| // Copyright 2006-2008 Google Inc. 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_ |
| |
| namespace v8 { namespace internal { |
| |
| // Defines all the roots in Heap. |
| #define STRONG_ROOT_LIST(V) \ |
| V(Map, meta_map) \ |
| V(Map, heap_number_map) \ |
| V(Map, short_string_map) \ |
| V(Map, medium_string_map) \ |
| V(Map, long_string_map) \ |
| V(Map, short_ascii_string_map) \ |
| V(Map, medium_ascii_string_map) \ |
| V(Map, long_ascii_string_map) \ |
| V(Map, short_symbol_map) \ |
| V(Map, medium_symbol_map) \ |
| V(Map, long_symbol_map) \ |
| V(Map, short_ascii_symbol_map) \ |
| V(Map, medium_ascii_symbol_map) \ |
| V(Map, long_ascii_symbol_map) \ |
| V(Map, short_cons_symbol_map) \ |
| V(Map, medium_cons_symbol_map) \ |
| V(Map, long_cons_symbol_map) \ |
| V(Map, short_cons_ascii_symbol_map) \ |
| V(Map, medium_cons_ascii_symbol_map) \ |
| V(Map, long_cons_ascii_symbol_map) \ |
| V(Map, short_sliced_symbol_map) \ |
| V(Map, medium_sliced_symbol_map) \ |
| V(Map, long_sliced_symbol_map) \ |
| V(Map, short_sliced_ascii_symbol_map) \ |
| V(Map, medium_sliced_ascii_symbol_map) \ |
| V(Map, long_sliced_ascii_symbol_map) \ |
| V(Map, short_external_symbol_map) \ |
| V(Map, medium_external_symbol_map) \ |
| V(Map, long_external_symbol_map) \ |
| V(Map, short_external_ascii_symbol_map) \ |
| V(Map, medium_external_ascii_symbol_map) \ |
| V(Map, long_external_ascii_symbol_map) \ |
| V(Map, short_cons_string_map) \ |
| V(Map, medium_cons_string_map) \ |
| V(Map, long_cons_string_map) \ |
| V(Map, short_cons_ascii_string_map) \ |
| V(Map, medium_cons_ascii_string_map) \ |
| V(Map, long_cons_ascii_string_map) \ |
| V(Map, short_sliced_string_map) \ |
| V(Map, medium_sliced_string_map) \ |
| V(Map, long_sliced_string_map) \ |
| V(Map, short_sliced_ascii_string_map) \ |
| V(Map, medium_sliced_ascii_string_map) \ |
| V(Map, long_sliced_ascii_string_map) \ |
| V(Map, short_external_string_map) \ |
| V(Map, medium_external_string_map) \ |
| V(Map, long_external_string_map) \ |
| V(Map, short_external_ascii_string_map) \ |
| V(Map, medium_external_ascii_string_map) \ |
| V(Map, long_external_ascii_string_map) \ |
| V(Map, undetectable_short_string_map) \ |
| V(Map, undetectable_medium_string_map) \ |
| V(Map, undetectable_long_string_map) \ |
| V(Map, undetectable_short_ascii_string_map) \ |
| V(Map, undetectable_medium_ascii_string_map) \ |
| V(Map, undetectable_long_ascii_string_map) \ |
| V(Map, byte_array_map) \ |
| V(Map, fixed_array_map) \ |
| V(Map, hash_table_map) \ |
| V(Map, context_map) \ |
| V(Map, global_context_map) \ |
| V(Map, code_map) \ |
| V(Map, oddball_map) \ |
| V(Map, boilerplate_function_map) \ |
| V(Map, shared_function_info_map) \ |
| V(Map, proxy_map) \ |
| V(Map, one_word_filler_map) \ |
| V(Map, two_word_filler_map) \ |
| V(Object, nan_value) \ |
| V(Object, infinity_value) \ |
| V(Object, negative_infinity_value) \ |
| V(Object, number_max_value) \ |
| V(Object, number_min_value) \ |
| V(Object, undefined_value) \ |
| V(Object, minus_zero_value) \ |
| V(Object, null_value) \ |
| V(Object, true_value) \ |
| V(Object, false_value) \ |
| V(String, empty_string) \ |
| V(FixedArray, empty_fixed_array) \ |
| V(Object, the_hole_value) \ |
| V(Map, neander_map) \ |
| V(JSObject, message_listeners) \ |
| V(Proxy, prototype_accessors) \ |
| V(JSObject, debug_event_listeners) \ |
| V(Dictionary, code_stubs) \ |
| V(Dictionary, non_monomorphic_cache) \ |
| V(Code, js_entry_code) \ |
| V(Code, js_construct_entry_code) \ |
| V(Code, c_entry_code) \ |
| V(Code, c_entry_debug_break_code) \ |
| V(FixedArray, number_string_cache) \ |
| V(FixedArray, single_character_string_cache) \ |
| V(FixedArray, natives_source_cache) |
| |
| #define ROOT_LIST(V) \ |
| STRONG_ROOT_LIST(V) \ |
| V(Object, symbol_table) |
| |
