Move V8 to external/v8
Change-Id: If68025d67453785a651c5dfb34fad298c16676a4
diff --git a/src/heap.h b/src/heap.h
new file mode 100644
index 0000000..e878efc
--- /dev/null
+++ b/src/heap.h
@@ -0,0 +1,1601 @@
+// Copyright 2006-2008 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 "zone-inl.h"
+
+
+namespace v8 {
+namespace internal {
+
+// Defines all the roots in Heap.
+#define UNCONDITIONAL_STRONG_ROOT_LIST(V) \
+ /* 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(Map, heap_number_map, HeapNumberMap) \
+ V(Map, global_context_map, GlobalContextMap) \
+ V(Map, fixed_array_map, FixedArrayMap) \
+ 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(Map, short_string_map, ShortStringMap) \
+ V(Map, medium_string_map, MediumStringMap) \
+ V(Map, long_string_map, LongStringMap) \
+ V(Map, short_ascii_string_map, ShortAsciiStringMap) \
+ V(Map, medium_ascii_string_map, MediumAsciiStringMap) \
+ V(Map, long_ascii_string_map, LongAsciiStringMap) \
+ V(Map, short_symbol_map, ShortSymbolMap) \
+ V(Map, medium_symbol_map, MediumSymbolMap) \
+ V(Map, long_symbol_map, LongSymbolMap) \
+ V(Map, short_ascii_symbol_map, ShortAsciiSymbolMap) \
+ V(Map, medium_ascii_symbol_map, MediumAsciiSymbolMap) \
+ V(Map, long_ascii_symbol_map, LongAsciiSymbolMap) \
+ V(Map, short_cons_symbol_map, ShortConsSymbolMap) \
+ V(Map, medium_cons_symbol_map, MediumConsSymbolMap) \
+ V(Map, long_cons_symbol_map, LongConsSymbolMap) \
+ V(Map, short_cons_ascii_symbol_map, ShortConsAsciiSymbolMap) \
+ V(Map, medium_cons_ascii_symbol_map, MediumConsAsciiSymbolMap) \
+ V(Map, long_cons_ascii_symbol_map, LongConsAsciiSymbolMap) \
+ V(Map, short_sliced_symbol_map, ShortSlicedSymbolMap) \
+ V(Map, medium_sliced_symbol_map, MediumSlicedSymbolMap) \
+ V(Map, long_sliced_symbol_map, LongSlicedSymbolMap) \
+ V(Map, short_sliced_ascii_symbol_map, ShortSlicedAsciiSymbolMap) \
+ V(Map, medium_sliced_ascii_symbol_map, MediumSlicedAsciiSymbolMap) \
+ V(Map, long_sliced_ascii_symbol_map, LongSlicedAsciiSymbolMap) \
+ V(Map, short_external_symbol_map, ShortExternalSymbolMap) \
+ V(Map, medium_external_symbol_map, MediumExternalSymbolMap) \
+ V(Map, long_external_symbol_map, LongExternalSymbolMap) \
+ V(Map, short_external_ascii_symbol_map, ShortExternalAsciiSymbolMap) \
+ V(Map, medium_external_ascii_symbol_map, MediumExternalAsciiSymbolMap) \
+ V(Map, long_external_ascii_symbol_map, LongExternalAsciiSymbolMap) \
+ V(Map, short_cons_string_map, ShortConsStringMap) \
+ V(Map, medium_cons_string_map, MediumConsStringMap) \
+ V(Map, long_cons_string_map, LongConsStringMap) \
+ V(Map, short_cons_ascii_string_map, ShortConsAsciiStringMap) \
+ V(Map, medium_cons_ascii_string_map, MediumConsAsciiStringMap) \
+ V(Map, long_cons_ascii_string_map, LongConsAsciiStringMap) \
+ V(Map, short_sliced_string_map, ShortSlicedStringMap) \
+ V(Map, medium_sliced_string_map, MediumSlicedStringMap) \
+ V(Map, long_sliced_string_map, LongSlicedStringMap) \
+ V(Map, short_sliced_ascii_string_map, ShortSlicedAsciiStringMap) \
+ V(Map, medium_sliced_ascii_string_map, MediumSlicedAsciiStringMap) \
+ V(Map, long_sliced_ascii_string_map, LongSlicedAsciiStringMap) \
+ V(Map, short_external_string_map, ShortExternalStringMap) \
+ V(Map, medium_external_string_map, MediumExternalStringMap) \
+ V(Map, long_external_string_map, LongExternalStringMap) \
+ V(Map, short_external_ascii_string_map, ShortExternalAsciiStringMap) \
+ V(Map, medium_external_ascii_string_map, MediumExternalAsciiStringMap) \
+ V(Map, long_external_ascii_string_map, LongExternalAsciiStringMap) \
