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v8/src/serialize.cc
erik.corry@gmail.com 1d0f872ef9 Fix full code generator to not use --debug-code if it is in 
mksnapshot or a VM that is booted from a snapshot.  --debug-code
can still have an effect on stub and optimized code and it still
works on the full code generator when running without snapshots.

The deoptimizer generates full-code-generator code and relies on it having
the same layout as last time.  This means that the code the full code
generator makes for the snapshot should be the same as the code it makes
later.  This change makes the full code generator create more consistent
code between mksnapshot time and run time.

This is a bug fix and a step towards making the snapshot code more robust.
Review URL: https://chromiumcodereview.appspot.com/10834085

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12239 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2012-07-31 14:59:32 +00:00

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// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "v8.h"
#include "accessors.h"
#include "api.h"
#include "bootstrapper.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 "snapshot.h"
#include "stub-cache.h"
#include "v8threads.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<uint32_t>(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* ExternalReferenceTable::instance(Isolate* isolate) {
ExternalReferenceTable* external_reference_table =
isolate->external_reference_table();
if (external_reference_table == NULL) {
external_reference_table = new ExternalReferenceTable(isolate);
isolate->set_external_reference_table(external_reference_table);
}
return external_reference_table;
}
void ExternalReferenceTable::AddFromId(TypeCode type,
uint16_t id,
const char* name,
Isolate* isolate) {
Address address;
switch (type) {
case C_BUILTIN: {
ExternalReference ref(static_cast<Builtins::CFunctionId>(id), isolate);
address = ref.address();
break;
}
case BUILTIN: {
ExternalReference ref(static_cast<Builtins::Name>(id), isolate);
address = ref.address();
break;
}
case RUNTIME_FUNCTION: {
ExternalReference ref(static_cast<Runtime::FunctionId>(id), isolate);
address = ref.address();
break;
}
case IC_UTILITY: {
ExternalReference ref(IC_Utility(static_cast<IC::UtilityId>(id)),
isolate);
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(Isolate* isolate) {
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::k##name, \
"Builtins::" #name },
#define DEF_ENTRY_A(name, kind, state, extra) 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,
isolate);
}
#ifdef ENABLE_DEBUGGER_SUPPORT
// Debug addresses
Add(Debug_Address(Debug::k_after_break_target_address).address(isolate),
DEBUG_ADDRESS,
Debug::k_after_break_target_address << kDebugIdShift,
"Debug::after_break_target_address()");
Add(Debug_Address(Debug::k_debug_break_slot_address).address(isolate),
DEBUG_ADDRESS,
Debug::k_debug_break_slot_address << kDebugIdShift,
"Debug::debug_break_slot_address()");
Add(Debug_Address(Debug::k_debug_break_return_address).address(isolate),
DEBUG_ADDRESS,
Debug::k_debug_break_return_address << kDebugIdShift,
"Debug::debug_break_return_address()");
Add(Debug_Address(Debug::k_restarter_frame_function_pointer).address(isolate),
DEBUG_ADDRESS,
Debug::k_restarter_frame_function_pointer << kDebugIdShift,
"Debug::restarter_frame_function_pointer_address()");
#endif
// Stat counters
struct StatsRefTableEntry {
StatsCounter* (Counters::*counter)();
uint16_t id;
const char* name;
};
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[].
