| // Copyright 2010 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 "globals.h" |
| #include "list.h" |
| #include "spaces.h" |
| #include "splay-tree-inl.h" |
| #include "v8-counters.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| // Defines all the roots in Heap. |
| #define UNCONDITIONAL_STRONG_ROOT_LIST(V) \ |
| /* Put the byte array map early. We need it to be in place by the time */ \ |
| /* the deserializer hits the next page, since it wants to put a byte */ \ |
| /* array in the unused space at the end of the page. */ \ |
| V(Map, byte_array_map, ByteArrayMap) \ |
| 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, stack_limit, StackLimit) \ |
| V(Object, undefined_value, UndefinedValue) \ |
| V(Object, the_hole_value, TheHoleValue) \ |
| V(Object, null_value, NullValue) \ |
| V(Object, true_value, TrueValue) \ |
| V(Object, false_value, FalseValue) \ |
| V(Object, arguments_marker, ArgumentsMarker) \ |
| V(Map, heap_number_map, HeapNumberMap) \ |
| V(Map, global_context_map, GlobalContextMap) \ |
| V(Map, fixed_array_map, FixedArrayMap) \ |
| V(Map, fixed_cow_array_map, FixedCOWArrayMap) \ |
| V(Object, no_interceptor_result_sentinel, NoInterceptorResultSentinel) \ |
| V(Map, meta_map, MetaMap) \ |
| V(Object, termination_exception, TerminationException) \ |
| V(Map, hash_table_map, HashTableMap) \ |
| V(FixedArray, empty_fixed_array, EmptyFixedArray) \ |
| V(ByteArray, empty_byte_array, EmptyByteArray) \ |
| V(Map, string_map, StringMap) \ |
| V(Map, ascii_string_map, AsciiStringMap) \ |
| V(Map, symbol_map, SymbolMap) \ |
| V(Map, ascii_symbol_map, AsciiSymbolMap) \ |
| V(Map, cons_symbol_map, ConsSymbolMap) \ |
| V(Map, cons_ascii_symbol_map, ConsAsciiSymbolMap) \ |
| V(Map, external_symbol_map, ExternalSymbolMap) \ |
| V(Map, external_symbol_with_ascii_data_map, ExternalSymbolWithAsciiDataMap) \ |
| V(Map, external_ascii_symbol_map, ExternalAsciiSymbolMap) \ |
| V(Map, cons_string_map, ConsStringMap) \ |
| V(Map, cons_ascii_string_map, ConsAsciiStringMap) \ |
| V(Map, external_string_map, ExternalStringMap) \ |
| V(Map, external_string_with_ascii_data_map, ExternalStringWithAsciiDataMap) \ |
| V(Map, external_ascii_string_map, ExternalAsciiStringMap) \ |
| V(Map, undetectable_string_map, UndetectableStringMap) \ |
| V(Map, undetectable_ascii_string_map, UndetectableAsciiStringMap) \ |
| V(Map, pixel_array_map, PixelArrayMap) \ |
| 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, context_map, ContextMap) \ |
| V(Map, catch_context_map, CatchContextMap) \ |
| V(Map, code_map, CodeMap) \ |
| V(Map, oddball_map, OddballMap) \ |
| V(Map, global_property_cell_map, GlobalPropertyCellMap) \ |
| V(Map, shared_function_info_map, SharedFunctionInfoMap) \ |
| V(Map, message_object_map, JSMessageObjectMap) \ |
| V(Map, proxy_map, ProxyMap) \ |
| V(Object, nan_value, NanValue) \ |
| V(Object, minus_zero_value, MinusZeroValue) \ |
| V(Object, instanceof_cache_function, InstanceofCacheFunction) \ |
| V(Object, instanceof_cache_map, InstanceofCacheMap) \ |
| V(Object, instanceof_cache_answer, InstanceofCacheAnswer) \ |
| V(String, empty_string, EmptyString) \ |
| V(DescriptorArray, empty_descriptor_array, EmptyDescriptorArray) \ |
| V(Map, neander_map, NeanderMap) \ |
| V(JSObject, message_listeners, MessageListeners) \ |
| V(Proxy, prototype_accessors, PrototypeAccessors) \ |
| V(NumberDictionary, code_stubs, CodeStubs) \ |
| V(NumberDictionary, non_monomorphic_cache, NonMonomorphicCache) \ |
| V(Code, js_entry_code, JsEntryCode) \ |
| V(Code, js_construct_entry_code, JsConstructEntryCode) \ |
| V(Code, c_entry_code, CEntryCode) \ |
| V(FixedArray, number_string_cache, NumberStringCache) \ |
| V(FixedArray, single_character_string_cache, SingleCharacterStringCache) \ |
| 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) \ |
| |
| #if V8_TARGET_ARCH_ARM && !V8_INTERPRETED_REGEXP |
| #define STRONG_ROOT_LIST(V) \ |
| UNCONDITIONAL_STRONG_ROOT_LIST(V) \ |
| V(Code, re_c_entry_code, RegExpCEntryCode) \ |
| V(Code, direct_c_entry_code, DirectCEntryCode) |
| #elif V8_TARGET_ARCH_ARM |
| #define STRONG_ROOT_LIST(V) \ |
| UNCONDITIONAL_STRONG_ROOT_LIST(V) \ |
| V(Code, direct_c_entry_code, DirectCEntryCode) |
| #else |
| #define STRONG_ROOT_LIST(V) UNCONDITIONAL_STRONG_ROOT_LIST(V) |
| #endif |
| |
| #define ROOT_LIST(V) \ |
| STRONG_ROOT_LIST(V) \ |
| V(SymbolTable, symbol_table, SymbolTable) |
| |
| #define SYMBOL_LIST(V) \ |
| V(Array_symbol, "Array") \ |
| V(Object_symbol, "Object") \ |
| V(Proto_symbol, "__proto__") \ |
| V(StringImpl_symbol, "StringImpl") \ |
| V(arguments_symbol, "arguments") \ |
| V(Arguments_symbol, "Arguments") \ |
| V(arguments_shadow_symbol, ".arguments") \ |
| V(call_symbol, "call") \ |
| V(apply_symbol, "apply") \ |
| V(caller_symbol, "caller") \ |
| V(boolean_symbol, "boolean") \ |
| V(Boolean_symbol, "Boolean") \ |
| V(callee_symbol, "callee") \ |
| V(constructor_symbol, "constructor") \ |
| V(code_symbol, ".code") \ |
| V(result_symbol, ".result") \ |
| V(catch_var_symbol, ".catch-var") \ |
| V(empty_symbol, "") \ |
| V(eval_symbol, "eval") \ |
| V(function_symbol, "function") \ |
| V(length_symbol, "length") \ |
| V(name_symbol, "name") \ |
| V(number_symbol, "number") \ |
| V(Number_symbol, "Number") \ |
| V(RegExp_symbol, "RegExp") \ |
| V(source_symbol, "source") \ |
| V(global_symbol, "global") \ |
| V(ignore_case_symbol, "ignoreCase") \ |
| V(multiline_symbol, "multiline") \ |
| V(input_symbol, "input") \ |
| V(index_symbol, "index") \ |
| V(last_index_symbol, "lastIndex") \ |
| V(object_symbol, "object") \ |
| V(prototype_symbol, "prototype") \ |
| V(string_symbol, "string") \ |
| V(String_symbol, "String") \ |
| V(Date_symbol, "Date") \ |
| V(this_symbol, "this") \ |
| V(to_string_symbol, "toString") \ |
| V(char_at_symbol, "CharAt") \ |
| V(undefined_symbol, "undefined") \ |
| V(value_of_symbol, "valueOf") \ |
| V(InitializeVarGlobal_symbol, "InitializeVarGlobal") \ |
| V(InitializeConstGlobal_symbol, "InitializeConstGlobal") \ |
| V(KeyedLoadSpecialized_symbol, "KeyedLoadSpecialized") \ |
| V(KeyedStoreSpecialized_symbol, "KeyedStoreSpecialized") \ |
| V(KeyedLoadPixelArray_symbol, "KeyedLoadPixelArray") \ |
| V(KeyedStorePixelArray_symbol, "KeyedStorePixelArray") \ |
| V(stack_overflow_symbol, "kStackOverflowBoilerplate") \ |
| V(illegal_access_symbol, "illegal access") \ |
| V(out_of_memory_symbol, "out-of-memory") \ |
| V(illegal_execution_state_symbol, "illegal execution state") \ |
| V(get_symbol, "get") \ |
| V(set_symbol, "set") \ |
| V(function_class_symbol, "Function") \ |
| V(illegal_argument_symbol, "illegal argument") \ |
| V(MakeReferenceError_symbol, "MakeReferenceError") \ |
| V(MakeSyntaxError_symbol, "MakeSyntaxError") \ |
| V(MakeTypeError_symbol, "MakeTypeError") \ |
| V(invalid_lhs_in_assignment_symbol, "invalid_lhs_in_assignment") \ |
| V(invalid_lhs_in_for_in_symbol, "invalid_lhs_in_for_in") \ |
| V(invalid_lhs_in_postfix_op_symbol, "invalid_lhs_in_postfix_op") \ |
| V(invalid_lhs_in_prefix_op_symbol, "invalid_lhs_in_prefix_op") \ |
| V(illegal_return_symbol, "illegal_return") \ |
| V(illegal_break_symbol, "illegal_break") \ |
| V(illegal_continue_symbol, "illegal_continue") \ |