+ V(Map, undetectable_short_string_map, UndetectableShortStringMap) \
+ V(Map, undetectable_medium_string_map, UndetectableMediumStringMap) \
+ V(Map, undetectable_long_string_map, UndetectableLongStringMap) \
+ V(Map, undetectable_short_ascii_string_map, UndetectableShortAsciiStringMap) \
+ V(Map, \
+ undetectable_medium_ascii_string_map, \
+ UndetectableMediumAsciiStringMap) \
+ V(Map, undetectable_long_ascii_string_map, UndetectableLongAsciiStringMap) \
+ V(Map, byte_array_map, ByteArrayMap) \
+ V(Map, pixel_array_map, PixelArrayMap) \
+ 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, boilerplate_function_map, BoilerplateFunctionMap) \
+ V(Map, shared_function_info_map, SharedFunctionInfoMap) \
+ V(Map, proxy_map, ProxyMap) \
+ V(Map, one_pointer_filler_map, OnePointerFillerMap) \
+ V(Map, two_pointer_filler_map, TwoPointerFillerMap) \
+ V(Object, nan_value, NanValue) \
+ V(Object, minus_zero_value, MinusZeroValue) \
+ 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(Code, c_entry_debug_break_code, CEntryDebugBreakCode) \
+ 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) \
+
+#if V8_TARGET_ARCH_ARM && V8_NATIVE_REGEXP
+#define STRONG_ROOT_LIST(V) \
+ UNCONDITIONAL_STRONG_ROOT_LIST(V) \
+ V(Code, re_c_entry_code, RegExpCEntryCode)
+#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(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(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")
+
+
+// Forward declaration of the GCTracer class.
+class GCTracer;
+
+
+// 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);
+ 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();
+
+ // Sets the stack limit in the roots_ array. Some architectures generate code
+ // that looks here, because it is faster than loading from the static jslimit_
+ // variable.
+ static void SetStackLimit(intptr_t limit);
+
+ // 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 in paged space.
+ static inline int MaxObjectSizeInPagedSpace();
+
+ // 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 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 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.
+ static Object* 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.
+ static Object* AllocateGlobalObject(JSFunction* constructor);
+
+ // Returns a deep copy of the JavaScript object.
+ // Properties and elements are copied too.
+ // Returns failure if allocation failed.
+ static Object* 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.
+ static Object* 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.
+ static Object* 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.
+ 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 inline Object* AllocateSymbol(Vector<const char> str,
+ int chars,
+ uint32_t length_field);
+
+ static Object* AllocateInternalSymbol(unibrow::CharacterStream* buffer,
+ int chars,
+ uint32_t length_field);
+
+ static Object* 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.
+ 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 note this does not perform a garbage collection.
+ static Object* 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.
+ static Object* 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.
+ static Object* AllocatePixelArray(int length,
+ uint8_t* 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.
+ static Object* 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.
+ static Object* AllocateFixedArray(int length, PretenureFlag pretenure);
+ // Allocate uninitialized, non-tenured fixed array with length elements.