Counters* counters = isolate->counters();
for (size_t i = 0; i < ARRAY_SIZE(stats_ref_table); ++i) {
Add(reinterpret_cast<Address>(GetInternalPointer(
(counters->*(stats_ref_table[i].counter))())),
STATS_COUNTER,
stats_ref_table[i].id,
stats_ref_table[i].name);
}
// Top addresses
const char* AddressNames[] = {
#define BUILD_NAME_LITERAL(CamelName, hacker_name) \
"Isolate::" #hacker_name "_address",
FOR_EACH_ISOLATE_ADDRESS_NAME(BUILD_NAME_LITERAL)
NULL
#undef BUILD_NAME_LITERAL
};
for (uint16_t i = 0; i < Isolate::kIsolateAddressCount; ++i) {
Add(isolate->get_address_from_id((Isolate::AddressId)i),
TOP_ADDRESS, i, AddressNames[i]);
}
// 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
StubCache* stub_cache = isolate->stub_cache();
// Stub cache tables
Add(stub_cache->key_reference(StubCache::kPrimary).address(),
STUB_CACHE_TABLE,
1,
"StubCache::primary_->key");
Add(stub_cache->value_reference(StubCache::kPrimary).address(),
STUB_CACHE_TABLE,
2,
"StubCache::primary_->value");
Add(stub_cache->map_reference(StubCache::kPrimary).address(),
STUB_CACHE_TABLE,
3,
"StubCache::primary_->map");
Add(stub_cache->key_reference(StubCache::kSecondary).address(),
STUB_CACHE_TABLE,
4,
"StubCache::secondary_->key");
Add(stub_cache->value_reference(StubCache::kSecondary).address(),
STUB_CACHE_TABLE,
5,
"StubCache::secondary_->value");
Add(stub_cache->map_reference(StubCache::kSecondary).address(),
STUB_CACHE_TABLE,
6,
"StubCache::secondary_->map");
// Runtime entries
Add(ExternalReference::perform_gc_function(isolate).address(),
RUNTIME_ENTRY,
1,
"Runtime::PerformGC");
Add(ExternalReference::fill_heap_number_with_random_function(
isolate).address(),
RUNTIME_ENTRY,
2,
"V8::FillHeapNumberWithRandom");
Add(ExternalReference::random_uint32_function(isolate).address(),
RUNTIME_ENTRY,
3,
"V8::Random");
Add(ExternalReference::delete_handle_scope_extensions(isolate).address(),
RUNTIME_ENTRY,
4,
"HandleScope::DeleteExtensions");
Add(ExternalReference::
incremental_marking_record_write_function(isolate).address(),
RUNTIME_ENTRY,
5,
"IncrementalMarking::RecordWrite");
Add(ExternalReference::store_buffer_overflow_function(isolate).address(),
RUNTIME_ENTRY,
6,
"StoreBuffer::StoreBufferOverflow");
Add(ExternalReference::
incremental_evacuation_record_write_function(isolate).address(),
RUNTIME_ENTRY,
7,
"IncrementalMarking::RecordWrite");
// Miscellaneous
Add(ExternalReference::roots_array_start(isolate).address(),
UNCLASSIFIED,
3,
"Heap::roots_array_start()");
Add(ExternalReference::address_of_stack_limit(isolate).address(),
UNCLASSIFIED,
4,
"StackGuard::address_of_jslimit()");
Add(ExternalReference::address_of_real_stack_limit(isolate).address(),
UNCLASSIFIED,
5,
"StackGuard::address_of_real_jslimit()");
#ifndef V8_INTERPRETED_REGEXP
Add(ExternalReference::address_of_regexp_stack_limit(isolate).address(),
UNCLASSIFIED,
6,
"RegExpStack::limit_address()");
Add(ExternalReference::address_of_regexp_stack_memory_address(
isolate).address(),
UNCLASSIFIED,
7,
"RegExpStack::memory_address()");
Add(ExternalReference::address_of_regexp_stack_memory_size(isolate).address(),
UNCLASSIFIED,
8,
"RegExpStack::memory_size()");
Add(ExternalReference::address_of_static_offsets_vector(isolate).address(),
UNCLASSIFIED,
9,
"OffsetsVector::static_offsets_vector");
#endif // V8_INTERPRETED_REGEXP
Add(ExternalReference::new_space_start(isolate).address(),
UNCLASSIFIED,
10,
"Heap::NewSpaceStart()");
Add(ExternalReference::new_space_mask(isolate).address(),
UNCLASSIFIED,
11,
"Heap::NewSpaceMask()");
Add(ExternalReference::heap_always_allocate_scope_depth(isolate).address(),
UNCLASSIFIED,
12,
"Heap::always_allocate_scope_depth()");
Add(ExternalReference::new_space_allocation_limit_address(isolate).address(),
UNCLASSIFIED,
14,
"Heap::NewSpaceAllocationLimitAddress()");
Add(ExternalReference::new_space_allocation_top_address(isolate).address(),
UNCLASSIFIED,
15,
"Heap::NewSpaceAllocationTopAddress()");
#ifdef ENABLE_DEBUGGER_SUPPORT
Add(ExternalReference::debug_break(isolate).address(),
UNCLASSIFIED,
16,
"Debug::Break()");
Add(ExternalReference::debug_step_in_fp_address(isolate).address(),
UNCLASSIFIED,
17,
"Debug::step_in_fp_addr()");
#endif
Add(ExternalReference::double_fp_operation(Token::ADD, isolate).address(),
UNCLASSIFIED,
18,
"add_two_doubles");
Add(ExternalReference::double_fp_operation(Token::SUB, isolate).address(),
UNCLASSIFIED,
19,
"sub_two_doubles");
Add(ExternalReference::double_fp_operation(Token::MUL, isolate).address(),
UNCLASSIFIED,
20,
"mul_two_doubles");
Add(ExternalReference::double_fp_operation(Token::DIV, isolate).address(),
UNCLASSIFIED,
21,
"div_two_doubles");
Add(ExternalReference::double_fp_operation(Token::MOD, isolate).address(),
UNCLASSIFIED,
22,
"mod_two_doubles");
Add(ExternalReference::compare_doubles(isolate).address(),
UNCLASSIFIED,
23,
"compare_doubles");
#ifndef V8_INTERPRETED_REGEXP
Add(ExternalReference::re_case_insensitive_compare_uc16(isolate).address(),
UNCLASSIFIED,
24,
"NativeRegExpMacroAssembler::CaseInsensitiveCompareUC16()");
Add(ExternalReference::re_check_stack_guard_state(isolate).address(),
UNCLASSIFIED,
25,
"RegExpMacroAssembler*::CheckStackGuardState()");
Add(ExternalReference::re_grow_stack(isolate).address(),
UNCLASSIFIED,
26,
"NativeRegExpMacroAssembler::GrowStack()");
Add(ExternalReference::re_word_character_map().address(),
UNCLASSIFIED,
27,
"NativeRegExpMacroAssembler::word_character_map");
#endif // V8_INTERPRETED_REGEXP
// Keyed lookup cache.