| V(unknown_label_symbol, "unknown_label") \ |
| V(redeclaration_symbol, "redeclaration") \ |
| V(failure_symbol, "<failure>") \ |
| V(space_symbol, " ") \ |
| V(exec_symbol, "exec") \ |
| V(zero_symbol, "0") \ |
| V(global_eval_symbol, "GlobalEval") \ |
| V(identity_hash_symbol, "v8::IdentityHash") \ |
| V(closure_symbol, "(closure)") \ |
| V(use_strict, "use strict") \ |
| V(KeyedLoadExternalArray_symbol, "KeyedLoadExternalArray") \ |
| V(KeyedStoreExternalArray_symbol, "KeyedStoreExternalArray") |
| |
| |
| // Forward declarations. |
| class GCTracer; |
| class HeapStats; |
| class WeakObjectRetainer; |
| |
| |
| typedef String* (*ExternalStringTableUpdaterCallback)(Object** pointer); |
| |
| typedef bool (*DirtyRegionCallback)(Address start, |
| Address end, |
| ObjectSlotCallback copy_object_func); |
| |
| |
| // The all static Heap captures the interface to the global object heap. |
| // All JavaScript contexts by this process share the same object heap. |
| |
| class Heap : public AllStatic { |
| public: |
| // Configure heap size before setup. Return false if the heap has been |
| // setup already. |
| static bool ConfigureHeap(int max_semispace_size, |
| int max_old_gen_size, |
| int max_executable_size); |
| static bool ConfigureHeapDefault(); |
| |
| // Initializes the global object heap. If create_heap_objects is true, |
| // also creates the basic non-mutable objects. |
| // Returns whether it succeeded. |
| static bool Setup(bool create_heap_objects); |
| |
| // Destroys all memory allocated by the heap. |
| static 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. |
| static void SetStackLimits(); |
| |
| // Returns whether Setup has been called. |
| static 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. |
| static intptr_t MaxReserved() { |
| return 4 * reserved_semispace_size_ + max_old_generation_size_; |
| } |
| static int MaxSemiSpaceSize() { return max_semispace_size_; } |
| static int ReservedSemiSpaceSize() { return reserved_semispace_size_; } |
| static int InitialSemiSpaceSize() { return initial_semispace_size_; } |
| static intptr_t MaxOldGenerationSize() { return max_old_generation_size_; } |
| static 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. |
| static intptr_t Capacity(); |
| |
| // Returns the amount of memory currently committed for the heap. |
| static intptr_t CommittedMemory(); |
| |
| // Returns the amount of executable memory currently committed for the heap. |
| static intptr_t CommittedMemoryExecutable(); |
| |
| // 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. |
| static intptr_t Available(); |
| |
| // Returns the maximum object size in paged space. |
| static inline int MaxObjectSizeInPagedSpace(); |
| |
| // Returns of size of all objects residing in the heap. |
| static 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. |
| static Address NewSpaceStart() { return new_space_.start(); } |
| static uintptr_t NewSpaceMask() { return new_space_.mask(); } |
| static Address NewSpaceTop() { return new_space_.top(); } |
| |
| static NewSpace* new_space() { return &new_space_; } |
| static OldSpace* old_pointer_space() { return old_pointer_space_; } |
| static OldSpace* old_data_space() { return old_data_space_; } |
| static OldSpace* code_space() { return code_space_; } |
| static MapSpace* map_space() { return map_space_; } |
| static CellSpace* cell_space() { return cell_space_; } |
| static LargeObjectSpace* lo_space() { return lo_space_; } |
| |
| static bool always_allocate() { return always_allocate_scope_depth_ != 0; } |
| static Address always_allocate_scope_depth_address() { |
| return reinterpret_cast<Address>(&always_allocate_scope_depth_); |
| } |
| static bool linear_allocation() { |
| return linear_allocation_scope_depth_ != 0; |
| } |
| |
| static Address* NewSpaceAllocationTopAddress() { |
| return new_space_.allocation_top_address(); |
| } |
| static Address* NewSpaceAllocationLimitAddress() { |
| return new_space_.allocation_limit_address(); |
| } |
| |
| // Uncommit unused semi space. |
| static bool UncommitFromSpace() { return new_space_.UncommitFromSpace(); } |
| |
| #ifdef ENABLE_HEAP_PROTECTION |
| // Protect/unprotect the heap by marking all spaces read-only/writable. |
| static void Protect(); |
| static void Unprotect(); |
| #endif |
| |
| // 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 static MaybeObject* AllocateJSObject( |
| JSFunction* constructor, 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 static 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 static MaybeObject* CopyJSObject(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 static MaybeObject* AllocateFunctionPrototype( |
| JSFunction* function); |
| |
| // 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 static 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 static MaybeObject* AllocateJSObjectFromMap( |
| Map* map, PretenureFlag pretenure = NOT_TENURED); |
| |
| // 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 static MaybeObject* Allocate(Map* map, AllocationSpace space); |
| |
| // 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 static MaybeObject* AllocateMap(InstanceType instance_type, |
| int instance_size); |
| |
| // Allocates a partial map for bootstrapping. |
| MUST_USE_RESULT static MaybeObject* AllocatePartialMap( |
| InstanceType instance_type, |
| int instance_size); |
| |
| // Allocate a map for the specified function |
| MUST_USE_RESULT static MaybeObject* AllocateInitialMap(JSFunction* fun); |
| |
| // Allocates an empty code cache. |
| MUST_USE_RESULT static MaybeObject* AllocateCodeCache(); |
| |
| // Clear the Instanceof cache (used when a prototype changes). |
| static void ClearInstanceofCache() { |
| set_instanceof_cache_function(the_hole_value()); |
| } |
| |
| // 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 static MaybeObject* AllocateStringFromAscii( |
| Vector<const char> str, |
| PretenureFlag pretenure = NOT_TENURED); |
| MUST_USE_RESULT static inline MaybeObject* AllocateStringFromUtf8( |
| Vector<const char> str, |
| PretenureFlag pretenure = NOT_TENURED); |
| MUST_USE_RESULT static MaybeObject* AllocateStringFromUtf8Slow( |
| Vector<const char> str, |
| PretenureFlag pretenure = NOT_TENURED); |
| MUST_USE_RESULT static MaybeObject* AllocateStringFromTwoByte( |
| Vector<const uc16> str, |
| PretenureFlag pretenure = NOT_TENURED); |
| |
| // Allocates a symbol 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 static inline MaybeObject* AllocateSymbol( |
| Vector<const char> str, |
| int chars, |
| uint32_t hash_field); |
| |
| MUST_USE_RESULT static inline MaybeObject* AllocateAsciiSymbol( |
| Vector<const char> str, |
| uint32_t hash_field); |
| |
| MUST_USE_RESULT static inline MaybeObject* AllocateTwoByteSymbol( |
| Vector<const uc16> str, |
| uint32_t hash_field); |
| |
| MUST_USE_RESULT static MaybeObject* AllocateInternalSymbol( |
| unibrow::CharacterStream* buffer, int chars, uint32_t hash_field); |
| |
| MUST_USE_RESULT static MaybeObject* AllocateExternalSymbol( |
| Vector<const char> str, |
| int chars); |
| |
| |
| // 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 static MaybeObject* AllocateRawAsciiString( |