+ static Object* AllocateFixedArray(int length);
+
+ // Make a copy of src and return it. Returns
+ // Failure::RetryAfterGC(requested_bytes, space) if the allocation failed.
+ static Object* CopyFixedArray(FixedArray* src);
+
+ // 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,
+ bool is_catch_context);
+
+ // Allocates a new utility object in the old generation.
+ static Object* 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.
+ 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. 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.
+ static inline Object* 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.
+ static Object* CreateCode(const CodeDesc& desc,
+ ZoneScopeInfo* sinfo,
+ Code::Flags flags,
+ Handle<Object> self_reference);
+
+ 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);
+ static bool LookupSymbolIfExists(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);
+
+ // 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();
+
+ // Code that should be executed after the garbage collection proper.
+ static void PostGarbageCollectionProcessing();
+
+ // Performs garbage collection operation.
+ // Returns whether required_space bytes are available after the collection.
+ static bool CollectGarbage(int required_space, AllocationSpace space);
+
+ // Performs a full garbage collection. Force compaction if the
+ // parameter is true.
+ static void CollectAllGarbage(bool force_compaction);
+
+ // Performs a full garbage collection if a context has been disposed
+ // since the last time the check was performed.
+ static void CollectAllGarbageIfContextDisposed();
+
+ // Notify the heap that a context has been disposed.
+ static void NotifyContextDisposed();
+
+ // 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 bool GarbageCollectionGreedyCheck();
+#endif
+
+ static void SetGlobalGCPrologueCallback(GCCallback callback) {
+ global_gc_prologue_callback_ = callback;
+ }
+ static void SetGlobalGCEpilogueCallback(GCCallback callback) {
+ 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_; }
+
+ // 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).
+ // Returns the number of bits that were set.
+ static int 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);
+
+ // 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;
+ }
+
+ // Sets the non_monomorphic_cache_ (only used when expanding the dictionary).
+ static void public_set_non_monomorphic_cache(NumberDictionary* value) {
+ roots_[kNonMonomorphicCacheRootIndex] = value;
+ }
+
+ // 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_; }
+
+#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.
+ static Object* CreateSymbol(const char* str, int length, int hash);
+ static Object* CreateSymbol(String* str);
+
+ // Write barrier support for address[offset] = o.
+ static inline void RecordWrite(Address address, int offset);
+
+ // 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();
+ 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);
+
+ // 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();
+
+ // Commits from space if it is uncommitted.
+ static void EnsureFromSpaceIsCommitted();
+
+ //
+ // 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;
+
+ // Adjusts the amount of registered external memory.
+ // Returns the adjusted value.
+ static inline int AdjustAmountOfExternalAllocatedMemory(int change_in_bytes);
+
+ // Allocate unitialized fixed array (pretenure == NON_TENURE).
+ static Object* AllocateRawFixedArray(int length);
+
+ // 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_;
+ }
+
+ // True if we have reached the allocation limit in the old generation that
+ // should artificially cause a GC right now.
+ static bool OldGenerationAllocationLimitReached() {
+ return (PromotedSpaceSize() + PromotedExternalMemorySize())
+ > old_gen_allocation_limit_;
+ }
+
+ // 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
+ };
+
+ static Object* NumberToString(Object* number);
+
+ private:
+ static int semispace_size_;
+ static int initial_semispace_size_;
+ static int young_generation_size_;
+ static int old_generation_size_;
+ static size_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 bool context_disposed_pending_;
+
+ static const int kMaxMapSpaceSize = 8*MB;
+
+#if defined(V8_TARGET_ARCH_X64)
+ static const int kMaxObjectSizeInNewSpace = 512*KB;
+#else
+ static const int kMaxObjectSizeInNewSpace = 256*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 int 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 gc_count_; // how many gc happened
+
+#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 int 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 int old_gen_allocation_limit_;
+
+ // Limit on the amount of externally allocated memory allowed
+ // between global GCs. If reached a global GC is forced.
