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44b7c59eb5
v8/src/serialize.cc
sgjesse@chromium.org 44b7c59eb5 Extend the maximum size map space 
On 32-bit the maps are now aligned on a 32-byte boundary in order to encode more maps during compacting GC. The actual size of a map on 32-bit is 28 bytes making this change waste 4 bytes per map.

On 64-bit the encoding for compacting GC is now using more than 32-bits and the maps here are still pointer size aligned. The actual size of a map on 64-bit is 48 bytes and this change does not intruduce any waste.

My choice of 16 bits for kMapPageIndexBits for 64-bit should give the same maximum number of pages (8K) for map space. As maps on 64-bit are larger than on 32-bit the total number of maps on 64-bit will be smaller than on 32-bit. We could consider raising this to 17 or 18.

I moved the kPageSizeBits to globals.h as the calculation of the encoding really depended on this.

There are still an #ifdef/#endif in objects.h and this constant could be moved to globaks.h as well, but I kept it together with the related constants.

All the tests run in debug mode with additional options --gc-global --always-compact as well (except for a few tests on which also fails before this change when run with --gc-global --always-compact).

BUG=http://code.google.com/p/v8/issues/detail?id=524
BUG=http://crbug.com/29428
TEST=test/mjsunit/regress/regress-524.js

Review URL: http://codereview.chromium.org/504026

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3481 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2009-12-17 08:53:18 +00:00