| int length, |
| PretenureFlag pretenure = NOT_TENURED); |
| MUST_USE_RESULT static 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 static 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 static 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 static MaybeObject* AllocateByteArray(int length); |
| |
| // Allocate a pixel 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 static MaybeObject* AllocatePixelArray(int length, |
| uint8_t* external_pointer, |
| PretenureFlag pretenure); |
| |
| // 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 static MaybeObject* AllocateExternalArray( |
| int length, |
| ExternalArrayType array_type, |
| void* external_pointer, |
| PretenureFlag pretenure); |
| |
| // 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 static 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 static MaybeObject* AllocateFixedArray( |
| int length, |
| PretenureFlag pretenure); |
| // Allocates a fixed array initialized with undefined values |
| MUST_USE_RESULT static 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 static MaybeObject* AllocateUninitializedFixedArray( |
| int length); |
| |
| // Make a copy of src and return it. Returns |
| // Failure::RetryAfterGC(requested_bytes, space) if the allocation failed. |
| MUST_USE_RESULT static 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 static MaybeObject* CopyFixedArrayWithMap(FixedArray* 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 static MaybeObject* AllocateFixedArrayWithHoles( |
| 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 static MaybeObject* AllocateHashTable( |
| int length, PretenureFlag pretenure = NOT_TENURED); |
| |
| // Allocate a global (but otherwise uninitialized) context. |
| MUST_USE_RESULT static MaybeObject* AllocateGlobalContext(); |
| |
| // Allocate a function context. |
| MUST_USE_RESULT static MaybeObject* AllocateFunctionContext( |
| int length, |
| JSFunction* closure); |
| |
| // Allocate a 'with' context. |
| MUST_USE_RESULT static MaybeObject* AllocateWithContext( |
| Context* previous, |
| JSObject* extension, |
| bool is_catch_context); |
| |
| // Allocates a new utility object in the old generation. |
| MUST_USE_RESULT static 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 static MaybeObject* AllocateFunction( |
| Map* function_map, |
| SharedFunctionInfo* shared, |
| Object* prototype, |
| PretenureFlag pretenure = TENURED); |
| |
| // Indicies for direct access into argument objects. |
| static const int kArgumentsObjectSize = |
| JSObject::kHeaderSize + 2 * kPointerSize; |
| static const int arguments_callee_index = 0; |
| static const int arguments_length_index = 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 static 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 static MaybeObject* NumberFromDouble( |
| double value, PretenureFlag pretenure = NOT_TENURED); |
| |
| // Allocated a HeapNumber from value. |
| MUST_USE_RESULT static MaybeObject* AllocateHeapNumber( |
| double value, |
| PretenureFlag pretenure); |
| // pretenure = NOT_TENURED. |
| MUST_USE_RESULT static 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 static inline MaybeObject* NumberFromInt32(int32_t 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 static inline MaybeObject* NumberFromUint32(uint32_t value); |
| |
| // Allocates a new proxy object. |
| // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation |
| // failed. |
| // Please note this does not perform a garbage collection. |
| MUST_USE_RESULT static MaybeObject* AllocateProxy( |
| Address proxy, |
| 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 static 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 static 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 static 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 static 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 static MaybeObject* AllocateExternalStringFromAscii( |
| ExternalAsciiString::Resource* resource); |
| MUST_USE_RESULT static MaybeObject* AllocateExternalStringFromTwoByte( |
| ExternalTwoByteString::Resource* resource); |
| |
| // Finalizes an external string by deleting the associated external |
| // data and clearing the resource pointer. |
| static inline void FinalizeExternalString(String* 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 static 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. |
| static 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 static MaybeObject* CreateCode(const CodeDesc& desc, |
| Code::Flags flags, |
| Handle<Object> self_reference); |
| |
| MUST_USE_RESULT static 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 static MaybeObject* CopyCode(Code* code, |
| Vector<byte> reloc_info); |
| |
| // Finds the symbol for string in the symbol table. |
| // If not found, a new symbol 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 static MaybeObject* LookupSymbol(Vector<const char> str); |
| MUST_USE_RESULT static MaybeObject* LookupAsciiSymbol(Vector<const char> str); |
| MUST_USE_RESULT static MaybeObject* LookupTwoByteSymbol( |
| Vector<const uc16> str); |
| MUST_USE_RESULT static MaybeObject* LookupAsciiSymbol(const char* str) { |
| return LookupSymbol(CStrVector(str)); |
| } |
| MUST_USE_RESULT static MaybeObject* LookupSymbol(String* str); |
| static bool LookupSymbolIfExists(String* str, String** symbol); |
| static bool LookupTwoCharsSymbolIfExists(String* str, String** symbol); |
| |
| // Compute the matching symbol map for a string if possible. |
| // NULL is returned if string is in new space or not flattened. |
| static Map* SymbolMapForString(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 static inline MaybeObject* PrepareForCompare(String* str); |
| |
| // Converts the given boolean condition to JavaScript boolean value. |
| static Object* ToBoolean(bool condition) { |
| return condition ? true_value() : false_value(); |
| } |
| |
| // Code that should be run before and after each GC. Includes some |
| // reporting/verification activities when compiled with DEBUG set. |
| static void GarbageCollectionPrologue(); |
| static void GarbageCollectionEpilogue(); |
| |
| // Performs garbage collection operation. |
| // Returns whether there is a chance that another major GC could |
| // collect more garbage. |
| static bool CollectGarbage(AllocationSpace space, GarbageCollector collector); |
| |
| // Performs garbage collection operation. |
| // Returns whether there is a chance that another major GC could |
| // collect more garbage. |
| inline static bool CollectGarbage(AllocationSpace space); |
| |
| // Performs a full garbage collection. Force compaction if the |
| // parameter is true. |
| static void CollectAllGarbage(bool force_compaction); |
| |
| // Last hope GC, should try to squeeze as much as possible. |
| static void CollectAllAvailableGarbage(); |
| |
| // Notify the heap that a context has been disposed. |
| static int NotifyContextDisposed() { return ++contexts_disposed_; } |
| |
| // Utility to invoke the scavenger. This is needed in test code to |
| // ensure correct callback for weak global handles. |