Add(ExternalReference::keyed_lookup_cache_keys(isolate).address(),
UNCLASSIFIED,
28,
"KeyedLookupCache::keys()");
Add(ExternalReference::keyed_lookup_cache_field_offsets(isolate).address(),
UNCLASSIFIED,
29,
"KeyedLookupCache::field_offsets()");
Add(ExternalReference::transcendental_cache_array_address(isolate).address(),
UNCLASSIFIED,
30,
"TranscendentalCache::caches()");
Add(ExternalReference::handle_scope_next_address().address(),
UNCLASSIFIED,
31,
"HandleScope::next");
Add(ExternalReference::handle_scope_limit_address().address(),
UNCLASSIFIED,
32,
"HandleScope::limit");
Add(ExternalReference::handle_scope_level_address().address(),
UNCLASSIFIED,
33,
"HandleScope::level");
Add(ExternalReference::new_deoptimizer_function(isolate).address(),
UNCLASSIFIED,
34,
"Deoptimizer::New()");
Add(ExternalReference::compute_output_frames_function(isolate).address(),
UNCLASSIFIED,
35,
"Deoptimizer::ComputeOutputFrames()");
Add(ExternalReference::address_of_min_int().address(),
UNCLASSIFIED,
36,
"LDoubleConstant::min_int");
Add(ExternalReference::address_of_one_half().address(),
UNCLASSIFIED,
37,
"LDoubleConstant::one_half");
Add(ExternalReference::isolate_address().address(),
UNCLASSIFIED,
38,
"isolate");
Add(ExternalReference::address_of_minus_zero().address(),
UNCLASSIFIED,
39,
"LDoubleConstant::minus_zero");
Add(ExternalReference::address_of_negative_infinity().address(),
UNCLASSIFIED,
40,
"LDoubleConstant::negative_infinity");
Add(ExternalReference::power_double_double_function(isolate).address(),
UNCLASSIFIED,
41,
"power_double_double_function");
Add(ExternalReference::power_double_int_function(isolate).address(),
UNCLASSIFIED,
42,
"power_double_int_function");
Add(ExternalReference::store_buffer_top(isolate).address(),
UNCLASSIFIED,
43,
"store_buffer_top");
Add(ExternalReference::address_of_canonical_non_hole_nan().address(),
UNCLASSIFIED,
44,
"canonical_nan");
Add(ExternalReference::address_of_the_hole_nan().address(),
UNCLASSIFIED,
45,
"the_hole_nan");
Add(ExternalReference::get_date_field_function(isolate).address(),
UNCLASSIFIED,
46,
"JSDate::GetField");
Add(ExternalReference::date_cache_stamp(isolate).address(),
UNCLASSIFIED,
47,
"date_cache_stamp");
Add(ExternalReference::address_of_pending_message_obj(isolate).address(),
UNCLASSIFIED,
48,
"address_of_pending_message_obj");
Add(ExternalReference::address_of_has_pending_message(isolate).address(),
UNCLASSIFIED,
49,
"address_of_has_pending_message");
Add(ExternalReference::address_of_pending_message_script(isolate).address(),
UNCLASSIFIED,
50,
"pending_message_script");
}
ExternalReferenceEncoder::ExternalReferenceEncoder()
: encodings_(Match),
isolate_(Isolate::Current()) {
ExternalReferenceTable* external_references =
ExternalReferenceTable::instance(isolate_);
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);
ASSERT(key == NULL || index >= 0);
return index >=0 ?
