// 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. #include "v8.h" #include "accessors.h" #include "api.h" #include "execution.h" #include "global-handles.h" #include "ic-inl.h" #include "natives.h" #include "platform.h" #include "runtime.h" #include "serialize.h" #include "stub-cache.h" #include "v8threads.h" #include "top.h" #include "bootstrapper.h" namespace v8 { namespace internal { // ----------------------------------------------------------------------------- // Coding of external references. // The encoding of an external reference. The type is in the high word. // The id is in the low word. static uint32_t EncodeExternal(TypeCode type, uint16_t id) { return static_cast(type) << 16 | id; } static int* GetInternalPointer(StatsCounter* counter) { // All counters refer to dummy_counter, if deserializing happens without // setting up counters. static int dummy_counter = 0; return counter->Enabled() ? counter->GetInternalPointer() : &dummy_counter; } // ExternalReferenceTable is a helper class that defines the relationship // between external references and their encodings. It is used to build // hashmaps in ExternalReferenceEncoder and ExternalReferenceDecoder. class ExternalReferenceTable { public: static ExternalReferenceTable* instance() { if (!instance_) instance_ = new ExternalReferenceTable(); return instance_; } int size() const { return refs_.length(); } Address address(int i) { return refs_[i].address; } uint32_t code(int i) { return refs_[i].code; } const char* name(int i) { return refs_[i].name; } int max_id(int code) { return max_id_[code]; } private: static ExternalReferenceTable* instance_; ExternalReferenceTable() : refs_(64) { PopulateTable(); } ~ExternalReferenceTable() { } struct ExternalReferenceEntry { Address address; uint32_t code; const char* name; }; void PopulateTable(); // For a few types of references, we can get their address from their id. void AddFromId(TypeCode type, uint16_t id, const char* name); // For other types of references, the caller will figure out the address. void Add(Address address, TypeCode type, uint16_t id, const char* name); List refs_; int max_id_[kTypeCodeCount]; }; ExternalReferenceTable* ExternalReferenceTable::instance_ = NULL; void ExternalReferenceTable::AddFromId(TypeCode type, uint16_t id, const char* name) { Address address; switch (type) { case C_BUILTIN: { ExternalReference ref(static_cast(id)); address = ref.address(); break; } case BUILTIN: { ExternalReference ref(static_cast(id)); address = ref.address(); break; } case RUNTIME_FUNCTION: { ExternalReference ref(static_cast(id)); address = ref.address(); break; } case IC_UTILITY: { ExternalReference ref(IC_Utility(static_cast(id))); address = ref.address(); break; } default: UNREACHABLE(); return; } Add(address, type, id, name); } void ExternalReferenceTable::Add(Address address, TypeCode type, uint16_t id, const char* name) { ASSERT_NE(NULL, address); ExternalReferenceEntry entry; entry.address = address; entry.code = EncodeExternal(type, id); entry.name = name; ASSERT_NE(0, entry.code); refs_.Add(entry); if (id > max_id_[type]) max_id_[type] = id; } void ExternalReferenceTable::PopulateTable() { for (int type_code = 0; type_code < kTypeCodeCount; type_code++) { max_id_[type_code] = 0; } // The following populates all of the different type of external references // into the ExternalReferenceTable. // // NOTE: This function was originally 100k of code. It has since been // rewritten to be mostly table driven, as the callback macro style tends to // very easily cause code bloat. Please be careful in the future when adding // new references. struct RefTableEntry { TypeCode type; uint16_t id; const char* name; }; static const RefTableEntry ref_table[] = { // Builtins #define DEF_ENTRY_C(name, ignored) \ { C_BUILTIN, \ Builtins::c_##name, \ "Builtins::" #name }, BUILTIN_LIST_C(DEF_ENTRY_C) #undef DEF_ENTRY_C #define DEF_ENTRY_C(name, ignored) \ { BUILTIN, \ Builtins::name, \ "Builtins::" #name }, #define DEF_ENTRY_A(name, kind, state) DEF_ENTRY_C(name, ignored) BUILTIN_LIST_C(DEF_ENTRY_C) BUILTIN_LIST_A(DEF_ENTRY_A) BUILTIN_LIST_DEBUG_A(DEF_ENTRY_A) #undef DEF_ENTRY_C #undef DEF_ENTRY_A // Runtime functions #define RUNTIME_ENTRY(name, nargs, ressize) \ { RUNTIME_FUNCTION, \ Runtime::k##name, \ "Runtime::" #name }, RUNTIME_FUNCTION_LIST(RUNTIME_ENTRY) #undef RUNTIME_ENTRY // IC utilities #define IC_ENTRY(name) \ { IC_UTILITY, \ IC::k##name, \ "IC::" #name }, IC_UTIL_LIST(IC_ENTRY) #undef IC_ENTRY }; // end of ref_table[]. for (size_t i = 0; i < ARRAY_SIZE(ref_table); ++i) { AddFromId(ref_table[i].type, ref_table[i].id, ref_table[i].name); } #ifdef ENABLE_DEBUGGER_SUPPORT // Debug addresses Add(Debug_Address(Debug::k_after_break_target_address).address(), DEBUG_ADDRESS, Debug::k_after_break_target_address << kDebugIdShift, "Debug::after_break_target_address()"); Add(Debug_Address(Debug::k_debug_break_slot_address).address(), DEBUG_ADDRESS, Debug::k_debug_break_slot_address << kDebugIdShift, "Debug::debug_break_slot_address()"); Add(Debug_Address(Debug::k_debug_break_return_address).address(), DEBUG_ADDRESS, Debug::k_debug_break_return_address << kDebugIdShift, "Debug::debug_break_return_address()"); const char* debug_register_format = "Debug::register_address(%i)"; int dr_format_length = StrLength(debug_register_format); for (int i = 0; i < kNumJSCallerSaved; ++i) { Vector name = Vector::New(dr_format_length + 1); OS::SNPrintF(name, debug_register_format, i); Add(Debug_Address(Debug::k_register_address, i).address(), DEBUG_ADDRESS, Debug::k_register_address << kDebugIdShift | i, name.start()); } #endif // Stat counters struct StatsRefTableEntry { StatsCounter* counter; uint16_t id; const char* name; }; static const StatsRefTableEntry stats_ref_table[] = { #define COUNTER_ENTRY(name, caption) \ { &Counters::name, \ Counters::k_##name, \ "Counters::" #name }, STATS_COUNTER_LIST_1(COUNTER_ENTRY) STATS_COUNTER_LIST_2(COUNTER_ENTRY) #undef COUNTER_ENTRY }; // end of stats_ref_table[]. for (size_t i = 0; i < ARRAY_SIZE(stats_ref_table); ++i) { Add(reinterpret_cast