| static void PerformScavenge(); |
| |
| #ifdef DEBUG |
| // Utility used with flag gc-greedy. |
| static void GarbageCollectionGreedyCheck(); |
| #endif |
| |
| static void AddGCPrologueCallback( |
| GCEpilogueCallback callback, GCType gc_type_filter); |
| static void RemoveGCPrologueCallback(GCEpilogueCallback callback); |
| |
| static void AddGCEpilogueCallback( |
| GCEpilogueCallback callback, GCType gc_type_filter); |
| static void RemoveGCEpilogueCallback(GCEpilogueCallback callback); |
| |
| static void SetGlobalGCPrologueCallback(GCCallback callback) { |
| ASSERT((callback == NULL) ^ (global_gc_prologue_callback_ == NULL)); |
| global_gc_prologue_callback_ = callback; |
| } |
| static 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. |
| #define ROOT_ACCESSOR(type, name, camel_name) \ |
| static inline type* name() { \ |
| return type::cast(roots_[k##camel_name##RootIndex]); \ |
| } \ |
| static inline 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) \ |
| static inline Map* name##_map() { \ |
| return Map::cast(roots_[k##Name##MapRootIndex]); \ |
| } |
| STRUCT_LIST(STRUCT_MAP_ACCESSOR) |
| #undef STRUCT_MAP_ACCESSOR |
| |
| #define SYMBOL_ACCESSOR(name, str) static inline String* name() { \ |
| return String::cast(roots_[k##name##RootIndex]); \ |
| } |
| SYMBOL_LIST(SYMBOL_ACCESSOR) |
| #undef SYMBOL_ACCESSOR |
| |
| // The hidden_symbol is special because it is the empty string, but does |
| // not match the empty string. |
| static String* hidden_symbol() { return hidden_symbol_; } |
| |
| static void set_global_contexts_list(Object* object) { |
| global_contexts_list_ = object; |
| } |
| static Object* global_contexts_list() { return global_contexts_list_; } |
| |
| // Iterates over all roots in the heap. |
| static void IterateRoots(ObjectVisitor* v, VisitMode mode); |
| // Iterates over all strong roots in the heap. |
| static void IterateStrongRoots(ObjectVisitor* v, VisitMode mode); |
| // Iterates over all the other roots in the heap. |
| static void IterateWeakRoots(ObjectVisitor* v, VisitMode mode); |
| |
| enum ExpectedPageWatermarkState { |
| WATERMARK_SHOULD_BE_VALID, |
| WATERMARK_CAN_BE_INVALID |
| }; |
| |
| // For each dirty region on a page in use from an old space call |
| // visit_dirty_region callback. |
| // If either visit_dirty_region or callback can cause an allocation |
| // in old space and changes in allocation watermark then |
| // can_preallocate_during_iteration should be set to true. |
| // All pages will be marked as having invalid watermark upon |
| // iteration completion. |
| static void IterateDirtyRegions( |
| PagedSpace* space, |
| DirtyRegionCallback visit_dirty_region, |
| ObjectSlotCallback callback, |
| ExpectedPageWatermarkState expected_page_watermark_state); |
| |
| // Interpret marks as a bitvector of dirty marks for regions of size |
| // Page::kRegionSize aligned by Page::kRegionAlignmentMask and covering |
| // memory interval from start to top. For each dirty region call a |
| // visit_dirty_region callback. Return updated bitvector of dirty marks. |
| static uint32_t IterateDirtyRegions(uint32_t marks, |
| Address start, |
| Address end, |
| DirtyRegionCallback visit_dirty_region, |
| ObjectSlotCallback callback); |
| |
| // Iterate pointers to from semispace of new space found in memory interval |
| // from start to end. |
| // Update dirty marks for page containing start address. |
| static void IterateAndMarkPointersToFromSpace(Address start, |
| Address end, |
| ObjectSlotCallback callback); |
| |
| // Iterate pointers to new space found in memory interval from start to end. |
| // Return true if pointers to new space was found. |
| static bool IteratePointersInDirtyRegion(Address start, |
| Address end, |
| ObjectSlotCallback callback); |
| |
| |
| // Iterate pointers to new space found in memory interval from start to end. |
| // This interval is considered to belong to the map space. |
| // Return true if pointers to new space was found. |
| static bool IteratePointersInDirtyMapsRegion(Address start, |
| Address end, |
| ObjectSlotCallback callback); |
| |
| |
| // Returns whether the object resides in new space. |
| static inline bool InNewSpace(Object* object); |
| static inline bool InFromSpace(Object* object); |
| static inline bool InToSpace(Object* object); |
| |
| // Checks whether an address/object in the heap (including auxiliary |
| // area and unused area). |
| static bool Contains(Address addr); |
| static bool Contains(HeapObject* value); |
| |
| // Checks whether an address/object in a space. |
| // Currently used by tests, serialization and heap verification only. |
| static bool InSpace(Address addr, AllocationSpace space); |
| static bool InSpace(HeapObject* value, AllocationSpace space); |
| |
| // Finds out which space an object should get promoted to based on its type. |
| static inline OldSpace* TargetSpace(HeapObject* object); |
| static inline AllocationSpace TargetSpaceId(InstanceType type); |
| |
| // Sets the stub_cache_ (only used when expanding the dictionary). |
| static void public_set_code_stubs(NumberDictionary* 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. |
| static HeapObjectCallback GcSafeSizeOfOldObjectFunction() { |
| return gc_safe_size_of_old_object_; |
| } |
| |
| // Sets the non_monomorphic_cache_ (only used when expanding the dictionary). |
| static void public_set_non_monomorphic_cache(NumberDictionary* value) { |
| roots_[kNonMonomorphicCacheRootIndex] = value; |
| } |
| |
| static void public_set_empty_script(Script* script) { |
| roots_[kEmptyScriptRootIndex] = script; |
| } |
| |
| // Update the next script id. |
| static inline void SetLastScriptId(Object* last_script_id); |
| |
| // Generated code can embed this address to get access to the roots. |
| static Object** roots_address() { return roots_; } |
| |
| // Get address of global contexts list for serialization support. |
| static Object** global_contexts_list_address() { |
| return &global_contexts_list_; |
| } |
| |
| #ifdef DEBUG |
| static void Print(); |
| static void PrintHandles(); |
| |
| // Verify the heap is in its normal state before or after a GC. |
| static void Verify(); |
| |
| // Report heap statistics. |
| static void ReportHeapStatistics(const char* title); |
| static void ReportCodeStatistics(const char* title); |
| |
| // Fill in bogus values in from space |
| static void ZapFromSpace(); |
| #endif |
| |
| #if defined(ENABLE_LOGGING_AND_PROFILING) |
| // Print short heap statistics. |
| static void PrintShortHeapStatistics(); |
| #endif |
| |
| // Makes a new symbol object |
| // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation |
| // failed. |
| // Please note this function does not perform a garbage collection. |
| MUST_USE_RESULT static MaybeObject* CreateSymbol(const char* str, |
| int length, |
| int hash); |
| MUST_USE_RESULT static MaybeObject* CreateSymbol(String* str); |
| |
| // Write barrier support for address[offset] = o. |
| static inline void RecordWrite(Address address, int offset); |
| |
| // Write barrier support for address[start : start + len[ = o. |
| static inline void RecordWrites(Address address, int start, int len); |
