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Diffstat (limited to 'src/3rdparty/v8/src/heap.h')
| -rw-r--r-- | src/3rdparty/v8/src/heap.h | 3009 |
1 files changed, 0 insertions, 3009 deletions
diff --git a/src/3rdparty/v8/src/heap.h b/src/3rdparty/v8/src/heap.h deleted file mode 100644 index d690e18..0000000 --- a/src/3rdparty/v8/src/heap.h +++ /dev/null @@ -1,3009 +0,0 @@ -// Copyright 2012 the V8 project authors. All rights reserved. -// Redistribution and use in source and binary forms, with or without -// modification, are permitted provided that the following conditions are -// met: -// -// * Redistributions of source code must retain the above copyright -// notice, this list of conditions and the following disclaimer. -// * Redistributions in binary form must reproduce the above -// copyright notice, this list of conditions and the following -// disclaimer in the documentation and/or other materials provided -// with the distribution. -// * Neither the name of Google Inc. nor the names of its -// contributors may be used to endorse or promote products derived -// from this software without specific prior written permission. -// -// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR -// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT -// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, -// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT -// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, -// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY -// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT -// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE -// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - -#ifndef V8_HEAP_H_ -#define V8_HEAP_H_ - -#include <math.h> - -#include "allocation.h" -#include "globals.h" -#include "incremental-marking.h" -#include "list.h" -#include "mark-compact.h" -#include "objects-visiting.h" -#include "spaces.h" -#include "splay-tree-inl.h" -#include "store-buffer.h" -#include "v8-counters.h" -#include "v8globals.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(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, 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(Object, no_interceptor_result_sentinel, NoInterceptorResultSentinel) \ - V(Map, hash_table_map, HashTableMap) \ - V(FixedArray, empty_fixed_array, EmptyFixedArray) \ - V(ByteArray, empty_byte_array, EmptyByteArray) \ - V(DescriptorArray, empty_descriptor_array, EmptyDescriptorArray) \ - V(Smi, stack_limit, StackLimit) \ - V(Oddball, arguments_marker, ArgumentsMarker) \ - /* The first 32 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(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(Object, termination_exception, TerminationException) \ - V(Smi, hash_seed, HashSeed) \ - V(Map, symbol_map, SymbolMap) \ - V(Map, string_map, StringMap) \ - V(Map, ascii_string_map, AsciiStringMap) \ - V(Map, cons_string_map, ConsStringMap) \ - V(Map, cons_ascii_string_map, ConsAsciiStringMap) \ - V(Map, sliced_string_map, SlicedStringMap) \ - V(Map, sliced_ascii_string_map, SlicedAsciiStringMap) \ - V(Map, external_string_map, ExternalStringMap) \ - V(Map, external_string_with_ascii_data_map, ExternalStringWithAsciiDataMap) \ - V(Map, external_ascii_string_map, ExternalAsciiStringMap) \ - V(Map, short_external_string_map, ShortExternalStringMap) \ - V(Map, \ - short_external_string_with_ascii_data_map, \ - ShortExternalStringWithAsciiDataMap) \ - V(Map, internalized_string_map, InternalizedStringMap) \ - V(Map, ascii_internalized_string_map, AsciiInternalizedStringMap) \ - V(Map, cons_internalized_string_map, ConsInternalizedStringMap) \ - V(Map, cons_ascii_internalized_string_map, ConsAsciiInternalizedStringMap) \ - V(Map, \ - external_internalized_string_map, \ - ExternalInternalizedStringMap) \ - V(Map, \ - external_internalized_string_with_ascii_data_map, \ - ExternalInternalizedStringWithAsciiDataMap) \ - V(Map, \ - external_ascii_internalized_string_map, \ - ExternalAsciiInternalizedStringMap) \ - V(Map, \ - short_external_internalized_string_map, \ - ShortExternalInternalizedStringMap) \ - V(Map, \ - short_external_internalized_string_with_ascii_data_map, \ - ShortExternalInternalizedStringWithAsciiDataMap) \ - V(Map, \ - short_external_ascii_internalized_string_map, \ - ShortExternalAsciiInternalizedStringMap) \ - V(Map, short_external_ascii_string_map, ShortExternalAsciiStringMap) \ - V(Map, undetectable_string_map, UndetectableStringMap) \ - V(Map, undetectable_ascii_string_map, UndetectableAsciiStringMap) \ - V(Map, external_pixel_array_map, ExternalPixelArrayMap) \ - V(Map, external_byte_array_map, ExternalByteArrayMap) \ - V(Map, external_unsigned_byte_array_map, ExternalUnsignedByteArrayMap) \ - V(Map, external_short_array_map, ExternalShortArrayMap) \ - V(Map, external_unsigned_short_array_map, ExternalUnsignedShortArrayMap) \ - V(Map, external_int_array_map, ExternalIntArrayMap) \ - V(Map, external_unsigned_int_array_map, ExternalUnsignedIntArrayMap) \ - V(Map, external_float_array_map, ExternalFloatArrayMap) \ - V(Map, external_double_array_map, ExternalDoubleArrayMap) \ - V(Map, non_strict_arguments_elements_map, NonStrictArgumentsElementsMap) \ - V(Map, function_context_map, FunctionContextMap) \ - 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, global_context_map, GlobalContextMap) \ - V(Map, oddball_map, OddballMap) \ - V(Map, message_object_map, JSMessageObjectMap) \ - V(Map, foreign_map, ForeignMap) \ - V(HeapNumber, nan_value, NanValue) \ - V(HeapNumber, infinity_value, InfinityValue) \ - V(HeapNumber, minus_zero_value, MinusZeroValue) \ - V(Map, neander_map, NeanderMap) \ - V(JSObject, message_listeners, MessageListeners) \ - V(Foreign, prototype_accessors, PrototypeAccessors) \ - 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(Object, last_script_id, LastScriptId) \ - V(Script, empty_script, EmptyScript) \ - V(Smi, real_stack_limit, RealStackLimit) \ - V(StringDictionary, intrinsic_function_names, IntrinsicFunctionNames) \ - 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) \ - V(JSObject, observation_state, ObservationState) \ - V(Map, external_map, ExternalMap) - -#define ROOT_LIST(V) \ - STRONG_ROOT_LIST(V) \ - V(StringTable, string_table, StringTable) - -#define INTERNALIZED_STRING_LIST(V) \ - V(Array_string, "Array") \ - V(Object_string, "Object") \ - V(proto_string, "__proto__") \ - V(StringImpl_string, "StringImpl") \ - V(arguments_string, "arguments") \ - V(Arguments_string, "Arguments") \ - V(call_string, "call") \ - V(apply_string, "apply") \ - V(caller_string, "caller") \ - V(boolean_string, "boolean") \ - V(Boolean_string, "Boolean") \ - V(callee_string, "callee") \ - V(constructor_string, "constructor") \ - V(code_string, ".code") \ - V(result_string, ".result") \ - V(dot_for_string, ".for.") \ - V(catch_var_string, ".catch-var") \ - V(empty_string, "") \ - V(eval_string, "eval") \ - V(function_string, "function") \ - V(length_string, "length") \ - V(module_string, "module") \ - V(name_string, "name") \ - V(native_string, "native") \ - V(null_string, "null") \ - V(number_string, "number") \ - V(Number_string, "Number") \ - V(nan_string, "NaN") \ - V(RegExp_string, "RegExp") \ - V(source_string, "source") \ - V(global_string, "global") \ - V(ignore_case_string, "ignoreCase") \ - V(multiline_string, "multiline") \ - V(input_string, "input") \ - V(index_string, "index") \ - V(last_index_string, "lastIndex") \ - V(object_string, "object") \ - V(prototype_string, "prototype") \ - V(string_string, "string") \ - V(String_string, "String") \ - V(Date_string, "Date") \ - V(Error_string, "Error") \ - V(this_string, "this") \ - V(to_string_string, "toString") \ - V(char_at_string, "CharAt") \ - V(undefined_string, "undefined") \ - V(value_of_string, "valueOf") \ - V(stack_string, "stack") \ - V(InitializeVarGlobal_string, "InitializeVarGlobal") \ - V(InitializeConstGlobal_string, "InitializeConstGlobal") \ - V(KeyedLoadElementMonomorphic_string, \ - "KeyedLoadElementMonomorphic") \ - V(KeyedStoreElementMonomorphic_string, \ - "KeyedStoreElementMonomorphic") \ - V(KeyedStoreAndGrowElementMonomorphic_string, \ - "KeyedStoreAndGrowElementMonomorphic") \ - V(stack_overflow_string, "kStackOverflowBoilerplate") \ - V(illegal_access_string, "illegal access") \ - V(out_of_memory_string, "out-of-memory") \ - V(illegal_execution_state_string, "illegal execution state") \ - V(get_string, "get") \ - V(set_string, "set") \ - V(map_field_string, "%map") \ - V(elements_field_string, "%elements") \ - V(length_field_string, "%length") \ - V(function_class_string, "Function") \ - V(illegal_argument_string, "illegal argument") \ - V(MakeReferenceError_string, "MakeReferenceError") \ - V(MakeSyntaxError_string, "MakeSyntaxError") \ - V(MakeTypeError_string, "MakeTypeError") \ - V(invalid_lhs_in_assignment_string, "invalid_lhs_in_assignment") \ - V(invalid_lhs_in_for_in_string, "invalid_lhs_in_for_in") \ - V(invalid_lhs_in_postfix_op_string, "invalid_lhs_in_postfix_op") \ - V(invalid_lhs_in_prefix_op_string, "invalid_lhs_in_prefix_op") \ - V(illegal_return_string, "illegal_return") \ - V(illegal_break_string, "illegal_break") \ - V(illegal_continue_string, "illegal_continue") \ - V(unknown_label_string, "unknown_label") \ - V(redeclaration_string, "redeclaration") \ - V(failure_string, "<failure>") \ - V(space_string, " ") \ - V(exec_string, "exec") \ - V(zero_string, "0") \ - V(global_eval_string, "GlobalEval") \ - V(identity_hash_string, "v8::IdentityHash") \ - V(closure_string, "(closure)") \ - V(use_strict_string, "use strict") \ - V(dot_string, ".") \ - V(anonymous_function_string, "(anonymous function)") \ - V(compare_ic_string, "==") \ - V(strict_compare_ic_string, "===") \ - V(infinity_string, "Infinity") \ - V(minus_infinity_string, "-Infinity") \ - V(hidden_stack_trace_string, "v8::hidden_stack_trace") \ - V(query_colon_string, "(?:)") \ - -// Forward declarations. -class GCTracer; -class HeapStats; -class Isolate; -class WeakObjectRetainer; - - -typedef HeapObject* (*ExternalStringTableUpdaterCallback)(Heap* heap, - Object** pointer); - -class StoreBufferRebuilder { - public: - explicit StoreBufferRebuilder(StoreBuffer* store_buffer) - : store_buffer_(store_buffer) { - } - - void Callback(MemoryChunk* page, StoreBufferEvent event); - - private: - StoreBuffer* store_buffer_; - - // We