( GetInternalPointer(stats_ref_table[i].counter)), STATS_COUNTER, stats_ref_table[i].id, stats_ref_table[i].name); } // Top addresses const char* top_address_format = "Top::%s"; const char* AddressNames[] = { #define C(name) #name, TOP_ADDRESS_LIST(C) TOP_ADDRESS_LIST_PROF(C) NULL #undef C }; int top_format_length = StrLength(top_address_format) - 2; for (uint16_t i = 0; i < Top::k_top_address_count; ++i) { const char* address_name = AddressNames[i]; Vector name = Vector::New(top_format_length + StrLength(address_name) + 1); const char* chars = name.start(); OS::SNPrintF(name, top_address_format, address_name); Add(Top::get_address_from_id((Top::AddressId)i), TOP_ADDRESS, i, chars); } // Extensions Add(FUNCTION_ADDR(GCExtension::GC), EXTENSION, 1, "GCExtension::GC"); // Accessors #define ACCESSOR_DESCRIPTOR_DECLARATION(name) \ Add((Address)&Accessors::name, \ ACCESSOR, \ Accessors::k##name, \ "Accessors::" #name); ACCESSOR_DESCRIPTOR_LIST(ACCESSOR_DESCRIPTOR_DECLARATION) #undef ACCESSOR_DESCRIPTOR_DECLARATION // Stub cache tables Add(SCTableReference::keyReference(StubCache::kPrimary).address(), STUB_CACHE_TABLE, 1, "StubCache::primary_->key"); Add(SCTableReference::valueReference(StubCache::kPrimary).address(), STUB_CACHE_TABLE, 2, "StubCache::primary_->value"); Add(SCTableReference::keyReference(StubCache::kSecondary).address(), STUB_CACHE_TABLE, 3, "StubCache::secondary_->key"); Add(SCTableReference::valueReference(StubCache::kSecondary).address(), STUB_CACHE_TABLE, 4, "StubCache::secondary_->value"); // Runtime entries Add(ExternalReference::perform_gc_function().address(), RUNTIME_ENTRY, 1, "Runtime::PerformGC"); Add(ExternalReference::fill_heap_number_with_random_function().address(), RUNTIME_ENTRY, 2, "V8::FillHeapNumberWithRandom"); Add(ExternalReference::random_uint32_function().address(), RUNTIME_ENTRY, 3, "V8::Random"); // Miscellaneous Add(ExternalReference::the_hole_value_location().address(), UNCLASSIFIED, 2, "Factory::the_hole_value().location()"); Add(ExternalReference::roots_address().address(), UNCLASSIFIED, 3, "Heap::roots_address()"); Add(ExternalReference::address_of_stack_limit().address(), UNCLASSIFIED, 4, "StackGuard::address_of_jslimit()"); Add(ExternalReference::address_of_real_stack_limit().address(), UNCLASSIFIED, 5, "StackGuard::address_of_real_jslimit()"); #ifndef V8_INTERPRETED_REGEXP Add(ExternalReference::address_of_regexp_stack_limit().address(), UNCLASSIFIED, 6, "RegExpStack::limit_address()"); Add(ExternalReference::address_of_regexp_stack_memory_address().address(), UNCLASSIFIED, 7, "RegExpStack::memory_address()"); Add(ExternalReference::address_of_regexp_stack_memory_size().address(), UNCLASSIFIED, 8, "RegExpStack::memory_size()"); Add(ExternalReference::address_of_static_offsets_vector().address(), UNCLASSIFIED, 9, "OffsetsVector::static_offsets_vector"); #endif // V8_INTERPRETED_REGEXP Add(ExternalReference::new_space_start().address(), UNCLASSIFIED, 10, "Heap::NewSpaceStart()"); Add(ExternalReference::new_space_mask().address(), UNCLASSIFIED, 11, "Heap::NewSpaceMask()"); Add(ExternalReference::heap_always_allocate_scope_depth().address(), UNCLASSIFIED, 12, "Heap::always_allocate_scope_depth()"); Add(ExternalReference::new_space_allocation_limit_address().address(), UNCLASSIFIED, 13, "Heap::NewSpaceAllocationLimitAddress()"); Add(ExternalReference::new_space_allocation_top_address().address(), UNCLASSIFIED, 14, "Heap::NewSpaceAllocationTopAddress()"); #ifdef ENABLE_DEBUGGER_SUPPORT Add(ExternalReference::debug_break().address(), UNCLASSIFIED, 15, "Debug::Break()"); Add(ExternalReference::debug_step_in_fp_address().address(), UNCLASSIFIED, 16, "Debug::step_in_fp_addr()"); #endif Add(ExternalReference::double_fp_operation(Token::ADD).address(), UNCLASSIFIED, 17, "add_two_doubles"); Add(ExternalReference::double_fp_operation(Token::SUB).address(), UNCLASSIFIED, 18, "sub_two_doubles"); Add(ExternalReference::double_fp_operation(Token::MUL).address(), UNCLASSIFIED, 19, "mul_two_doubles"); Add(ExternalReference::double_fp_operation(Token::DIV).address(), UNCLASSIFIED, 20, "div_two_doubles"); Add(ExternalReference::double_fp_operation(Token::MOD).address(), UNCLASSIFIED, 21, "mod_two_doubles"); Add(ExternalReference::compare_doubles().address(), UNCLASSIFIED, 22, "compare_doubles"); #ifndef V8_INTERPRETED_REGEXP Add(ExternalReference::re_case_insensitive_compare_uc16().address(), UNCLASSIFIED, 23, "NativeRegExpMacroAssembler::CaseInsensitiveCompareUC16()"); Add(ExternalReference::re_check_stack_guard_state().address(), UNCLASSIFIED, 24, "RegExpMacroAssembler*::CheckStackGuardState()"); Add(ExternalReference::re_grow_stack().address(), UNCLASSIFIED, 25, "NativeRegExpMacroAssembler::GrowStack()"); Add(ExternalReference::re_word_character_map().address(), UNCLASSIFIED, 26, "NativeRegExpMacroAssembler::word_character_map"); #endif // V8_INTERPRETED_REGEXP // Keyed lookup cache. Add(ExternalReference::keyed_lookup_cache_keys().address(), UNCLASSIFIED, 