ExternalReferenceTable::instance(isolate_)->code(index) : 0;
}
const char* ExternalReferenceEncoder::NameOfAddress(Address key) const {
int index = IndexOf(key);
return index >= 0 ?
ExternalReferenceTable::instance(isolate_)->name(index) : NULL;
}
int ExternalReferenceEncoder::IndexOf(Address key) const {
if (key == NULL) return -1;
HashMap::Entry* entry =
const_cast<HashMap&>(encodings_).Lookup(key, Hash(key), false);
return entry == NULL
? -1
: static_cast<int>(reinterpret_cast<intptr_t>(entry->value));
}
void ExternalReferenceEncoder::Put(Address key, int index) {
HashMap::Entry* entry = encodings_.Lookup(key, Hash(key), true);
entry->value = reinterpret_cast<void*>(index);
}
ExternalReferenceDecoder::ExternalReferenceDecoder()
: encodings_(NewArray<Address*>(kTypeCodeCount)),
isolate_(Isolate::Current()) {
ExternalReferenceTable* external_references =
ExternalReferenceTable::instance(isolate_);
for (int type = kFirstTypeCode; type < kTypeCodeCount; ++type) {
int max = external_references->max_id(type) + 1;
encodings_[type] = NewArray<Address>(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;
Deserializer::Deserializer(SnapshotByteSource* source)
: isolate_(NULL),
source_(source),
external_reference_decoder_(NULL) {
}
// 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);
MaybeObject* maybe_new_allocation;
if (space_index == NEW_SPACE) {
maybe_new_allocation =
reinterpret_cast<NewSpace*>(space)->AllocateRaw(size);
} else {
maybe_new_allocation =
reinterpret_cast<PagedSpace*>(space)->AllocateRaw(size);
}
ASSERT(!maybe_new_allocation->IsFailure());
Object* new_allocation = maybe_new_allocation->ToObjectUnchecked();
HeapObject* new_object = HeapObject::cast(new_allocation);
address = new_object->address();
high_water_[space_index] = address + size;
} else {
ASSERT(SpaceIsLarge(space_index));
LargeObjectSpace* lo_space = reinterpret_cast<LargeObjectSpace*>(space);
Object* new_allocation;
if (space_index == kLargeData || space_index == kLargeFixedArray) {
new_allocation =
lo_space->AllocateRaw(size, NOT_EXECUTABLE)->ToObjectUnchecked();
} else {
ASSERT_EQ(kLargeCode, space_index);
new_allocation =
lo_space->AllocateRaw(size, EXECUTABLE)->ToObjectUnchecked();
}
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() {
isolate_ = Isolate::Current();
ASSERT(isolate_ != NULL);
// 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, isolate_->thread_manager()->FirstThreadStateInUse());
// No active handles.
ASSERT(isolate_->handle_scope_implementer()->blocks()->is_empty());
ASSERT_EQ(NULL, external_reference_decoder_);
external_reference_decoder_ = new ExternalReferenceDecoder();
isolate_->heap()->IterateStrongRoots(this, VISIT_ONLY_STRONG);
isolate_->heap()->IterateWeakRoots(this, VISIT_ALL);
isolate_->heap()->set_global_contexts_list(
isolate_->heap()->undefined_value());
// Update data pointers to the external strings containing natives sources.
for (int i = 0; i < Natives::GetBuiltinsCount(); i++) {
Object* source = isolate_->heap()->natives_source_cache()->get(i);
if (!source->IsUndefined()) {
ExternalAsciiString::cast(source)->update_data_cache();
}
}
}
void Deserializer::DeserializePartial(Object** root) {
isolate_ = Isolate::Current();
// 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_) {
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 FreeSpace map is not set up by the
// time we need to use it to mark the space at the end of a page free.