record in this variable how full the store buffer was when we started - // iterating over the current page, finding pointers to new space. If the - // store buffer overflows again we can exempt the page from the store buffer - // by rewinding to this point instead of having to search the store buffer. - Object*** start_of_current_page_; - // The current page we are scanning in the store buffer iterator. - MemoryChunk* current_page_; -}; - - - -// A queue of objects promoted during scavenge. Each object is accompanied -// by it's size to avoid dereferencing a map pointer for scanning. -class PromotionQueue { - public: - explicit PromotionQueue(Heap* heap) - : front_(NULL), - rear_(NULL), - limit_(NULL), - emergency_stack_(0), - heap_(heap) { } - - void Initialize(); - - void Destroy() { - ASSERT(is_empty()); - delete emergency_stack_; - emergency_stack_ = NULL; - } - - inline void ActivateGuardIfOnTheSamePage(); - - Page* GetHeadPage() { - return Page::FromAllocationTop(reinterpret_cast<Address>(rear_)); - } - - void SetNewLimit(Address limit) { - if (!guard_) { - return; - } - - ASSERT(GetHeadPage() == Page::FromAllocationTop(limit)); - limit_ = reinterpret_cast<intptr_t*>(limit); - - if (limit_ <= rear_) { - return; - } - - RelocateQueueHead(); - } - - 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) { - ASSERT(!is_empty()); - if (front_ == rear_) { - Entry e = emergency_stack_->RemoveLast(); - *target = e.obj_; - *size = e.size_; - return; - } - - if (NewSpacePage::IsAtStart(reinterpret_cast<Address>(front_))) { - NewSpacePage* front_page = - NewSpacePage::FromAddress(reinterpret_cast<Address>(front_)); - ASSERT(!front_page->prev_page()->is_anchor()); - front_ = - reinterpret_cast<intptr_t*>(front_page->prev_page()->area_end()); - } - *target = reinterpret_cast<HeapObject*>(*(--front_)); - *size = static_cast<int>(*(--front_)); - // Assert no underflow. - SemiSpace::AssertValidRange(reinterpret_cast<Address>(rear_), - reinterpret_cast<Address>(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_; - - bool guard_; - - static const int kEntrySizeInWords = 2; - - struct Entry { - Entry(HeapObject* obj, int size) : obj_(obj), size_(size) { } - - HeapObject* obj_; - int size_; - }; - List<Entry>* emergency_stack_; - - Heap* heap_; - - void RelocateQueueHead(); - - DISALLOW_COPY_AND_ASSIGN(PromotionQueue); -}; - - -typedef void (*ScavengingCallback)(Map* map, - HeapObject** slot, - HeapObject* object); - - -// External strings table is a place where all external strings are -// registered. We need to keep track of such strings to properly -// finalize them. -// The ExternalStringTable can contain both strings and objects with -// external resources. It was not renamed to make the patch simpler. -class ExternalStringTable { - public: - // Registers an external string. - inline void AddString(String* string); - // Registers an external object. - inline void AddObject(HeapObject* 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: - ExternalStringTable() { } - - friend class Heap; - - inline void Verify(); - - inline void AddOldObject(HeapObject* string); - - // Notifies the table that only a prefix of the new list is valid. - inline void ShrinkNewObjects(int position); - - // To speed up scavenge collections new space string are kept - // separate from old space strings. - List<Object*> new_space_strings_; - List<Object*> old_space_strings_; - - Heap* heap_; - - DISALLOW_COPY_AND_ASSIGN(ExternalStringTable); -}; - - -// The stack property of an error object is implemented as a getter that -// formats the attached raw stack trace into a string. This raw stack trace -// keeps code and function objects alive until the getter is called the first -// time. To release those objects, we call the getter after each GC for -// newly tenured error objects that are kept in a list. -class ErrorObjectList { - public: - inline void Add(JSObject* object); - - inline void Iterate(ObjectVisitor* v); - - void TearDown(); - - void RemoveUnmarked(Heap* heap); - - void DeferredFormatStackTrace(Isolate* isolate); - - void UpdateReferences(); - - void UpdateReferencesInNewSpace(Heap* heap); - - private: - static const int kBudgetPerGC = 16; - - ErrorObjectList() : nested_(false) { } - - friend class Heap; - - List<Object*> list_; - bool nested_; - - DISALLOW_COPY_AND_ASSIGN(ErrorObjectList); -}; - - -enum ArrayStorageAllocationMode { - DONT_INITIALIZE_ARRAY_ELEMENTS, - INITIALIZE_ARRAY_ELEMENTS_WITH_HOLE -}; - -class Heap { - public: - // Configure heap size before setup. Return false if the heap has been - // set up already. - bool ConfigureHeap(int max_semispace_size, - intptr_t max_old_gen_size, - intptr_t max_executable_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(); - - // 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(); - - // Returns whether SetUp has been called. - bool HasBeenSetUp(); - - // 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_semispace_size_; } - int ReservedSemiSpaceSize() { return reserved_semispace_size_; } - int InitialSemiSpaceSize() { return initial_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 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 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(); - - // 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_pointer_space() { return old_pointer_space_; } - OldSpace* old_data_space() { return old_data_space_; } - OldSpace* code_space() { return code_space_; } - MapSpace* map_space() { return map_space_; } - CellSpace* cell_space() { return cell_space_; } - LargeObjectSpace* lo_space() { return lo_space_; } - PagedSpace* paged_space(int idx) { - switch (idx) { - case OLD_POINTER_SPACE: - return old_pointer_space(); - case OLD_DATA_SPACE: - return old_data_space(); - case MAP_SPACE: - return map_space(); - case CELL_SPACE: - return cell_space(); - case CODE_SPACE: - return code_space(); - case NEW_SPACE: - case LO_SPACE: - UNREACHABLE(); - } - return NULL; - } - - bool always_allocate() { return always_allocate_scope_depth_ != 0; } - Address always_allocate_scope_depth_address() { - return reinterpret_cast<Address>(&always_allocate_scope_depth_); - } - bool linear_allocation() { - return linear_allocation_scope_depth_ != 0; - } - - Address* NewSpaceAllocationTopAddress() { - return new_space_.allocation_top_address(); - } - Address* NewSpaceAllocationLimitAddress() { - return new_space_.allocation_limit_address(); - } - - // Uncommit unused semi space. - bool UncommitFromSpace() { return new_space_.UncommitFromSpace(); } - - // Allocates and initializes a new JavaScript object based on a - // constructor. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateJSObject( - JSFunction* constructor, - PretenureFlag pretenure = NOT_TENURED); - - MUST_USE_RESULT MaybeObject* AllocateJSObjectWithAllocationSite( - JSFunction* constructor, - Handle<Object> allocation_site_info_payload); - - MUST_USE_RESULT MaybeObject* AllocateJSModule(Context* context, - ScopeInfo* scope_info); - - // Allocate a JSArray with no elements - MUST_USE_RESULT MaybeObject* AllocateEmptyJSArray( - ElementsKind elements_kind, - PretenureFlag pretenure = NOT_TENURED) { - return AllocateJSArrayAndStorage(elements_kind, 0, 0, - DONT_INITIALIZE_ARRAY_ELEMENTS, - pretenure); - } - - inline MUST_USE_RESULT MaybeObject* AllocateEmptyJSArrayWithAllocationSite( - ElementsKind elements_kind, - Handle<Object> allocation_site_payload); - - // Allocate a JSArray with a specified length but elements that are left - // uninitialized. - MUST_USE_RESULT MaybeObject* AllocateJSArrayAndStorage( - ElementsKind elements_kind, - int length, - int capacity, - ArrayStorageAllocationMode mode = DONT_INITIALIZE_ARRAY_ELEMENTS, - PretenureFlag pretenure = NOT_TENURED); - - MUST_USE_RESULT MaybeObject* AllocateJSArrayAndStorageWithAllocationSite( - ElementsKind elements_kind, - int length, - int capacity, - Handle<Object> allocation_site_payload, - ArrayStorageAllocationMode mode = DONT_INITIALIZE_ARRAY_ELEMENTS); - - MUST_USE_RESULT MaybeObject* AllocateJSArrayStorage( - JSArray* array, - int length, - int capacity, - ArrayStorageAllocationMode mode = DONT_INITIALIZE_ARRAY_ELEMENTS); - - // Allocate a JSArray with no elements - MUST_USE_RESULT MaybeObject* AllocateJSArrayWithElements( - FixedArrayBase* array_base, - ElementsKind elements_kind, - int length, - PretenureFlag pretenure = NOT_TENURED); - - // Allocates and initializes a new global object based on a constructor. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateGlobalObject(JSFunction* constructor); - - // Returns a deep copy of the JavaScript object. - // Properties and elements are copied too. - // Returns failure if allocation failed. - MUST_USE_RESULT MaybeObject* CopyJSObject(JSObject* source); - - MUST_USE_RESULT MaybeObject* CopyJSObjectWithAllocationSite(JSObject* source); - - // Allocates the function prototype. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateFunctionPrototype(JSFunction* function); - - // Allocates a Harmony proxy or function proxy. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateJSProxy(Object* handler, - Object* prototype); - - MUST_USE_RESULT MaybeObject* AllocateJSFunctionProxy(Object* handler, - Object* call_trap, - Object* construct_trap, - Object* prototype); - - // Reinitialize a JSReceiver into an (empty) JS object of respective type and - // size, but keeping the original prototype. The receiver must have at least - // the size of the new object. The object is reinitialized and behaves as an - // object that has been freshly allocated. - // Returns failure if an error occured, otherwise object. - MUST_USE_RESULT MaybeObject* ReinitializeJSReceiver(JSReceiver* object, - InstanceType type, - int size); - - // Reinitialize an JSGlobalProxy based on a constructor. The object - // must have the same size as objects allocated using the - // constructor. The object is reinitialized and behaves as an - // object that has been freshly allocated using the constructor. - MUST_USE_RESULT MaybeObject* ReinitializeJSGlobalProxy( - JSFunction* constructor, JSGlobalProxy* global); - - // Allocates and initializes a new JavaScript object based on a map. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateJSObjectFromMap( - Map* map, PretenureFlag pretenure = NOT_TENURED); - - MUST_USE_RESULT MaybeObject* AllocateJSObjectFromMapWithAllocationSite( - Map* map, Handle<Object> allocation_site_info_payload); - - // Allocates a heap object based on the map. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this function does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* Allocate(Map* map, AllocationSpace space); - - MUST_USE_RESULT MaybeObject* AllocateWithAllocationSite(Map* map, - AllocationSpace space, Handle<Object> allocation_site_info_payload); - - // Allocates a JS Map in the heap. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this function does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateMap( - InstanceType instance_type, - int instance_size, - ElementsKind elements_kind = TERMINAL_FAST_ELEMENTS_KIND); - - // Allocates a partial map for bootstrapping. - MUST_USE_RESULT MaybeObject* AllocatePartialMap(InstanceType instance_type, - int instance_size); - - // Allocate a map for the specified function - MUST_USE_RESULT MaybeObject* AllocateInitialMap(JSFunction* fun); - - // Allocates an empty code cache. - MUST_USE_RESULT MaybeObject* AllocateCodeCache(); - - // Allocates a serialized scope info. - MUST_USE_RESULT MaybeObject* AllocateScopeInfo(int length); - - // Allocates an External object for v8's external API. - MUST_USE_RESULT MaybeObject* AllocateExternal(void* value); - - // Allocates an empty PolymorphicCodeCache. - MUST_USE_RESULT MaybeObject* AllocatePolymorphicCodeCache(); - - // Allocates a pre-tenured empty AccessorPair. - MUST_USE_RESULT MaybeObject* AllocateAccessorPair(); - - // Allocates an empty TypeFeedbackInfo. - MUST_USE_RESULT MaybeObject* AllocateTypeFeedbackInfo(); - - // Allocates an AliasedArgumentsEntry. - MUST_USE_RESULT MaybeObject* AllocateAliasedArgumentsEntry(int slot); - - // Clear the Instanceof cache (used when a prototype changes). - inline void ClearInstanceofCache(); - - // For use during bootup. - void RepairFreeListsAfterBoot(); - - // Allocates and fully initializes a String. There are two String - // encodings: ASCII and two byte. One should choose between the three string - // allocation functions based on the encoding of the string buffer used to - // initialized the string. - // - ...FromAscii initializes the string from a buffer that is ASCII - // encoded (it does not check that the buffer is ASCII encoded) and the - // result will be ASCII encoded. - // - ...FromUTF8 initializes the string from a buffer that is UTF-8 - // encoded. If the characters are all single-byte characters, the - // result will be ASCII encoded, otherwise it will converted to two - // byte. - // - ...FromTwoByte initializes the string from a buffer that is two-byte - // encoded. If the characters are all single-byte characters, the - // result will be converted to ASCII, otherwise it will be left as - // two-byte. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateStringFromOneByte( - Vector<const uint8_t> str, - PretenureFlag pretenure = NOT_TENURED); - // TODO(dcarney): remove this function. - MUST_USE_RESULT inline MaybeObject* AllocateStringFromOneByte( - Vector<const char> str, - PretenureFlag pretenure = NOT_TENURED) { - return AllocateStringFromOneByte(Vector<const uint8_t>::cast(str), - pretenure); - } - MUST_USE_RESULT inline MaybeObject* AllocateStringFromUtf8( - Vector<const char> str, - PretenureFlag pretenure = NOT_TENURED); - MUST_USE_RESULT MaybeObject* AllocateStringFromUtf8Slow( - Vector<const char> str, - int non_ascii_start, - PretenureFlag pretenure = NOT_TENURED); - MUST_USE_RESULT MaybeObject* AllocateStringFromTwoByte( - Vector<const uc16> str, - PretenureFlag pretenure = NOT_TENURED); - - // Allocates an internalized string in old space based on the character - // stream. Returns Failure::RetryAfterGC(requested_bytes, space) if the - // allocation failed. - // Please note this function does not perform a garbage collection. - MUST_USE_RESULT inline MaybeObject* AllocateInternalizedStringFromUtf8( - Vector<const char> str, - int chars, - uint32_t hash_field); - - MUST_USE_RESULT inline MaybeObject* AllocateOneByteInternalizedString( - Vector<const uint8_t> str, - uint32_t hash_field); - - MUST_USE_RESULT inline MaybeObject* AllocateTwoByteInternalizedString( - Vector<const uc16> str, - uint32_t hash_field); - - template<typename T> - static inline bool IsOneByte(T t, int chars); - - template<typename T> - MUST_USE_RESULT inline MaybeObject* AllocateInternalizedStringImpl( - T t, int chars, uint32_t hash_field); - - template<bool is_one_byte, typename T> - MUST_USE_RESULT MaybeObject* AllocateInternalizedStringImpl( - T t, int chars, uint32_t hash_field); - - // Allocates and partially initializes a String. There are two String - // encodings: ASCII 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. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateRawOneByteString( - int length, - PretenureFlag pretenure = NOT_TENURED); - MUST_USE_RESULT MaybeObject* AllocateRawTwoByteString( - int length, - PretenureFlag pretenure = NOT_TENURED); - - // Computes a single character string where the character has code. - // A cache is used for ASCII codes. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* LookupSingleCharacterStringFromCode( - uint16_t code); - - // Allocate a byte array of the specified length - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateByteArray(int length, - PretenureFlag pretenure); - - // Allocate a non-tenured byte array of the specified length - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateByteArray(int length); - - // Allocates an external array of the specified length and type. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateExternalArray( - int length, - ExternalArrayType array_type, - void* external_pointer, - PretenureFlag pretenure); - - // Allocate a symbol. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateSymbol( - PretenureFlag pretenure = NOT_TENURED); - - // Allocate a tenured JS global property cell. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateJSGlobalPropertyCell(Object* value); - - // Allocates a fixed array initialized with undefined values - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateFixedArray(int length, - PretenureFlag pretenure); - // Allocates a fixed array initialized with undefined values - MUST_USE_RESULT MaybeObject* AllocateFixedArray(int length); - - // Allocates an uninitialized fixed array. It must be filled by the caller. - // - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateUninitializedFixedArray(int length); - - // 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); - - // Make a copy of src and return it. Returns - // Failure::RetryAfterGC(requested_bytes, space) if the allocation failed. - MUST_USE_RESULT inline MaybeObject* CopyFixedArray(FixedArray* src); - - // Make a copy of src, set the map, and return the copy. Returns - // Failure::RetryAfterGC(requested_bytes, space) if the allocation failed. - MUST_USE_RESULT MaybeObject* CopyFixedArrayWithMap(FixedArray* src, Map* map); - - // Make a copy of src and return it. Returns - // Failure::RetryAfterGC(requested_bytes, space) if the allocation failed. - MUST_USE_RESULT inline MaybeObject* CopyFixedDoubleArray( - FixedDoubleArray* src); - - // Make a copy of src, set the map, and return the copy. Returns - // Failure::RetryAfterGC(requested_bytes, space) if the allocation failed. - MUST_USE_RESULT MaybeObject* CopyFixedDoubleArrayWithMap( - FixedDoubleArray* src, Map* map); - - // Allocates a fixed array initialized with the hole values. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateFixedArrayWithHoles( - int length, - PretenureFlag pretenure = NOT_TENURED); - - MUST_USE_RESULT MaybeObject* AllocateRawFixedDoubleArray( - int length, - PretenureFlag pretenure); - - // Allocates a fixed double array with uninitialized values. Returns - // Failure::RetryAfterGC(requested_bytes, space) if the allocation failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateUninitializedFixedDoubleArray( - int length, - PretenureFlag pretenure = NOT_TENURED); - - // Allocates a fixed double array with hole values. Returns - // Failure::RetryAfterGC(requested_bytes, space) if the allocation failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateFixedDoubleArrayWithHoles( - int length, - PretenureFlag pretenure = NOT_TENURED); - - // AllocateHashTable is identical to AllocateFixedArray except - // that the resulting object has hash_table_map as map. - MUST_USE_RESULT MaybeObject* AllocateHashTable( - int length, PretenureFlag pretenure = NOT_TENURED); - - // Allocate a native (but otherwise uninitialized) context. - MUST_USE_RESULT MaybeObject* AllocateNativeContext(); - - // Allocate a global context. - MUST_USE_RESULT MaybeObject* AllocateGlobalContext(JSFunction* function, - ScopeInfo* scope_info); - - // Allocate a module context. - MUST_USE_RESULT MaybeObject* AllocateModuleContext(ScopeInfo* scope_info); - - // Allocate a function context. - MUST_USE_RESULT MaybeObject* AllocateFunctionContext(int length, - JSFunction* function); - - // Allocate a catch context. - MUST_USE_RESULT MaybeObject* AllocateCatchContext(JSFunction* function, - Context* previous, - String* name, - Object* thrown_object); - // Allocate a 'with' context. - MUST_USE_RESULT MaybeObject* AllocateWithContext(JSFunction* function, - Context* previous, - JSObject* extension); - - // Allocate a block context. - MUST_USE_RESULT MaybeObject* AllocateBlockContext(JSFunction* function, - Context* previous, - ScopeInfo* info); - - // Allocates a new utility object in the old generation. - MUST_USE_RESULT MaybeObject* AllocateStruct(InstanceType type); - - // Allocates a function initialized with a shared part. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateFunction( - Map* function_map, - SharedFunctionInfo* shared, - Object* prototype, - PretenureFlag pretenure = TENURED); - - // Arguments object size. - static const int kArgumentsObjectSize = - JSObject::kHeaderSize + 2 * kPointerSize; - // Strict mode arguments has no callee so it is smaller. - static const int kArgumentsObjectSizeStrict = - JSObject::kHeaderSize + 1 * kPointerSize; - // Indicies for direct access into argument objects. - static const int kArgumentsLengthIndex = 0; - // callee is only valid in non-strict mode. - static const int kArgumentsCalleeIndex = 1; - - // Allocates an arguments object - optionally with an elements array. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateArgumentsObject( - Object* callee, int length); - - // Same as NewNumberFromDouble, but may return a preallocated/immutable - // number object (e.g., minus_zero_value_, nan_value_) - MUST_USE_RESULT MaybeObject* NumberFromDouble( - double value, PretenureFlag pretenure = NOT_TENURED); - - // Allocated a HeapNumber from value. - MUST_USE_RESULT MaybeObject* AllocateHeapNumber( - double value, - PretenureFlag pretenure); - // pretenure = NOT_TENURED - MUST_USE_RESULT MaybeObject* AllocateHeapNumber(double value); - - // Converts an int into either a Smi or a HeapNumber object. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT inline MaybeObject* NumberFromInt32( - int32_t value, PretenureFlag pretenure = NOT_TENURED); - - // Converts an int into either a Smi or a HeapNumber object. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT inline MaybeObject* NumberFromUint32( - uint32_t value, PretenureFlag pretenure = NOT_TENURED); - - // Allocates a new foreign object. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateForeign( - Address address, PretenureFlag pretenure = NOT_TENURED); - - // Allocates a new SharedFunctionInfo object. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateSharedFunctionInfo(Object* name); - - // Allocates a new JSMessageObject object. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note that this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateJSMessageObject( - String* type, - JSArray* arguments, - int start_position, - int end_position, - Object* script, - Object* stack_trace, - Object* stack_frames); - - // Allocates a new cons string object. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateConsString(String* first, - String* second); - - // Allocates a new sub string object which is a substring of an underlying - // string buffer stretching from the index start (inclusive) to the index - // end (exclusive). - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateSubString( - String* buffer, - int start, - int end, - PretenureFlag pretenure = NOT_TENURED); - - // Allocate a new external string object, which is backed by a string - // resource that resides outside the V8 heap. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* AllocateExternalStringFromAscii( - const ExternalAsciiString::Resource* resource); - MUST_USE_RESULT MaybeObject* AllocateExternalStringFromTwoByte( - const ExternalTwoByteString::Resource* resource); - - // Finalizes an external string by deleting the associated external - // data and clearing the resource pointer. - inline void FinalizeExternalString(HeapObject* string); - - // Allocates an uninitialized object. The memory is non-executable if the - // hardware and OS allow. - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this function does not perform a garbage collection. - MUST_USE_RESULT inline MaybeObject* AllocateRaw(int size_in_bytes, - AllocationSpace space, - AllocationSpace retry_space); - - // Initialize a filler object to keep the ability to iterate over the heap - // when shortening objects. - void CreateFillerObjectAt(Address addr, int size); - - // Makes a new native code object - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. On success, the pointer to the Code object is stored in the - // self_reference. This allows generated code to reference its own Code - // object by containing this pointer. - // Please note this function does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* CreateCode(const CodeDesc& desc, - Code::Flags flags, - Handle<Object> self_reference, - bool immovable = false); - - MUST_USE_RESULT MaybeObject* CopyCode(Code* code); - - // Copy the code and scope info part of the code object, but insert - // the provided data as the relocation information. - MUST_USE_RESULT MaybeObject* CopyCode(Code* code, Vector<byte> reloc_info); - - // Finds the internalized copy for string in the string table. - // If not found, a new string is added to the table and returned. - // Returns Failure::RetryAfterGC(requested_bytes, space) if allocation - // failed. - // Please note this function does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* InternalizeUtf8String(Vector<const char> str); - MUST_USE_RESULT MaybeObject* InternalizeUtf8String(const char* str) { - return InternalizeUtf8String(CStrVector(str)); - } - MUST_USE_RESULT MaybeObject* InternalizeOneByteString( - Vector<const uint8_t> str); - MUST_USE_RESULT MaybeObject* InternalizeTwoByteString(Vector<const uc16> str); - MUST_USE_RESULT MaybeObject* InternalizeString(String* str); - MUST_USE_RESULT MaybeObject* InternalizeOneByteString( - Handle<SeqOneByteString> string, int from, int length); - - bool InternalizeStringIfExists(String* str, String** result); - bool InternalizeTwoCharsStringIfExists(String* str, String** result); - - // Compute the matching internalized string map for a string if possible. - // NULL is returned if string is in new space or not flattened. - Map* InternalizedStringMapForString(String* str); - - // Tries to flatten a string before compare operation. - // - // Returns a failure in case it was decided that flattening was - // necessary and failed. Note, if flattening is not necessary the - // string might stay non-flat even when not a failure is returned. - // - // Please note this function does not perform a garbage collection. - MUST_USE_RESULT inline MaybeObject* PrepareForCompare(String* str); - - // Converts the given boolean condition to JavaScript boolean value. - inline Object* ToBoolean(bool condition); - - // 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 garbage collection operation. - // Returns whether there is a chance that another major GC could - // collect more garbage. - bool CollectGarbage(AllocationSpace space, - GarbageCollector collector, - const char* gc_reason, - const char* collector_reason); - - // 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); - - static const int kNoGCFlags = 0; - static const int kSweepPreciselyMask = 1; - static const int kReduceMemoryFootprintMask = 2; - static const int kAbortIncrementalMarkingMask = 4; - - // Making the heap iterable requires us to sweep precisely and abort any - // incremental marking as well. - static const int kMakeHeapIterableMask = - kSweepPreciselyMask | kAbortIncrementalMarkingMask; - - // 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, const char* gc_reason = NULL); - - // Last hope GC, should try to squeeze as much as possible. - void CollectAllAvailableGarbage(const char* gc_reason = NULL); - - // Check whether the heap is currently iterable. - bool IsHeapIterable(); - - // Ensure that we have swept all spaces in such a way that we can iterate - // over all objects. May cause a GC. - void EnsureHeapIsIterable(); - - // Notify the heap that a context has been disposed. - int NotifyContextDisposed() { - flush_monomorphic_ics_ = true; - return ++contexts_disposed_; - } - - // Utility to invoke the scavenger. This is needed in test code to - // ensure correct callback for weak global handles. - void PerformScavenge(); - - 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_); - } - } - - PromotionQueue* promotion_queue() { return &promotion_queue_; } - -#ifdef DEBUG - // Utility used with flag gc-greedy. - void GarbageCollectionGreedyCheck(); -#endif - - void AddGCPrologueCallback( - GCPrologueCallback callback, GCType gc_type_filter); - void RemoveGCPrologueCallback(GCPrologueCallback callback); - - void AddGCEpilogueCallback( - GCEpilogueCallback callback, GCType gc_type_filter); - void RemoveGCEpilogueCallback(GCEpilogueCallback callback); - - void SetGlobalGCPrologueCallback(GCCallback callback) { - ASSERT((callback == NULL) ^ (global_gc_prologue_callback_ == NULL)); - global_gc_prologue_callback_ = callback; - } - void SetGlobalGCEpilogueCallback(GCCallback callback) { - ASSERT((callback == NULL) ^ (global_gc_epilogue_callback_ == NULL)); - global_gc_epilogue_callback_ = callback; - } - - // Heap root getters. We have versions with and without type::cast() here. - // You can't use type::cast during GC because the assert fails. - // TODO(1490): Try removing the unchecked accessors, now that GC marking does - // not corrupt the map. -#define ROOT_ACCESSOR(type, name, camel_name) \ - type* name() { \ - return type::cast(roots_[k##camel_name##RootIndex]); \ - } \ - type* raw_unchecked_##name() { \ - return reinterpret_cast<type*>(roots_[k##camel_name##RootIndex]); \ - } - ROOT_LIST(ROOT_ACCESSOR) -#undef ROOT_ACCESSOR - -// Utility type maps -#define STRUCT_MAP_ACCESSOR(NAME, Name, name) \ - Map* name##_map() { \ - return Map::cast(roots_[k##Name##MapRootIndex]); \ - } - STRUCT_LIST(STRUCT_MAP_ACCESSOR) -#undef STRUCT_MAP_ACCESSOR - -#define STRING_ACCESSOR(name, str) String* name() { \ - return String::cast(roots_[k##name##RootIndex]); \ - } - INTERNALIZED_STRING_LIST(STRING_ACCESSOR) -#undef STRING_ACCESSOR - - // The hidden_string is special because it is the empty string, but does - // not match the empty string. - String* hidden_string() { return hidden_string_; } - - void set_native_contexts_list(Object* object) { - native_contexts_list_ = object; - } - Object* native_contexts_list() { return native_contexts_list_; } - - // Number of mark-sweeps. - unsigned int ms_count() { return ms_count_; } - - // 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 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. - void IterateAndMarkPointersToFromSpace(Address start, - Address end, - ObjectSlotCallback callback); - - // Returns whether the object resides in new space. - inline bool InNewSpace(Object* object); - inline bool InNewSpace(Address addr); - inline bool InNewSpacePage(Address addr); - inline bool InFromSpace(Object* object); - inline bool InToSpace(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); - - // Finds out which space an object should get promoted to based on its type. - inline OldSpace* TargetSpace(HeapObject* object); - inline AllocationSpace TargetSpaceId(InstanceType type); - - // Sets the stub_cache_ (only used when expanding the dictionary). - void public_set_code_stubs(UnseededNumberDictionary* value) { - roots_[kCodeStubsRootIndex] = value; - } - - // Support for computing object sizes for