27, "KeyedLookupCache::keys()"); Add(ExternalReference::keyed_lookup_cache_field_offsets().address(), UNCLASSIFIED, 28, "KeyedLookupCache::field_offsets()"); Add(ExternalReference::transcendental_cache_array_address().address(), UNCLASSIFIED, 29, "TranscendentalCache::caches()"); } ExternalReferenceEncoder::ExternalReferenceEncoder() : encodings_(Match) { ExternalReferenceTable* external_references = ExternalReferenceTable::instance(); for (int i = 0; i < external_references->size(); ++i) { Put(external_references->address(i), i); } } uint32_t ExternalReferenceEncoder::Encode(Address key) const { int index = IndexOf(key); return index >=0 ? ExternalReferenceTable::instance()->code(index) : 0; } const char* ExternalReferenceEncoder::NameOfAddress(Address key) const { int index = IndexOf(key); return index >=0 ? ExternalReferenceTable::instance()->name(index) : NULL; } int ExternalReferenceEncoder::IndexOf(Address key) const { if (key == NULL) return -1; HashMap::Entry* entry = const_cast(encodings_).Lookup(key, Hash(key), false); return entry == NULL ? -1 : static_cast(reinterpret_cast(entry->value)); } void ExternalReferenceEncoder::Put(Address key, int index) { HashMap::Entry* entry = encodings_.Lookup(key, Hash(key), true); entry->value = reinterpret_cast(index); } ExternalReferenceDecoder::ExternalReferenceDecoder() : encodings_(NewArray(kTypeCodeCount)) { ExternalReferenceTable* external_references = ExternalReferenceTable::instance(); for (int type = kFirstTypeCode; type < kTypeCodeCount; ++type) { int max = external_references->max_id(type) + 1; encodings_[type] = NewArray
(max + 1); } for (int i = 0; i < external_references->size(); ++i) { Put(external_references->code(i), external_references->address(i)); } } ExternalReferenceDecoder::~ExternalReferenceDecoder() { for (int type = kFirstTypeCode; type < kTypeCodeCount; ++type) { DeleteArray(encodings_[type]); } DeleteArray(encodings_); } bool Serializer::serialization_enabled_ = false; bool Serializer::too_late_to_enable_now_ = false; ExternalReferenceDecoder* Deserializer::external_reference_decoder_ = NULL; Deserializer::Deserializer(SnapshotByteSource* source) : source_(source) { } // This routine both allocates a new object, and also keeps // track of where objects have been allocated so that we can // fix back references when deserializing. Address Deserializer::Allocate(int space_index, Space* space, int size) { Address address; if (!SpaceIsLarge(space_index)) { ASSERT(!SpaceIsPaged(space_index) || size <= Page::kPageSize - Page::kObjectStartOffset); Object* new_allocation; if (space_index == NEW_SPACE) { new_allocation = reinterpret_cast(space)->AllocateRaw(size); } else { new_allocation = reinterpret_cast(space)->AllocateRaw(size); } HeapObject* new_object = HeapObject::cast(new_allocation); ASSERT(!new_object->IsFailure()); address = new_object->address(); high_water_[space_index] = address + size; } else { ASSERT(SpaceIsLarge(space_index)); ASSERT(size > Page::kPageSize - Page::kObjectStartOffset); LargeObjectSpace* lo_space = reinterpret_cast(space); Object* new_allocation; if (space_index == kLargeData) { new_allocation = lo_space->AllocateRaw(size); } else if (space_index == kLargeFixedArray) { new_allocation = lo_space->AllocateRawFixedArray(size); } else { ASSERT_EQ(kLargeCode, space_index); new_allocation = lo_space->AllocateRawCode(size); } ASSERT(!new_allocation->IsFailure()); HeapObject* new_object = HeapObject::cast(new_allocation); // Record all large objects in the same space. address = new_object->address(); pages_[LO_SPACE].Add(address); } last_object_address_ = address; return address; } // This returns the address of an object that has been described in the // snapshot as being offset bytes back in a particular space. HeapObject* Deserializer::GetAddressFromEnd(int space) { int offset = source_->GetInt(); ASSERT(!SpaceIsLarge(space)); offset <<= kObjectAlignmentBits; return HeapObject::FromAddress(high_water_[space] - offset); } // This returns the address of an object that has been described in the // snapshot as being offset bytes into a particular space. HeapObject* Deserializer::GetAddressFromStart(int space) { int offset = source_->GetInt(); if (SpaceIsLarge(space)) { // Large spaces have one object per 'page'. return HeapObject::FromAddress(pages_[LO_SPACE][offset]); } offset <<= kObjectAlignmentBits; if (space == NEW_SPACE) { // New space has only one space - numbered 0. return HeapObject::FromAddress(pages_[space][0] + offset); } ASSERT(SpaceIsPaged(space)); int page_of_pointee = offset >> kPageSizeBits; Address object_address = pages_[space][page_of_pointee] + (offset & Page::kPageAlignmentMask); return HeapObject::FromAddress(object_address); } void Deserializer::Deserialize() { // Don't GC while deserializing - just expand the heap. AlwaysAllocateScope always_allocate; // Don't use the free lists while deserializing. LinearAllocationScope allocate_linearly; // No active threads. ASSERT_EQ(NULL, ThreadState::FirstInUse()); // No active handles. ASSERT(HandleScopeImplementer::instance()->blocks()->is_empty()); // Make sure the entire partial snapshot cache is traversed, filling it with // valid object pointers. partial_snapshot_cache_length_ = kPartialSnapshotCacheCapacity; ASSERT_EQ(NULL, external_reference_decoder_); external_reference_decoder_ = new ExternalReferenceDecoder(); Heap::IterateStrongRoots(this, VISIT_ONLY_STRONG); Heap::IterateWeakRoots(this, VISIT_ALL); } void Deserializer::DeserializePartial(Object** root) { // Don't