| |
| // Given an address occupied by a live code object, return that object. |
| static Object* FindCodeObject(Address a); |
| |
| // Invoke Shrink on shrinkable spaces. |
| static void Shrink(); |
| |
| enum HeapState { NOT_IN_GC, SCAVENGE, MARK_COMPACT }; |
| static inline HeapState gc_state() { return gc_state_; } |
| |
| #ifdef DEBUG |
| static bool IsAllocationAllowed() { return allocation_allowed_; } |
| static inline bool allow_allocation(bool enable); |
| |
| static bool disallow_allocation_failure() { |
| return disallow_allocation_failure_; |
| } |
| |
| static void TracePathToObject(Object* target); |
| static 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 void ScavengePointer(HeapObject** p); |
| static inline void ScavengeObject(HeapObject** p, HeapObject* object); |
| |
| // Commits from space if it is uncommitted. |
| static void EnsureFromSpaceIsCommitted(); |
| |
| // Support for partial snapshots. After calling this we can allocate a |
| // certain number of bytes using only linear allocation (with a |
| // LinearAllocationScope and an AlwaysAllocateScope) without using freelists |
| // or causing a GC. It returns true of space was reserved or false if a GC is |
| // needed. For paged spaces the space requested must include the space wasted |
| // at the end of each page when allocating linearly. |
| static void ReserveSpace( |
| int new_space_size, |
| int pointer_space_size, |
| int data_space_size, |
| int code_space_size, |
| int map_space_size, |
| int cell_space_size, |
| int large_object_size); |
| |
| // |
| // Support for the API. |
| // |
| |
| static 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. |
| static Object* GetNumberStringCache(Object* number); |
| |
| // Update the cache with a new number-string pair. |
| static void SetNumberStringCache(Object* number, String* str); |
| |
| // Adjusts the amount of registered external memory. |
| // Returns the adjusted value. |
| static inline int AdjustAmountOfExternalAllocatedMemory(int change_in_bytes); |
| |
| // Allocate uninitialized fixed array. |
| MUST_USE_RESULT static MaybeObject* AllocateRawFixedArray(int length); |
| MUST_USE_RESULT static MaybeObject* AllocateRawFixedArray( |
| int length, |
| PretenureFlag pretenure); |
| |
| // 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. |
| static bool OldGenerationPromotionLimitReached() { |
| return (PromotedSpaceSize() + PromotedExternalMemorySize()) |
| > old_gen_promotion_limit_; |
| } |
| |
| static intptr_t OldGenerationSpaceAvailable() { |
| return old_gen_allocation_limit_ - |
| (PromotedSpaceSize() + PromotedExternalMemorySize()); |
| } |
| |
| // True if we have reached the allocation limit in the old generation that |
| // should artificially cause a GC right now. |
| static bool OldGenerationAllocationLimitReached() { |
| return OldGenerationSpaceAvailable() < 0; |
| } |
| |
| // Can be called when the embedding application is idle. |
| static bool IdleNotification(); |
| |
| // 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 |
| |
| // Utility type maps |
| #define DECLARE_STRUCT_MAP(NAME, Name, name) k##Name##MapRootIndex, |
| STRUCT_LIST(DECLARE_STRUCT_MAP) |
| #undef DECLARE_STRUCT_MAP |
| |
| #define SYMBOL_INDEX_DECLARATION(name, str) k##name##RootIndex, |
| SYMBOL_LIST(SYMBOL_INDEX_DECLARATION) |
| #undef SYMBOL_DECLARATION |
| |
| kSymbolTableRootIndex, |
| kStrongRootListLength = kSymbolTableRootIndex, |
| kRootListLength |
| }; |
| |
| MUST_USE_RESULT static MaybeObject* NumberToString( |
| Object* number, |
| bool check_number_string_cache = true); |
| |
| static Map* MapForExternalArrayType(ExternalArrayType array_type); |
| static RootListIndex RootIndexForExternalArrayType( |
| ExternalArrayType array_type); |
| |
| static 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); |
| |
| static inline void CopyBlockToOldSpaceAndUpdateRegionMarks(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); |
| |
| static inline void MoveBlockToOldSpaceAndUpdateRegionMarks(Address dst, |
| Address src, |
| int byte_size); |
| |
| // Check new space expansion criteria and expand semispaces if it was hit. |
| static void CheckNewSpaceExpansionCriteria(); |
| |
| static inline void IncrementYoungSurvivorsCounter(int survived) { |
| young_survivors_after_last_gc_ = survived; |
| survived_since_last_expansion_ += survived; |
| } |
| |
| static void UpdateNewSpaceReferencesInExternalStringTable( |
| ExternalStringTableUpdaterCallback updater_func); |
| |
| static void ProcessWeakReferences(WeakObjectRetainer* retainer); |
| |
| // 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. |
| static inline bool ShouldBePromoted(Address old_address, int object_size); |
| |
| static int MaxObjectSizeInNewSpace() { return kMaxObjectSizeInNewSpace; } |
| |
| static void ClearJSFunctionResultCaches(); |
| |
| static void ClearNormalizedMapCaches(); |
| |
| static GCTracer* tracer() { return tracer_; } |
| |
| private: |
| static int reserved_semispace_size_; |
| static int max_semispace_size_; |
| static int initial_semispace_size_; |
| static intptr_t max_old_generation_size_; |
| static intptr_t max_executable_size_; |
| static intptr_t code_range_size_; |
| |
| // For keeping track of how much data has survived |
| // scavenge since last new space expansion. |
| static int survived_since_last_expansion_; |
| |
| static int always_allocate_scope_depth_; |
| static int linear_allocation_scope_depth_; |
| |
| // For keeping track of context disposals. |
| static int contexts_disposed_; |
| |
| #if defined(V8_TARGET_ARCH_X64) |
| static const int kMaxObjectSizeInNewSpace = 1024*KB; |
| #else |
| static const int kMaxObjectSizeInNewSpace = 512*KB; |
| #endif |
| |
| static NewSpace new_space_; |
| static OldSpace* old_pointer_space_; |
| static OldSpace* old_data_space_; |
| static OldSpace* code_space_; |
| static MapSpace* map_space_; |
| static CellSpace* cell_space_; |
| static LargeObjectSpace* lo_space_; |
| static HeapState gc_state_; |
| |
| // Returns the size of object residing in non new spaces. |
| static intptr_t PromotedSpaceSize(); |
| |
| // Returns the amount of external memory registered since last global gc. |
| static int PromotedExternalMemorySize(); |
| |
| static int mc_count_; // how many mark-compact collections happened |
| static int ms_count_; // how many mark-sweep collections happened |
| static unsigned int gc_count_; // how many gc happened |
| |
| // Total length of the strings we failed to flatten since the last GC. |
| static int unflattened_strings_length_; |
| |
| #define ROOT_ACCESSOR(type, name, camel_name) \ |
| static inline void set_##name(type* value) { \ |
| roots_[k##camel_name##RootIndex] = value; \ |
| } |
| ROOT_LIST(ROOT_ACCESSOR) |
| #undef ROOT_ACCESSOR |
| |
| #ifdef DEBUG |
| static 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. |
| static int allocation_timeout_; |
| |
| // Do we expect to be able to handle allocation failure at this |
| // time? |
| static bool disallow_allocation_failure_; |
| #endif // DEBUG |
| |
| // Limit that triggers a global GC on the next (normally caused) GC. This |