old objects during GCs. Returns - // a function that is guaranteed to be safe for computing object sizes in - // the current GC phase. - HeapObjectCallback GcSafeSizeOfOldObjectFunction() { - return gc_safe_size_of_old_object_; - } - - // Sets the non_monomorphic_cache_ (only used when expanding the dictionary). - void public_set_non_monomorphic_cache(UnseededNumberDictionary* value) { - roots_[kNonMonomorphicCacheRootIndex] = value; - } - - void public_set_empty_script(Script* script) { - roots_[kEmptyScriptRootIndex] = script; - } - - void public_set_store_buffer_top(Address* top) { - roots_[kStoreBufferTopRootIndex] = reinterpret_cast<Smi*>(top); - } - - // Update the next script id. - inline void SetLastScriptId(Object* last_script_id); - - // Generated code can embed this address to get access to the roots. - Object** roots_array_start() { return roots_; } - - Address* store_buffer_top_address() { - return reinterpret_cast<Address*>(&roots_[kStoreBufferTopRootIndex]); - } - - // Get address of native contexts list for serialization support. - Object** native_contexts_list_address() { - return &native_contexts_list_; - } - -#ifdef VERIFY_HEAP - // Verify the heap is in its normal state before or after a GC. - void Verify(); - - - bool weak_embedded_maps_verification_enabled() { - return no_weak_embedded_maps_verification_scope_depth_ == 0; - } -#endif - -#ifdef DEBUG - void Print(); - void PrintHandles(); - - void OldPointerSpaceCheckStoreBuffer(); - void MapSpaceCheckStoreBuffer(); - void LargeObjectSpaceCheckStoreBuffer(); - - // Report heap statistics. - void ReportHeapStatistics(const char* title); - void ReportCodeStatistics(const char* title); -#endif - - // 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 - } - - // Fill in bogus values in from space - void ZapFromSpace(); - - // Print short heap statistics. - void PrintShortHeapStatistics(); - - // Makes a new internalized string object - // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation - // failed. - // Please note this function does not perform a garbage collection. - MUST_USE_RESULT MaybeObject* CreateInternalizedString( - const char* str, int length, int hash); - MUST_USE_RESULT MaybeObject* CreateInternalizedString(String* str); - - // 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)); - - // Given an address occupied by a live code object, return that object. - Object* FindCodeObject(Address a); - - enum HeapState { NOT_IN_GC, SCAVENGE, MARK_COMPACT }; - inline HeapState gc_state() { return gc_state_; } - - inline bool IsInGCPostProcessing() { return gc_post_processing_depth_ > 0; } - -#ifdef DEBUG - bool IsAllocationAllowed() { return allocation_allowed_; } - inline bool allow_allocation(bool enable); - - bool disallow_allocation_failure() { - return disallow_allocation_failure_; - } - - void TracePathToObjectFrom(Object* target, Object* root); - void TracePathToObject(Object* target); - void TracePathToGlobal(); -#endif - - // Callback function passed to Heap::Iterate etc. Copies an object if - // necessary, the object might be promoted to an old space. The caller must - // ensure the precondition that the object is (a) a heap object and (b) in - // the heap's from space. - static inline void ScavengePointer(HeapObject** p); - static inline void ScavengeObject(HeapObject** p, HeapObject* object); - - // Commits from space if it is uncommitted. - void EnsureFromSpaceIsCommitted(); - - // Support for partial snapshots. After calling this we have a linear - // space to write objects in each space. - void ReserveSpace(int *sizes, Address* addresses); - - // - // Support for the API. - // - - bool CreateApiObjects(); - - // Attempt to find the number in a small cache. If we finds it, return - // the string representation of the number. Otherwise return undefined. - Object* GetNumberStringCache(Object* number); - - // Update the cache with a new number-string pair. - void SetNumberStringCache(Object* number, String* str); - - // Adjusts the amount of registered external memory. - // Returns the adjusted value. - inline intptr_t AdjustAmountOfExternalAllocatedMemory( - intptr_t change_in_bytes); - - // Allocate uninitialized fixed array. - MUST_USE_RESULT MaybeObject* AllocateRawFixedArray(int length); - MUST_USE_RESULT MaybeObject* AllocateRawFixedArray(int length, - PretenureFlag pretenure); - - inline intptr_t PromotedTotalSize() { - return PromotedSpaceSizeOfObjects() + PromotedExternalMemorySize(); - } - - // True if we have reached the allocation limit in the old generation that - // should force the next GC (caused normally) to be a full one. - inline bool OldGenerationPromotionLimitReached() { - return PromotedTotalSize() > old_gen_promotion_limit_; - } - - inline intptr_t OldGenerationSpaceAvailable() { - return old_gen_allocation_limit_ - PromotedTotalSize(); - } - - inline intptr_t OldGenerationCapacityAvailable() { - return max_old_generation_size_ - PromotedTotalSize(); - } - - static const intptr_t kMinimumPromotionLimit = 5 * Page::kPageSize; - static const intptr_t kMinimumAllocationLimit = - 8 * (Page::kPageSize > MB ? Page::kPageSize : MB); - - intptr_t OldGenPromotionLimit(intptr_t old_gen_size) { - const int divisor = FLAG_stress_compaction ? 10 : 3; - intptr_t limit = - Max(old_gen_size + old_gen_size / divisor, kMinimumPromotionLimit); - limit += new_space_.Capacity(); - limit *= old_gen_limit_factor_; - intptr_t halfway_to_the_max = (old_gen_size + max_old_generation_size_) / 2; - return Min(limit, halfway_to_the_max); - } - - intptr_t OldGenAllocationLimit(intptr_t old_gen_size) { - const int divisor = FLAG_stress_compaction ? 8 : 2; - intptr_t limit = - Max(old_gen_size + old_gen_size / divisor, kMinimumAllocationLimit); - limit += new_space_.Capacity(); - limit *= old_gen_limit_factor_; - intptr_t halfway_to_the_max = (old_gen_size + max_old_generation_size_) / 2; - return Min(limit, halfway_to_the_max); - } - - // Implements the corresponding V8 API function. - bool IdleNotification(int hint); - - // Declare all the root indices. - 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 - - // Utility type maps -#define DECLARE_STRUCT_MAP(NAME, Name, name) k##Name##MapRootIndex, - STRUCT_LIST(DECLARE_STRUCT_MAP) -#undef DECLARE_STRUCT_MAP - - kStringTableRootIndex, - kStrongRootListLength = kStringTableRootIndex, - kRootListLength - }; - - STATIC_CHECK(kUndefinedValueRootIndex == Internals::kUndefinedValueRootIndex); - STATIC_CHECK(kNullValueRootIndex == Internals::kNullValueRootIndex); - STATIC_CHECK(kTrueValueRootIndex == Internals::kTrueValueRootIndex); - STATIC_CHECK(kFalseValueRootIndex == Internals::kFalseValueRootIndex); - STATIC_CHECK(kempty_stringRootIndex == Internals::kEmptyStringRootIndex); - - // Generated code can embed direct references to non-writable roots if - // they are in new space. - static bool RootCanBeWrittenAfterInitialization(RootListIndex root_index); - - MUST_USE_RESULT MaybeObject* NumberToString( - Object* number, bool check_number_string_cache = true); - MUST_USE_RESULT MaybeObject* Uint32ToString( - uint32_t value, bool check_number_string_cache = true); - - Map* MapForExternalArrayType(ExternalArrayType array_type); - RootListIndex RootIndexForExternalArrayType( - ExternalArrayType array_type); - - void RecordStats(HeapStats* stats, bool take_snapshot = false); - - // 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); - - // Check new space expansion criteria and expand semispaces if it was hit. - void CheckNewSpaceExpansionCriteria(); - - inline void IncrementYoungSurvivorsCounter(int survived) { - ASSERT(survived >= 0); - young_survivors_after_last_gc_ = survived; - survived_since_last_expansion_ += survived; - } - - inline bool NextGCIsLikelyToBeFull() { - if (FLAG_gc_global) return true; - - if (FLAG_stress_compaction && (gc_count_ & 1) != 0) return true; - - intptr_t total_promoted = PromotedTotalSize(); - - intptr_t adjusted_promotion_limit = - old_gen_promotion_limit_ - new_space_.Capacity(); - - if (total_promoted >= adjusted_promotion_limit) return true; - - intptr_t adjusted_allocation_limit = - old_gen_allocation_limit_ - new_space_.Capacity() / 5; - - if (PromotedSpaceSizeOfObjects() >= adjusted_allocation_limit) return true; - - return false; - } - - - void UpdateNewSpaceReferencesInExternalStringTable( - ExternalStringTableUpdaterCallback updater_func); - - void UpdateReferencesInExternalStringTable( - ExternalStringTableUpdaterCallback updater_func); - - void ProcessWeakReferences(WeakObjectRetainer* retainer); - - void VisitExternalResources(v8::ExternalResourceVisitor* visitor); - - // Helper function that governs the promotion policy from new space to - // old. If the object's old address lies below the new space's age - // mark or if we've already filled the bottom 1/16th of the to space, - // we try to promote this object. - inline bool ShouldBePromoted(Address old_address, int object_size); - - int MaxObjectSizeInNewSpace() { return kMaxObjectSizeInNewSpace; } - - void ClearJSFunctionResultCaches(); - - void ClearNormalizedMapCaches(); - - GCTracer* tracer() { return tracer_; } - - // 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; - } - - // 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_; } - - // TODO(hpayer): remove, should be handled by GCTracer - void AddMarkingTime(double marking_time) { - marking_time_ += marking_time; - } - - double marking_time() const { - return marking_time_; - } - - // TODO(hpayer): remove, should be handled by GCTracer - void AddSweepingTime(double sweeping_time) { - sweeping_time_ += sweeping_time; - } - - double sweeping_time() const { - return sweeping_time_; - } - - MarkCompactCollector* mark_compact_collector() { - return &mark_compact_collector_; - } - - StoreBuffer* store_buffer() { - return &store_buffer_; - } - - Marking* marking() { - return &marking_; - } - - IncrementalMarking* incremental_marking() { - return &incremental_marking_; - } - - bool IsSweepingComplete() { - return !mark_compact_collector()->IsConcurrentSweepingInProgress() && - old_data_space()->IsLazySweepingComplete() && - old_pointer_space()->IsLazySweepingComplete(); - } - - bool AdvanceSweepers(int step_size) { - ASSERT(!FLAG_parallel_sweeping && !FLAG_concurrent_sweeping); - bool sweeping_complete = old_data_space()->AdvanceSweeper(step_size); - sweeping_complete &= old_pointer_space()->AdvanceSweeper(step_size); - return sweeping_complete; - } - - ExternalStringTable* external_string_table() { - return &external_string_table_; - } - - ErrorObjectList* error_object_list() { - return &error_object_list_; - } - - // Returns the current sweep generation. - int sweep_generation() { - return sweep_generation_; - } - - inline Isolate* isolate(); - - void CallGCPrologueCallbacks(GCType gc_type); - void CallGCEpilogueCallbacks(GCType gc_type); - - inline bool OldGenerationAllocationLimitReached(); - - inline void DoScavengeObject(Map* map, HeapObject** slot, HeapObject* obj) { - scavenging_visitors_table_.GetVisitor(map)(map, slot, obj); - } - - void QueueMemoryChunkForFree(MemoryChunk* chunk); - void FreeQueuedChunks(); - - // Completely clear the Instanceof cache (to stop it keeping objects alive - // around a GC). - inline void CompletelyClearInstanceofCache(); - - // The roots that have an index less than this are always in old space. - static const int kOldSpaceRoots = 0x20; - - uint32_t HashSeed() { - uint32_t seed = static_cast<uint32_t>(hash_seed()->value()); - ASSERT(FLAG_randomize_hashes || seed == 0); - return seed; - } - - void SetArgumentsAdaptorDeoptPCOffset(int pc_offset) { - ASSERT(arguments_adaptor_deopt_pc_offset() == Smi::FromInt(0)); - set_arguments_adaptor_deopt_pc_offset(Smi::FromInt(pc_offset)); - } - - void SetConstructStubDeoptPCOffset(int pc_offset) { - ASSERT(construct_stub_deopt_pc_offset() == Smi::FromInt(0)); - set_construct_stub_deopt_pc_offset(Smi::FromInt(pc_offset)); - } - - void SetGetterStubDeoptPCOffset(int pc_offset) { - ASSERT(getter_stub_deopt_pc_offset() == Smi::FromInt(0)); - set_getter_stub_deopt_pc_offset(Smi::FromInt(pc_offset)); - } - - void SetSetterStubDeoptPCOffset(int pc_offset) { - ASSERT(setter_stub_deopt_pc_offset() == Smi::FromInt(0)); - set_setter_stub_deopt_pc_offset(Smi::FromInt(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; - } - - bool flush_monomorphic_ics() { return flush_monomorphic_ics_; } - - intptr_t amount_of_external_allocated_memory() { - return amount_of_external_allocated_memory_; - } - - // ObjectStats are kept in two arrays, counts and sizes. Related stats are - // stored in a contiguous linear buffer. Stats groups are stored one after - // another. - enum { - FIRST_CODE_KIND_SUB_TYPE = LAST_TYPE + 1, - FIRST_FIXED_ARRAY_SUB_TYPE = - FIRST_CODE_KIND_SUB_TYPE + Code::LAST_CODE_KIND + 1, - OBJECT_STATS_COUNT = - FIRST_FIXED_ARRAY_SUB_TYPE + LAST_FIXED_ARRAY_SUB_TYPE + 1 - }; - - void RecordObjectStats(InstanceType type, int sub_type, size_t size) { - ASSERT(type <= LAST_TYPE); - if (sub_type < 0) { - object_counts_[type]++; - object_sizes_[type] += size; - } else { - if (type == CODE_TYPE) { - ASSERT(sub_type <= Code::LAST_CODE_KIND); - object_counts_[FIRST_CODE_KIND_SUB_TYPE + sub_type]++; - object_sizes_[FIRST_CODE_KIND_SUB_TYPE + sub_type] += size; - } else if (type == FIXED_ARRAY_TYPE) { - ASSERT(sub_type <= LAST_FIXED_ARRAY_SUB_TYPE); - object_counts_[FIRST_FIXED_ARRAY_SUB_TYPE + sub_type]++; - object_sizes_[FIRST_FIXED_ARRAY_SUB_TYPE + sub_type] += size; - } - } - } - - void CheckpointObjectStats(); - - // We don't use a ScopedLock here since we want to lock the heap - // only when FLAG_parallel_recompilation is true. - class RelocationLock { - public: - explicit RelocationLock(Heap* heap) : heap_(heap) { - if (FLAG_parallel_recompilation) { - heap_->relocation_mutex_->Lock(); - } - } - ~RelocationLock() { - if (FLAG_parallel_recompilation) { - heap_->relocation_mutex_->Unlock(); - } - } - - private: - Heap* heap_; - }; - - private: - Heap(); - - // 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]; - - intptr_t code_range_size_; - int reserved_semispace_size_; - int max_semispace_size_; - int initial_semispace_size_; - intptr_t max_old_generation_size_; - intptr_t max_executable_size_; - - // For keeping track of how much data has survived - // scavenge since last new space expansion. - int survived_since_last_expansion_; - - // For keeping track on when to flush RegExp code. - int sweep_generation_; - - int always_allocate_scope_depth_; - int linear_allocation_scope_depth_; - - // For keeping track of context disposals. - int contexts_disposed_; - - int global_ic_age_; - - bool flush_monomorphic_ics_; - - int scan_on_scavenge_pages_; - -#if defined(V8_TARGET_ARCH_X64) - static const int kMaxObjectSizeInNewSpace = 1024*KB; -#else - static const int kMaxObjectSizeInNewSpace = 512*KB; -#endif - - NewSpace new_space_; - OldSpace* old_pointer_space_; - OldSpace* old_data_space_; - OldSpace* code_space_; - MapSpace* map_space_; - CellSpace* cell_space_; - LargeObjectSpace* lo_space_; - HeapState gc_state_; - int gc_post_processing_depth_; - - // Returns the amount of external memory registered since last global gc. - intptr_t PromotedExternalMemorySize(); - - unsigned int ms_count_; // how many mark-sweep collections happened - unsigned int gc_count_; // how many gc happened - - // For post mortem debugging. - static const int kRememberedUnmappedPages = 128; - int remembered_unmapped_pages_index_; - Address remembered_unmapped_pages_[kRememberedUnmappedPages]; - - // Total length of the strings we failed to flatten since the last GC. - int unflattened_strings_length_; - -#define ROOT_ACCESSOR(type, name, camel_name) \ - inline void set_##name(type* value) { \ - /* The deserializer makes use of the fact that these common roots are */ \ - /* never in new space and never on a page that is being compacted. */ \ - ASSERT(k##camel_name##RootIndex >= kOldSpaceRoots || !InNewSpace(value)); \ - roots_[k##camel_name##RootIndex] = value; \ - } - ROOT_LIST(ROOT_ACCESSOR) -#undef ROOT_ACCESSOR - -#ifdef DEBUG - bool allocation_allowed_; - - // 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_; - - // Do we expect to be able to handle allocation failure at this - // time? - bool disallow_allocation_failure_; -#endif // DEBUG - - // Indicates that the new space should be kept small due to high promotion - // rates caused by the mutator allocating a lot of long-lived objects. - bool new_space_high_promotion_mode_active_; - - // 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. - intptr_t old_gen_promotion_limit_; - - // Limit that triggers a global GC as soon as is reasonable. This is - // checked before expanding a paged space in the old generation and on - // every allocation in large object space. - intptr_t old_gen_allocation_limit_; - - // Sometimes the heuristics dictate that those limits are increased. This - // variable records that fact. - int old_gen_limit_factor_; - - // Used to adjust the limits that control the timing of the next GC. - intptr_t size_of_old_gen_at_last_old_space_gc_; - - // Limit on the amount of externally allocated memory allowed - // between global GCs. If reached a global GC is forced. - intptr_t external_allocation_limit_; - - // The amount of external memory registered through the API kept alive - // by global handles - intptr_t amount_of_external_allocated_memory_; - - // Caches the amount of external memory registered at the last global gc. - intptr_t amount_of_external_allocated_memory_at_last_global_gc_; - - // Indicates that an allocation has failed in the old generation since the - // last GC. - int old_gen_exhausted_; - - Object* native_contexts_list_; - - StoreBufferRebuilder store_buffer_rebuilder_; - - struct StringTypeTable { - InstanceType type; - int size; - RootListIndex index; - }; - - struct ConstantStringTable { - const char* contents; - RootListIndex index; - }; - - struct StructTable { - InstanceType type; - int size; - RootListIndex index; - }; - - static const StringTypeTable string_type_table[]; - static const ConstantStringTable constant_string_table[]; - static const StructTable struct_table[]; - - // The special hidden string which is an empty string, but does not match - // any string when looked up in properties. - String* hidden_string_; - - // GC callback function, called before and after mark-compact GC. - // Allocations in the callback function are disallowed. - struct GCPrologueCallbackPair { - GCPrologueCallbackPair(GCPrologueCallback callback, GCType gc_type) - : callback(callback), gc_type(gc_type) { - } - bool operator==(const GCPrologueCallbackPair& pair) const { - return pair.callback == callback; - } - GCPrologueCallback callback; - GCType gc_type; - }; - List<GCPrologueCallbackPair> gc_prologue_callbacks_; - - struct GCEpilogueCallbackPair { - GCEpilogueCallbackPair(GCEpilogueCallback callback, GCType gc_type) - : callback(callback), gc_type(gc_type) { - } - bool operator==(const GCEpilogueCallbackPair& pair) const { - return pair.callback == callback; - } - GCEpilogueCallback callback; - GCType gc_type; - }; - List<GCEpilogueCallbackPair> gc_epilogue_callbacks_; - - GCCallback global_gc_prologue_callback_; - GCCallback global_gc_epilogue_callback_; - - // Support for computing object sizes during GC. - HeapObjectCallback gc_safe_size_of_old_object_; - static int GcSafeSizeOfOldObject(HeapObject* object); - - // Update the GC state. Called from the mark-compact collector. - void MarkMapPointersAsEncoded(bool encoded) { - ASSERT(!encoded); - gc_safe_size_of_old_object_ = &GcSafeSizeOfOldObject; - } - - // Checks whether a global GC is necessary - GarbageCollector SelectGarbageCollector(AllocationSpace space, - const char** reason); - - // Performs garbage collection - // Returns whether there is a chance another major GC could - // collect more garbage. - bool PerformGarbageCollection(GarbageCollector collector, - GCTracer* tracer); - - inline void UpdateOldSpaceLimits(); - - // Allocate an uninitialized object in map space. The behavior is identical - // to Heap::AllocateRaw(size_in_bytes, MAP_SPACE), except that (a) it doesn't - // have to test the allocation space argument and (b) can reduce code size - // (since both AllocateRaw and AllocateRawMap are inlined). - MUST_USE_RESULT inline MaybeObject* AllocateRawMap(); - - // Allocate an uninitialized object in the global property cell space. - MUST_USE_RESULT inline MaybeObject* AllocateRawCell(); - - // Initializes a JSObject based on its map. - void InitializeJSObjectFromMap(JSObject* obj, - FixedArray* properties, - Map* map); - - bool CreateInitialMaps(); - bool 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(); - - MUST_USE_RESULT