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<Object**>(address);
Object** limit = current + (size >> kPointerSizeLog2);
if (FLAG_log_snapshot_positions) {
LOG(isolate_, SnapshotPositionEvent(address, source_->position()));
}
ReadChunk(current, limit, space_number, address);
#ifdef DEBUG
bool is_codespace = (space == HEAP->code_space()) ||
((space == HEAP->lo_space()) && (space_number == kLargeCode));
ASSERT(HeapObject::FromAddress(address)->IsCode() == is_codespace);
#endif
}
// 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 = isolate->heap()->new_space(); \
} else if (space_number == OLD_POINTER_SPACE) { \
dest_space = isolate->heap()->old_pointer_space(); \
} else if (space_number == OLD_DATA_SPACE) { \
dest_space = isolate->heap()->old_data_space(); \
} else if (space_number == CODE_SPACE) { \
dest_space = isolate->heap()->code_space(); \
} else if (space_number == MAP_SPACE) { \
dest_space = isolate->heap()->map_space(); \
} else if (space_number == CELL_SPACE) { \
dest_space = isolate->heap()->cell_space(); \
} else { \
ASSERT(space_number >= LO_SPACE); \
dest_space = isolate->heap()->lo_space(); \
}
static const int kUnknownOffsetFromStart = -1;
void Deserializer::ReadChunk(Object** current,
Object** limit,
int source_space,
Address current_object_address) {
Isolate* const isolate = isolate_;
bool write_barrier_needed = (current_object_address != NULL &&
source_space != NEW_SPACE &&
source_space != CELL_SPACE &&
source_space != CODE_SPACE &&
source_space != OLD_DATA_SPACE);
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); \
} 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 = isolate->heap()->roots_array_start()[root_id]; \
emit_write_barrier = isolate->heap()->InNewSpace(new_object); \
} else if (where == kPartialSnapshotCache) { \
int cache_index = source_->GetInt(); \
new_object = isolate->serialize_partial_snapshot_cache() \
[cache_index]; \
emit_write_barrier = isolate->heap()->InNewSpace(new_object); \
} else if (where == kExternalReference) { \
int reference_id = source_->GetInt(); \
Address address = external_reference_decoder_-> \
Decode(reference_id); \
new_object = reinterpret_cast<Object*>(address); \
} else if (where == kBackref) { \
emit_write_barrier = (space_number == NEW_SPACE); \
new_object = GetAddressFromEnd(data & kSpaceMask); \
} else { \
ASSERT(where == kFromStart); \
if (offset_from_start == kUnknownOffsetFromStart) { \
emit_write_barrier = (space_number == 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 == kInnerPointer) { \
if (space_number != CODE_SPACE || new_object->IsCode()) { \
Code* new_code_object = reinterpret_cast<Code*>(new_object); \
new_object = reinterpret_cast<Object*>( \
new_code_object->instruction_start()); \
} else { \
ASSERT(space_number == CODE_SPACE || space_number == kLargeCode);\
JSGlobalPropertyCell* cell = \
JSGlobalPropertyCell::cast(new_object); \
new_object = reinterpret_cast<Object*>( \
cell->ValueAddress()); \
} \
} \
if (how == kFromCode) { \
Address location_of_branch_data = \
reinterpret_cast<Address>(current); \
Assembler::deserialization_set_special_target_at( \
location_of_branch_data, \
reinterpret_cast<Address>(new_object)); \
location_of_branch_data += Assembler::kSpecialTargetSize; \
current = reinterpret_cast<Object**>(location_of_branch_data); \
current_was_incremented = true; \
} else { \
*current = new_object; \
} \
} \
if (emit_write_barrier && write_barrier_needed) { \
Address current_address = reinterpret_cast<Address>(current); \
isolate->heap()->RecordWrite( \
current_object_address, \
static_cast<int>(current_address - current_object_address)); \
} \
if (!current_was_incremented) { \
current++; \
} \
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 ONE_PER_CODE_SPACE(where, how, within) \
CASE_STATEMENT(where, how, within, CODE_SPACE) \
CASE_BODY(where, how, within, CODE_SPACE, kUnknownOffsetFromStart) \
CASE_STATEMENT(where, how, within, kLargeCode) \
CASE_BODY(where, how, within, kLargeCode, kUnknownOffsetFromStart)
#define FOUR_CASES(byte_code) \
case byte_code: \
case byte_code + 1: \
case byte_code + 2: \
case byte_code + 3:
#define SIXTEEN_CASES(byte_code) \
FOUR_CASES(byte_code) \
FOUR_CASES(byte_code + 4) \
FOUR_CASES(byte_code + 8) \
FOUR_CASES(byte_code + 12)
// 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<byte*>(current); \
source_->CopyRaw(raw_data_out, size); \
current = reinterpret_cast<Object**>(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<byte*>(current);
source_->CopyRaw(raw_data_out, size);
current = reinterpret_cast<Object**>(raw_data_out + size);
break;
}
SIXTEEN_CASES(kRootArrayLowConstants)
SIXTEEN_CASES(kRootArrayHighConstants) {
int root_id = RootArrayConstantFromByteCode(data);
Object* object = isolate->heap()->roots_array_start()[root_id];
ASSERT(!isolate->heap()->InNewSpace(object));
*current++ = object;
break;
}
case kRepeat: {
int repeats = source_->GetInt();
Object* object = current[-1];
ASSERT(!isolate->heap()->InNewSpace(object));
for (int i = 0; i < repeats; i++) current[i] = object;
current += repeats;
break;
}
STATIC_ASSERT(kRootArrayNumberOfConstantEncodings ==
Heap::kOldSpaceRoots);
STATIC_ASSERT(kMaxRepeats == 12);
FOUR_CASES(kConstantRepeat)
FOUR_CASES(kConstantRepeat + 4)
FOUR_CASES(kConstantRepeat + 8) {
int repeats = RepeatsForCode(data);
Object* object = current[-1];
ASSERT(!isolate->heap()->InNewSpace(object));
for (int i = 0; i < repeats; i++) current[i] = object;
current += repeats;
break;
}
// Deserialize a new object and write a pointer to it to the current
// object.