| // is checked when we have already decided to do a GC to help determine |
| // which collector to invoke. |
| static 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. |
| static intptr_t old_gen_allocation_limit_; |
| |
| // Limit on the amount of externally allocated memory allowed |
| // between global GCs. If reached a global GC is forced. |
| static intptr_t external_allocation_limit_; |
| |
| // The amount of external memory registered through the API kept alive |
| // by global handles |
| static int amount_of_external_allocated_memory_; |
| |
| // Caches the amount of external memory registered at the last global gc. |
| static int amount_of_external_allocated_memory_at_last_global_gc_; |
| |
| // Indicates that an allocation has failed in the old generation since the |
| // last GC. |
| static int old_gen_exhausted_; |
| |
| static Object* roots_[kRootListLength]; |
| |
| static Object* global_contexts_list_; |
| |
| struct StringTypeTable { |
| InstanceType type; |
| int size; |
| RootListIndex index; |
| }; |
| |
| struct ConstantSymbolTable { |
| const char* contents; |
| RootListIndex index; |
| }; |
| |
| struct StructTable { |
| InstanceType type; |
| int size; |
| RootListIndex index; |
| }; |
| |
| static const StringTypeTable string_type_table[]; |
| static const ConstantSymbolTable constant_symbol_table[]; |
| static const StructTable struct_table[]; |
| |
| // The special hidden symbol which is an empty string, but does not match |
| // any string when looked up in properties. |
| static String* hidden_symbol_; |
| |
| // 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; |
| }; |
| static 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; |
| }; |
| static List<GCEpilogueCallbackPair> gc_epilogue_callbacks_; |
| |
| static GCCallback global_gc_prologue_callback_; |
| static GCCallback global_gc_epilogue_callback_; |
| |
| // Support for computing object sizes during GC. |
| static HeapObjectCallback gc_safe_size_of_old_object_; |
| static int GcSafeSizeOfOldObject(HeapObject* object); |
| static int GcSafeSizeOfOldObjectWithEncodedMap(HeapObject* object); |
| |
| // Update the GC state. Called from the mark-compact collector. |
| static void MarkMapPointersAsEncoded(bool encoded) { |
| gc_safe_size_of_old_object_ = encoded |
| ? &GcSafeSizeOfOldObjectWithEncodedMap |
| : &GcSafeSizeOfOldObject; |
| } |
| |
| // Checks whether a global GC is necessary |
| static GarbageCollector SelectGarbageCollector(AllocationSpace space); |
| |
| // Performs garbage collection |
| // Returns whether there is a chance another major GC could |
| // collect more garbage. |
| static bool PerformGarbageCollection(GarbageCollector collector, |
| GCTracer* tracer); |
| |
| // 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 static inline MaybeObject* AllocateRawMap(); |
| |
| // Allocate an uninitialized object in the global property cell space. |
| MUST_USE_RESULT static inline MaybeObject* AllocateRawCell(); |
| |
| // Initializes a JSObject based on its map. |
| static void InitializeJSObjectFromMap(JSObject* obj, |
| FixedArray* properties, |
| Map* map); |
| |
| static bool CreateInitialMaps(); |
| static 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(static void CreateCEntryStub()); |
| NO_INLINE(static void CreateJSEntryStub()); |
| NO_INLINE(static void CreateJSConstructEntryStub()); |
| NO_INLINE(static void CreateRegExpCEntryStub()); |
| NO_INLINE(static void CreateDirectCEntryStub()); |
| |
| static void CreateFixedStubs(); |
| |
| MUST_USE_RESULT static MaybeObject* CreateOddball(const char* to_string, |
| Object* to_number); |
| |
| // Allocate empty fixed array. |
| MUST_USE_RESULT static MaybeObject* AllocateEmptyFixedArray(); |
| |
| // Performs a minor collection in new generation. |
| static void Scavenge(); |
| |
| static String* UpdateNewSpaceReferenceInExternalStringTableEntry( |
| Object** pointer); |
| |
| static Address DoScavenge(ObjectVisitor* scavenge_visitor, |
| Address new_space_front); |
| |
| // Performs a major collection in the whole heap. |
| static void MarkCompact(GCTracer* tracer); |
| |
| // Code to be run before and after mark-compact. |
| static void MarkCompactPrologue(bool is_compacting); |
| |
| // Completely clear the Instanceof cache (to stop it keeping objects alive |
| // around a GC). |
| static void CompletelyClearInstanceofCache() { |
| set_instanceof_cache_map(the_hole_value()); |
| set_instanceof_cache_function(the_hole_value()); |
| } |
| |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| // Record statistics before and after garbage collection. |
| static void ReportStatisticsBeforeGC(); |
| static void ReportStatisticsAfterGC(); |
| #endif |
| |
| // Slow part of scavenge object. |
| static void ScavengeObjectSlow(HeapObject** p, HeapObject* object); |
| |
| // Initializes a function with a shared part and prototype. |
| // Returns the function. |
| // 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. |
| MUST_USE_RESULT static inline MaybeObject* InitializeFunction( |
| JSFunction* function, |
| SharedFunctionInfo* shared, |
| Object* prototype); |
| |
| static GCTracer* tracer_; |
| |
| |
| // Initializes the number to string cache based on the max semispace size. |
| MUST_USE_RESULT static MaybeObject* InitializeNumberStringCache(); |
| // Flush the number to string cache. |
| static void FlushNumberStringCache(); |
| |
| static void UpdateSurvivalRateTrend(int start_new_space_size); |
| |
| enum SurvivalRateTrend { INCREASING, STABLE, DECREASING, FLUCTUATING }; |
| |
| static const int kYoungSurvivalRateThreshold = 90; |
| static const int kYoungSurvivalRateAllowedDeviation = 15; |
| |
| static int young_survivors_after_last_gc_; |
| static int high_survival_rate_period_length_; |
| static double survival_rate_; |
| static SurvivalRateTrend previous_survival_rate_trend_; |
| static SurvivalRateTrend survival_rate_trend_; |
| |
| static 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; |
| } |
| |
| static 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_; |
| } |
| } |
| |
| static bool IsStableOrIncreasingSurvivalTrend() { |
| switch (survival_rate_trend()) { |
| case STABLE: |
| case INCREASING: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| static bool IsIncreasingSurvivalTrend() { |
| return survival_rate_trend() == INCREASING; |
| } |
| |
| static bool IsHighSurvivalRate() { |
| return high_survival_rate_period_length_ > 0; |
| } |
| |
| static const int kInitialSymbolTableSize = 2048; |
| static const int kInitialEvalCacheSize = 64; |
| |
| friend class Factory; |
| friend class DisallowAllocationFailure; |
| friend class AlwaysAllocateScope; |
| friend class LinearAllocationScope; |
| friend class MarkCompactCollector; |
| }; |
| |
| |
| 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* destroyed_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 AlwaysAllocateScope { |
| public: |
| AlwaysAllocateScope() { |
| // We shouldn't hit any nested scopes, because that requires |
| // non-handle code to call handle code. The code still works but |
| // performance will degrade, so we want to catch this situation |
| // in debug mode. |