GC while deserializing - just expand the heap. AlwaysAllocateScope always_allocate; // Don't use the free lists while deserializing. LinearAllocationScope allocate_linearly; if (external_reference_decoder_ == NULL) { external_reference_decoder_ = new ExternalReferenceDecoder(); } VisitPointer(root); } Deserializer::~Deserializer() { ASSERT(source_->AtEOF()); if (external_reference_decoder_ != NULL) { delete external_reference_decoder_; external_reference_decoder_ = NULL; } } // This is called on the roots. It is the driver of the deserialization // process. It is also called on the body of each function. void Deserializer::VisitPointers(Object** start, Object** end) { // The space must be new space. Any other space would cause ReadChunk to try // to update the remembered using NULL as the address. ReadChunk(start, end, NEW_SPACE, NULL); } // This routine writes the new object into the pointer provided and then // returns true if the new object was in young space and false otherwise. // The reason for this strange interface is that otherwise the object is // written very late, which means the ByteArray map is not set up by the // time we need to use it to mark the space at the end of a page free (by // making it into a byte array). void Deserializer::ReadObject(int space_number, Space* space, Object** write_back) { int size = source_->GetInt() << kObjectAlignmentBits; Address address = Allocate(space_number, space, size); *write_back = HeapObject::FromAddress(address); Object** current = reinterpret_cast(address); Object** limit = current + (size >> kPointerSizeLog2); if (FLAG_log_snapshot_positions) { LOG(SnapshotPositionEvent(address, source_->position())); } ReadChunk(current, limit, space_number, address); if (space == Heap::map_space()) { ASSERT(size == Map::kSize); HeapObject* obj = HeapObject::FromAddress(address); Map* map = reinterpret_cast(obj); map->set_scavenger(Heap::GetScavenger(map->instance_type(), map->instance_size())); } } // This macro is always used with a constant argument so it should all fold // away to almost nothing in the generated code. It might be nicer to do this // with the ternary operator but there are type issues with that. #define ASSIGN_DEST_SPACE(space_number) \ Space* dest_space; \ if (space_number == NEW_SPACE) { \ dest_space = Heap::new_space(); \ } else if (space_number == OLD_POINTER_SPACE) { \ dest_space = Heap::old_pointer_space(); \ } else if (space_number == OLD_DATA_SPACE) { \ dest_space = Heap::old_data_space(); \ } else if (space_number == CODE_SPACE) { \ dest_space = Heap::code_space(); \ } else if (space_number == MAP_SPACE) { \ dest_space = Heap::map_space(); \ } else if (space_number == CELL_SPACE) { \ dest_space = Heap::cell_space(); \ } else { \ ASSERT(space_number >= LO_SPACE); \ dest_space = Heap::lo_space(); \ } static const int kUnknownOffsetFromStart = -1; void Deserializer::ReadChunk(Object** current, Object** limit, int source_space, Address address) { while (current < limit) { int data = source_->Get(); switch (data) { #define CASE_STATEMENT(where, how, within, space_number) \ case where + how + within + space_number: \ ASSERT((where & ~kPointedToMask) == 0); \ ASSERT((how & ~kHowToCodeMask) == 0); \ ASSERT((within & ~kWhereToPointMask) == 0); \ ASSERT((space_number & ~kSpaceMask) == 0); #define CASE_BODY(where, how, within, space_number_if_any, offset_from_start) \ { \ bool emit_write_barrier = false; \ bool current_was_incremented = false; \ int space_number = space_number_if_any == kAnyOldSpace ? \ (data & kSpaceMask) : space_number_if_any; \ if (where == kNewObject && how == kPlain && within == kStartOfObject) {\ ASSIGN_DEST_SPACE(space_number) \ ReadObject(space_number, dest_space, current); \ emit_write_barrier = \ (space_number == NEW_SPACE && source_space != NEW_SPACE); \ } else { \ Object* new_object = NULL; /* May not be a real Object pointer. */ \ if (where == kNewObject) { \ ASSIGN_DEST_SPACE(space_number) \ ReadObject(space_number, dest_space, &new_object); \ } else if (where == kRootArray) { \ int root_id = source_->GetInt(); \ new_object = Heap::roots_address()[root_id]; \ } else if (where == kPartialSnapshotCache) { \ int cache_index = source_->GetInt(); \ new_object = partial_snapshot_cache_[cache_index]; \ } else if (where == kExternalReference) { \ int reference_id = source_->GetInt(); \ Address address = \ external_reference_decoder_->Decode(reference_id); \ new_object = reinterpret_cast(address); \ } else if (where == kBackref) { \ emit_write_barrier = \ (space_number == NEW_SPACE && source_space != NEW_SPACE); \ new_object = GetAddressFromEnd(data & kSpaceMask); \ } else { \ ASSERT(where == kFromStart); \ if (offset_from_start == kUnknownOffsetFromStart) { \ emit_write_barrier = \ (space_number == NEW_SPACE && source_space != NEW_SPACE); \ new_object = GetAddressFromStart(data & kSpaceMask); \ } else { \ Address object_address = pages_[space_number][0] + \ (offset_from_start << kObjectAlignmentBits); \ new_object = HeapObject::FromAddress(object_address); \ } \ } \ if (within == kFirstInstruction) { \ Code* new_code_object = reinterpret_cast(new_object); \ new_object = reinterpret_cast( \ new_code_object->instruction_start()); \ } \ if (how == kFromCode) { \ Address location_of_branch_data = \ reinterpret_cast
(current); \ Assembler::set_target_at(location_of_branch_data, \ reinterpret_cast