+ static int 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];
+
+ 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.
+ 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,
+ GCTracer* tracer);
+
+ // 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();
+
+ // Allocate an uninitialized object in the global property cell space.
+ static inline Object* AllocateRawCell();
+
+ // Initializes a JSObject based on its map.
+ static void InitializeJSObjectFromMap(JSObject* obj,
+ FixedArray* properties,
+ Map* map);
+
+ static bool CreateInitialMaps();
+ static bool CreateInitialObjects();
+
+ // These four Create*EntryStub functions are here because of a gcc-4.4 bug
+ // that assigns wrong vtable entries.
+ static void CreateCEntryStub();
+ static void CreateCEntryDebugBreakStub();
+ static void CreateJSEntryStub();
+ static void CreateJSConstructEntryStub();
+ static void CreateRegExpCEntryStub();
+
+ 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(GCTracer* tracer);
+
+ // Code to be run before and after mark-compact.
+ static void MarkCompactPrologue(bool is_compacting);
+ static void MarkCompactEpilogue(bool is_compacting);
+
+ // 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,
+ 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);
+
+ // Slow part of scavenge object.
+ static void ScavengeObjectSlow(HeapObject** p, HeapObject* object);
+
+ // Copy memory from src to dst.
+ static inline void CopyBlock(Object** dst, Object** src, int byte_size);
+
+ // 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 inline Object* InitializeFunction(JSFunction* function,
+ SharedFunctionInfo* shared,
+ Object* prototype);
+
+ static const int kInitialSymbolTableSize = 2048;
+ static const int kInitialEvalCacheSize = 64;
+
+ friend class Factory;
+ friend class DisallowAllocationFailure;
+ friend class AlwaysAllocateScope;
+};
+
+
+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);
+ }
+};
+
+
+#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
+
+
+// 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 and code 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();
+ virtual ~SpaceIterator();
+
+ bool has_next();
+ ObjectIterator* next();
+
+ private:
+ ObjectIterator* CreateIterator();
+
+ int current_space_; // from enum AllocationSpace.
+ ObjectIterator* iterator_; // object iterator for the current space.
+};
+
+
+// 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_;
+};
+
+
+// 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();
+ private:
+ static inline int Hash(Map* map, String* name);
+ static const int kLength = 64;
+ struct Key {
+ Map* map;
+ String* name;
+ };
+ static Key keys_[kLength];
+ static int field_offsets_[kLength];
+};
+
+
+
+// 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.
+ uintptr_t array_hash =
+ static_cast<uint32_t>(reinterpret_cast<uintptr_t>(array)) >> 2;
+ uintptr_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:
+ GCTracer();
+
+ ~GCTracer();
+
+ // Sets the collector.
+ void set_collector(GarbageCollector collector) { collector_ = collector; }
+
+ // Sets the GC count.
+ void set_gc_count(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; }
+
+ // 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_; }
+
+ 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.
+ double 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.
+ 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_;
+};
+
+
+class TranscendentalCache {
+ public:
+ enum Type {ACOS, ASIN, ATAN, COS, EXP, LOG, SIN, TAN, kNumberOfCaches};
+
+ explicit TranscendentalCache(Type t);
+
+ // Returns a heap number with f(input), where f is a math function specified
+ // by the 'type' argument.
+ static inline Object* 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:
+ inline Object* 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);
+ return e.output;
+ }
+ double answer = Calculate(input);
+ Object* heap_number = Heap::AllocateHeapNumber(answer);
+ if (!heap_number->IsFailure()) {
+ 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 ^= hash >> 16;
+ hash ^= hash >> 8;
+ return (hash & (kCacheSize - 1));
+ }
+ static TranscendentalCache* caches_[kNumberOfCaches];
+ Element elements_[kCacheSize];
+ Type type_;
+};
+
+
+} } // namespace v8::internal
+
+#endif // V8_HEAP_H_