| ASSERT(Heap::always_allocate_scope_depth_ == 0); |
| Heap::always_allocate_scope_depth_++; |
| } |
| |
| ~AlwaysAllocateScope() { |
| Heap::always_allocate_scope_depth_--; |
| ASSERT(Heap::always_allocate_scope_depth_ == 0); |
| } |
| }; |
| |
| |
| class LinearAllocationScope { |
| public: |
| LinearAllocationScope() { |
| Heap::linear_allocation_scope_depth_++; |
| } |
| |
| ~LinearAllocationScope() { |
| Heap::linear_allocation_scope_depth_--; |
| ASSERT(Heap::linear_allocation_scope_depth_ >= 0); |
| } |
| }; |
| |
| |
| #ifdef DEBUG |
| // 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: |
| void VisitPointers(Object** start, Object** end) { |
| for (Object** current = start; current < end; current++) { |
| if ((*current)->IsHeapObject()) { |
| HeapObject* object = HeapObject::cast(*current); |
| ASSERT(Heap::Contains(object)); |
| ASSERT(object->map()->IsMap()); |
| } |
| } |
| } |
| }; |
| |
| |
| // Visitor class to verify interior pointers in spaces that use region marks |
| // to keep track of intergenerational references. |
| // As VerifyPointersVisitor but also checks that dirty marks are set |
| // for regions covering intergenerational references. |
| class VerifyPointersAndDirtyRegionsVisitor: public ObjectVisitor { |
| public: |
| void VisitPointers(Object** start, Object** end) { |
| for (Object** current = start; current < end; current++) { |
| if ((*current)->IsHeapObject()) { |
| HeapObject* object = HeapObject::cast(*current); |
| ASSERT(Heap::Contains(object)); |
| ASSERT(object->map()->IsMap()); |
| if (Heap::InNewSpace(object)) { |
| ASSERT(Heap::InToSpace(object)); |
| Address addr = reinterpret_cast<Address>(current); |
| ASSERT(Page::FromAddress(addr)->IsRegionDirty(addr)); |
| } |
| } |
| } |
| } |
| }; |
| #endif |
| |
| |
| // 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: |
| Space* next(); |
| AllSpaces() { counter_ = FIRST_SPACE; } |
| private: |
| 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: |
| OldSpace* next(); |
| OldSpaces() { counter_ = OLD_POINTER_SPACE; } |
| private: |
| 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: |
| PagedSpace* next(); |
| PagedSpaces() { counter_ = OLD_POINTER_SPACE; } |
| private: |
| 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: |
| SpaceIterator(); |
| explicit SpaceIterator(HeapObjectCallback size_func); |
| virtual ~SpaceIterator(); |
| |
| bool has_next(); |
| ObjectIterator* next(); |
| |
| private: |
| ObjectIterator* CreateIterator(); |
| |
| 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, |
| kFilterFreeListNodes, |
| kFilterUnreachable |
| }; |
| |
| HeapIterator(); |
| explicit HeapIterator(HeapObjectsFiltering filtering); |
| ~HeapIterator(); |
| |
| HeapObject* next(); |
| void reset(); |
| |
| private: |
| // Perform the initialization. |
| void Init(); |
| // Perform all necessary shutdown (destruction) work. |
| void Shutdown(); |
| HeapObject* NextObject(); |
| |
| 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. |
| static int Lookup(Map* map, String* name); |
| |
| // Update an element in the cache. |
| static void Update(Map* map, String* name, int field_offset); |
| |
| // Clear the cache. |
| static void Clear(); |
| |
| static const int kLength = 64; |
| static const int kCapacityMask = kLength - 1; |
| static const int kMapHashShift = 2; |
| |
| private: |
| 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. |
| static Address keys_address() { |
| return reinterpret_cast<Address>(&keys_); |
| } |
| |
| static Address field_offsets_address() { |
| return reinterpret_cast<Address>(&field_offsets_); |
| } |
| |
| struct Key { |
| Map* map; |
| String* name; |
| }; |
| static Key keys_[kLength]; |
| static int field_offsets_[kLength]; |
| |
| friend class ExternalReference; |
| }; |
| |
| |
| // Cache for mapping (array, 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. |
| static int Lookup(DescriptorArray* array, String* name) { |
| if (!StringShape(name).IsSymbol()) return kAbsent; |
| int index = Hash(array, name); |
| Key& key = keys_[index]; |
| if ((key.array == array) && (key.name == name)) return results_[index]; |
| return kAbsent; |
| } |
| |
| // Update an element in the cache. |
| static void Update(DescriptorArray* array, String* name, int result) { |
| ASSERT(result != kAbsent); |
| if (StringShape(name).IsSymbol()) { |
| int index = Hash(array, name); |
| Key& key = keys_[index]; |
| key.array = array; |
| key.name = name; |
| results_[index] = result; |
| } |
| } |
| |
| // Clear the cache. |
| static void Clear(); |
| |
| static const int kAbsent = -2; |
| private: |
| static int Hash(DescriptorArray* array, String* name) { |
| // Uses only lower 32 bits if pointers are larger. |
| uint32_t array_hash = |
| static_cast<uint32_t>(reinterpret_cast<uintptr_t>(array)) >> 2; |
| uint32_t name_hash = |
| static_cast<uint32_t>(reinterpret_cast<uintptr_t>(name)) >> 2; |
| return (array_hash ^ name_hash) % kLength; |
| } |
| |
| static const int kLength = 64; |
| struct Key { |
| DescriptorArray* array; |
| String* name; |
| }; |
| |
| static Key keys_[kLength]; |
| static int results_[kLength]; |
| }; |
| |
| |
| // ---------------------------------------------------------------------------- |
| // Marking stack for tracing live objects. |
| |
| class MarkingStack { |
| public: |
| void Initialize(Address low, Address high) { |
| top_ = low_ = reinterpret_cast<HeapObject**>(low); |
| high_ = reinterpret_cast<HeapObject**>(high); |
| overflowed_ = false; |
| } |
| |
| bool is_full() { return top_ >= high_; } |
| |
| bool is_empty() { return top_ <= low_; } |
| |
| bool overflowed() { return overflowed_; } |
| |
| void clear_overflowed() { overflowed_ = false; } |
| |
| // Push the (marked) object on the marking stack if there is room, |
| // otherwise mark the object as overflowed and wait for a rescan of the |
| // heap. |
| void Push(HeapObject* object) { |
| CHECK(object->IsHeapObject()); |
| if (is_full()) { |
| object->SetOverflow(); |
| overflowed_ = true; |
| } else { |
| *(top_++) = object; |
| } |
| } |
| |
| HeapObject* Pop() { |
| ASSERT(!is_empty()); |
| HeapObject* object = *(--top_); |
| CHECK(object->IsHeapObject()); |
| return object; |
| } |
| |
| private: |
| HeapObject** low_; |
| HeapObject** top_; |
| HeapObject** high_; |
| bool overflowed_; |
| }; |
| |
| |
| // 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; |
| // ... |
| // } |
| |
| #ifdef DEBUG |
| |
| class DisallowAllocationFailure { |
| public: |
| DisallowAllocationFailure() { |
| old_state_ = Heap::disallow_allocation_failure_; |
| Heap::disallow_allocation_failure_ = true; |
| } |
| ~DisallowAllocationFailure() { |
| Heap::disallow_allocation_failure_ = old_state_; |
| } |
| private: |
| bool old_state_; |
| }; |
| |
| class AssertNoAllocation { |
| public: |
| AssertNoAllocation() { |
| old_state_ = Heap::allow_allocation(false); |
| } |
| |
| ~AssertNoAllocation() { |
| Heap::allow_allocation(old_state_); |
| } |
| |
| private: |
| bool old_state_; |
| }; |
| |
| class DisableAssertNoAllocation { |
| public: |
| DisableAssertNoAllocation() { |
| old_state_ = Heap::allow_allocation(true); |
| } |
| |
