FixedArray, empty_fixed_array, EmptyFixedArray) \ V(ByteArray, empty_byte_array, EmptyByteArray) \ V(DescriptorArray, empty_descriptor_array, EmptyDescriptorArray) \ /* The roots above this line should be boring from a GC point of view. */ \ /* This means they are never in new space and never on a page that is */ \ /* being compacted. */ \ V(Oddball, no_interceptor_result_sentinel, NoInterceptorResultSentinel) \ V(Oddball, arguments_marker, ArgumentsMarker) \ V(Oddball, exception, Exception) \ V(Oddball, termination_exception, TerminationException) \ V(FixedArray, number_string_cache, NumberStringCache) \ V(Object, instanceof_cache_function, InstanceofCacheFunction) \ V(Object, instanceof_cache_map, InstanceofCacheMap) \ V(Object, instanceof_cache_answer, InstanceofCacheAnswer) \ V(FixedArray, single_character_string_cache, SingleCharacterStringCache) \ V(FixedArray, string_split_cache, StringSplitCache) \ V(FixedArray, regexp_multiple_cache, RegExpMultipleCache) \ V(Smi, hash_seed, HashSeed) \ V(Map, hash_table_map, HashTableMap) \ V(Map, ordered_hash_table_map, OrderedHashTableMap) \ V(Map, symbol_map, SymbolMap) \ V(Map, string_map, StringMap) \ V(Map, cons_one_byte_string_map, ConsOneByteStringMap) \ V(Map, cons_string_map, ConsStringMap) \ V(Map, sliced_string_map, SlicedStringMap) \ V(Map, sliced_one_byte_string_map, SlicedOneByteStringMap) \ V(Map, external_string_map, ExternalStringMap) \ V(Map, external_string_with_one_byte_data_map, \ ExternalStringWithOneByteDataMap) \ V(Map, external_one_byte_string_map, ExternalOneByteStringMap) \ V(Map, native_source_string_map, NativeSourceStringMap) \ V(Map, short_external_string_map, ShortExternalStringMap) \ V(Map, short_external_string_with_one_byte_data_map, \ ShortExternalStringWithOneByteDataMap) \ V(Map, internalized_string_map, InternalizedStringMap) \ V(Map, external_internalized_string_map, ExternalInternalizedStringMap) \ V(Map, external_internalized_string_with_one_byte_data_map, \ ExternalInternalizedStringWithOneByteDataMap) \ V(Map, external_one_byte_internalized_string_map, \ ExternalOneByteInternalizedStringMap) \ V(Map, short_external_internalized_string_map, \ ShortExternalInternalizedStringMap) \ V(Map, short_external_internalized_string_with_one_byte_data_map, \ ShortExternalInternalizedStringWithOneByteDataMap) \ V(Map, short_external_one_byte_internalized_string_map, \ ShortExternalOneByteInternalizedStringMap) \ V(Map, short_external_one_byte_string_map, ShortExternalOneByteStringMap) \ V(Map, fixed_uint8_array_map, FixedUint8ArrayMap) \ V(Map, fixed_int8_array_map, FixedInt8ArrayMap) \ V(Map, fixed_uint16_array_map, FixedUint16ArrayMap) \ V(Map, fixed_int16_array_map, FixedInt16ArrayMap) \ V(Map, fixed_uint32_array_map, FixedUint32ArrayMap) \ V(Map, fixed_int32_array_map, FixedInt32ArrayMap) \ V(Map, fixed_float32_array_map, FixedFloat32ArrayMap) \ V(Map, fixed_float64_array_map, FixedFloat64ArrayMap) \ V(Map, fixed_uint8_clamped_array_map, FixedUint8ClampedArrayMap) \ V(FixedTypedArrayBase, empty_fixed_uint8_array, EmptyFixedUint8Array) \ V(FixedTypedArrayBase, empty_fixed_int8_array, EmptyFixedInt8Array) \ V(FixedTypedArrayBase, empty_fixed_uint16_array, EmptyFixedUint16Array) \ V(FixedTypedArrayBase, empty_fixed_int16_array, EmptyFixedInt16Array) \ V(FixedTypedArrayBase, empty_fixed_uint32_array, EmptyFixedUint32Array) \ V(FixedTypedArrayBase, empty_fixed_int32_array, EmptyFixedInt32Array) \ V(FixedTypedArrayBase, empty_fixed_float32_array, EmptyFixedFloat32Array) \ V(FixedTypedArrayBase, empty_fixed_float64_array, EmptyFixedFloat64Array) \ V(FixedTypedArrayBase, empty_fixed_uint8_clamped_array, \ EmptyFixedUint8ClampedArray) \ V(Map, sloppy_arguments_elements_map, SloppyArgumentsElementsMap) \ V(Map, catch_context_map, CatchContextMap) \ V(Map, with_context_map, WithContextMap) \ V(Map, block_context_map, BlockContextMap) \ V(Map, module_context_map, ModuleContextMap) \ V(Map, script_context_map, ScriptContextMap) \ V(Map, script_context_table_map, ScriptContextTableMap) \ V(Map, undefined_map, UndefinedMap) \ V(Map, the_hole_map, TheHoleMap) \ V(Map, null_map, NullMap) \ V(Map, boolean_map, BooleanMap) \ V(Map, uninitialized_map, UninitializedMap) \ V(Map, arguments_marker_map, ArgumentsMarkerMap) \ V(Map, no_interceptor_result_sentinel_map, NoInterceptorResultSentinelMap) \ V(Map, exception_map, ExceptionMap) \ V(Map, termination_exception_map, TerminationExceptionMap) \ V(Map, message_object_map, JSMessageObjectMap) \ V(Map, foreign_map, ForeignMap) \ V(Map, neander_map, NeanderMap) \ V(Map, external_map, ExternalMap) \ V(HeapNumber, nan_value, NanValue) \ V(HeapNumber, infinity_value, InfinityValue) \ V(HeapNumber, minus_zero_value, MinusZeroValue) \ V(HeapNumber, minus_infinity_value, MinusInfinityValue) \ V(JSObject, message_listeners, MessageListeners) \ V(UnseededNumberDictionary, code_stubs, CodeStubs) \ V(UnseededNumberDictionary, non_monomorphic_cache, NonMonomorphicCache) \ V(PolymorphicCodeCache, polymorphic_code_cache, PolymorphicCodeCache) \ V(Code, js_entry_code, JsEntryCode) \ V(Code, js_construct_entry_code, JsConstructEntryCode) \ V(FixedArray, natives_source_cache, NativesSourceCache) \ V(FixedArray, experimental_natives_source_cache, \ ExperimentalNativesSourceCache) \ V(FixedArray, extra_natives_source_cache, ExtraNativesSourceCache) \ V(FixedArray, experimental_extra_natives_source_cache, \ ExperimentalExtraNativesSourceCache) \ V(FixedArray, code_stub_natives_source_cache, CodeStubNativesSourceCache) \ V(Script, empty_script, EmptyScript) \ V(NameDictionary, intrinsic_function_names, IntrinsicFunctionNames) \ V(Cell, undefined_cell, UndefinedCell) \ V(JSObject, observation_state, ObservationState) \ V(Object, symbol_registry, SymbolRegistry) \ V(Object, script_list, ScriptList) \ V(SeededNumberDictionary, empty_slow_element_dictionary, \ EmptySlowElementDictionary) \ V(FixedArray, materialized_objects, MaterializedObjects) \ V(FixedArray, allocation_sites_scratchpad, AllocationSitesScratchpad) \ V(FixedArray, microtask_queue, MicrotaskQueue) \ V(TypeFeedbackVector, dummy_vector, DummyVector) \ V(FixedArray, detached_contexts, DetachedContexts) \ V(ArrayList, retained_maps, RetainedMaps) \ V(WeakHashTable, weak_object_to_code_table, WeakObjectToCodeTable) \ V(PropertyCell, array_protector, ArrayProtector) \ V(PropertyCell, empty_property_cell, EmptyPropertyCell) \ V(Object, weak_stack_trace_list, WeakStackTraceList) \ V(Object, code_stub_context, CodeStubContext) \ V(JSObject, code_stub_exports_object, CodeStubExportsObject) \ V(Object, noscript_shared_function_infos, NoScriptSharedFunctionInfos) \ V(FixedArray, interpreter_table, InterpreterTable) \ V(Map, bytecode_array_map, BytecodeArrayMap) \ V(BytecodeArray, empty_bytecode_array, EmptyBytecodeArray) // Entries in this list are limited to Smis and are not visited during GC. #define SMI_ROOT_LIST(V) \ V(Smi, stack_limit, StackLimit) \ V(Smi, real_stack_limit, RealStackLimit) \ V(Smi, last_script_id, LastScriptId) \ V(Smi, arguments_adaptor_deopt_pc_offset, ArgumentsAdaptorDeoptPCOffset) \ V(Smi, construct_stub_deopt_pc_offset, ConstructStubDeoptPCOffset) \ V(Smi, getter_stub_deopt_pc_offset, GetterStubDeoptPCOffset) \ V(Smi, setter_stub_deopt_pc_offset, SetterStubDeoptPCOffset) #define ROOT_LIST(V) \ STRONG_ROOT_LIST(V) \ SMI_ROOT_LIST(V) \ V(StringTable, string_table, StringTable) #define INTERNALIZED_STRING_LIST(V) \ V(anonymous_string, "anonymous") \ V(arguments_string, "arguments") \ V(Arguments_string, "Arguments") \ V(Array_string, "Array") \ V(bool16x8_string, "bool16x8") \ V(Bool16x8_string, "Bool16x8") \ V(bool32x4_string, "bool32x4") \ V(Bool32x4_string, "Bool32x4") \ V(bool8x16_string, "bool8x16") \ V(Bool8x16_string, "Bool8x16") \ V(boolean_string, "boolean") \ V(Boolean_string, "Boolean") \ V(byte_length_string, "byteLength") \ V(byte_offset_string, "byteOffset") \ V(callee_string, "callee") \ V(caller_string, "caller") \ V(cell_value_string, "%cell_value") \ V(char_at_string, "CharAt") \ V(closure_string, "(closure)") \ V(compare_ic_string, "==") \ V(configurable_string, "configurable") \ V(constructor_string, "constructor") \ V(Date_string, "Date") \ V(default_string, "default") \ V(done_string, "done") \ V(dot_result_string, ".result") \ V(dot_string, ".") \ V(enumerable_string, "enumerable") \ V(Error_string, "Error") \ V(eval_string, "eval") \ V(float32x4_string, "float32x4") \ V(Float32x4_string, "Float32x4") \ V(for_api_string, "for_api") \ V(for_string, "for") \ V(function_string, "function") \ V(Function_string, "Function") \ V(Generator_string, "Generator") \ V(get_string, "get") \ V(global_string, "global") \ V(illegal_access_string, "illegal access") \ V(illegal_argument_string, "illegal argument") \ V(index_string, "index") \ V(infinity_string, "Infinity") \ V(input_string, "input") \ V(int16x8_string, "int16x8") \ V(Int16x8_string, "Int16x8") \ V(int32x4_string, "int32x4") \ V(Int32x4_string, "Int32x4") \ V(int8x16_string, "int8x16") \ V(Int8x16_string, "Int8x16") \ V(KeyedLoadMonomorphic_string, "KeyedLoadMonomorphic") \ V(KeyedStoreMonomorphic_string, "KeyedStoreMonomorphic") \ V(last_index_string, "lastIndex") \ V(length_string, "length") \ V(Map_string, "Map") \ V(minus_infinity_string, "-Infinity") \ V(minus_zero_string, "-0") \ V(name_string, "name") \ V(nan_string, "NaN") \ V(next_string, "next") \ V(null_string, "null") \ V(number_string, "number") \ V(Number_string, "Number") \ V(object_string, "object") \ V(Object_string, "Object") \ V(private_api_string, "private_api") \ V(proto_string, "__proto__") \ V(prototype_string, "prototype") \ V(query_colon_string, "(?:)") \ V(RegExp_string, "RegExp") \ V(set_string, "set") \ V(Set_string, "Set") \ V(source_mapping_url_string, "source_mapping_url") \ V(source_string, "source") \ V(source_url_string, "source_url") \ V(stack_string, "stack") \ V(strict_compare_ic_string, "===") \ V(string_string, "string") \ V(String_string, "String") \ V(symbol_string, "symbol") \ V(Symbol_string, "Symbol") \ V(this_string, "this") \ V(throw_string, "throw") \ V(toJSON_string, "toJSON") \ V(toString_string, "toString") \ V(uint16x8_string, "uint16x8") \ V(Uint16x8_string, "Uint16x8") \ V(uint32x4_string, "uint32x4") \ V(Uint32x4_string, "Uint32x4") \ V(uint8x16_string, "uint8x16") \ V(Uint8x16_string, "Uint8x16") \ V(undefined_string, "undefined") \ V(valueOf_string, "valueOf") \ V(value_string, "value") \ V(WeakMap_string, "WeakMap") \ V(WeakSet_string, "WeakSet") \ V(writable_string, "writable") #define PRIVATE_SYMBOL_LIST(V) \ V(array_iteration_kind_symbol) \ V(array_iterator_next_symbol) \ V(array_iterator_object_symbol) \ V(call_site_function_symbol) \ V(call_site_position_symbol) \ V(call_site_receiver_symbol) \ V(call_site_strict_symbol) \ V(class_end_position_symbol) \ V(class_start_position_symbol) \ V(detailed_stack_trace_symbol) \ V(elements_transition_symbol) \ V(error_end_pos_symbol) \ V(error_script_symbol) \ V(error_start_pos_symbol) \ V(formatted_stack_trace_symbol) \ V(frozen_symbol) \ V(hash_code_symbol) \ V(home_object_symbol) \ V(internal_error_symbol) \ V(intl_impl_object_symbol) \ V(intl_initialized_marker_symbol) \ V(megamorphic_symbol) \ V(nonexistent_symbol) \ V(nonextensible_symbol) \ V(normal_ic_symbol) \ V(not_mapped_symbol) \ V(observed_symbol) \ V(premonomorphic_symbol) \ V(promise_combined_deferred_symbol) \ V(promise_debug_marker_symbol) \ V(promise_has_handler_symbol) \ V(promise_on_resolve_symbol) \ V(promise_on_reject_symbol) \ V(promise_raw_symbol) \ V(promise_status_symbol) \ V(promise_value_symbol) \ V(regexp_flags_symbol) \ V(regexp_source_symbol) \ V(sealed_symbol) \ V(stack_trace_symbol) \ V(string_iterator_iterated_string_symbol) \ V(string_iterator_next_index_symbol) \ V(uninitialized_symbol) #define PUBLIC_SYMBOL_LIST(V) \ V(has_instance_symbol, Symbol.hasInstance) \ V(iterator_symbol, Symbol.iterator) \ V(match_symbol, Symbol.match) \ V(replace_symbol, Symbol.replace) \ V(search_symbol, Symbol.search) \ V(split_symbol, Symbol.split) \ V(to_primitive_symbol, Symbol.toPrimitive) \ V(unscopables_symbol, Symbol.unscopables) // Well-Known Symbols are "Public" symbols, which have a bit set which causes // them to produce an undefined value when a load results in a failed access // check. Because this behaviour is not specified properly as of yet, it only // applies to a subset of spec-defined Well-Known Symbols. #define WELL_KNOWN_SYMBOL_LIST(V) \ V(is_concat_spreadable_symbol, Symbol.isConcatSpreadable) \ V(to_string_tag_symbol, Symbol.toStringTag) // Heap roots that are known to be immortal immovable, for which we can safely // skip write barriers. This list is not complete and has omissions. #define IMMORTAL_IMMOVABLE_ROOT_LIST(V) \ V(ByteArrayMap) \ V(BytecodeArrayMap) \ V(FreeSpaceMap) \ V(OnePointerFillerMap) \ V(TwoPointerFillerMap) \ V(UndefinedValue) \ V(TheHoleValue) \ V(NullValue) \ V(TrueValue) \ V(FalseValue) \ V(UninitializedValue) \ V(CellMap) \ V(GlobalPropertyCellMap) \ V(SharedFunctionInfoMap) \ V(MetaMap) \ V(HeapNumberMap) \ V(MutableHeapNumberMap) \ V(Float32x4Map) \ V(Int32x4Map) \ V(Uint32x4Map) \ V(Bool32x4Map) \ V(Int16x8Map) \ V(Uint16x8Map) \ V(Bool16x8Map) \ V(Int8x16Map) \ V(Uint8x16Map) \ V(Bool8x16Map) \ V(NativeContextMap) \ V(FixedArrayMap) \ V(CodeMap) \ V(ScopeInfoMap) \ V(FixedCOWArrayMap) \ V(FixedDoubleArrayMap) \ V(WeakCellMap) \ V(NoInterceptorResultSentinel) \ V(HashTableMap) \ V(OrderedHashTableMap) \ V(EmptyFixedArray) \ V(EmptyByteArray) \ V(EmptyBytecodeArray) \ V(EmptyDescriptorArray) \ V(ArgumentsMarker) \ V(SymbolMap) \ V(SloppyArgumentsElementsMap) \ V(FunctionContextMap) \ V(CatchContextMap) \ V(WithContextMap) \ V(BlockContextMap) \ V(ModuleContextMap) \ V(ScriptContextMap) \ V(UndefinedMap) \ V(TheHoleMap) \ V(NullMap) \ V(BooleanMap) \ V(UninitializedMap) \ V(ArgumentsMarkerMap) \ V(JSMessageObjectMap) \ V(ForeignMap) \ V(NeanderMap) \ V(empty_string) \ PRIVATE_SYMBOL_LIST(V) // Forward declarations. class ArrayBufferTracker; class GCIdleTimeAction; class GCIdleTimeHandler; class GCIdleTimeHeapState; class GCTracer; class HeapObjectsFilter; class HeapStats; class HistogramTimer; class Isolate; class MemoryReducer; class ObjectStats; class Scavenger; class ScavengeJob; class WeakObjectRetainer; // A queue of objects promoted during scavenge. Each object is accompanied // by it's size to avoid dereferencing a map pointer for scanning. // The last page in to-space is used for the promotion queue. On conflict // during scavenge, the promotion queue is allocated externally and all // entries are copied to the external queue. class PromotionQueue { public: explicit PromotionQueue(Heap* heap) : front_(NULL), rear_(NULL), limit_(NULL), emergency_stack_(0), heap_(heap) {} void Initialize(); void Destroy() { DCHECK(is_empty()); delete emergency_stack_; emergency_stack_ = NULL; } Page* GetHeadPage() { return Page::FromAllocationTop(reinterpret_cast
(rear_)); } void SetNewLimit(Address limit) { // If we are already using an emergency stack, we can ignore it. if (emergency_stack_) return; // If the limit is not on the same page, we can ignore it. if (Page::FromAllocationTop(limit) != GetHeadPage()) return; limit_ = reinterpret_cast(limit); if (limit_ <= rear_) { return; } RelocateQueueHead(); } bool IsBelowPromotionQueue(Address to_space_top) { // If an emergency stack is used, the to-space address cannot interfere // with the promotion queue. if (emergency_stack_) return true; // If the given to-space top pointer and the head of the promotion queue // are not on the same page, then the to-space objects are below the // promotion queue. if (GetHeadPage() != Page::FromAddress(to_space_top)) { return true; } // If the to space top pointer is smaller or equal than the promotion // queue head, then the to-space objects are below the promotion queue. return reinterpret_cast(to_space_top) <= rear_; } bool is_empty() { return (front_ == rear_) && (emergency_stack_ == NULL || emergency_stack_->length() == 0); } inline void insert(HeapObject* target, int size); void remove(HeapObject** target, int* size) { DCHECK(!is_empty()); if (front_ == rear_) { Entry e = emergency_stack_->RemoveLast(); *target = e.obj_; *size = e.size_; return; } *target = reinterpret_cast(*(--front_)); *size = static_cast(*(--front_)); // Assert no underflow. SemiSpace::AssertValidRange(reinterpret_cast
(rear_), reinterpret_cast
(front_)); } private: // The front of the queue is higher in the memory page chain than the rear. intptr_t* front_; intptr_t* rear_; intptr_t* limit_; static const int kEntrySizeInWords = 2; struct Entry { Entry(HeapObject* obj, int size) : obj_(obj), size_(size) {} HeapObject* obj_; int size_; }; List* emergency_stack_; Heap* heap_; void RelocateQueueHead(); DISALLOW_COPY_AND_ASSIGN(PromotionQueue); }; enum ArrayStorageAllocationMode { DONT_INITIALIZE_ARRAY_ELEMENTS, INITIALIZE_ARRAY_ELEMENTS_WITH_HOLE }; class Heap { public: // Declare all the root indices. This defines the root list order. enum RootListIndex { #define ROOT_INDEX_DECLARATION(type, name, camel_name) k##camel_name##RootIndex, STRONG_ROOT_LIST(ROOT_INDEX_DECLARATION) #undef ROOT_INDEX_DECLARATION #define STRING_INDEX_DECLARATION(name, str) k##name##RootIndex, INTERNALIZED_STRING_LIST(STRING_INDEX_DECLARATION) #undef STRING_DECLARATION #define SYMBOL_INDEX_DECLARATION(name) k##name##RootIndex, PRIVATE_SYMBOL_LIST(SYMBOL_INDEX_DECLARATION) #undef SYMBOL_INDEX_DECLARATION #define SYMBOL_INDEX_DECLARATION(name, description) k##name##RootIndex, PUBLIC_SYMBOL_LIST(SYMBOL_INDEX_DECLARATION) WELL_KNOWN_SYMBOL_LIST(SYMBOL_INDEX_DECLARATION) #undef SYMBOL_INDEX_DECLARATION // Utility type maps #define DECLARE_STRUCT_MAP(NAME, Name, name) k##Name##MapRootIndex, STRUCT_LIST(DECLARE_STRUCT_MAP) #undef DECLARE_STRUCT_MAP kStringTableRootIndex, #define ROOT_INDEX_DECLARATION(type, name, camel_name) k##camel_name##RootIndex, SMI_ROOT_LIST(ROOT_INDEX_DECLARATION) #undef ROOT_INDEX_DECLARATION kRootListLength, kStrongRootListLength = kStringTableRootIndex, kSmiRootsStart = kStringTableRootIndex + 1 }; // Indicates whether live bytes adjustment is triggered // - from within the GC code before sweeping started (SEQUENTIAL_TO_SWEEPER), // - or from within GC (CONCURRENT_TO_SWEEPER), // - or mutator code (CONCURRENT_TO_SWEEPER). enum InvocationMode { SEQUENTIAL_TO_SWEEPER, CONCURRENT_TO_SWEEPER }; enum ScratchpadSlotMode { IGNORE_SCRATCHPAD_SLOT, RECORD_SCRATCHPAD_SLOT }; enum HeapState { NOT_IN_GC, SCAVENGE, MARK_COMPACT }; // Taking this lock prevents the GC from entering a phase that relocates // object references. class RelocationLock { public: explicit RelocationLock(Heap* heap) : heap_(heap) { heap_->relocation_mutex_.Lock(); } ~RelocationLock() { heap_->relocation_mutex_.Unlock(); } private: Heap* heap_; }; // Support for partial snapshots. After calling this we have a linear // space to write objects in each space. struct Chunk { uint32_t size; Address start; Address end; }; typedef List Reservation; static const intptr_t kMinimumOldGenerationAllocationLimit = 8 * (Page::kPageSize > MB ? Page::kPageSize : MB); static const int kInitalOldGenerationLimitFactor = 2; #if V8_OS_ANDROID // Don't apply pointer multiplier on Android since it has no swap space and // should instead adapt it's heap size based on available physical memory. static const int kPointerMultiplier = 1; #else static const int kPointerMultiplier = i::kPointerSize / 4; #endif // The new space size has to be a power of 2. Sizes are in MB. static const int kMaxSemiSpaceSizeLowMemoryDevice = 1 * kPointerMultiplier; static const int kMaxSemiSpaceSizeMediumMemoryDevice = 4 * kPointerMultiplier; static const int kMaxSemiSpaceSizeHighMemoryDevice = 8 * kPointerMultiplier; static const int kMaxSemiSpaceSizeHugeMemoryDevice = 8 * kPointerMultiplier; // The old space size has to be a multiple of Page::kPageSize. // Sizes are in MB. static const int kMaxOldSpaceSizeLowMemoryDevice = 128 * kPointerMultiplier; static const int kMaxOldSpaceSizeMediumMemoryDevice = 256 * kPointerMultiplier; static const int kMaxOldSpaceSizeHighMemoryDevice = 512 * kPointerMultiplier; static const int kMaxOldSpaceSizeHugeMemoryDevice = 700 * kPointerMultiplier; // The executable size has to be a multiple of Page::kPageSize. // Sizes are in MB. static const int kMaxExecutableSizeLowMemoryDevice = 96 * kPointerMultiplier; static const int kMaxExecutableSizeMediumMemoryDevice = 192 * kPointerMultiplier; static const int kMaxExecutableSizeHighMemoryDevice = 256 * kPointerMultiplier; static const int kMaxExecutableSizeHugeMemoryDevice = 256 * kPointerMultiplier; static const int kTraceRingBufferSize = 512; static const int kStacktraceBufferSize = 512; static const double kMinHeapGrowingFactor; static const double kMaxHeapGrowingFactor; static const double kMaxHeapGrowingFactorMemoryConstrained; static const double kMaxHeapGrowingFactorIdle; static const double kTargetMutatorUtilization; // Sloppy mode arguments object size. static const int kSloppyArgumentsObjectSize = JSObject::kHeaderSize + 2 * kPointerSize; // Strict mode arguments has no callee so it is smaller. static const int kStrictArgumentsObjectSize = JSObject::kHeaderSize + 1 * kPointerSize; // Indicies for direct access into argument objects. static const int kArgumentsLengthIndex = 0; // callee is only valid in sloppy mode. static const int kArgumentsCalleeIndex = 1; static const int kNoGCFlags = 0; static const int kReduceMemoryFootprintMask = 1; static const int kAbortIncrementalMarkingMask = 2; static const int kFinalizeIncrementalMarkingMask = 4; // Making the heap iterable requires us to abort incremental marking. static const int kMakeHeapIterableMask = kAbortIncrementalMarkingMask; // The roots that have an index less than this are always in old space. static const int kOldSpaceRoots = 0x20; // The minimum size of a HeapObject on the heap. static const int kMinObjectSizeInWords = 2; STATIC_ASSERT(kUndefinedValueRootIndex == Internals::kUndefinedValueRootIndex); STATIC_ASSERT(kNullValueRootIndex == Internals::kNullValueRootIndex); STATIC_ASSERT(kTrueValueRootIndex == Internals::kTrueValueRootIndex); STATIC_ASSERT(kFalseValueRootIndex == Internals::kFalseValueRootIndex); STATIC_ASSERT(kempty_stringRootIndex == Internals::kEmptyStringRootIndex); // Calculates the maximum amount of filler that could be required by the // given alignment. static int GetMaximumFillToAlign(AllocationAlignment alignment); // Calculates the actual amount of filler required for a given address at the // given alignment. static int GetFillToAlign(Address address, AllocationAlignment alignment); template static inline bool IsOneByte(T t, int chars); static void FatalProcessOutOfMemory(const char* location, bool take_snapshot = false); static bool RootIsImmortalImmovable(int root_index); // Checks whether the space is valid. static bool IsValidAllocationSpace(AllocationSpace space); // An object may have an AllocationSite associated with it through a trailing // AllocationMemento. Its feedback should be updated when objects are found // in the heap. static inline void UpdateAllocationSiteFeedback(HeapObject* object, ScratchpadSlotMode mode); // Generated code can embed direct references to non-writable roots if // they are in new space. static bool RootCanBeWrittenAfterInitialization(RootListIndex root_index); // Zapping is needed for verify heap, and always done in debug builds. static inline bool ShouldZapGarbage() { #ifdef DEBUG return true; #else #ifdef VERIFY_HEAP return FLAG_verify_heap; #else return false; #endif #endif } static double HeapGrowingFactor(double gc_speed, double mutator_speed); // Copy block of memory from src to dst. Size of block should be aligned // by pointer size. static inline void CopyBlock(Address dst, Address src, int byte_size); // Optimized version of memmove for blocks with pointer size aligned sizes and // pointer size aligned addresses. static inline void MoveBlock(Address dst, Address src, int byte_size); // Determines a static visitor id based on the given {map} that can then be // stored on the map to facilitate fast dispatch for {StaticVisitorBase}. static int GetStaticVisitorIdForMap(Map* map); // Notifies the heap that is ok to start marking or other activities that // should not happen during deserialization. void NotifyDeserializationComplete(); intptr_t old_generation_allocation_limit() const { return old_generation_allocation_limit_; } bool always_allocate() { return always_allocate_scope_count_.Value() != 0; } Address* NewSpaceAllocationTopAddress() { return new_space_.allocation_top_address(); } Address* NewSpaceAllocationLimitAddress() { return new_space_.allocation_limit_address(); } Address* OldSpaceAllocationTopAddress() { return old_space_->allocation_top_address(); } Address* OldSpaceAllocationLimitAddress() { return old_space_->allocation_limit_address(); } // TODO(hpayer): There is still a missmatch between capacity and actual // committed memory size. bool CanExpandOldGeneration(int size) { return (CommittedOldGenerationMemory() + size) < MaxOldGenerationSize(); } // Clear the Instanceof cache (used when a prototype changes). inline void ClearInstanceofCache(); // Iterates the whole code space to clear all keyed store ICs. void ClearAllKeyedStoreICs(); // FreeSpace objects have a null map after deserialization. Update the map. void RepairFreeListsAfterDeserialization(); // Move len elements within a given array from src_index index to dst_index // index. void MoveElements(FixedArray* array, int dst_index, int src_index, int len); // Initialize a filler object to keep the ability to iterate over the heap // when introducing gaps within pages. void CreateFillerObjectAt(Address addr, int size); bool CanMoveObjectStart(HeapObject* object); // Maintain consistency of live bytes during incremental marking. void AdjustLiveBytes(HeapObject* object, int by, InvocationMode mode); // Trim the given array from the left. Note that this relocates the object // start and hence is only valid if there is only a single reference to it. FixedArrayBase* LeftTrimFixedArray(FixedArrayBase* obj, int elements_to_trim); // Trim the given array from the right. template void RightTrimFixedArray(FixedArrayBase* obj, int elements_to_trim); // Converts the given boolean condition to JavaScript boolean value. inline Object* ToBoolean(bool condition); // Check whether the heap is currently iterable. bool IsHeapIterable(); // Notify the heap that a context has been disposed. int NotifyContextDisposed(bool dependant_context); inline void increment_scan_on_scavenge_pages() { scan_on_scavenge_pages_++; if (FLAG_gc_verbose) { PrintF("Scan-on-scavenge pages: %d\n", scan_on_scavenge_pages_); } } inline void decrement_scan_on_scavenge_pages() { scan_on_scavenge_pages_--; if (FLAG_gc_verbose) { PrintF("Scan-on-scavenge pages: %d\n", scan_on_scavenge_pages_); } } void set_native_contexts_list(Object* object) { native_contexts_list_ = object; } Object* native_contexts_list() const { return native_contexts_list_; } void set_allocation_sites_list(Object* object) { allocation_sites_list_ = object; } Object* allocation_sites_list() { return allocation_sites_list_; } // Used in CreateAllocationSiteStub and the (de)serializer. Object** allocation_sites_list_address() { return &allocation_sites_list_; } void set_encountered_weak_collections(Object* weak_collection) { encountered_weak_collections_ = weak_collection; } Object* encountered_weak_collections() const { return encountered_weak_collections_; } void set_encountered_weak_cells(Object* weak_cell) { encountered_weak_cells_ = weak_cell; } Object* encountered_weak_cells() const { return encountered_weak_cells_; } // Number of mark-sweeps. int ms_count() const { return ms_count_; } // Checks whether the given object is allowed to be migrated from it's // current space into the given destination space. Used for debugging. inline bool AllowedToBeMigrated(HeapObject* object, AllocationSpace dest); void CheckHandleCount(); // Number of "runtime allocations" done so far. uint32_t allocations_count() { return allocations_count_; } // Returns deterministic "time" value in ms. Works only with // FLAG_verify_predictable. double synthetic_time() { return allocations_count() / 2.0; } // Print short heap statistics. void PrintShortHeapStatistics(); inline HeapState gc_state() { return gc_state_; } inline bool IsInGCPostProcessing() { return gc_post_processing_depth_ > 0; } // If an object has an AllocationMemento trailing it, return it, otherwise // return NULL; inline AllocationMemento* FindAllocationMemento(HeapObject* object); // Returns false if not able to reserve. bool ReserveSpace(Reservation* reservations); // // Support for the API. // void CreateApiObjects(); // Implements the corresponding V8 API function. bool IdleNotification(double deadline_in_seconds); bool IdleNotification(int idle_time_in_ms); double MonotonicallyIncreasingTimeInMs(); void RecordStats(HeapStats* stats, bool take_snapshot = false); // Check new space expansion criteria and expand semispaces if it was hit. void CheckNewSpaceExpansionCriteria(); inline bool HeapIsFullEnoughToStartIncrementalMarking(intptr_t limit) { if (FLAG_stress_compaction && (gc_count_ & 1) != 0) return true; intptr_t adjusted_allocation_limit = limit - new_space_.Capacity(); if (PromotedTotalSize() >= adjusted_allocation_limit) return true; return false; } void VisitExternalResources(v8::ExternalResourceVisitor* visitor); // An object should be promoted if the object has survived a // scavenge operation. inline bool ShouldBePromoted(Address old_address, int object_size); void ClearNormalizedMapCaches(); void IncrementDeferredCount(v8::Isolate::UseCounterFeature feature); bool concurrent_sweeping_enabled() { return concurrent_sweeping_enabled_; } inline bool OldGenerationAllocationLimitReached(); void QueueMemoryChunkForFree(MemoryChunk* chunk); void FilterStoreBufferEntriesOnAboutToBeFreedPages(); void FreeQueuedChunks(MemoryChunk* list_head); void FreeQueuedChunks(); void WaitUntilUnmappingOfFreeChunksCompleted(); // Completely clear the Instanceof cache (to stop it keeping objects alive // around a GC). inline void CompletelyClearInstanceofCache(); inline uint32_t HashSeed(); inline int NextScriptId(); inline void SetArgumentsAdaptorDeoptPCOffset(int pc_offset); inline void SetConstructStubDeoptPCOffset(int pc_offset); inline void SetGetterStubDeoptPCOffset(int pc_offset); inline void SetSetterStubDeoptPCOffset(int pc_offset); // For post mortem debugging. void RememberUnmappedPage(Address page, bool compacted); // Global inline caching age: it is incremented on some GCs after context // disposal. We use it to flush inline caches. int global_ic_age() { return global_ic_age_; } void AgeInlineCaches() { global_ic_age_ = (global_ic_age_ + 1) & SharedFunctionInfo::ICAgeBits::kMax; } int64_t amount_of_external_allocated_memory() { return amount_of_external_allocated_memory_; } void update_amount_of_external_allocated_memory(int64_t delta) { amount_of_external_allocated_memory_ += delta; } void DeoptMarkedAllocationSites(); bool DeoptMaybeTenuredAllocationSites() { return new_space_.IsAtMaximumCapacity() && maximum_size_scavenges_ == 0; } void AddWeakObjectToCodeDependency(Handle obj, Handle dep); DependentCode* LookupWeakObjectToCodeDependency(Handle obj); void AddRetainedMap(Handle map); // This event is triggered after successful allocation of a new object made // by runtime. Allocations of target space for object evacuation do not // trigger the event. In order to track ALL allocations one must turn off // FLAG_inline_new and FLAG_use_allocation_folding. inline void OnAllocationEvent(HeapObject* object, int size_in_bytes); // This event is triggered after object is moved to a new place. inline void OnMoveEvent(HeapObject* target, HeapObject* source, int size_in_bytes); bool deserialization_complete() const { return deserialization_complete_; } bool HasLowAllocationRate(); bool HasHighFragmentation(); bool HasHighFragmentation(intptr_t used, intptr_t committed); void SetOptimizeForLatency() { optimize_for_memory_usage_ = false; } void SetOptimizeForMemoryUsage() { optimize_for_memory_usage_ = true; } bool ShouldOptimizeForMemoryUsage() { return optimize_for_memory_usage_; } // =========================================================================== // Initialization. =========================================================== // =========================================================================== // Configure heap size in MB before setup. Return false if the heap has been // set up already. bool ConfigureHeap(int max_semi_space_size, int max_old_space_size, int max_executable_size, size_t code_range_size); bool ConfigureHeapDefault(); // Prepares the heap, setting up memory areas that are needed in the isolate // without actually creating any objects. bool SetUp(); // Bootstraps the object heap with the core set of objects required to run. // Returns whether it succeeded. bool CreateHeapObjects(); // Destroys all memory allocated by the heap. void TearDown(); // Returns whether SetUp has been called. bool HasBeenSetUp(); // =========================================================================== // Getters for spaces. ======================================================= // =========================================================================== // Return