| #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_shadow_symbol, ".arguments") \ |
| V(call_symbol, "call") \ |
| V(apply_symbol, "apply") \ |
| V(caller_symbol, "caller") \ |
| 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(finally_state_symbol, ".finally-state") \ |
| V(empty_symbol, "") \ |
| V(eval_symbol, "eval") \ |
| V(function_symbol, "function") \ |
| V(length_symbol, "length") \ |
| V(name_symbol, "name") \ |
| V(number_symbol, "number") \ |
| V(object_symbol, "object") \ |
| V(prototype_symbol, "prototype") \ |
| V(string_symbol, "string") \ |
| V(this_symbol, "this") \ |
| V(to_string_symbol, "toString") \ |
| V(char_at_symbol, "CharAt") \ |
| V(undefined_symbol, "undefined") \ |
| V(value_of_symbol, "valueOf") \ |
| V(CreateObjectLiteralBoilerplate_symbol, "CreateObjectLiteralBoilerplate") \ |
| V(CreateArrayLiteral_symbol, "CreateArrayLiteral") \ |
| V(InitializeVarGlobal_symbol, "InitializeVarGlobal") \ |
| V(InitializeConstGlobal_symbol, "InitializeConstGlobal") \ |
| 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") |
| |
| |
| // 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 semispace_size, int old_gen_size); |
| |
| // 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(); |
| |
| // Returns whether Setup has been called. |
| static bool HasBeenSetup(); |
| |
| // Returns the maximum heap capacity. |
| static int MaxCapacity() { |
| return young_generation_size_ + old_generation_size_; |
| } |
| static int SemiSpaceSize() { return semispace_size_; } |
| static int InitialSemiSpaceSize() { return initial_semispace_size_; } |
| static int YoungGenerationSize() { return young_generation_size_; } |
| static int OldGenerationSize() { return old_generation_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 int Capacity(); |
| |
| // 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 int Available(); |
| |
| // Returns the maximum object size that heap supports. Objects larger than |
| // the maximum heap object size are allocated in a large object space. |
| static inline int MaxHeapObjectSize(); |
| |
| // Returns of size of all objects residing in the heap. |
| static int 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 uint32_t NewSpaceMask() { return new_space_->mask(); } |
| static Address NewSpaceTop() { return new_space_->top(); } |
| |
| static NewSpace* new_space() { return new_space_; } |
| static OldSpace* old_space() { return old_space_; } |
| static OldSpace* code_space() { return code_space_; } |
| static MapSpace* map_space() { return map_space_; } |
| static LargeObjectSpace* lo_space() { return lo_space_; } |
| |
| static Address* NewSpaceAllocationTopAddress() { |
| return new_space_->allocation_top_address(); |
| } |
| static Address* NewSpaceAllocationLimitAddress() { |
| return new_space_->allocation_limit_address(); |
| } |
| |
| // 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. |
| static Object* AllocateJSObject(JSFunction* constructor, |
| PretenureFlag pretenure = NOT_TENURED); |
| |
| // Allocates the function prototype. |
| // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation |
| // failed. |
| // Please note this does not perform a garbage collection. |
| static Object* AllocateFunctionPrototype(JSFunction* function); |
| |
| // Reinitialize a JSGlobalObject based on a constructor. The JSObject |
| // must have the same size as objects allocated using the |
| // constructor. The JSObject is reinitialized and behaves as an |
| // object that has been freshly allocated using the constructor. |
| static Object* ReinitializeJSGlobalObject(JSFunction* constructor, |
| JSGlobalObject* 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. |
| static Object* 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. |
| static Object* 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. |