MaybeObject* CreateOddball(const char* to_string, - Object* to_number, - byte kind); - - // Allocate a JSArray with no elements - MUST_USE_RESULT MaybeObject* AllocateJSArray( - ElementsKind elements_kind, - PretenureFlag pretenure = NOT_TENURED); - - MUST_USE_RESULT MaybeObject* AllocateJSArrayWithAllocationSite( - ElementsKind elements_kind, - Handle<Object> allocation_site_info_payload); - - // Allocate empty fixed array. - MUST_USE_RESULT MaybeObject* AllocateEmptyFixedArray(); - - // Allocate empty fixed double array. - MUST_USE_RESULT MaybeObject* AllocateEmptyFixedDoubleArray(); - - // Performs a minor collection in new generation. - void Scavenge(); - - static HeapObject* UpdateNewSpaceReferenceInExternalStringTableEntry( - Heap* heap, - Object** pointer); - - Address DoScavenge(ObjectVisitor* scavenge_visitor, Address new_space_front); - static void ScavengeStoreBufferCallback(Heap* heap, - MemoryChunk* page, - StoreBufferEvent event); - - // Performs a major collection in the whole heap. - void MarkCompact(GCTracer* tracer); - - // Code to be run before and after mark-compact. - void MarkCompactPrologue(); - - // Record statistics before and after garbage collection. - void ReportStatisticsBeforeGC(); - void ReportStatisticsAfterGC(); - - // Slow part of scavenge object. - static void ScavengeObjectSlow(HeapObject** p, HeapObject* object); - - // Initializes a function with a shared part and prototype. - // Note: this code was factored out of AllocateFunction such that - // other parts of the VM could use it. Specifically, a function that creates - // instances of type JS_FUNCTION_TYPE benefit from the use of this function. - // Please note this does not perform a garbage collection. - inline void InitializeFunction( - JSFunction* function, - SharedFunctionInfo* shared, - Object* prototype); - - // Total RegExp code ever generated - double total_regexp_code_generated_; - - GCTracer* tracer_; - - // Allocates a small number to string cache. - MUST_USE_RESULT MaybeObject* AllocateInitialNumberStringCache(); - // Creates and installs the full-sized number string cache. - void AllocateFullSizeNumberStringCache(); - // Get the length of the number to string cache based on the max semispace - // size. - int FullSizeNumberStringCacheLength(); - // Flush the number to string cache. - void FlushNumberStringCache(); - - void UpdateSurvivalRateTrend(int start_new_space_size); - - enum SurvivalRateTrend { INCREASING, STABLE, DECREASING, FLUCTUATING }; - - static const int kYoungSurvivalRateHighThreshold = 90; - static const int kYoungSurvivalRateLowThreshold = 10; - static const int kYoungSurvivalRateAllowedDeviation = 15; - - int young_survivors_after_last_gc_; - int high_survival_rate_period_length_; - int low_survival_rate_period_length_; - double survival_rate_; - SurvivalRateTrend previous_survival_rate_trend_; - SurvivalRateTrend survival_rate_trend_; - - void set_survival_rate_trend(SurvivalRateTrend survival_rate_trend) { - ASSERT(survival_rate_trend != FLUCTUATING); - previous_survival_rate_trend_ = survival_rate_trend_; - survival_rate_trend_ = survival_rate_trend; - } - - SurvivalRateTrend survival_rate_trend() { - if (survival_rate_trend_ == STABLE) { - return STABLE; - } else if (previous_survival_rate_trend_ == STABLE) { - return survival_rate_trend_; - } else if (survival_rate_trend_ != previous_survival_rate_trend_) { - return FLUCTUATING; - } else { - return survival_rate_trend_; - } - } - - bool IsStableOrIncreasingSurvivalTrend() { - switch (survival_rate_trend()) { - case STABLE: - case INCREASING: - return true; - default: - return false; - } - } - - bool IsStableOrDecreasingSurvivalTrend() { - switch (survival_rate_trend()) { - case STABLE: - case DECREASING: - return true; - default: - return false; - } - } - - bool IsIncreasingSurvivalTrend() { - return survival_rate_trend() == INCREASING; - } - - bool IsHighSurvivalRate() { - return high_survival_rate_period_length_ > 0; - } - - bool IsLowSurvivalRate() { - return low_survival_rate_period_length_ > 0; - } - - void SelectScavengingVisitorsTable(); - - void StartIdleRound() { - mark_sweeps_since_idle_round_started_ = 0; - ms_count_at_last_idle_notification_ = ms_count_; - } - - void FinishIdleRound() { - mark_sweeps_since_idle_round_started_ = kMaxMarkSweepsInIdleRound; - scavenges_since_last_idle_round_ = 0; - } - - bool EnoughGarbageSinceLastIdleRound() { - return (scavenges_since_last_idle_round_ >= kIdleScavengeThreshold); - } - - // Estimates how many milliseconds a Mark-Sweep would take to complete. - // In idle notification handler we assume that this function will return: - // - a number less than 10 for small heaps, which are less than 8Mb. - // - a number greater than 10 for large heaps, which are greater than 32Mb. - int TimeMarkSweepWouldTakeInMs() { - // Rough estimate of how many megabytes of heap can be processed in 1 ms. - static const int kMbPerMs = 2; - - int heap_size_mb = static_cast<int>(SizeOfObjects() / MB); - return heap_size_mb / kMbPerMs; - } - - // Returns true if no more GC work is left. - bool IdleGlobalGC(); - - void AdvanceIdleIncrementalMarking(intptr_t step_size); - - void ClearObjectStats(bool clear_last_time_stats = false); - - static const int kInitialStringTableSize = 2048; - static const int kInitialEvalCacheSize = 64; - static const int kInitialNumberStringCacheSize = 256; - - // Object counts and used memory by InstanceType - size_t object_counts_[OBJECT_STATS_COUNT]; - size_t object_counts_last_time_[OBJECT_STATS_COUNT]; - size_t object_sizes_[OBJECT_STATS_COUNT]; - size_t object_sizes_last_time_[OBJECT_STATS_COUNT]; - - // 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_; - - // Size of objects alive after last GC. - intptr_t alive_after_last_gc_; - - double last_gc_end_timestamp_; - - // Cumulative GC time spent in marking - double marking_time_; - - // Cumulative GC time spent in sweeping - double sweeping_time_; - - MarkCompactCollector mark_compact_collector_; - - StoreBuffer store_buffer_; - - Marking marking_; - - IncrementalMarking incremental_marking_; - - int number_idle_notifications_; - unsigned int last_idle_notification_gc_count_; - bool last_idle_notification_gc_count_init_; - - int mark_sweeps_since_idle_round_started_; - int ms_count_at_last_idle_notification_; - unsigned int gc_count_at_last_idle_gc_; - int scavenges_since_last_idle_round_; - -#ifdef VERIFY_HEAP - int no_weak_embedded_maps_verification_scope_depth_; -#endif - - static const int kMaxMarkSweepsInIdleRound = 7; - static const int kIdleScavengeThreshold = 5; - - // 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_; - - ExternalStringTable external_string_table_; - - ErrorObjectList error_object_list_; - - VisitorDispatchTable<ScavengingCallback> scavenging_visitors_table_; - - MemoryChunk* chunks_queued_for_free_; - - Mutex* relocation_mutex_; - - friend class Factory; - friend class GCTracer; - friend class DisallowAllocationFailure; - friend class AlwaysAllocateScope; - friend class Page; - friend class Isolate; - friend class MarkCompactCollector; - friend class MarkCompactMarkingVisitor; - friend class MapCompact; -#ifdef VERIFY_HEAP - friend class NoWeakEmbeddedMapsVerificationScope; -#endif - - 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_pointer_space_size; // 3 - intptr_t* old_pointer_space_capacity; // 4 - intptr_t* old_data_space_size; // 5 - intptr_t* old_data_space_capacity; // 6 - intptr_t* code_space_size; // 7 - intptr_t* code_space_capacity; // 8 - intptr_t* map_space_size; // 9 - intptr_t* map_space_capacity; // 10 - intptr_t* cell_space_size; // 11 - intptr_t* cell_space_capacity; // 12 - intptr_t* lo_space_size; // 13 - int* global_handle_count; // 14 - int* weak_global_handle_count; // 15 - int* pending_global_handle_count; // 16 - int* near_death_global_handle_count; // 17 - int* free_global_handle_count; // 18 - intptr_t* memory_allocator_size; // 19 - intptr_t* memory_allocator_capacity; // 20 - int* objects_per_type; // 21 - int* size_per_type; // 22 - int* os_error; // 23 - int* end_marker; // 24 -}; - - -class DisallowAllocationFailure { - public: - inline DisallowAllocationFailure(); - inline ~DisallowAllocationFailure(); - -#ifdef DEBUG - private: - bool old_state_; -#endif -}; - - -class AlwaysAllocateScope { - public: - inline AlwaysAllocateScope(); - inline ~AlwaysAllocateScope(); - - private: - // Implicitly disable artificial allocation failures. - DisallowAllocationFailure disallow_allocation_failure_; -}; - -#ifdef VERIFY_HEAP -class NoWeakEmbeddedMapsVerificationScope { - public: - inline NoWeakEmbeddedMapsVerificationScope(); - inline ~NoWeakEmbeddedMapsVerificationScope(); -}; -#endif - - -// 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); -}; - - -// 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 pointer -// space, old data 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_POINTER_SPACE) {} - OldSpace* next(); - private: - Heap* heap_; - int counter_; -}; - - -// Space iterator for iterating over all the paged spaces of the heap: Map -// space, old pointer space, old data 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_POINTER_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); - SpaceIterator(Heap* heap, HeapObjectCallback size_func); - 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. - HeapObjectCallback size_func_; -}; - - -// 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 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 HeapObjectsFilter; - -class HeapIterator BASE_EMBEDDED { - public: - enum HeapObjectsFiltering { - kNoFiltering, - kFilterUnreachable - }; - - explicit HeapIterator(Heap* heap); - HeapIterator(Heap* heap, HeapObjectsFiltering filtering); - ~HeapIterator(); - - HeapObject* next(); - void reset(); - - private: - // Perform the initialization. - void Init(); - // Perform all necessary shutdown (destruction) work. - void Shutdown(); - HeapObject* NextObject(); - - 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(Map* map, String* name); - - // Update an element in the cache. - void Update(Map* map, String* 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 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(Map* map, String* 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<Address>(&keys_); - } - - Address