the starting address and a mask for the new space. And-masking an // address with the mask will result in the start address of the new space // for all addresses in either semispace. Address NewSpaceStart() { return new_space_.start(); } uintptr_t NewSpaceMask() { return new_space_.mask(); } Address NewSpaceTop() { return new_space_.top(); } NewSpace* new_space() { return &new_space_; } OldSpace* old_space() { return old_space_; } OldSpace* code_space() { return code_space_; } MapSpace* map_space() { return map_space_; } LargeObjectSpace* lo_space() { return lo_space_; } PagedSpace* paged_space(int idx) { switch (idx) { case OLD_SPACE: return old_space(); case MAP_SPACE: return map_space(); case CODE_SPACE: return code_space(); case NEW_SPACE: case LO_SPACE: UNREACHABLE(); } return NULL; } Space* space(int idx) { switch (idx) { case NEW_SPACE: return new_space(); case LO_SPACE: return lo_space(); default: return paged_space(idx); } } // Returns name of the space. const char* GetSpaceName(int idx); // =========================================================================== // Getters to other components. ============================================== // =========================================================================== GCTracer* tracer() { return tracer_; } PromotionQueue* promotion_queue() { return &promotion_queue_; } inline Isolate* isolate(); MarkCompactCollector* mark_compact_collector() { return mark_compact_collector_; } // =========================================================================== // Root set access. ========================================================== // =========================================================================== // Heap root getters. #define ROOT_ACCESSOR(type, name, camel_name) inline type* name(); ROOT_LIST(ROOT_ACCESSOR) #undef ROOT_ACCESSOR // Utility type maps. #define STRUCT_MAP_ACCESSOR(NAME, Name, name) inline Map* name##_map(); STRUCT_LIST(STRUCT_MAP_ACCESSOR) #undef STRUCT_MAP_ACCESSOR #define STRING_ACCESSOR(name, str) inline String* name(); INTERNALIZED_STRING_LIST(STRING_ACCESSOR) #undef STRING_ACCESSOR #define SYMBOL_ACCESSOR(name) inline Symbol* name(); PRIVATE_SYMBOL_LIST(SYMBOL_ACCESSOR) #undef SYMBOL_ACCESSOR #define SYMBOL_ACCESSOR(name, description) inline Symbol* name(); PUBLIC_SYMBOL_LIST(SYMBOL_ACCESSOR) WELL_KNOWN_SYMBOL_LIST(SYMBOL_ACCESSOR) #undef SYMBOL_ACCESSOR Object* root(RootListIndex index) { return roots_[index]; } Handle root_handle(RootListIndex index) { return Handle(&roots_[index]); } // Generated code can embed this address to get access to the roots. Object** roots_array_start() { return roots_; } // Sets the stub_cache_ (only used when expanding the dictionary). void SetRootCodeStubs(UnseededNumberDictionary* value) { roots_[kCodeStubsRootIndex] = value; } // Sets the non_monomorphic_cache_ (only used when expanding the dictionary). void SetRootNonMonomorphicCache(UnseededNumberDictionary* value) { roots_[kNonMonomorphicCacheRootIndex] = value; } void SetRootMaterializedObjects(FixedArray* objects) { roots_[kMaterializedObjectsRootIndex] = objects; } void SetRootCodeStubContext(Object* value) { roots_[kCodeStubContextRootIndex] = value; } void SetRootCodeStubExportsObject(JSObject* value) { roots_[kCodeStubExportsObjectRootIndex] = value; } void SetRootScriptList(Object* value) { roots_[kScriptListRootIndex] = value; } void SetRootStringTable(StringTable* value) { roots_[kStringTableRootIndex] = value; } void SetRootNoScriptSharedFunctionInfos(Object* value) { roots_[kNoScriptSharedFunctionInfosRootIndex] = value; } // Set the stack limit in the roots_ array. Some architectures generate // code that looks here, because it is faster than loading from the static // jslimit_/real_jslimit_ variable in the StackGuard. void SetStackLimits(); // Generated code can treat direct references to this root as constant. bool RootCanBeTreatedAsConstant(RootListIndex root_index); Map* MapForFixedTypedArray(ExternalArrayType array_type); RootListIndex RootIndexForFixedTypedArray(ExternalArrayType array_type); RootListIndex RootIndexForEmptyFixedTypedArray(ElementsKind kind); FixedTypedArrayBase* EmptyFixedTypedArrayForMap(Map* map); void RegisterStrongRoots(Object** start, Object** end); void UnregisterStrongRoots(Object** start); // =========================================================================== // Inline allocation. ======================================================== // =========================================================================== // Indicates whether inline bump-pointer allocation has been disabled. bool inline_allocation_disabled() { return inline_allocation_disabled_; } // Switch whether inline bump-pointer allocation should be used. void EnableInlineAllocation(); void DisableInlineAllocation(); // =========================================================================== // Methods triggering GCs. =================================================== // =========================================================================== // Performs garbage collection operation. // Returns whether there is a chance that another major GC could // collect more garbage. inline bool CollectGarbage( AllocationSpace space, const char* gc_reason = NULL, const GCCallbackFlags gc_callback_flags = kNoGCCallbackFlags); // Performs a full garbage collection. If (flags & kMakeHeapIterableMask) is // non-zero, then the slower precise sweeper is used, which leaves the heap // in a state where we can iterate over the heap visiting all objects. void CollectAllGarbage( int flags = kFinalizeIncrementalMarkingMask, const char* gc_reason = NULL, const GCCallbackFlags gc_callback_flags = kNoGCCallbackFlags); // Last hope GC, should try to squeeze as much as possible. void CollectAllAvailableGarbage(const char* gc_reason = NULL); // Reports and external memory pressure event, either performs a major GC or // completes incremental marking in order to free external resources. void ReportExternalMemoryPressure(const char* gc_reason = NULL); // Invoked when GC was requested via the stack guard. void HandleGCRequest(); // =========================================================================== // Iterators. ================================================================ // =========================================================================== // Iterates over all roots in the heap. void IterateRoots(ObjectVisitor* v, VisitMode mode); // Iterates over all strong roots in the heap. void IterateStrongRoots(ObjectVisitor* v, VisitMode mode); // Iterates over entries in the smi roots list. Only interesting to the // serializer/deserializer, since GC does not care about smis. void IterateSmiRoots(ObjectVisitor* v); // Iterates over all the other roots in the heap. void IterateWeakRoots(ObjectVisitor* v, VisitMode mode); // Iterate pointers to from semispace of new space found in memory interval // from start to end within |object|. void IteratePointersToFromSpace(HeapObject* target, int size, ObjectSlotCallback callback); void IterateAndMarkPointersToFromSpace(HeapObject* object, Address start, Address end, bool record_slots, ObjectSlotCallback callback); // =========================================================================== // Store buffer API. ========================================================= // =========================================================================== // Write barrier support for address[offset] = o. INLINE(void RecordWrite(Address address, int offset)); // Write barrier support for address[start : start + len[ = o. INLINE(void RecordWrites(Address address, int start, int len)); Address* store_buffer_top_address() { return reinterpret_cast(&roots_[kStoreBufferTopRootIndex]); } // =========================================================================== // Incremental marking API. ================================================== // =========================================================================== // Start incremental marking and ensure that idle time handler can perform // incremental steps. void StartIdleIncrementalMarking(); // Starts incremental marking assuming incremental marking is currently // stopped. void StartIncrementalMarking(int gc_flags = kNoGCFlags, const GCCallbackFlags gc_callback_flags = GCCallbackFlags::kNoGCCallbackFlags, const char* reason = nullptr); void FinalizeIncrementalMarkingIfComplete(const char* comment); bool TryFinalizeIdleIncrementalMarking(double idle_time_in_ms); IncrementalMarking* incremental_marking() { return incremental_marking_; } // =========================================================================== // External string table API. ================================================ // =========================================================================== // Registers an external string. inline void RegisterExternalString(String* string); // Finalizes an external string by deleting the associated external // data and clearing the resource pointer. inline void FinalizeExternalString(String* string); // =========================================================================== // Methods checking/returning the space of a given object/address. =========== // =========================================================================== // Returns whether the object resides in new space. inline bool InNewSpace(Object* object); inline bool InNewSpace(Address address); inline bool InNewSpacePage(Address address); inline bool InFromSpace(Object* object); inline bool InToSpace(Object* object); // Returns whether the object resides in old space. inline bool InOldSpace(Address address); inline bool InOldSpace(Object* object); // Checks whether an address/object in the heap (including auxiliary // area and unused area). bool Contains(Address addr); bool Contains(HeapObject* value); // Checks whether an address/object in a space. // Currently used by tests, serialization and heap verification only. bool InSpace(Address addr, AllocationSpace space); bool InSpace(HeapObject* value, AllocationSpace space); // =========================================================================== // Object statistics tracking. =============================================== // =========================================================================== // Returns the number of buckets used by object statistics tracking during a // major GC. Note that the following methods fail gracefully when the bounds // are exceeded though. size_t NumberOfTrackedHeapObjectTypes(); // Returns object statistics about count and size at the last major GC. // Objects are being grouped into buckets that roughly resemble existing // instance types. size_t ObjectCountAtLastGC(size_t index); size_t ObjectSizeAtLastGC(size_t index); // Retrieves names of buckets used by object statistics tracking. bool GetObjectTypeName(size_t index, const char** object_type, const char** object_sub_type); // =========================================================================== // GC statistics. ============================================================ // =========================================================================== // Returns the maximum amount of memory reserved for the heap. For // the young generation, we reserve 4 times the amount needed for a // semi space. The young generation consists of two semi spaces and // we reserve twice the amount needed for those in order to ensure // that new space can be aligned to its size. intptr_t MaxReserved() { return 4 * reserved_semispace_size_ + max_old_generation_size_; } int MaxSemiSpaceSize() { return max_semi_space_size_; } int ReservedSemiSpaceSize() { return reserved_semispace_size_; } int InitialSemiSpaceSize() { return initial_semispace_size_; } int TargetSemiSpaceSize() { return target_semispace_size_; } intptr_t MaxOldGenerationSize() { return max_old_generation_size_; } intptr_t MaxExecutableSize() { return max_executable_size_; } // Returns the capacity of the heap in bytes w/o growing. Heap grows when // more spaces are needed until it reaches the limit. intptr_t Capacity(); // Returns the amount of memory currently committed for the heap. intptr_t CommittedMemory(); // Returns the amount of memory currently committed for the old space. intptr_t CommittedOldGenerationMemory(); // Returns the amount of executable memory currently committed for the heap. intptr_t CommittedMemoryExecutable(); // Returns the amount of phyical memory currently committed for the heap. size_t CommittedPhysicalMemory(); // Returns the maximum amount of memory ever committed for the heap. intptr_t MaximumCommittedMemory() { return maximum_committed_; } // Updates the maximum committed memory for the heap. Should be called // whenever a space grows. void UpdateMaximumCommitted(); // Returns the available bytes in space w/o growing. // Heap doesn't guarantee that it can allocate an object that requires // all available bytes. Check MaxHeapObjectSize() instead. intptr_t Available(); // Returns of size of all objects residing in the heap. intptr_t SizeOfObjects(); void UpdateSurvivalStatistics(int start_new_space_size); inline void IncrementPromotedObjectsSize(int object_size) { DCHECK(object_size > 0); promoted_objects_size_ += object_size; } inline intptr_t promoted_objects_size() { return promoted_objects_size_; } inline void IncrementSemiSpaceCopiedObjectSize(int object_size) { DCHECK(object_size > 0); semi_space_copied_object_size_ += object_size; } inline intptr_t semi_space_copied_object_size() { return semi_space_copied_object_size_; } inline intptr_t SurvivedNewSpaceObjectSize() { return promoted_objects_size_ + semi_space_copied_object_size_; } inline void IncrementNodesDiedInNewSpace() { nodes_died_in_new_space_++; } inline void IncrementNodesCopiedInNewSpace() { nodes_copied_in_new_space_++; } inline void IncrementNodesPromoted() { nodes_promoted_++; } inline void IncrementYoungSurvivorsCounter(int survived) { DCHECK(survived >= 0); survived_last_scavenge_ = survived; survived_since_last_expansion_ += survived; } inline intptr_t PromotedTotalSize() { int64_t total = PromotedSpaceSizeOfObjects() + PromotedExternalMemorySize(); if (total > std::numeric_limits::max()) { // TODO(erikcorry): Use uintptr_t everywhere we do heap size calculations. return std::numeric_limits::max(); } if (total < 0) return 0; return static_cast(total); } void UpdateNewSpaceAllocationCounter() { new_space_allocation_counter_ = NewSpaceAllocationCounter(); } size_t NewSpaceAllocationCounter() { return new_space_allocation_counter_ + new_space()->AllocatedSinceLastGC(); } // This should be used only for testing. void set_new_space_allocation_counter(size_t new_value) { new_space_allocation_counter_ = new_value; } void UpdateOldGenerationAllocationCounter() { old_generation_allocation_counter_ = OldGenerationAllocationCounter(); } size_t OldGenerationAllocationCounter() { return old_generation_allocation_counter_ + PromotedSinceLastGC(); } // This should be used only for testing. void set_old_generation_allocation_counter(size_t new_value) { old_generation_allocation_counter_ = new_value; } size_t PromotedSinceLastGC() { return PromotedSpaceSizeOfObjects() - old_generation_size_at_last_gc_; } int gc_count() const { return gc_count_; } // Returns the size of objects residing in non new spaces. intptr_t PromotedSpaceSizeOfObjects(); double total_regexp_code_generated() { return total_regexp_code_generated_; } void IncreaseTotalRegexpCodeGenerated(int size) { total_regexp_code_generated_ += size; } void IncrementCodeGeneratedBytes(bool is_crankshafted, int size) { if (is_crankshafted) { crankshaft_codegen_bytes_generated_ += size; } else { full_codegen_bytes_generated_ += size; } } // =========================================================================== // Prologue/epilogue callback methods.======================================== // =========================================================================== void AddGCPrologueCallback(v8::Isolate::GCCallback callback, GCType gc_type_filter, bool pass_isolate = true); void RemoveGCPrologueCallback(v8::Isolate::GCCallback callback); void AddGCEpilogueCallback(v8::Isolate::GCCallback callback, GCType gc_type_filter, bool pass_isolate = true); void RemoveGCEpilogueCallback(v8::Isolate::GCCallback callback); void CallGCPrologueCallbacks(GCType gc_type, GCCallbackFlags flags); void CallGCEpilogueCallbacks(GCType gc_type, GCCallbackFlags flags); // =========================================================================== // Allocation methods. ======================================================= // =========================================================================== // Creates a filler object and returns a heap object immediately after it. MUST_USE_RESULT HeapObject* PrecedeWithFiller(HeapObject* object, int filler_size); // Creates a filler object if needed for alignment and returns a heap object // immediately after it. If any space is left after the returned object, // another filler object is created so the over allocated memory is iterable. MUST_USE_RESULT HeapObject* AlignWithFiller(HeapObject* object, int object_size, int allocation_size, AllocationAlignment alignment); // =========================================================================== // ArrayBuffer tracking. ===================================================== // =========================================================================== void RegisterNewArrayBuffer(JSArrayBuffer* buffer); void UnregisterArrayBuffer(JSArrayBuffer* buffer); inline ArrayBufferTracker* array_buffer_tracker() { return array_buffer_tracker_; } // ============================================================================= #ifdef VERIFY_HEAP // Verify the heap is in its normal state before or after a GC. void Verify(); #endif #ifdef DEBUG void set_allocation_timeout(int timeout) { allocation_timeout_ = timeout; } void TracePathToObjectFrom(Object* target, Object* root); void TracePathToObject(Object* target); void TracePathToGlobal(); void Print(); void PrintHandles(); // Report heap statistics. void ReportHeapStatistics(const char* title); void ReportCodeStatistics(const char* title); #endif private: class UnmapFreeMemoryTask; // External strings table is a place where all external strings are // registered. We need to keep track of such strings to properly // finalize them. class ExternalStringTable { public: // Registers an external string. inline void AddString(String* string); inline void Iterate(ObjectVisitor* v); // Restores internal invariant and gets rid of collected strings. // Must be called after each Iterate() that modified the strings. void CleanUp(); // Destroys all allocated memory. void TearDown(); private: explicit ExternalStringTable(Heap* heap) : heap_(heap) {} inline void Verify(); inline void AddOldString(String* string); // Notifies the table that only a prefix of the new list is valid. inline void ShrinkNewStrings(int position); // To speed up scavenge collections new space string are kept // separate from old space strings. List new_space_strings_; List old_space_strings_; Heap* heap_; friend class Heap; DISALLOW_COPY_AND_ASSIGN(ExternalStringTable); }; struct StrongRootsList; struct StringTypeTable { InstanceType type; int size; RootListIndex index; }; struct ConstantStringTable { const char* contents; RootListIndex index; }; struct StructTable { InstanceType type; int size; RootListIndex index; }; struct GCCallbackPair { GCCallbackPair(v8::Isolate::GCCallback callback, GCType gc_type, bool pass_isolate) : callback(callback), gc_type(gc_type), pass_isolate(pass_isolate) {} bool operator==(const GCCallbackPair& other) const { return other.callback == callback; } v8::Isolate::GCCallback callback; GCType gc_type; bool pass_isolate; }; typedef String* (*ExternalStringTableUpdaterCallback)(Heap* heap, Object** pointer); static const int kInitialStringTableSize = 2048; static const int kInitialEvalCacheSize = 64; static const int kInitialNumberStringCacheSize = 256; static const int kRememberedUnmappedPages = 128; static const StringTypeTable string_type_table[]; static const ConstantStringTable constant_string_table[]; static const StructTable struct_table[]; static const int kYoungSurvivalRateHighThreshold = 90; static const int kYoungSurvivalRateAllowedDeviation = 15; static const int kOldSurvivalRateLowThreshold = 10; static const int kMaxMarkCompactsInIdleRound = 7; static const int kIdleScavengeThreshold = 5; static const int kAllocationSiteScratchpadSize = 256; Heap(); static String* UpdateNewSpaceReferenceInExternalStringTableEntry( Heap* heap, Object** pointer); static void ScavengeStoreBufferCallback(Heap* heap, MemoryChunk* page, StoreBufferEvent event); // Selects the proper allocation space based on the pretenuring decision. static AllocationSpace SelectSpace(PretenureFlag pretenure) { return (pretenure == TENURED) ? OLD_SPACE : NEW_SPACE; } #define ROOT_ACCESSOR(type, name, camel_name) \ inline void set_##name(type* value); ROOT_LIST(ROOT_ACCESSOR) #undef ROOT_ACCESSOR StoreBuffer* store_buffer() { return &store_buffer_; } void set_current_gc_flags(int flags) { current_gc_flags_ = flags; DCHECK(!ShouldFinalizeIncrementalMarking() || !ShouldAbortIncrementalMarking()); } inline bool ShouldReduceMemory() const { return current_gc_flags_ & kReduceMemoryFootprintMask; } inline bool ShouldAbortIncrementalMarking() const { return current_gc_flags_ & kAbortIncrementalMarkingMask; } inline bool ShouldFinalizeIncrementalMarking() const { return current_gc_flags_ & kFinalizeIncrementalMarkingMask; } void PreprocessStackTraces(); // Pretenuring decisions are made based on feedback collected during new // space evacuation. Note that between feedback collection and calling this // method object in old space must not move. // Right now we only process pretenuring feedback in high promotion mode. bool ProcessPretenuringFeedback(); // Checks whether a global GC is necessary GarbageCollector SelectGarbageCollector(AllocationSpace space, const char** reason); // Make sure there is a filler value behind the top of the new space // so that the GC does not confuse some unintialized/stale memory // with the allocation memento of the object