ONE_PER_SPACE(kNewObject, kPlain, kStartOfObject)
// Support for direct instruction pointers in functions. It's an inner
// pointer because it points at the entry point, not at the start of the
// code object.
ONE_PER_CODE_SPACE(kNewObject, kPlain, kInnerPointer)
// Deserialize a new code object and write a pointer to its first
// instruction to the current code object.
ONE_PER_SPACE(kNewObject, kFromCode, kInnerPointer)
// 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)
#if V8_TARGET_ARCH_MIPS
// Deserialize a new object from pointer found in code and write
// a pointer to it to the current object. Required only for MIPS, and
// omitted on the other architectures because it is fully unrolled and
// would cause bloat.
ONE_PER_SPACE(kNewObject, kFromCode, kStartOfObject)
// Find a recently deserialized code object using its offset from the
// current allocation point and write a pointer to it to the current
// object. Required only for MIPS.
ALL_SPACES(kBackref, kFromCode, kStartOfObject)
// Find an already deserialized code object using its offset from
// the start and write a pointer to it to the current object.
// Required only for MIPS.
ALL_SPACES(kFromStart, kFromCode, kStartOfObject)
#endif
// 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 or the instruction pointer in a function
// object.
ALL_SPACES(kBackref, kFromCode, kInnerPointer)
ALL_SPACES(kBackref, kPlain, kInnerPointer)
// 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)
ALL_SPACES(kFromStart, kPlain, kInnerPointer)
// 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, kInnerPointer)
// 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 code entry in the partial snapshots cache and
// write a pointer to it to the current object.
CASE_STATEMENT(kPartialSnapshotCache, kPlain, kInnerPointer, 0)
CASE_BODY(kPartialSnapshotCache,
kPlain,
kInnerPointer,
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 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 kSkip: {
current++;
break;
}
case kNativesStringResource: {
int index = source_->Get();
Vector<const char> source_vector = Natives::GetRawScriptSource(index);
NativesExternalStringResource* resource =
new NativesExternalStringResource(isolate->bootstrapper(),
source_vector.start(),
source_vector.length());
*current++ = reinterpret_cast<Object*>(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<uintptr_t>(1u) << shift) {
Put((static_cast<int>((integer >> shift)) & 0x7f) | 0x80, "IntPart");
}
}
PutSection(static_cast<int>(integer & 0x7f), "IntLastPart");
}
Serializer::Serializer(SnapshotByteSink* sink)
: sink_(sink),
current_root_index_(0),
external_reference_encoder_(new ExternalReferenceEncoder),
large_object_total_(0),
root_index_wave_front_(0) {
isolate_ = Isolate::Current();
// The serializer is meant to be used only to generate initial heap images
// from a context in which there is only one isolate.
ASSERT(isolate_->IsDefaultIsolate());
for (int i = 0; i <= LAST_SPACE; i++) {
fullness_[i] = 0;
}
}
Serializer::~Serializer() {
delete external_reference_encoder_;
}
void StartupSerializer::SerializeStrongReferences() {
Isolate* isolate = Isolate::Current();
// No active threads.
CHECK_EQ(NULL, Isolate::Current()->thread_manager()->FirstThreadStateInUse());
// No active or weak handles.
CHECK(isolate->handle_scope_implementer()->blocks()->is_empty());
CHECK_EQ(0, isolate->global_handles()->NumberOfWeakHandles());
// We don't support serializing installed extensions.