field_offsets_address() { - return reinterpret_cast<Address>(&field_offsets_); - } - - struct Key { - Map* map; - String* 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. - int Lookup(Map* source, String* name) { - if (!StringShape(name).IsInternalized()) return kAbsent; - int index = Hash(source, name); - Key& key = keys_[index]; - if ((key.source == source) && (key.name == name)) return results_[index]; - return kAbsent; - } - - // Update an element in the cache. - void Update(Map* source, String* name, int result) { - ASSERT(result != kAbsent); - if (StringShape(name).IsInternalized()) { - int index = Hash(source, name); - Key& key = keys_[index]; - key.source = source; - key.name = name; - results_[index] = 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, String* name) { - // Uses only lower 32 bits if pointers are larger. - uint32_t source_hash = - static_cast<uint32_t>(reinterpret_cast<uintptr_t>(source)) - >> kPointerSizeLog2; - uint32_t name_hash = - static_cast<uint32_t>(reinterpret_cast<uintptr_t>(name)) - >> kPointerSizeLog2; - return (source_hash ^ name_hash) % kLength; - } - - static const int kLength = 64; - struct Key { - Map* source; - String* name; - }; - - Key keys_[kLength]; - int results_[kLength]; - - friend class Isolate; - DISALLOW_COPY_AND_ASSIGN(DescriptorLookupCache); -}; - - -// A helper class to document/test C++ scopes where we do not -// expect a GC. Usage: -// -// /* Allocation not allowed: we cannot handle a GC in this scope. */ -// { AssertNoAllocation nogc; -// ... -// } -class AssertNoAllocation { - public: - inline AssertNoAllocation(); - inline ~AssertNoAllocation(); - -#ifdef DEBUG - private: - bool old_state_; - bool active_; -#endif -}; - - -class DisableAssertNoAllocation { - public: - inline DisableAssertNoAllocation(); - inline ~DisableAssertNoAllocation(); - -#ifdef DEBUG - private: - bool old_state_; - bool active_; -#endif -}; - -// GCTracer collects and prints ONE line after each garbage collector -// invocation IFF --trace_gc is used. - -class GCTracer BASE_EMBEDDED { - public: - class Scope BASE_EMBEDDED { - public: - enum ScopeId { - EXTERNAL, - MC_MARK, - MC_SWEEP, - MC_SWEEP_NEWSPACE, - MC_EVACUATE_PAGES, - MC_UPDATE_NEW_TO_NEW_POINTERS, - MC_UPDATE_ROOT_TO_NEW_POINTERS, - MC_UPDATE_OLD_TO_NEW_POINTERS, - MC_UPDATE_POINTERS_TO_EVACUATED, - MC_UPDATE_POINTERS_BETWEEN_EVACUATED, - MC_UPDATE_MISC_POINTERS, - MC_FLUSH_CODE, - kNumberOfScopes - }; - - Scope(GCTracer* tracer, ScopeId scope) - : tracer_(tracer), - scope_(scope) { - start_time_ = OS::TimeCurrentMillis(); - } - - ~Scope() { - ASSERT(scope_ < kNumberOfScopes); // scope_ is unsigned. - tracer_->scopes_[scope_] += OS::TimeCurrentMillis() - start_time_; - } - - private: - GCTracer* tracer_; - ScopeId scope_; - double start_time_; - }; - - explicit GCTracer(Heap* heap, - const char* gc_reason, - const char* collector_reason); - ~GCTracer(); - - // Sets the collector. - void set_collector(GarbageCollector collector) { collector_ = collector; } - - // Sets the GC count. - void set_gc_count(unsigned int count) { gc_count_ = count; } - - // Sets the full GC count. - void set_full_gc_count(int count) { full_gc_count_ = count; } - - void increment_promoted_objects_size(int object_size) { - promoted_objects_size_ += object_size; - } - - void increment_nodes_died_in_new_space() { - nodes_died_in_new_space_++; - } - - void increment_nodes_copied_in_new_space() { - nodes_copied_in_new_space_++; - } - - void increment_nodes_promoted() { - nodes_promoted_++; - } - - private: - // Returns a string matching the collector. - const char* CollectorString(); - - // Returns size of object in heap (in MB). - inline double SizeOfHeapObjects(); - - // Timestamp set in the constructor. - double start_time_; - - // Size of objects in heap set in constructor. - intptr_t start_object_size_; - - // Size of memory allocated from OS set in constructor. - intptr_t start_memory_size_; - - // Type of collector. - GarbageCollector collector_; - - // A count (including this one, e.g. the first collection is 1) of the - // number of garbage collections. - unsigned int gc_count_; - - // A count (including this one) of the number of full garbage collections. - int full_gc_count_; - - // Amounts of time spent in different scopes during GC. - double scopes_[Scope::kNumberOfScopes]; - - // Total amount of space either wasted or contained in one of free lists - // before the current GC. - intptr_t in_free_list_or_wasted_before_gc_; - - // Difference between space used in the heap at the beginning of the current - // collection and the end of the previous collection. - intptr_t allocated_since_last_gc_; - - // Amount of time spent in mutator that is time elapsed between end of the - // previous collection and the beginning of the current one. - double spent_in_mutator_; - - // Size of objects promoted during the current collection. - intptr_t promoted_objects_size_; - - // Number of died nodes in the new space. - int nodes_died_in_new_space_; - - // Number of copied nodes to the new space. - int nodes_copied_in_new_space_; - - // Number of promoted nodes to the old space. - int nodes_promoted_; - - // Incremental marking steps counters. - int steps_count_; - double steps_took_; - double longest_step_; - int steps_count_since_last_gc_; - double steps_took_since_last_gc_; - - Heap* heap_; - - const char* gc_reason_; - const char* collector_reason_; -}; - - -class RegExpResultsCache { - public: - enum ResultsCacheType { REGEXP_MULTIPLE_INDICES, STRING_SPLIT_SUBSTRINGS }; - - // Attempt to retrieve a cached result. On failure, 0 is returned as a Smi. - // On success, the returned result is guaranteed to be a COW-array. - static Object* Lookup(Heap* heap, - String* key_string, - Object* key_pattern, - ResultsCacheType type); - // Attempt to add value_array to the cache specified by type. On success, - // value_array is turned into a COW-array. - static void Enter(Heap* heap, - String* key_string, - Object* key_pattern, - FixedArray* value_array, - ResultsCacheType type); - static void Clear(FixedArray* cache); - static const int kRegExpResultsCacheSize = 0x100; - - private: - static const int kArrayEntriesPerCacheEntry = 4; - static const int kStringOffset = 0; - static const int kPatternOffset = 1; - static const int kArrayOffset = 2; -}; - - -class TranscendentalCache { - public: - enum Type {ACOS, ASIN, ATAN, COS, EXP, LOG, SIN, TAN, kNumberOfCaches}; - static const int kTranscendentalTypeBits = 3; - STATIC_ASSERT((1 << kTranscendentalTypeBits) >= kNumberOfCaches); - - // Returns a heap number with f(input), where f is a math function specified - // by the 'type' argument. - MUST_USE_RESULT inline MaybeObject* Get(Type type, double input); - - // The cache contains raw Object pointers. This method disposes of - // them before a garbage collection. - void Clear(); - - private: - class SubCache { - static const int kCacheSize = 512; - - explicit SubCache(Type t); - - MUST_USE_RESULT inline MaybeObject* Get(double input); - - inline double Calculate(double input); - - struct Element { - uint32_t in[2]; - Object* output; - }; - - union Converter { - double dbl; - uint32_t integers[2]; - }; - - inline static int Hash(const Converter& c) { - uint32_t hash = (c.integers[0] ^ c.integers[1]); - hash ^= static_cast<int32_t>(hash) >> 16; - hash ^= static_cast<int32_t>(hash) >> 8; - return (hash & (kCacheSize - 1)); - } - - Element elements_[kCacheSize]; - Type type_; - Isolate* isolate_; - - // Allow access to the caches_ array as an ExternalReference. - friend class ExternalReference; - // Inline implementation of the cache. - friend class TranscendentalCacheStub; - // For evaluating value. - friend class TranscendentalCache; - - DISALLOW_COPY_AND_ASSIGN(SubCache); - }; - - TranscendentalCache() { - for (int i = 0; i < kNumberOfCaches; ++i) caches_[i] = NULL; - } - - // Used to create an external reference. - inline Address cache_array_address(); - - // Instantiation - friend class Isolate; - // Inline implementation of the caching. - friend class TranscendentalCacheStub; - // Allow access to the caches_ array as an ExternalReference. - friend class ExternalReference; - - SubCache* caches_[kNumberOfCaches]; - DISALLOW_COPY_AND_ASSIGN(TranscendentalCache); -}; - - -// 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; -}; - - -// Intrusive object marking uses least significant bit of -// heap object's map word to mark objects. -// Normally all map words have least significant bit set -// because they contain tagged map pointer. -// If the bit is not set object is marked. -// All objects should be unmarked before resuming -// JavaScript execution. -class IntrusiveMarking { - public: - static bool IsMarked(HeapObject* object) { - return (object->map_word().ToRawValue() & kNotMarkedBit) == 0; - } - - static void ClearMark(HeapObject* object) { - uintptr_t map_word = object->map_word().ToRawValue(); - object->set_map_word(MapWord::FromRawValue(map_word | kNotMarkedBit)); - ASSERT(!IsMarked(object)); - } - - static void SetMark(HeapObject* object) { - uintptr_t map_word = object->map_word().ToRawValue(); - object->set_map_word(MapWord::FromRawValue(map_word & ~kNotMarkedBit)); - ASSERT(IsMarked(object)); - } - - static Map* MapOfMarkedObject(HeapObject* object) { - uintptr_t map_word = object->map_word().ToRawValue(); - return MapWord::FromRawValue(map_word | kNotMarkedBit).ToMap(); - } - - static int SizeOfMarkedObject(HeapObject* object) { - return object->SizeFromMap(MapOfMarkedObject(object)); - } - - private: - static const uintptr_t kNotMarkedBit = 0x1; - STATIC_ASSERT((kHeapObjectTag & kNotMarkedBit) != 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. - }; - - // 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_alloc() {} - - 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(); - - // Tags 0, 1, and 3 are used. Use 2 for marking visited HeapObject. - static const int kMarkTag = 2; - - Object* search_target_; - bool found_target_; - bool found_target_in_trace_; - WhatToFind what_to_find_; - VisitMode visit_mode_; - List<Object*> object_stack_; - - AssertNoAllocation no_alloc; // i.e. no gc allowed. - - private: - DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer); -}; -#endif // DEBUG - -} } // namespace v8::internal - -#endif // V8_HEAP_H_ |