(new_object)); \ if (within == kFirstInstruction) { \ location_of_branch_data += Assembler::kCallTargetSize; \ current = reinterpret_cast(location_of_branch_data); \ current_was_incremented = true; \ } \ } else { \ *current = new_object; \ } \ } \ if (emit_write_barrier) { \ Heap::RecordWrite(address, static_cast( \ reinterpret_cast
(current) - address)); \ } \ if (!current_was_incremented) { \ current++; /* Increment current if it wasn't done above. */ \ } \ break; \ } \ // This generates a case and a body for each space. The large object spaces are // very rare in snapshots so they are grouped in one body. #define ONE_PER_SPACE(where, how, within) \ CASE_STATEMENT(where, how, within, NEW_SPACE) \ CASE_BODY(where, how, within, NEW_SPACE, kUnknownOffsetFromStart) \ CASE_STATEMENT(where, how, within, OLD_DATA_SPACE) \ CASE_BODY(where, how, within, OLD_DATA_SPACE, kUnknownOffsetFromStart) \ CASE_STATEMENT(where, how, within, OLD_POINTER_SPACE) \ CASE_BODY(where, how, within, OLD_POINTER_SPACE, kUnknownOffsetFromStart) \ CASE_STATEMENT(where, how, within, CODE_SPACE) \ CASE_BODY(where, how, within, CODE_SPACE, kUnknownOffsetFromStart) \ CASE_STATEMENT(where, how, within, CELL_SPACE) \ CASE_BODY(where, how, within, CELL_SPACE, kUnknownOffsetFromStart) \ CASE_STATEMENT(where, how, within, MAP_SPACE) \ CASE_BODY(where, how, within, MAP_SPACE, kUnknownOffsetFromStart) \ CASE_STATEMENT(where, how, within, kLargeData) \ CASE_STATEMENT(where, how, within, kLargeCode) \ CASE_STATEMENT(where, how, within, kLargeFixedArray) \ CASE_BODY(where, how, within, kAnyOldSpace, kUnknownOffsetFromStart) // This generates a case and a body for the new space (which has to do extra // write barrier handling) and handles the other spaces with 8 fall-through // cases and one body. #define ALL_SPACES(where, how, within) \ CASE_STATEMENT(where, how, within, NEW_SPACE) \ CASE_BODY(where, how, within, NEW_SPACE, kUnknownOffsetFromStart) \ CASE_STATEMENT(where, how, within, OLD_DATA_SPACE) \ CASE_STATEMENT(where, how, within, OLD_POINTER_SPACE) \ CASE_STATEMENT(where, how, within, CODE_SPACE) \ CASE_STATEMENT(where, how, within, CELL_SPACE) \ CASE_STATEMENT(where, how, within, MAP_SPACE) \ CASE_STATEMENT(where, how, within, kLargeData) \ CASE_STATEMENT(where, how, within, kLargeCode) \ CASE_STATEMENT(where, how, within, kLargeFixedArray) \ CASE_BODY(where, how, within, kAnyOldSpace, kUnknownOffsetFromStart) #define EMIT_COMMON_REFERENCE_PATTERNS(pseudo_space_number, \ space_number, \ offset_from_start) \ CASE_STATEMENT(kFromStart, kPlain, kStartOfObject, pseudo_space_number) \ CASE_BODY(kFromStart, kPlain, kStartOfObject, space_number, offset_from_start) // We generate 15 cases and bodies that process special tags that combine // the raw data tag and the length into one byte. #define RAW_CASE(index, size) \ case kRawData + index: { \ byte* raw_data_out = reinterpret_cast(current); \ source_->CopyRaw(raw_data_out, size); \ current = reinterpret_cast(raw_data_out + size); \ break; \ } COMMON_RAW_LENGTHS(RAW_CASE) #undef RAW_CASE // Deserialize a chunk of raw data that doesn't have one of the popular // lengths. case kRawData: { int size = source_->GetInt(); byte* raw_data_out = reinterpret_cast(current); source_->CopyRaw(raw_data_out, size); current = reinterpret_cast(raw_data_out + size); break; } // Deserialize a new object and write a pointer to it to the current // object. ONE_PER_SPACE(kNewObject, kPlain, kStartOfObject) // Deserialize a new code object and write a pointer to its first // instruction to the current code object. ONE_PER_SPACE(kNewObject, kFromCode, kFirstInstruction) // Find a recently deserialized object using its offset from the current // allocation point and write a pointer to it to the current object. ALL_SPACES(kBackref, kPlain, kStartOfObject) // Find a recently deserialized code object using its offset from the // current allocation point and write a pointer to its first instruction // to the current code object. ALL_SPACES(kBackref, kFromCode, kFirstInstruction) // Find an already deserialized object using its offset from the start // and write a pointer to it to the current object. ALL_SPACES(kFromStart, kPlain, kStartOfObject) // Find an already deserialized code object using its offset from the // start and write a pointer to its first instruction to the current code // object. ALL_SPACES(kFromStart, kFromCode, kFirstInstruction) // Find an already deserialized object at one of the predetermined popular // offsets from the start and write a pointer to it in the current object. COMMON_REFERENCE_PATTERNS(EMIT_COMMON_REFERENCE_PATTERNS) // Find an object in the roots array and write a pointer to it to the // current object. CASE_STATEMENT(kRootArray, kPlain, kStartOfObject, 0) CASE_BODY(kRootArray, kPlain, kStartOfObject, 0, kUnknownOffsetFromStart) // Find an object in the partial snapshots cache and write a pointer to it // to the current object. CASE_STATEMENT(kPartialSnapshotCache, kPlain, kStartOfObject, 0) CASE_BODY(kPartialSnapshotCache, kPlain, kStartOfObject, 0, kUnknownOffsetFromStart) // Find an external reference and write a pointer to it to the current // object. CASE_STATEMENT(kExternalReference, kPlain, kStartOfObject, 0) CASE_BODY(kExternalReference, kPlain, kStartOfObject, 0, kUnknownOffsetFromStart) // Find an external reference and write a pointer to it in the current // code object. CASE_STATEMENT(kExternalReference, kFromCode, kStartOfObject, 0) CASE_BODY(kExternalReference, kFromCode, kStartOfObject, 0, kUnknownOffsetFromStart) #undef CASE_STATEMENT #undef CASE_BODY #undef ONE_PER_SPACE #undef ALL_SPACES #undef EMIT_COMMON_REFERENCE_PATTERNS #undef ASSIGN_DEST_SPACE