CHECK(!isolate->has_installed_extensions());
HEAP->IterateStrongRoots(this, VISIT_ONLY_STRONG);
}
void PartialSerializer::Serialize(Object** object) {
this->VisitPointer(object);
}
void Serializer::VisitPointers(Object** start, Object** end) {
Isolate* isolate = Isolate::Current();
for (Object** current = start; current < end; current++) {
if (start == isolate->heap()->roots_array_start()) {
root_index_wave_front_ =
Max(root_index_wave_front_, static_cast<intptr_t>(current - start));
}
if (reinterpret_cast<Address>(current) ==
isolate->heap()->store_buffer()->TopAddress()) {
sink_->Put(kSkip, "Skip");
} else if ((*current)->IsSmi()) {
sink_->Put(kRawData, "RawData");
sink_->PutInt(kPointerSize, "length");
for (int i = 0; i < kPointerSize; i++) {
sink_->Put(reinterpret_cast<byte*>(current)[i], "Byte");
}
} else {
SerializeObject(*current, kPlain, kStartOfObject);
}
}
}
// 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 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) {
if (Serializer::enabled()) return;
Isolate* isolate = Isolate::Current();
for (int i = 0; ; i++) {
if (isolate->serialize_partial_snapshot_cache_length() <= i) {
// Extend the array ready to get a value from the visitor when
// deserializing.
isolate->PushToPartialSnapshotCache(Smi::FromInt(0));
}
Object** cache = isolate->serialize_partial_snapshot_cache();
visitor->VisitPointers(&cache[i], &cache[i + 1]);
// Sentinel is the undefined object, which is a root so it will not normally
// be found in the cache.
if (cache[i] == isolate->heap()->undefined_value()) {
break;
}
}
}
int PartialSerializer::PartialSnapshotCacheIndex(HeapObject* heap_object) {
Isolate* isolate = Isolate::Current();
for (int i = 0;
i < isolate->serialize_partial_snapshot_cache_length();
i++) {
Object* entry = isolate->serialize_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 = isolate->serialize_partial_snapshot_cache_length();
isolate->PushToPartialSnapshotCache(heap_object);
startup_serializer_->VisitPointer(reinterpret_cast<Object**>(&heap_object));
// We don't recurse from the startup snapshot generator into the partial
// snapshot generator.
ASSERT(length == isolate->serialize_partial_snapshot_cache_length() - 1);
return length;
}
int Serializer::RootIndex(HeapObject* heap_object, HowToCode from) {
Heap* heap = HEAP;
if (heap->InNewSpace(heap_object)) return kInvalidRootIndex;
for (int i = 0; i < root_index_wave_front_; i++) {
Object* root = heap->roots_array_start()[i];
if (!root->IsSmi() && root == heap_object) {
#if V8_TARGET_ARCH_MIPS
if (from == kFromCode) {
// In order to avoid code bloat in the deserializer we don't have
// support for the encoding that specifies a particular root should
// be written into the lui/ori instructions on MIPS. Therefore we
// should not generate such serialization data for MIPS.
return kInvalidRootIndex;
}
#endif
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) {
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);
int root_index;
if ((root_index = RootIndex(heap_object, how_to_code)) != kInvalidRootIndex) {
PutRoot(root_index, heap_object, how_to_code, where_to_point);
return;
}
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() {
// This phase comes right after the partial serialization (of the snapshot).
// After we have done the partial serialization the partial snapshot cache
// will contain some references needed to decode the partial snapshot. We
// add one entry with 'undefined' which is the sentinel that the deserializer
// uses to know it is done deserializing the array.
Isolate* isolate = Isolate::Current();
Object* undefined = isolate->heap()->undefined_value();
VisitPointer(&undefined);
HEAP->IterateWeakRoots(this, VISIT_ALL);
}
void Serializer::PutRoot(int root_index,
HeapObject* object,
SerializerDeserializer::HowToCode how_to_code,
SerializerDeserializer::WhereToPoint where_to_point) {
if (how_to_code == kPlain &&
where_to_point == kStartOfObject &&
root_index < kRootArrayNumberOfConstantEncodings &&
!HEAP->InNewSpace(object)) {
if (root_index < kRootArrayNumberOfLowConstantEncodings) {
sink_->Put(kRootArrayLowConstants + root_index, "RootLoConstant");
} else {
sink_->Put(kRootArrayHighConstants + root_index -
kRootArrayNumberOfLowConstantEncodings,
"RootHiConstant");
}
} else {
sink_->Put(kRootArray + how_to_code + where_to_point, "RootSerialization");
sink_->PutInt(root_index, "root_index");
}
}
void PartialSerializer::SerializeObject(
Object* o,
HowToCode how_to_code,
WhereToPoint where_to_point) {
CHECK(o->IsHeapObject());
HeapObject* heap_object = HeapObject::cast(o);
if (heap_object->IsMap()) {
// The code-caches link to context-specific code objects, which
// the startup and context serializes cannot currently handle.