| static Object* AllocateMap(InstanceType instance_type, int instance_size); |
| |
| // Allocates a partial map for bootstrapping. |
| static Object* AllocatePartialMap(InstanceType instance_type, |
| int instance_size); |
| |
| // Allocate a map for the specified function |
| static Object* AllocateInitialMap(JSFunction* fun); |
| |
| // 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. |
| static Object* AllocateStringFromAscii( |
| Vector<const char> str, |
| PretenureFlag pretenure = NOT_TENURED); |
| static Object* AllocateStringFromUtf8( |
| Vector<const char> str, |
| PretenureFlag pretenure = NOT_TENURED); |
| static Object* 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. |
| static Object* AllocateSymbol(unibrow::CharacterStream* buffer, |
| int chars, |
| int hash); |
| |
| // 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. |
| static Object* AllocateRawAsciiString( |
| int length, |
| PretenureFlag pretenure = NOT_TENURED); |
| static Object* 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. |
| static Object* LookupSingleCharacterStringFromCode(uint16_t code); |
| |
| // Allocate a byte array of the specified length |
| // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation |
| // failed. |
| // Please not this does not perform a garbage collection. |
| static Object* AllocateByteArray(int length); |
| |
| // 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. |
| static Object* AllocateFixedArray(int length, |
| PretenureFlag pretenure = NOT_TENURED); |
| |
| |
| // 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. |
| static Object* AllocateFixedArrayWithHoles(int length); |
| |
| // AllocateHashTable is identical to AllocateFixedArray except |
| // that the resulting object has hash_table_map as map. |
| static Object* AllocateHashTable(int length); |
| |
| // Allocate a global (but otherwise uninitialized) context. |
| static Object* AllocateGlobalContext(); |
| |
| // Allocate a function context. |
| static Object* AllocateFunctionContext(int length, JSFunction* closure); |
| |
| // Allocate a 'with' context. |
| static Object* AllocateWithContext(Context* previous, JSObject* extension); |
| |
| // Allocates a new utility object in the old generation. |
| static Object* AllocateStruct(InstanceType type); |
| |
| |
| // 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. |
| static Object* InitializeFunction(JSFunction* function, |
| SharedFunctionInfo* shared, |
| Object* prototype); |
| |
| // 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. |
| static Object* AllocateFunction(Map* function_map, |
| SharedFunctionInfo* shared, |
| Object* prototype); |
| |
| // Indicies for direct access into argument objects. |
| 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. |
| static Object* AllocateArgumentsObject(Object* callee, int length); |
| |
| // Converts a double 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. |
| static Object* NewNumberFromDouble(double value, |
| PretenureFlag pretenure = NOT_TENURED); |
| |
| // Same as NewNumberFromDouble, but may return a preallocated/immutable |
| // number object (e.g., minus_zero_value_, nan_value_) |
| static Object* NumberFromDouble(double value, |
| PretenureFlag pretenure = NOT_TENURED); |
| |
| // Allocated a HeapNumber from value. |
| static Object* AllocateHeapNumber(double value, PretenureFlag pretenure); |
| static Object* AllocateHeapNumber(double value); // 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. |
| static inline Object* 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. |
| static inline Object* 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. |
| static Object* 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. |
| static Object* AllocateSharedFunctionInfo(Object* name); |
| |
| // 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. |