at the top void EnsureFillerObjectAtTop(); // Ensure that we have swept all spaces in such a way that we can iterate // over all objects. May cause a GC. void MakeHeapIterable(); // Performs garbage collection operation. // Returns whether there is a chance that another major GC could // collect more garbage. bool CollectGarbage( GarbageCollector collector, const char* gc_reason, const char* collector_reason, const GCCallbackFlags gc_callback_flags = kNoGCCallbackFlags); // Performs garbage collection // Returns whether there is a chance another major GC could // collect more garbage. bool PerformGarbageCollection( GarbageCollector collector, const GCCallbackFlags gc_callback_flags = kNoGCCallbackFlags); inline void UpdateOldSpaceLimits(); // Initializes a JSObject based on its map. void InitializeJSObjectFromMap(JSObject* obj, FixedArray* properties, Map* map); void InitializeAllocationMemento(AllocationMemento* memento, AllocationSite* allocation_site); bool CreateInitialMaps(); void CreateInitialObjects(); // These five Create*EntryStub functions are here and forced to not be inlined // because of a gcc-4.4 bug that assigns wrong vtable entries. NO_INLINE(void CreateJSEntryStub()); NO_INLINE(void CreateJSConstructEntryStub()); void CreateFixedStubs(); HeapObject* DoubleAlignForDeserialization(HeapObject* object, int size); // Commits from space if it is uncommitted. void EnsureFromSpaceIsCommitted(); // Uncommit unused semi space. bool UncommitFromSpace() { return new_space_.UncommitFromSpace(); } // Fill in bogus values in from space void ZapFromSpace(); // Deopts all code that contains allocation instruction which are tenured or // not tenured. Moreover it clears the pretenuring allocation site statistics. void ResetAllAllocationSitesDependentCode(PretenureFlag flag); // Evaluates local pretenuring for the old space and calls // ResetAllTenuredAllocationSitesDependentCode if too many objects died in // the old space. void EvaluateOldSpaceLocalPretenuring(uint64_t size_of_objects_before_gc); // Record statistics before and after garbage collection. void ReportStatisticsBeforeGC(); void ReportStatisticsAfterGC(); // Creates and installs the full-sized number string cache. int FullSizeNumberStringCacheLength(); // Flush the number to string cache. void FlushNumberStringCache(); // Sets used allocation sites entries to undefined. void FlushAllocationSitesScratchpad(); // Initializes the allocation sites scratchpad with undefined values. void InitializeAllocationSitesScratchpad(); // Adds an allocation site to the scratchpad if there is space left. void AddAllocationSiteToScratchpad(AllocationSite* site, ScratchpadSlotMode mode); // TODO(hpayer): Allocation site pretenuring may make this method obsolete. // Re-visit incremental marking heuristics. bool IsHighSurvivalRate() { return high_survival_rate_period_length_ > 0; } void ConfigureInitialOldGenerationSize(); bool HasLowYoungGenerationAllocationRate(); bool HasLowOldGenerationAllocationRate(); double YoungGenerationMutatorUtilization(); double OldGenerationMutatorUtilization(); void ReduceNewSpaceSize(); bool TryFinalizeIdleIncrementalMarking( double idle_time_in_ms, size_t size_of_objects, size_t mark_compact_speed_in_bytes_per_ms); GCIdleTimeHeapState ComputeHeapState(); bool PerformIdleTimeAction(GCIdleTimeAction action, GCIdleTimeHeapState heap_state, double deadline_in_ms); void IdleNotificationEpilogue(GCIdleTimeAction action, GCIdleTimeHeapState heap_state, double start_ms, double deadline_in_ms); inline void UpdateAllocationsHash(HeapObject* object); inline void UpdateAllocationsHash(uint32_t value); void PrintAlloctionsHash(); void AddToRingBuffer(const char* string); void GetFromRingBuffer(char* buffer); // Attempt to over-approximate the weak closure by marking object groups and // implicit references from global handles, but don't atomically complete // marking. If we continue to mark incrementally, we might have marked // objects that die later. void FinalizeIncrementalMarking(const char* gc_reason); // Returns the timer used for a given GC type. // - GCScavenger: young generation GC // - GCCompactor: full GC // - GCFinalzeMC: finalization of incremental full GC // - GCFinalizeMCReduceMemory: finalization of incremental full GC with // memory reduction HistogramTimer* GCTypeTimer(GarbageCollector collector); // =========================================================================== // Actual GC. ================================================================ // =========================================================================== // Code that should be run before and after each GC. Includes some // reporting/verification activities when compiled with DEBUG set. void GarbageCollectionPrologue(); void GarbageCollectionEpilogue(); // Performs a major collection in the whole heap. void MarkCompact(); // Code to be run before and after mark-compact. void MarkCompactPrologue(); void MarkCompactEpilogue(); // Performs a minor collection in new generation. void Scavenge(); Address DoScavenge(ObjectVisitor* scavenge_visitor, Address new_space_front); void UpdateNewSpaceReferencesInExternalStringTable( ExternalStringTableUpdaterCallback updater_func); void UpdateReferencesInExternalStringTable( ExternalStringTableUpdaterCallback updater_func); void ProcessAllWeakReferences(WeakObjectRetainer* retainer); void ProcessYoungWeakReferences(WeakObjectRetainer* retainer); void ProcessNativeContexts(WeakObjectRetainer* retainer); void ProcessAllocationSites(WeakObjectRetainer* retainer); // =========================================================================== // GC statistics. ============================================================ // =========================================================================== inline intptr_t OldGenerationSpaceAvailable() { return old_generation_allocation_limit_ - PromotedTotalSize(); } // Returns maximum GC pause. double get_max_gc_pause() { return max_gc_pause_; } // Returns maximum size of objects alive after GC. intptr_t get_max_alive_after_gc() { return max_alive_after_gc_; } // Returns minimal interval between two subsequent collections. double get_min_in_mutator() { return min_in_mutator_; } // Update GC statistics that are tracked on the Heap. void UpdateCumulativeGCStatistics(double duration, double spent_in_mutator, double marking_time); bool MaximumSizeScavenge() { return maximum_size_scavenges_ > 0; } // =========================================================================== // Growing strategy. ========================================================= // =========================================================================== // Decrease the allocation limit if the new limit based on the given // parameters is lower than the current limit. void DampenOldGenerationAllocationLimit(intptr_t old_gen_size, double gc_speed, double mutator_speed); // Calculates the allocation limit based on a given growing factor and a // given old generation size. intptr_t CalculateOldGenerationAllocationLimit(double factor, intptr_t old_gen_size); // Sets the allocation limit to trigger the next full garbage collection. void SetOldGenerationAllocationLimit(intptr_t old_gen_size, double gc_speed, double mutator_speed); // =========================================================================== // Inline allocation. ======================================================== // =========================================================================== void LowerInlineAllocationLimit(intptr_t step); void ResetInlineAllocationLimit(); // =========================================================================== // Idle notification. ======================================================== // =========================================================================== bool RecentIdleNotificationHappened(); void ScheduleIdleScavengeIfNeeded(int bytes_allocated); // =========================================================================== // Allocation methods. ======================================================= // =========================================================================== // Returns a deep copy of the JavaScript object. // Properties and elements are copied too. // Optionally takes an AllocationSite to be appended in an AllocationMemento. MUST_USE_RESULT AllocationResult CopyJSObject(JSObject* source, AllocationSite* site = NULL); // Allocates a JS Map in the heap. MUST_USE_RESULT AllocationResult AllocateMap(InstanceType instance_type, int instance_size, ElementsKind elements_kind = TERMINAL_FAST_ELEMENTS_KIND); // Allocates and initializes a new JavaScript object based on a // constructor. // If allocation_site is non-null, then a memento is emitted after the object // that points to the site. MUST_USE_RESULT AllocationResult AllocateJSObject( JSFunction* constructor, PretenureFlag pretenure = NOT_TENURED, AllocationSite* allocation_site = NULL); // Allocates and initializes a new JavaScript object based on a map. // Passing an allocation site means that a memento will be created that // points to the site. MUST_USE_RESULT AllocationResult AllocateJSObjectFromMap(Map* map, PretenureFlag pretenure = NOT_TENURED, AllocationSite* allocation_site = NULL); // Allocates a HeapNumber from value. MUST_USE_RESULT AllocationResult AllocateHeapNumber(double value, MutableMode mode = IMMUTABLE, PretenureFlag pretenure = NOT_TENURED); // Allocates SIMD values from the given lane values. #define SIMD_ALLOCATE_DECLARATION(TYPE, Type, type, lane_count, lane_type) \ AllocationResult Allocate##Type(lane_type lanes[lane_count], \ PretenureFlag pretenure = NOT_TENURED); SIMD128_TYPES(SIMD_ALLOCATE_DECLARATION) #undef SIMD_ALLOCATE_DECLARATION // Allocates a byte array of the specified length MUST_USE_RESULT AllocationResult AllocateByteArray(int length, PretenureFlag pretenure = NOT_TENURED); // Allocates a bytecode array with given contents. MUST_USE_RESULT AllocationResult AllocateBytecodeArray(int length, const byte* raw_bytecodes, int frame_size, int parameter_count, FixedArray* constant_pool); // Copy the code and scope info part of the code object, but insert // the provided data as the relocation information. MUST_USE_RESULT AllocationResult CopyCode(Code* code, Vector reloc_info); MUST_USE_RESULT AllocationResult CopyCode(Code* code); // Allocates a fixed array initialized with undefined values MUST_USE_RESULT AllocationResult AllocateFixedArray(int length, PretenureFlag pretenure = NOT_TENURED); // Allocate an uninitialized object. The memory is non-executable if the // hardware and OS allow. This is the single choke-point for allocations // performed by the runtime and should not be bypassed (to extend this to // inlined allocations, use the Heap::DisableInlineAllocation() support). MUST_USE_RESULT inline AllocationResult AllocateRaw( int size_in_bytes, AllocationSpace space, AllocationAlignment aligment = kWordAligned); // Allocates a heap object based on the map. MUST_USE_RESULT AllocationResult Allocate(Map* map, AllocationSpace space, AllocationSite* allocation_site = NULL); // Allocates a partial