ASSERT(Map::cast(heap_object)->code_cache() ==
heap_object->GetHeap()->raw_unchecked_empty_fixed_array());
}
int root_index;
if ((root_index = RootIndex(heap_object, how_to_code)) != kInvalidRootIndex) {
PutRoot(root_index, heap_object, how_to_code, where_to_point);
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(i::Isolate::Current(),
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<Address>(current));
while (current < end && !(*current)->IsSmi()) {
HeapObject* current_contents = HeapObject::cast(*current);
int root_index = serializer_->RootIndex(current_contents, kPlain);
// Repeats are not subject to the write barrier so there are only some
// objects that can be used in a repeat encoding. These are the early
// ones in the root array that are never in new space.
if (current != start &&
root_index != kInvalidRootIndex &&
root_index < kRootArrayNumberOfConstantEncodings &&
current_contents == current[-1]) {
ASSERT(!HEAP->InNewSpace(current_contents));
int repeat_count = 1;
while (current < end - 1 && current[repeat_count] == current_contents) {
repeat_count++;
}
current += repeat_count;
bytes_processed_so_far_ += repeat_count * kPointerSize;
if (repeat_count > kMaxRepeats) {
sink_->Put(kRepeat, "SerializeRepeats");
sink_->PutInt(repeat_count, "SerializeRepeats");
} else {
sink_->Put(CodeForRepeats(repeat_count), "SerializeRepeats");
}
} else {
serializer_->SerializeObject(current_contents, kPlain, kStartOfObject);
bytes_processed_so_far_ += kPointerSize;
current++;
}
}
}
}
void Serializer::ObjectSerializer::VisitEmbeddedPointer(RelocInfo* rinfo) {
Object** current = rinfo->target_object_address();
OutputRawData(rinfo->target_address_address());
HowToCode representation = rinfo->IsCodedSpecially() ? kFromCode : kPlain;
serializer_->SerializeObject(*current, representation, kStartOfObject);
bytes_processed_so_far_ += rinfo->target_address_size();
}
void Serializer::ObjectSerializer::VisitExternalReferences(Address* start,
Address* end) {
Address references_start = reinterpret_cast<Address>(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<int>((end - start) * kPointerSize);
}
void Serializer::ObjectSerializer::VisitExternalReference(RelocInfo* rinfo) {
Address references_start = rinfo->target_address_address();
OutputRawData(references_start);
Address* current = rinfo->target_reference_address();
int representation = rinfo->IsCodedSpecially() ?
kFromCode + kStartOfObject : kPlain + kStartOfObject;
sink_->Put(kExternalReference + representation, "ExternalRef");
int reference_id = serializer_->EncodeExternalReference(*current);
sink_->PutInt(reference_id, "reference id");
bytes_processed_so_far_ += rinfo->target_address_size();
}
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, kInnerPointer);
bytes_processed_so_far_ += rinfo->target_address_size();
}
void Serializer::ObjectSerializer::VisitCodeEntry(Address entry_address) {
Code* target = Code::cast(Code::GetObjectFromEntryAddress(entry_address));
OutputRawData(entry_address);
serializer_->SerializeObject(target, kPlain, kInnerPointer);
bytes_processed_so_far_ += kPointerSize;
}
void Serializer::ObjectSerializer::VisitGlobalPropertyCell(RelocInfo* rinfo) {
ASSERT(rinfo->rmode() == RelocInfo::GLOBAL_PROPERTY_CELL);
JSGlobalPropertyCell* cell =
JSGlobalPropertyCell::cast(rinfo->target_cell());
OutputRawData(rinfo->pc());
serializer_->SerializeObject(cell, kPlain, kInnerPointer);
}
void Serializer::ObjectSerializer::VisitExternalAsciiString(
v8::String::ExternalAsciiStringResource** resource_pointer) {
Address references_start = reinterpret_cast<Address>(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;
const 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<int>(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<AllocationSpace>(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<AllocationSpace>(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 <= SpaceAreaSize(space));
if (used_in_this_page + size > SpaceAreaSize(space)) {
*new_page = true;
fullness_[space] = RoundUp(fullness_[space], Page::kPageSize);
}
}
int allocation_address = fullness_[space];
fullness_[space] = allocation_address + size;
return allocation_address;
}
int Serializer::SpaceAreaSize(int space) {
if (space == CODE_SPACE) {
return isolate_->memory_allocator()->CodePageAreaSize();
} else {
return Page::kPageSize - Page::kObjectStartOffset;
}
}
} } // namespace v8::internal
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