| static Object* AllocateConsString(String* first, String* second); |
| |
| // Allocates a new sliced string object which is a slice 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. |
| static Object* AllocateSlicedString(String* buffer, int start, int end); |
| |
| // 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. |
| static Object* AllocateSubString(String* buffer, int start, int end); |
| |
| // 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. |
| static Object* AllocateExternalStringFromAscii( |
| ExternalAsciiString::Resource* resource); |
| static Object* AllocateExternalStringFromTwoByte( |
| ExternalTwoByteString::Resource* resource); |
| |
| // Allocates an uninitialized object. |
| // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation |
| // failed. |
| // Please note this function does not perform a garbage collection. |
| static inline Object* AllocateRaw(int size_in_bytes, AllocationSpace space); |
| |
| // Makes a new native code object |
| // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation |
| // failed. |
| // Please note this function does not perform a garbage collection. |
| static Object* CreateCode(const CodeDesc& desc, |
| ScopeInfo<>* sinfo, |
| Code::Flags flags); |
| |
| static Object* CopyCode(Code* code); |
| // 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. |
| static Object* LookupSymbol(Vector<const char> str); |
| static Object* LookupAsciiSymbol(const char* str) { |
| return LookupSymbol(CStrVector(str)); |
| } |
| static Object* LookupSymbol(String* str); |
| |
| // 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); |
| |
| // 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 required_space bytes are available after the collection. |
| static bool CollectGarbage(int required_space, AllocationSpace space); |
| |
| // Utility to invoke the scavenger. This is needed in test code to |
| // ensure correct callback for weak global handles. |
| static void PerformScavenge() { |
| PerformGarbageCollection(NEW_SPACE, SCAVENGER); |
| } |
| |
| static void SetGlobalGCPrologueCallback(GCCallback callback) { |
| global_gc_prologue_callback_ = callback; |
| } |
| static void SetGlobalGCEpilogueCallback(GCCallback callback) { |
| global_gc_epilogue_callback_ = callback; |
| } |
| |
| // Heap roots |
| #define ROOT_ACCESSOR(type, name) static type* name() { return name##_; } |
| ROOT_LIST(ROOT_ACCESSOR) |
| #undef ROOT_ACCESSOR |
| |
| // Utility type maps |
| #define STRUCT_MAP_ACCESSOR(NAME, Name, name) \ |
| static Map* name##_map() { return name##_map_; } |
| STRUCT_LIST(STRUCT_MAP_ACCESSOR) |
| #undef STRUCT_MAP_ACCESSOR |
| |
| #define SYMBOL_ACCESSOR(name, str) static String* name() { return name##_; } |
| SYMBOL_LIST(SYMBOL_ACCESSOR) |
| #undef SYMBOL_ACCESSOR |
| |
| // Iterates over all roots in the heap. |
| static void IterateRoots(ObjectVisitor* v); |
| // Iterates over all strong roots in the heap. |
| static void IterateStrongRoots(ObjectVisitor* v); |
| |
| // Iterates remembered set of an old space. |
| static void IterateRSet(PagedSpace* space, ObjectSlotCallback callback); |
| |
| // Iterates a range of remembered set addresses starting with rset_start |
| // corresponding to the range of allocated pointers |
| // [object_start, object_end). |
| static void IterateRSetRange(Address object_start, |
| Address object_end, |
| Address rset_start, |
| ObjectSlotCallback copy_object_func); |
| |
| // 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 and heap verification only. |
| static bool InSpace(Address addr, AllocationSpace space); |
| static bool InSpace(HeapObject* value, AllocationSpace space); |
| |
| // Sets the stub_cache_ (only used when expanding the dictionary). |
| static void set_code_stubs(Dictionary* value) { code_stubs_ = value; } |