case kNewPage: { int space = source_->Get(); pages_[space].Add(last_object_address_); if (space == CODE_SPACE) { CPU::FlushICache(last_object_address_, Page::kPageSize); } break; } case kNativesStringResource: { int index = source_->Get(); Vector source_vector = Natives::GetScriptSource(index); NativesExternalStringResource* resource = new NativesExternalStringResource(source_vector.start()); *current++ = reinterpret_cast(resource); break; } case kSynchronize: { // If we get here then that indicates that you have a mismatch between // the number of GC roots when serializing and deserializing. UNREACHABLE(); } default: UNREACHABLE(); } } ASSERT_EQ(current, limit); } void SnapshotByteSink::PutInt(uintptr_t integer, const char* description) { const int max_shift = ((kPointerSize * kBitsPerByte) / 7) * 7; for (int shift = max_shift; shift > 0; shift -= 7) { if (integer >= static_cast(1u) << shift) { Put((static_cast((integer >> shift)) & 0x7f) | 0x80, "IntPart"); } } PutSection(static_cast(integer & 0x7f), "IntLastPart"); } #ifdef DEBUG void Deserializer::Synchronize(const char* tag) { int data = source_->Get(); // If this assert fails then that indicates that you have a mismatch between // the number of GC roots when serializing and deserializing. ASSERT_EQ(kSynchronize, data); do { int character = source_->Get(); if (character == 0) break; if (FLAG_debug_serialization) { PrintF("%c", character); } } while (true); if (FLAG_debug_serialization) { PrintF("\n"); } } void Serializer::Synchronize(const char* tag) { sink_->Put(kSynchronize, tag); int character; do { character = *tag++; sink_->PutSection(character, "TagCharacter"); } while (character != 0); } #endif Serializer::Serializer(SnapshotByteSink* sink) : sink_(sink), current_root_index_(0), external_reference_encoder_(new ExternalReferenceEncoder), large_object_total_(0) { for (int i = 0; i <= LAST_SPACE; i++) { fullness_[i] = 0; } } Serializer::~Serializer() { delete external_reference_encoder_; } void StartupSerializer::SerializeStrongReferences() { // No active threads. CHECK_EQ(NULL, ThreadState::FirstInUse()); // No active or weak handles. CHECK(HandleScopeImplementer::instance()->blocks()->is_empty()); CHECK_EQ(0, GlobalHandles::NumberOfWeakHandles()); // We don't support serializing installed extensions. for (RegisteredExtension* ext = RegisteredExtension::first_extension(); ext != NULL; ext = ext->next()) { CHECK_NE(v8::INSTALLED, ext->state()); } Heap::IterateStrongRoots(this, VISIT_ONLY_STRONG); } void PartialSerializer::Serialize(Object** object) { this->VisitPointer(object); // After we have done the partial serialization the partial snapshot cache // will contain some references needed to decode the partial snapshot. We // fill it up with undefineds so it has a predictable length so the // deserialization code doesn't need to know the length. for (int index = partial_snapshot_cache_length_; index < kPartialSnapshotCacheCapacity; index++) { partial_snapshot_cache_[index] = Heap::undefined_value(); startup_serializer_->VisitPointer(&partial_snapshot_cache_[index]); } partial_snapshot_cache_length_ = kPartialSnapshotCacheCapacity; } void Serializer::VisitPointers(Object** start, Object** end) { for (Object** current = start; current < end; current++) { if ((*current)->IsSmi()) { sink_->Put(kRawData, "RawData"); sink_->PutInt(kPointerSize, "length"); for (int i = 0; i < kPointerSize; i++) { sink_->Put(reinterpret_cast(current)[i], "Byte"); } } else { SerializeObject(*current, kPlain, kStartOfObject); } } } Object* SerializerDeserializer::partial_snapshot_cache_[ kPartialSnapshotCacheCapacity]; int SerializerDeserializer::partial_snapshot_cache_length_ = 0; // This ensures that the partial snapshot cache keeps things alive during GC and // tracks their movement. When it is called during serialization of the startup // snapshot the partial snapshot is empty, so nothing happens. When the partial // (context) snapshot is created, this array is populated with the pointers that // the partial snapshot will need. As that happens we emit serialized objects to // the startup snapshot that correspond to the elements of this cache array. On // deserialization we therefore need to visit the cache array. This fills it up // with pointers to deserialized objects. void SerializerDeserializer::Iterate(ObjectVisitor* visitor) { visitor->VisitPointers( &partial_snapshot_cache_[0], &partial_snapshot_cache_[partial_snapshot_cache_length_]); } // When deserializing we need to set the size of the snapshot cache. This means // the root iteration code (above) will iterate over array elements, writing the // references to deserialized objects in them. void SerializerDeserializer::SetSnapshotCacheSize(int size) { partial_snapshot_cache_length_ = size; } int PartialSerializer::PartialSnapshotCacheIndex(HeapObject* heap_object) { for (int i = 0; i < partial_snapshot_cache_length_; i++) { Object* entry = partial_snapshot_cache_[i]; if (entry == heap_object) return i; } // We didn't find the object in the cache. So we add it to the cache and // then visit the pointer so that it becomes part of the startup snapshot // and we can refer to it from the partial snapshot. int length = partial_snapshot_cache_length_; CHECK(length < kPartialSnapshotCacheCapacity); partial_snapshot_cache_[length] = heap_object; startup_serializer_->VisitPointer(&partial_snapshot_cache_[length]); // We don't recurse from the startup snapshot generator into the partial // snapshot generator. ASSERT(length == partial_snapshot_cache_length_); return partial_snapshot_cache_length_++; } int PartialSerializer::RootIndex(HeapObject* heap_object) { for (int i = 0; i < Heap::kRootListLength; i++) { Object* root = Heap::roots_address()[i]; if (root == heap_object) return i; } return kInvalidRootIndex; } // Encode the location of an already deserialized object in order to write its // location into a later object. We can encode the location as an offset from // the start of the deserialized objects or as an offset backwards from the // current allocation pointer. void Serializer::SerializeReferenceToPreviousObject( int space, int address, HowToCode how_to_code, WhereToPoint where_to_point) { int offset = CurrentAllocationAddress(space) - address; bool from_start = true; if (SpaceIsPaged(space)) { // For paged space it is simple to encode back from current allocation if // the object is on the same page as the current allocation pointer. if ((CurrentAllocationAddress(space) >> kPageSizeBits) == (address >> kPageSizeBits)) { from_start = false; address = offset; } } else if (space == NEW_SPACE) { // For new space it is always simple to encode back from current allocation. if (offset < address) { from_start = false; address = offset; } } // If we are actually dealing with real offsets (and not a numbering of // all objects) then we should shift out the bits that are always 0. if (!SpaceIsLarge(space)) address >>= kObjectAlignmentBits; if (from_start) { #define COMMON_REFS_CASE(pseudo_space, actual_space, offset) \ if (space == actual_space && address == offset && \ how_to_code == kPlain && where_to_point == kStartOfObject) { \ sink_->Put(kFromStart + how_to_code + where_to_point + \ pseudo_space, "RefSer"); \ } else /* NOLINT */ COMMON_REFERENCE_PATTERNS(COMMON_REFS_CASE) #undef COMMON_REFS_CASE { /* NOLINT */ sink_->Put(kFromStart + how_to_code + where_to_point + space, "RefSer"); sink_->PutInt(address, "address"); } } else { sink_->Put(kBackref + how_to_code + where_to_point + space, "BackRefSer"); sink_->PutInt(address, "address"); } } void StartupSerializer::SerializeObject( Object* o, HowToCode how_to_code, WhereToPoint where_to_point) { CHECK(o->IsHeapObject()); HeapObject* heap_object = HeapObject::cast(o); if (address_mapper_.IsMapped(heap_object)) { int space = SpaceOfAlreadySerializedObject(heap_object); int address = address_mapper_.MappedTo(heap_object); SerializeReferenceToPreviousObject(space, address, how_to_code, where_to_point); } else { // Object has not yet been serialized. Serialize it here. ObjectSerializer object_serializer(this, heap_object, sink_, how_to_code, where_to_point); object_serializer.Serialize(); } } void StartupSerializer::SerializeWeakReferences() { for (int i = partial_snapshot_cache_length_; i < kPartialSnapshotCacheCapacity; i++) { sink_->Put(kRootArray + kPlain + kStartOfObject, "RootSerialization"); sink_->PutInt(Heap::kUndefinedValueRootIndex, "root_index"); } Heap::IterateWeakRoots(this, VISIT_ALL); } void PartialSerializer::SerializeObject( Object* o, HowToCode how_to_code, WhereToPoint where_to_point) { CHECK(o->IsHeapObject()); HeapObject* heap_object = HeapObject::cast(o); int root_index; if ((root_index = RootIndex(heap_object)) != kInvalidRootIndex) { sink_->Put(kRootArray + how_to_code + where_to_point, "RootSerialization"); sink_->PutInt(root_index, "root_index"); return; } if (ShouldBeInThePartialSnapshotCache(heap_object)) { int cache_index = PartialSnapshotCacheIndex(heap_object); sink_->Put(kPartialSnapshotCache + how_to_code + where_to_point, "PartialSnapshotCache"); sink_->PutInt(cache_index, "partial_snapshot_cache_index"); return; } // Pointers from the partial snapshot to the objects in the startup snapshot // should go through the root array or through the partial snapshot cache. // If this is not the case you may have to add something to the root array. ASSERT(!startup_serializer_->address_mapper()->IsMapped(heap_object)); // All the symbols that the partial snapshot needs should be either in the // root table or in the partial snapshot cache. ASSERT(!heap_object->IsSymbol()); if (address_mapper_.IsMapped(heap_object)) { int space = SpaceOfAlreadySerializedObject(heap_object); int address = address_mapper_.MappedTo(heap_object); SerializeReferenceToPreviousObject(space, address, how_to_code, where_to_point); } else { // Object has not yet been serialized. Serialize it here. ObjectSerializer serializer(this, heap_object, sink_, how_to_code, where_to_point); serializer.Serialize(); } } void Serializer::ObjectSerializer::Serialize() { int space = Serializer::SpaceOfObject(object_); int size = object_->Size(); sink_->Put(kNewObject + reference_representation_ + space, "ObjectSerialization"); sink_->PutInt(size >> kObjectAlignmentBits, "Size in words"); LOG(SnapshotPositionEvent(object_->address(), sink_->Position())); // Mark this object as already serialized. bool start_new_page; int offset = serializer_->Allocate(space, size, &start_new_page); serializer_->address_mapper()->AddMapping(object_, offset); if (start_new_page) { sink_->Put(kNewPage, "NewPage"); sink_->PutSection(space, "NewPageSpace"); } // Serialize the map (first word of the object). serializer_->SerializeObject(object_->map(), kPlain, kStartOfObject); // Serialize the rest of the object. CHECK_EQ(0, bytes_processed_so_far_); bytes_processed_so_far_ = kPointerSize; object_->IterateBody(object_->map()->instance_type(), size, this); OutputRawData(object_->address() + size); } void Serializer::ObjectSerializer::VisitPointers(Object** start, Object** end) { Object** current = start; while (current < end) { while (current < end && (*current)->IsSmi()) current++; if (current < end) OutputRawData(reinterpret_cast