| ~DisableAssertNoAllocation() { |
| Heap::allow_allocation(old_state_); |
| } |
| |
| private: |
| bool old_state_; |
| }; |
| |
| #else // ndef DEBUG |
| |
| class AssertNoAllocation { |
| public: |
| AssertNoAllocation() { } |
| ~AssertNoAllocation() { } |
| }; |
| |
| class DisableAssertNoAllocation { |
| public: |
| DisableAssertNoAllocation() { } |
| ~DisableAssertNoAllocation() { } |
| }; |
| |
| #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_COMPACT, |
| 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_; |
| }; |
| |
| GCTracer(); |
| ~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; } |
| |
| // Sets the flag that this is a compacting full GC. |
| void set_is_compacting() { is_compacting_ = true; } |
| bool is_compacting() const { return is_compacting_; } |
| |
| // Increment and decrement the count of marked objects. |
| void increment_marked_count() { ++marked_count_; } |
| void decrement_marked_count() { --marked_count_; } |
| |
| int marked_count() { return marked_count_; } |
| |
| void increment_promoted_objects_size(int object_size) { |
| promoted_objects_size_ += object_size; |
| } |
| |
| // Returns maximum GC pause. |
| static int get_max_gc_pause() { return max_gc_pause_; } |
| |
| // Returns maximum size of objects alive after GC. |
| static intptr_t get_max_alive_after_gc() { return max_alive_after_gc_; } |
| |
| // Returns minimal interval between two subsequent collections. |
| static int get_min_in_mutator() { return min_in_mutator_; } |
| |
| private: |
| // Returns a string matching the collector. |
| const char* CollectorString(); |
| |
| // Returns size of object in heap (in MB). |
| double SizeOfHeapObjects() { |
| return (static_cast<double>(Heap::SizeOfObjects())) / MB; |
| } |
| |
| double start_time_; // Timestamp set in the constructor. |
| intptr_t start_size_; // Size of objects in heap set in constructor. |
| GarbageCollector collector_; // Type of collector. |
| |
| // A count (including this one, eg, 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_; |
| |
| // True if the current GC is a compacting full collection, false |
| // otherwise. |
| bool is_compacting_; |
| |
| // True if the *previous* full GC cwas a compacting collection (will be |
| // false if there has not been a previous full GC). |
| bool previous_has_compacted_; |
| |
| // On a full GC, a count of the number of marked objects. Incremented |
| // when an object is marked and decremented when an object's mark bit is |
| // cleared. Will be zero on a scavenge collection. |
| int marked_count_; |
| |
| // The count from the end of the previous full GC. Will be zero if there |
| // was no previous full GC. |
| int previous_marked_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_; |
| |
| // Maximum GC pause. |
| static int max_gc_pause_; |
| |
| // Maximum size of objects alive after GC. |
| static intptr_t max_alive_after_gc_; |
| |
| // Minimal interval between two subsequent collections. |
| static int min_in_mutator_; |
| |
| // Size of objects alive after last GC. |
| static intptr_t alive_after_last_gc_; |
| |
| static double last_gc_end_timestamp_; |
| }; |
| |
| |
| class TranscendentalCache { |
| public: |
| enum Type {ACOS, ASIN, ATAN, COS, EXP, LOG, SIN, TAN, kNumberOfCaches}; |
| static const int kTranscendentalTypeBits = 3; |
| STATIC_ASSERT((1 << kTranscendentalTypeBits) >= kNumberOfCaches); |
| |
| explicit TranscendentalCache(Type t); |
| |
| // Returns a heap number with f(input), where f is a math function specified |
| // by the 'type' argument. |
| MUST_USE_RESULT static inline MaybeObject* Get(Type type, double input) { |
| TranscendentalCache* cache = caches_[type]; |
| if (cache == NULL) { |
| caches_[type] = cache = new TranscendentalCache(type); |
| } |
| return cache->Get(input); |
| } |
| |
| // The cache contains raw Object pointers. This method disposes of |
| // them before a garbage collection. |
| static void Clear(); |
| |
| private: |
| MUST_USE_RESULT inline MaybeObject* Get(double input) { |
| Converter c; |
| c.dbl = input; |
| int hash = Hash(c); |
| Element e = elements_[hash]; |
| if (e.in[0] == c.integers[0] && |
| e.in[1] == c.integers[1]) { |
| ASSERT(e.output != NULL); |
| Counters::transcendental_cache_hit.Increment(); |
| return e.output; |
| } |
| double answer = Calculate(input); |
| Counters::transcendental_cache_miss.Increment(); |
| Object* heap_number; |
| { MaybeObject* maybe_heap_number = Heap::AllocateHeapNumber(answer); |
| if (!maybe_heap_number->ToObject(&heap_number)) return maybe_heap_number; |
| } |
| elements_[hash].in[0] = c.integers[0]; |
| elements_[hash].in[1] = c.integers[1]; |
| elements_[hash].output = heap_number; |
| return heap_number; |
| } |
| |
| inline double Calculate(double input) { |
| switch (type_) { |
| case ACOS: |
| return acos(input); |
| case ASIN: |
| return asin(input); |
| case ATAN: |
| return atan(input); |
| case COS: |
| return cos(input); |
| case EXP: |
| return exp(input); |
| case LOG: |
| return log(input); |
| case SIN: |
| return sin(input); |
| case TAN: |
| return tan(input); |
| default: |
| return 0.0; // Never happens. |
| } |
| } |
| static const int kCacheSize = 512; |
| 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)); |
| } |
| |
| static Address cache_array_address() { |
| // Used to create an external reference. |
| return reinterpret_cast<Address>(caches_); |
| } |
| |
| // Allow access to the caches_ array as an ExternalReference. |
| friend class ExternalReference; |
| // Inline implementation of the cache. |
| friend class TranscendentalCacheStub; |
| |
| static TranscendentalCache* caches_[kNumberOfCaches]; |
| Element elements_[kCacheSize]; |
| Type type_; |
| }; |
| |
| |
| // External strings table is a place where all external strings are |
| // registered. We need to keep track of such strings to properly |
| // finalize them. |
| class ExternalStringTable : public AllStatic { |
| public: |
| // Registers an external string. |
| inline static void AddString(String* string); |
| |
| inline static void Iterate(ObjectVisitor* v); |
| |
| // Restores internal invariant and gets rid of collected strings. |
| // Must be called after each Iterate() that modified the strings. |
| static void CleanUp(); |
| |
| // Destroys all allocated memory. |
| static void TearDown(); |
| |
| private: |
| friend class Heap; |
| |
| inline static void Verify(); |
| |
| inline static void AddOldString(String* string); |
| |
| // Notifies the table that only a prefix of the new list is valid. |
| inline static void ShrinkNewStrings(int position); |
| |
| // To speed up scavenge collections new space string are kept |
| // separate from old space strings. |
| static List<Object*> new_space_strings_; |
| static List<Object*> old_space_strings_; |
| }; |
| |
| |
| // 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; |
| }; |
| |
| |
| #if defined(DEBUG) || defined(LIVE_OBJECT_LIST) |
| // 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. |
| |
| DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer); |
| }; |
| #endif // DEBUG || LIVE_OBJECT_LIST |
| |
| |
| } } // namespace v8::internal |
| |
| #endif // V8_HEAP_H_ |