| |
| // Sets the non_monomorphic_cache_ (only used when expanding the dictionary). |
| static void set_non_monomorphic_cache(Dictionary* value) { |
| non_monomorphic_cache_ = value; |
| } |
| |
| #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 |
| |
| // 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. |
| static Object* CreateSymbol(const char* str, int length, int hash); |
| static Object* CreateSymbol(String* str); |
| |
| // Write barrier support for address[offset] = o. |
| inline static void RecordWrite(Address address, int offset); |
| |
| // Given an address in the heap, returns a pointer to the object which |
| // body contains the address. Returns Failure::Exception() if the |
| // operation fails. |
| 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(); |
| static void TracePathToGlobal(); |
| #endif |
| |
| // Helper for Serialization/Deserialization that restricts memory allocation |
| // to the predictable LINEAR_ONLY policy |
| static void SetLinearAllocationOnly(bool linear_only) { |
| old_space_->SetLinearAllocationOnly(linear_only); |
| code_space_->SetLinearAllocationOnly(linear_only); |
| map_space_->SetLinearAllocationOnly(linear_only); |
| } |
| |
| // Callback function pased 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 CopyObject(HeapObject** p); |
| |
| // Clear a range of remembered set addresses corresponding to the object |
| // area address 'start' with size 'size_in_bytes', eg, when adding blocks |
| // to the free list. |
| static void ClearRSetRange(Address start, int size_in_bytes); |
| |
| // Rebuild remembered set in old and map spaces. |
| static void RebuildRSets(); |
| |
| // |
| // 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); |
| |
| // Entries in the cache. Must be a power of 2. |
| static const int kNumberStringCacheSize = 64; |
| |
| private: |
| static int semispace_size_; |
| static int initial_semispace_size_; |
| static int young_generation_size_; |
| static int old_generation_size_; |
| |
| static int new_space_growth_limit_; |
| static int scavenge_count_; |
| |
| static const int kMaxMapSpaceSize = 8*MB; |
| |
| static NewSpace* new_space_; |
| static OldSpace* old_space_; |
| static OldSpace* code_space_; |
| static MapSpace* map_space_; |
| static LargeObjectSpace* lo_space_; |
| static HeapState gc_state_; |
| |
| // Returns the size of object residing in non new spaces. |
| static int PromotedSpaceSize(); |
| |
| #ifdef DEBUG |
| static bool allocation_allowed_; |
| static int mc_count_; // how many mark-compact collections happened |
| static int gc_count_; // how many gc happened |
| |
| // 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 |
| |
| // Promotion limit that trigger a global GC |
| static int promoted_space_limit_; |
| |
| // Indicates that an allocation has failed in the old generation since the |
| // last GC. |
| static int old_gen_exhausted_; |
| |
| // Declare all the roots |
| #define ROOT_DECLARATION(type, name) static type* name##_; |
| ROOT_LIST(ROOT_DECLARATION) |
| #undef ROOT_DECLARATION |
| |
| // Utility type maps |
| #define DECLARE_STRUCT_MAP(NAME, Name, name) static Map* name##_map_; |
| STRUCT_LIST(DECLARE_STRUCT_MAP) |
| #undef DECLARE_STRUCT_MAP |
| |
| #define SYMBOL_DECLARATION(name, str) static String* name##_; |
| SYMBOL_LIST(SYMBOL_DECLARATION) |
| #undef SYMBOL_DECLARATION |
| |
| // GC callback function, called before and after mark-compact GC. |
| // Allocations in the callback function are disallowed. |
| static GCCallback global_gc_prologue_callback_; |
| static GCCallback global_gc_epilogue_callback_; |
| |
| // Checks whether a global GC is necessary |
| static GarbageCollector SelectGarbageCollector(AllocationSpace space); |
| |
| // Performs garbage collection |
| static void PerformGarbageCollection(AllocationSpace space, |