(current)); while (current < end && !(*current)->IsSmi()) { serializer_->SerializeObject(*current, kPlain, kStartOfObject); bytes_processed_so_far_ += kPointerSize; current++; } } } void Serializer::ObjectSerializer::VisitExternalReferences(Address* start, Address* end) { Address references_start = reinterpret_cast
(start); OutputRawData(references_start); for (Address* current = start; current < end; current++) { sink_->Put(kExternalReference + kPlain + kStartOfObject, "ExternalRef"); int reference_id = serializer_->EncodeExternalReference(*current); sink_->PutInt(reference_id, "reference id"); } bytes_processed_so_far_ += static_cast((end - start) * kPointerSize); } void Serializer::ObjectSerializer::VisitRuntimeEntry(RelocInfo* rinfo) { Address target_start = rinfo->target_address_address(); OutputRawData(target_start); Address target = rinfo->target_address(); uint32_t encoding = serializer_->EncodeExternalReference(target); CHECK(target == NULL ? encoding == 0 : encoding != 0); int representation; // Can't use a ternary operator because of gcc. if (rinfo->IsCodedSpecially()) { representation = kStartOfObject + kFromCode; } else { representation = kStartOfObject + kPlain; } sink_->Put(kExternalReference + representation, "ExternalReference"); sink_->PutInt(encoding, "reference id"); bytes_processed_so_far_ += rinfo->target_address_size(); } void Serializer::ObjectSerializer::VisitCodeTarget(RelocInfo* rinfo) { CHECK(RelocInfo::IsCodeTarget(rinfo->rmode())); Address target_start = rinfo->target_address_address(); OutputRawData(target_start); Code* target = Code::GetCodeFromTargetAddress(rinfo->target_address()); serializer_->SerializeObject(target, kFromCode, kFirstInstruction); bytes_processed_so_far_ += rinfo->target_address_size(); } void Serializer::ObjectSerializer::VisitExternalAsciiString( v8::String::ExternalAsciiStringResource** resource_pointer) { Address references_start = reinterpret_cast
(resource_pointer); OutputRawData(references_start); for (int i = 0; i < Natives::GetBuiltinsCount(); i++) { Object* source = Heap::natives_source_cache()->get(i); if (!source->IsUndefined()) { ExternalAsciiString* string = ExternalAsciiString::cast(source); typedef v8::String::ExternalAsciiStringResource Resource; Resource* resource = string->resource(); if (resource == *resource_pointer) { sink_->Put(kNativesStringResource, "NativesStringResource"); sink_->PutSection(i, "NativesStringResourceEnd"); bytes_processed_so_far_ += sizeof(resource); return; } } } // One of the strings in the natives cache should match the resource. We // can't serialize any other kinds of external strings. UNREACHABLE(); } void Serializer::ObjectSerializer::OutputRawData(Address up_to) { Address object_start = object_->address(); int up_to_offset = static_cast(up_to - object_start); int skipped = up_to_offset - bytes_processed_so_far_; // This assert will fail if the reloc info gives us the target_address_address // locations in a non-ascending order. Luckily that doesn't happen. ASSERT(skipped >= 0); if (skipped != 0) { Address base = object_start + bytes_processed_so_far_; #define RAW_CASE(index, length) \ if (skipped == length) { \ sink_->PutSection(kRawData + index, "RawDataFixed"); \ } else /* NOLINT */ COMMON_RAW_LENGTHS(RAW_CASE) #undef RAW_CASE { /* NOLINT */ sink_->Put(kRawData, "RawData"); sink_->PutInt(skipped, "length"); } for (int i = 0; i < skipped; i++) { unsigned int data = base[i]; sink_->PutSection(data, "Byte"); } bytes_processed_so_far_ += skipped; } } int Serializer::SpaceOfObject(HeapObject* object) { for (int i = FIRST_SPACE; i <= LAST_SPACE; i++) { AllocationSpace s = static_cast(i); if (Heap::InSpace(object, s)) { if (i == LO_SPACE) { if (object->IsCode()) { return kLargeCode; } else if (object->IsFixedArray()) { return kLargeFixedArray; } else { return kLargeData; } } return i; } } UNREACHABLE(); return 0; } int Serializer::SpaceOfAlreadySerializedObject(HeapObject* object) { for (int i = FIRST_SPACE; i <= LAST_SPACE; i++) { AllocationSpace s = static_cast(i); if (Heap::InSpace(object, s)) { return i; } } UNREACHABLE(); return 0; } int Serializer::Allocate(int space, int size, bool* new_page) { CHECK(space >= 0 && space < kNumberOfSpaces); if (SpaceIsLarge(space)) { // In large object space we merely number the objects instead of trying to // determine some sort of address. *new_page = true; large_object_total_ += size; return fullness_[LO_SPACE]++; } *new_page = false; if (fullness_[space] == 0) { *new_page = true; } if (SpaceIsPaged(space)) { // Paged spaces are a little special. We encode their addresses as if the // pages were all contiguous and each page were filled up in the range // 0 - Page::kObjectAreaSize. In practice the pages may not be contiguous // and allocation does not start at offset 0 in the page, but this scheme // means the deserializer can get the page number quickly by shifting the // serialized address. CHECK(IsPowerOf2(Page::kPageSize)); int used_in_this_page = (fullness_[space] & (Page::kPageSize - 1)); CHECK(size <= Page::kObjectAreaSize); if (used_in_this_page + size > Page::kObjectAreaSize) { *new_page = true; fullness_[space] = RoundUp(fullness_[space], Page::kPageSize); } } int allocation_address = fullness_[space]; fullness_[space] = allocation_address + size; return allocation_address; } } } // namespace v8::internal