map for bootstrapping. MUST_USE_RESULT AllocationResult AllocatePartialMap(InstanceType instance_type, int instance_size); // Allocate a block of memory in the given space (filled with a filler). // Used as a fall-back for generated code when the space is full. MUST_USE_RESULT AllocationResult AllocateFillerObject(int size, bool double_align, AllocationSpace space); // Allocate an uninitialized fixed array. MUST_USE_RESULT AllocationResult AllocateRawFixedArray(int length, PretenureFlag pretenure); // Allocate an uninitialized fixed double array. MUST_USE_RESULT AllocationResult AllocateRawFixedDoubleArray(int length, PretenureFlag pretenure); // Allocate an initialized fixed array with the given filler value. MUST_USE_RESULT AllocationResult AllocateFixedArrayWithFiller(int length, PretenureFlag pretenure, Object* filler); // Allocate and partially initializes a String. There are two String // encodings: one-byte and two-byte. These functions allocate a string of // the given length and set its map and length fields. The characters of // the string are uninitialized. MUST_USE_RESULT AllocationResult AllocateRawOneByteString(int length, PretenureFlag pretenure); MUST_USE_RESULT AllocationResult AllocateRawTwoByteString(int length, PretenureFlag pretenure); // Allocates an internalized string in old space based on the character // stream. MUST_USE_RESULT inline AllocationResult AllocateInternalizedStringFromUtf8( Vector str, int chars, uint32_t hash_field); MUST_USE_RESULT inline AllocationResult AllocateOneByteInternalizedString( Vector str, uint32_t hash_field); MUST_USE_RESULT inline AllocationResult AllocateTwoByteInternalizedString( Vector str, uint32_t hash_field); template MUST_USE_RESULT AllocationResult AllocateInternalizedStringImpl(T t, int chars, uint32_t hash_field); template MUST_USE_RESULT inline AllocationResult AllocateInternalizedStringImpl( T t, int chars, uint32_t hash_field); // Allocates an uninitialized fixed array. It must be filled by the caller. MUST_USE_RESULT AllocationResult AllocateUninitializedFixedArray(int length); // Make a copy of src and return it. MUST_USE_RESULT inline AllocationResult CopyFixedArray(FixedArray* src); // Make a copy of src, also grow the copy, and return the copy. MUST_USE_RESULT AllocationResult CopyFixedArrayAndGrow(FixedArray* src, int grow_by, PretenureFlag pretenure); // Make a copy of src, set the map, and return the copy. MUST_USE_RESULT AllocationResult CopyFixedArrayWithMap(FixedArray* src, Map* map); // Make a copy of src and return it. MUST_USE_RESULT inline AllocationResult CopyFixedDoubleArray( FixedDoubleArray* src); // Computes a single character string where the character has code. // A cache is used for one-byte (Latin1) codes. MUST_USE_RESULT AllocationResult LookupSingleCharacterStringFromCode(uint16_t code); // Allocate a symbol in old space. MUST_USE_RESULT AllocationResult AllocateSymbol(); // Allocates an external array of the specified length and type. MUST_USE_RESULT AllocationResult AllocateFixedTypedArrayWithExternalPointer( int length, ExternalArrayType array_type, void* external_pointer, PretenureFlag pretenure); // Allocates a fixed typed array of the specified length and type. MUST_USE_RESULT AllocationResult AllocateFixedTypedArray(int length, ExternalArrayType array_type, bool initialize, PretenureFlag pretenure); // Make a copy of src and return it. MUST_USE_RESULT AllocationResult CopyAndTenureFixedCOWArray(FixedArray* src); // Make a copy of src, set the map, and return the copy. MUST_USE_RESULT AllocationResult CopyFixedDoubleArrayWithMap(FixedDoubleArray* src, Map* map); // Allocates a fixed double array with uninitialized values. Returns MUST_USE_RESULT AllocationResult AllocateUninitializedFixedDoubleArray( int length, PretenureFlag pretenure = NOT_TENURED); // Allocate empty fixed array. MUST_USE_RESULT AllocationResult AllocateEmptyFixedArray(); // Allocate empty fixed typed array of given type. MUST_USE_RESULT AllocationResult AllocateEmptyFixedTypedArray(ExternalArrayType array_type); // Allocate a tenured simple cell. MUST_USE_RESULT AllocationResult AllocateCell(Object* value); // Allocate a tenured JS global property cell initialized with the hole. MUST_USE_RESULT AllocationResult AllocatePropertyCell(); MUST_USE_RESULT AllocationResult AllocateWeakCell(HeapObject* value); // Allocates a new utility object in the old generation. MUST_USE_RESULT AllocationResult AllocateStruct(InstanceType type); // Allocates a new foreign object. MUST_USE_RESULT AllocationResult AllocateForeign(Address address, PretenureFlag pretenure = NOT_TENURED); MUST_USE_RESULT AllocationResult AllocateCode(int object_size, bool immovable); MUST_USE_RESULT AllocationResult InternalizeStringWithKey(HashTableKey* key); MUST_USE_RESULT AllocationResult InternalizeString(String* str); // The amount of external memory registered through the API kept alive // by global handles int64_t amount_of_external_allocated_memory_; // Caches the amount of external memory registered at the last global gc. int64_t amount_of_external_allocated_memory_at_last_global_gc_; // This can be calculated directly from a pointer to the heap; however, it is // more expedient to get at the isolate directly from within Heap methods. Isolate* isolate_; Object* roots_[kRootListLength]; size_t code_range_size_; int reserved_semispace_size_; int max_semi_space_size_; int initial_semispace_size_; int target_semispace_size_; intptr_t max_old_generation_size_; intptr_t initial_old_generation_size_; bool old_generation_size_configured_; intptr_t max_executable_size_; intptr_t maximum_committed_; // For keeping track of how much data has survived // scavenge since last new space expansion. int survived_since_last_expansion_; // ... and since the last scavenge. int survived_last_scavenge_; // This is not the depth of nested AlwaysAllocateScope's but rather a single // count, as scopes can be acquired from multiple tasks (read: threads). AtomicNumber always_allocate_scope_count_; // For keeping track of context disposals. int contexts_disposed_; int global_ic_age_; int scan_on_scavenge_pages_; NewSpace new_space_; OldSpace* old_space_; OldSpace* code_space_; MapSpace* map_space_; LargeObjectSpace* lo_space_; HeapState gc_state_; int gc_post_processing_depth_; Address new_space_top_after_last_gc_; // Returns the amount of external memory registered since last global gc. int64_t PromotedExternalMemorySize(); // How many "runtime allocations" happened. uint32_t allocations_count_; // Running hash over allocations performed. uint32_t raw_allocations_hash_; // Countdown counter, dumps allocation hash when 0. uint32_t dump_allocations_hash_countdown_; // How many mark-sweep collections happened. unsigned int ms_count_; // How many gc happened. unsigned int gc_count_; // For post mortem debugging. int remembered_unmapped_pages_index_; Address remembered_unmapped_pages_[kRememberedUnmappedPages]; #ifdef DEBUG // If the --gc-interval flag is set to a positive value, this // variable holds the value indicating the number of allocations // remain until the next failure and garbage collection. int allocation_timeout_; #endif // DEBUG // Limit that triggers a global GC on the next (normally caused) GC. This // is checked when we have already decided to do a GC to help determine // which collector to invoke, before expanding a paged space in the old // generation and on every allocation in large object space. intptr_t old_generation_allocation_limit_; // Indicates that an allocation has failed in the old generation since the // last GC. bool old_gen_exhausted_; // Indicates that memory usage is more important than latency. // TODO(ulan): Merge it with memory reducer once chromium:490559 is fixed. bool optimize_for_memory_usage_; // Indicates that inline bump-pointer allocation has been globally disabled // for all spaces. This is used to disable allocations in generated code. bool inline_allocation_disabled_; // Weak list heads, threaded through the objects. // List heads are initialized lazily and contain the undefined_value at start. Object* native_contexts_list_; Object* allocation_sites_list_; // List of encountered weak collections (JSWeakMap and JSWeakSet) during // marking. It is initialized during marking, destroyed after marking and // contains Smi(0) while marking is not active. Object* encountered_weak_collections_; Object* encountered_weak_cells_; StoreBufferRebuilder store_buffer_rebuilder_; List gc_epilogue_callbacks_; List gc_prologue_callbacks_; // Total RegExp code ever generated double total_regexp_code_generated_; int deferred_counters_[v8::Isolate::kUseCounterFeatureCount]; GCTracer* tracer_; int high_survival_rate_period_length_; intptr_t promoted_objects_size_; double promotion_ratio_; double promotion_rate_; intptr_t semi_space_copied_object_size_; intptr_t previous_semi_space_copied_object_size_; double semi_space_copied_rate_; int nodes_died_in_new_space_; int nodes_copied_in_new_space_; int nodes_promoted_; // This is the pretenuring trigger for allocation sites that are in maybe // tenure state. When we switched to the maximum new space size we deoptimize // the code that belongs to the allocation site and derive the lifetime // of the allocation site. unsigned int maximum_size_scavenges_; // Maximum GC pause. double max_gc_pause_; // Total time spent in GC. double total_gc_time_ms_; // Maximum size of objects alive after GC. intptr_t max_alive_after_gc_; // Minimal interval between two subsequent collections. double min_in_mutator_; // Cumulative GC time spent in marking. double marking_time_; // Cumulative GC time spent in sweeping. double sweeping_time_; // Last time an idle notification happened. double last_idle_notification_time_; // Last time a garbage collection happened. double last_gc_time_; Scavenger* scavenge_collector_; MarkCompactCollector* mark_compact_collector_; StoreBuffer store_buffer_; IncrementalMarking* incremental_marking_; GCIdleTimeHandler* gc_idle_time_handler_; MemoryReducer* memory_reducer_; ObjectStats* object_stats_; ScavengeJob* scavenge_job_; // These two counters are monotomically increasing and never reset. size_t full_codegen_bytes_generated_; size_t crankshaft_codegen_bytes_generated_; // This counter is increased before each GC and never reset. // To account for the bytes allocated since the last GC, use the // NewSpaceAllocationCounter() function. size_t new_space_allocation_counter_; // This counter is increased before each GC and never reset. To // account for the bytes allocated since the last GC, use the // OldGenerationAllocationCounter() function. size_t old_generation_allocation_counter_; // The size of objects in old generation after the last MarkCompact GC. size_t old_generation_size_at_last_gc_; // If the --deopt_every_n_garbage_collections flag is set to a positive value, // this variable holds the number of garbage collections since the last // deoptimization triggered by garbage collection. int gcs_since_last_deopt_; int allocation_sites_scratchpad_length_; char trace_ring_buffer_[kTraceRingBufferSize]; // If it's not full then