| GarbageCollector collector); |
| |
| // Returns either a Smi or a Number object from 'value'. If 'new_object' |
| // is false, it may return a preallocated immutable object. |
| static Object* SmiOrNumberFromDouble(double value, |
| bool new_object, |
| PretenureFlag pretenure = NOT_TENURED); |
| |
| // 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). |
| static inline Object* AllocateRawMap(int size_in_bytes); |
| |
| // Allocate storage for JSObject properties. |
| // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation |
| // failed. |
| static inline Object* AllocatePropertyStorageForMap(Map* map); |
| |
| // Initializes a JSObject based on its map. |
| static void InitializeJSObjectFromMap(JSObject* obj, |
| FixedArray* properties, |
| Map* map); |
| |
| static bool CreateInitialMaps(); |
| static bool CreateInitialObjects(); |
| static void CreateFixedStubs(); |
| static Object* CreateOddball(Map* map, |
| const char* to_string, |
| Object* to_number); |
| |
| // Allocate empty fixed array. |
| static Object* AllocateEmptyFixedArray(); |
| |
| // Performs a minor collection in new generation. |
| static void Scavenge(); |
| |
| // Performs a major collection in the whole heap. |
| static void MarkCompact(); |
| |
| // Code to be run before and after mark-compact. |
| static void MarkCompactPrologue(); |
| static void MarkCompactEpilogue(); |
| |
| // Helper function used by CopyObject to copy a source object to an |
| // allocated target object and update the forwarding pointer in the source |
| // object. Returns the target object. |
| static HeapObject* MigrateObject(HeapObject** source_p, |
| HeapObject* target, |
| int size); |
| |
| // 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); |
| #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING) |
| // Record the copy of an object in the NewSpace's statistics. |
| static void RecordCopiedObject(HeapObject* obj); |
| |
| // Record statistics before and after garbage collection. |
| static void ReportStatisticsBeforeGC(); |
| static void ReportStatisticsAfterGC(); |
| #endif |
| |
| // Update an old object's remembered set |
| static int UpdateRSet(HeapObject* obj); |
| |
| // Rebuild remembered set in an old space. |
| static void RebuildRSets(PagedSpace* space); |
| |
| // Rebuild remembered set in the large object space. |
| static void RebuildRSets(LargeObjectSpace* space); |
| |
| static const int kInitialSymbolTableSize = 2048; |
| |
| friend class Factory; |
| friend class DisallowAllocationFailure; |
| }; |
| |
| |
| #ifdef DEBUG |
| // Visitor class to verify interior pointers that do not have remembered set |
| // bits. 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 that have remembered set bits. |
| // As VerifyPointersVisitor but also checks that remembered set bits are |
| // always set for pointers into new space. |
| class VerifyPointersAndRSetVisitor: 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(Page::IsRSetSet(reinterpret_cast<Address>(current), 0)); |
| } |
| } |
| } |
| } |
| }; |
| #endif |
| |
| |
| // A HeapIterator provides iteration over the whole heap It aggregates a the |
| // specific iterators for the different spaces as these can only iterate over |
| // one space only. |
| |
| class HeapIterator BASE_EMBEDDED { |
| public: |
| explicit HeapIterator(); |
| virtual ~HeapIterator(); |
| |
| bool has_next(); |
| HeapObject* next(); |
| void reset(); |
| |
| private: |
| // Perform the initialization. |
| void Init(); |
| |
| // Perform all necessary shutdown (destruction) work. |
| void Shutdown(); |
| |
| // Space iterator for iterating all the spaces. |
| SpaceIterator* space_iterator_; |
| // Object iterator for the space currently being iterated. |
| ObjectIterator* object_iterator_; |
| }; |
| |
| |