the data is from 0 to ring_buffer_end_. If it's // full then the data is from ring_buffer_end_ to the end of the buffer and // from 0 to ring_buffer_end_. bool ring_buffer_full_; size_t ring_buffer_end_; // Shared state read by the scavenge collector and set by ScavengeObject. PromotionQueue promotion_queue_; // Flag is set when the heap has been configured. The heap can be repeatedly // configured through the API until it is set up. bool configured_; // Currently set GC flags that are respected by all GC components. int current_gc_flags_; // Currently set GC callback flags that are used to pass information between // the embedder and V8's GC. GCCallbackFlags current_gc_callback_flags_; ExternalStringTable external_string_table_; MemoryChunk* chunks_queued_for_free_; size_t concurrent_unmapping_tasks_active_; base::Semaphore pending_unmapping_tasks_semaphore_; base::Mutex relocation_mutex_; int gc_callbacks_depth_; bool deserialization_complete_; bool concurrent_sweeping_enabled_; StrongRootsList* strong_roots_list_; ArrayBufferTracker* array_buffer_tracker_; // Classes in "heap" can be friends. friend class AlwaysAllocateScope; friend class GCCallbacksScope; friend class GCTracer; friend class HeapIterator; friend class IncrementalMarking; friend class MarkCompactCollector; friend class MarkCompactMarkingVisitor; friend class NewSpace; friend class ObjectStatsVisitor; friend class Page; friend class Scavenger; friend class StoreBuffer; // The allocator interface. friend class Factory; // The Isolate constructs us. friend class Isolate; // Used in cctest. friend class HeapTester; DISALLOW_COPY_AND_ASSIGN(Heap); }; class HeapStats { public: static const int kStartMarker = 0xDECADE00; static const int kEndMarker = 0xDECADE01; int* start_marker; // 0 int* new_space_size; // 1 int* new_space_capacity; // 2 intptr_t* old_space_size; // 3 intptr_t* old_space_capacity; // 4 intptr_t* code_space_size; // 5 intptr_t* code_space_capacity; // 6 intptr_t* map_space_size; // 7 intptr_t* map_space_capacity; // 8 intptr_t* lo_space_size; // 9 int* global_handle_count; // 10 int* weak_global_handle_count; // 11 int* pending_global_handle_count; // 12 int* near_death_global_handle_count; // 13 int* free_global_handle_count; // 14 intptr_t* memory_allocator_size; // 15 intptr_t* memory_allocator_capacity; // 16 int* objects_per_type; // 17 int* size_per_type; // 18 int* os_error; // 19 char* last_few_messages; // 20 char* js_stacktrace; // 21 int* end_marker; // 22 }; class AlwaysAllocateScope { public: explicit inline AlwaysAllocateScope(Isolate* isolate); inline ~AlwaysAllocateScope(); private: Heap* heap_; }; // Visitor class to verify interior pointers in spaces that do not contain // or care about intergenerational references. All heap object pointers have to // point into the heap to a location that has a map pointer at its first word. // Caveat: Heap::Contains is an approximation because it can return true for // objects in a heap space but above the allocation pointer. class VerifyPointersVisitor : public ObjectVisitor { public: inline void VisitPointers(Object** start, Object** end); }; // Verify that all objects are Smis. class VerifySmisVisitor : public ObjectVisitor { public: inline void VisitPointers(Object** start, Object** end); }; // Space iterator for iterating over all spaces of the heap. Returns each space // in turn, and null when it is done. class AllSpaces BASE_EMBEDDED { public: explicit AllSpaces(Heap* heap) : heap_(heap), counter_(FIRST_SPACE) {} Space* next(); private: Heap* heap_; int counter_; }; // Space iterator for iterating over all old spaces of the heap: Old space // and code space. Returns each space in turn, and null when it is done. class OldSpaces BASE_EMBEDDED { public: explicit OldSpaces(Heap* heap) : heap_(heap), counter_(OLD_SPACE) {} OldSpace* next(); private: Heap* heap_; int counter_; }; // Space iterator for iterating over all the paged spaces of the heap: Map // space, old space, code space and cell space. Returns // each space in turn, and null when it is done. class PagedSpaces BASE_EMBEDDED { public: explicit PagedSpaces(Heap* heap) : heap_(heap), counter_(OLD_SPACE) {} PagedSpace* next(); private: Heap* heap_; int counter_; }; // Space iterator for iterating over all spaces of the heap. // For each space an object iterator is provided. The deallocation of the // returned object iterators is handled by the space iterator. class SpaceIterator : public Malloced { public: explicit SpaceIterator(Heap* heap); virtual ~SpaceIterator(); bool has_next(); ObjectIterator* next(); private: ObjectIterator* CreateIterator(); Heap* heap_; int current_space_; // from enum AllocationSpace. ObjectIterator* iterator_; // object iterator for the current space. }; // A HeapIterator provides iteration over the whole heap. It // aggregates the specific iterators for the different spaces as // these can only iterate over one space only. // // HeapIterator ensures there is no allocation during its lifetime // (using an embedded DisallowHeapAllocation instance). // // HeapIterator can skip free list nodes (that is, de-allocated heap // objects that still remain in the heap). As implementation of free // nodes filtering uses GC marks, it can't be used during MS/MC GC // phases. Also, it is forbidden to interrupt iteration in this mode, // as this will leave heap objects marked (and thus, unusable). class HeapIterator BASE_EMBEDDED { public: enum HeapObjectsFiltering { kNoFiltering, kFilterUnreachable }; explicit HeapIterator(Heap* heap, HeapObjectsFiltering filtering = kNoFiltering); ~HeapIterator(); HeapObject* next(); private: struct MakeHeapIterableHelper { explicit MakeHeapIterableHelper(Heap* heap) { heap->MakeHeapIterable(); } }; HeapObject* NextObject(); // The following two fields need to be declared in this order. Initialization // order guarantees that we first make the heap iterable (which may involve // allocations) and only then lock it down by not allowing further // allocations. MakeHeapIterableHelper make_heap_iterable_helper_; DisallowHeapAllocation no_heap_allocation_; Heap* heap_; HeapObjectsFiltering filtering_; HeapObjectsFilter* filter_; // Space iterator for iterating all the spaces. SpaceIterator* space_iterator_; // Object iterator for the space currently being iterated. ObjectIterator* object_iterator_; }; // Cache for mapping (map, property name) into field offset. // Cleared at startup and prior to mark sweep collection. class KeyedLookupCache { public: // Lookup field offset for (map, name). If absent, -1 is returned. int Lookup(Handle map, Handle name); // Update an element in the cache. void Update(Handle map, Handle name, int field_offset); // Clear the cache. void Clear(); static const int kLength = 256; static const int kCapacityMask = kLength - 1; static const int kMapHashShift = 5; static const int kHashMask = -4; // Zero the last two bits. static const int kEntriesPerBucket = 4; static const int kEntryLength = 2; static const int kMapIndex = 0; static const int kKeyIndex = 1; static const int kNotFound = -1; // kEntriesPerBucket should be a power of 2. STATIC_ASSERT((kEntriesPerBucket & (kEntriesPerBucket - 1)) == 0); STATIC_ASSERT(kEntriesPerBucket == -kHashMask); private: KeyedLookupCache() { for (int i = 0; i < kLength; ++i) { keys_[i].map = NULL; keys_[i].name = NULL; field_offsets_[i] = kNotFound; } } static inline int Hash(Handle map, Handle name); // Get the address of the keys and field_offsets arrays. Used in // generated code to perform cache lookups. Address keys_address() { return reinterpret_cast
(&keys_); } Address field_offsets_address() { return reinterpret_cast
(&field_offsets_); } struct Key { Map* map; Name* name; }; Key keys_[kLength]; int field_offsets_[kLength]; friend class ExternalReference; friend class Isolate; DISALLOW_COPY_AND_ASSIGN(KeyedLookupCache); }; // Cache for mapping (map, property name) into descriptor index. // The cache contains both positive and negative results. // Descriptor index equals kNotFound means the property is absent. // Cleared at startup and prior to any gc. class DescriptorLookupCache { public: // Lookup descriptor index for (map, name). // If absent, kAbsent is returned. inline int Lookup(Map* source, Name* name); // Update an element in the cache. inline void Update(Map* source, Name* name, int result); // Clear the cache. void Clear(); static const int kAbsent = -2; private: DescriptorLookupCache() { for (int i = 0; i < kLength; ++i) { keys_[i].source = NULL; keys_[i].name = NULL; results_[i] = kAbsent; } } static int Hash(Object* source, Name* name) { // Uses only lower 32 bits if pointers are larger. uint32_t source_hash = static_cast(reinterpret_cast(source)) >> kPointerSizeLog2; uint32_t name_hash = static_cast(reinterpret_cast(name)) >> kPointerSizeLog2; return (source_hash ^ name_hash) % kLength; } static const int kLength = 64; struct Key { Map* source; Name* name; }; Key keys_[kLength]; int results_[kLength]; friend class Isolate; DISALLOW_COPY_AND_ASSIGN(DescriptorLookupCache); }; // Abstract base class for checking whether a weak object should be retained. class WeakObjectRetainer { public: virtual ~WeakObjectRetainer() {} // Return whether this object should be retained. If NULL is returned the // object has no references. Otherwise the address of the retained object // should be returned as in some GC situations the object has been moved. virtual Object* RetainAs(Object* object) = 0; }; #ifdef DEBUG // Helper class for tracing paths to a search target Object from all roots. // The TracePathFrom() method can be used to trace paths from a specific // object to the search target object. class PathTracer : public ObjectVisitor { public: enum WhatToFind { FIND_ALL, // Will find all matches. FIND_FIRST // Will stop the search after first match. }; // Tags 0, 1, and 3 are used. Use 2 for marking visited HeapObject. static const int kMarkTag = 2; // For the WhatToFind arg, if FIND_FIRST is specified, tracing will stop // after the first match. If FIND_ALL is specified, then tracing will be // done for all matches. PathTracer(Object* search_target, WhatToFind what_to_find, VisitMode visit_mode) : search_target_(search_target), found_target_(false), found_target_in_trace_(false), what_to_find_(what_to_find), visit_mode_(visit_mode), object_stack_(20), no_allocation() {} virtual void VisitPointers(Object** start, Object** end); void Reset(); void TracePathFrom(Object** root); bool found() const { return found_target_; } static Object* const kAnyGlobalObject; protected: class MarkVisitor; class UnmarkVisitor; void MarkRecursively(Object** p, MarkVisitor* mark_visitor); void UnmarkRecursively(Object** p, UnmarkVisitor* unmark_visitor); virtual void ProcessResults(); Object* search_target_; bool found_target_; bool found_target_in_trace_; WhatToFind what_to_find_; VisitMode visit_mode_; List object_stack_; DisallowHeapAllocation no_allocation; // i.e. no gc allowed. private: DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer); }; #endif // DEBUG } // namespace internal } // namespace v8 #endif // V8_HEAP_HEAP_H_