| // ---------------------------------------------------------------------------- |
| // 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; } |
| |
| void Push(HeapObject* p) { |
| ASSERT(!is_full()); |
| *(top_++) = p; |
| if (is_full()) overflowed_ = true; |
| } |
| |
| HeapObject* Pop() { |
| ASSERT(!is_empty()); |
| return *(--top_); |
| } |
| |
| private: |
| HeapObject** low_; |
| HeapObject** top_; |
| HeapObject** high_; |
| bool overflowed_; |
| }; |
| |
| |
| // ---------------------------------------------------------------------------- |
| // Functions and constants used for marking live objects. |
| // |
| |
| // Many operations (eg, Object::Size()) are based on an object's map. When |
| // objects are marked as live or overflowed, their map pointer is changed. |
| // Use clear_mark_bit and/or clear_overflow_bit to recover the original map |
| // word. |
| static inline intptr_t clear_mark_bit(intptr_t map_word) { |
| return map_word | kMarkingMask; |
| } |
| |
| |
| static inline intptr_t clear_overflow_bit(intptr_t map_word) { |
| return map_word & ~kOverflowMask; |
| } |
| |
| |
| // True if the object is marked live. |
| static inline bool is_marked(HeapObject* obj) { |
| intptr_t map_word = reinterpret_cast<intptr_t>(obj->map()); |
| return (map_word & kMarkingMask) == 0; |
| } |
| |
| |
| // Mutate an object's map pointer to indicate that the object is live. |
| static inline void set_mark(HeapObject* obj) { |
| ASSERT(!is_marked(obj)); |
| intptr_t map_word = reinterpret_cast<intptr_t>(obj->map()); |
| obj->set_map(reinterpret_cast<Map*>(map_word & ~kMarkingMask)); |
| } |
| |
| |
| // Mutate an object's map pointer to remove the indication that the object |
| // is live, ie, (partially) restore the map pointer. |
| static inline void clear_mark(HeapObject* obj) { |
| ASSERT(is_marked(obj)); |
| intptr_t map_word = reinterpret_cast<intptr_t>(obj->map()); |
| obj->set_map(reinterpret_cast<Map*>(clear_mark_bit(map_word))); |
| } |
| |
| |
| // True if the object is marked overflowed. |
| static inline bool is_overflowed(HeapObject* obj) { |
| intptr_t map_word = reinterpret_cast<intptr_t>(obj->map()); |
| return (map_word & kOverflowMask) != 0; |
| } |
| |
| |
| // Mutate an object's map pointer to indicate that the object is overflowed. |
| // Overflowed objects have been reached during marking of the heap but not |
| // pushed on the marking stack (and thus their children have not necessarily |
| // been marked). |
| static inline void set_overflow(HeapObject* obj) { |
| intptr_t map_word = reinterpret_cast<intptr_t>(obj->map()); |
| obj->set_map(reinterpret_cast<Map*>(map_word | kOverflowMask)); |
| } |
| |
| |
| // Mutate an object's map pointer to remove the indication that the object |
| // is overflowed, ie, (partially) restore the map pointer. |
| static inline void clear_overflow(HeapObject* obj) { |
| ASSERT(is_overflowed(obj)); |
| intptr_t map_word = reinterpret_cast<intptr_t>(obj->map()); |
| obj->set_map(reinterpret_cast<Map*>(clear_overflow_bit(map_word))); |
| } |
| |
| |
| // 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_; |
| }; |
| |
| #else // ndef DEBUG |
| |
| class AssertNoAllocation { |
| public: |
| AssertNoAllocation() { } |
| ~AssertNoAllocation() { } |
| }; |
| |
| #endif |
| |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| // The HeapProfiler writes data to the log files, which can be postprocessed |
| // to generate .hp files for use by the GHC/Valgrind tool hp2ps. |
| class HeapProfiler { |
| public: |
| // Write a single heap sample to the log file. |
| static void WriteSample(); |
| |
| private: |
| // Update the array info with stats from obj. |
| static void CollectStats(HeapObject* obj, HistogramInfo* info); |
| }; |
| #endif |
| |
| } } // namespace v8::internal |
| |
| #endif // V8_HEAP_H_ |