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// 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 {
// Mapping objects to their location after deserialization.
// This is used during building, but not at runtime by V8.
class SerializationAddressMapper {
public:
static bool IsMapped(HeapObject* obj) {
EnsureMapExists();
return serialization_map_->Lookup(Key(obj), Hash(obj), false) != NULL;
}
static int MappedTo(HeapObject* obj) {
ASSERT(IsMapped(obj));
return static_cast<int>(reinterpret_cast<intptr_t>(
serialization_map_->Lookup(Key(obj), Hash(obj), false)->value));
}
static void Map(HeapObject* obj, int to) {
EnsureMapExists();
ASSERT(!IsMapped(obj));
HashMap::Entry* entry =
serialization_map_->Lookup(Key(obj), Hash(obj), true);
entry->value = Value(to);
}
static void Zap() {
if (serialization_map_ != NULL) {
delete serialization_map_;
}
serialization_map_ = NULL;
}
private:
static bool SerializationMatchFun(void* key1, void* key2) {
return key1 == key2;
}
static uint32_t Hash(HeapObject* obj) {
return static_cast<int32_t>(reinterpret_cast<intptr_t>(obj->address()));
}
static void* Key(HeapObject* obj) {
return reinterpret_cast<void*>(obj->address());
}
static void* Value(int v) {
return reinterpret_cast<void*>(v);
}
static void EnsureMapExists() {
if (serialization_map_ == NULL) {
serialization_map_ = new HashMap(&SerializationMatchFun);
}
}
static HashMap* serialization_map_;
};
HashMap* SerializationAddressMapper::serialization_map_ = NULL;
// -----------------------------------------------------------------------------
// 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 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<ExternalReferenceEntry> 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<Builtins::CFunctionId>(id));
address = ref.address();
break;
}
case BUILTIN: {
ExternalReference ref(static_cast<Builtins::Name>(id));
address = ref.address();
break;
}
case RUNTIME_FUNCTION: {
ExternalReference ref(static_cast<Runtime::FunctionId>(id));
address = ref.address();
break;
}
case IC_UTILITY: {
ExternalReference ref(IC_Utility(static_cast<IC::UtilityId>(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) \
{ C_BUILTIN, \
Builtins::c_##name, \
"Builtins::" #name },
BUILTIN_LIST_C(DEF_ENTRY_C)
#undef DEF_ENTRY_C
#define DEF_ENTRY_C(name) \
{ BUILTIN, \
Builtins::name, \
"Builtins::" #name },
#define DEF_ENTRY_A(name, kind, state) DEF_ENTRY_C(name)
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_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<char> name = Vector<char>::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<Address>(
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<char> name =
Vector<char>::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::random_positive_smi_function().address(),
RUNTIME_ENTRY,
2,
"V8::RandomPositiveSmi");
// Miscellaneous
Add(ExternalReference::builtin_passed_function().address(),
UNCLASSIFIED,
1,
"Builtins::builtin_passed_function");
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()");
Add(ExternalReference::address_of_regexp_stack_limit().address(),
UNCLASSIFIED,
6,
"RegExpStack::limit_address()");
Add(ExternalReference::new_space_start().address(),
UNCLASSIFIED,
7,
"Heap::NewSpaceStart()");
Add(ExternalReference::heap_always_allocate_scope_depth().address(),
UNCLASSIFIED,
8,
"Heap::always_allocate_scope_depth()");
Add(ExternalReference::new_space_allocation_limit_address().address(),
UNCLASSIFIED,
9,
"Heap::NewSpaceAllocationLimitAddress()");
Add(ExternalReference::new_space_allocation_top_address().address(),
UNCLASSIFIED,
10,
"Heap::NewSpaceAllocationTopAddress()");
#ifdef ENABLE_DEBUGGER_SUPPORT
Add(ExternalReference::debug_break().address(),
UNCLASSIFIED,
11,
"Debug::Break()");
Add(ExternalReference::debug_step_in_fp_address().address(),
UNCLASSIFIED,
12,
"Debug::step_in_fp_addr()");
#endif
Add(ExternalReference::double_fp_operation(Token::ADD).address(),
UNCLASSIFIED,
13,
"add_two_doubles");
Add(ExternalReference::double_fp_operation(Token::SUB).address(),
UNCLASSIFIED,
14,
"sub_two_doubles");
Add(ExternalReference::double_fp_operation(Token::MUL).address(),
UNCLASSIFIED,
15,
"mul_two_doubles");
Add(ExternalReference::double_fp_operation(Token::DIV).address(),
UNCLASSIFIED,
16,
"div_two_doubles");
Add(ExternalReference::double_fp_operation(Token::MOD).address(),
UNCLASSIFIED,
17,
"mod_two_doubles");
Add(ExternalReference::compare_doubles().address(),
UNCLASSIFIED,
18,
"compare_doubles");
#ifdef V8_NATIVE_REGEXP
Add(ExternalReference::re_case_insensitive_compare_uc16().address(),
UNCLASSIFIED,
19,
"NativeRegExpMacroAssembler::CaseInsensitiveCompareUC16()");
Add(ExternalReference::re_check_stack_guard_state().address(),
UNCLASSIFIED,
20,
"RegExpMacroAssembler*::CheckStackGuardState()");
Add(ExternalReference::re_grow_stack().address(),
UNCLASSIFIED,
21,
"NativeRegExpMacroAssembler::GrowStack()");
#endif
// Keyed lookup cache.
Add(ExternalReference::keyed_lookup_cache_keys().address(),
UNCLASSIFIED,
22,
"KeyedLookupCache::keys()");
Add(ExternalReference::keyed_lookup_cache_field_offsets().address(),
UNCLASSIFIED,
23,
"KeyedLookupCache::field_offsets()");
}
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<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)) {
ExternalReferenceTable* external_references =
ExternalReferenceTable::instance();
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)
: 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);
Object* new_allocation;
if (space_index == NEW_SPACE) {
new_allocation = reinterpret_cast<NewSpace*>(space)->AllocateRaw(size);
} else {
new_allocation = reinterpret_cast<PagedSpace*>(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<LargeObjectSpace*>(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();
high_water_[LO_SPACE] = address + size;
}
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());
ASSERT_EQ(NULL, external_reference_decoder_);
external_reference_decoder_ = new ExternalReferenceDecoder();
Heap::IterateRoots(this, VISIT_ONLY_STRONG);
ASSERT(source_->AtEOF());
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<Object**>(address);
Object** limit = current + (size >> kPointerSizeLog2);
ReadChunk(current, limit, space_number, address);
}
#define ONE_CASE_PER_SPACE(base_tag) \
case (base_tag) + NEW_SPACE: /* NOLINT */ \
case (base_tag) + OLD_POINTER_SPACE: /* NOLINT */ \
case (base_tag) + OLD_DATA_SPACE: /* NOLINT */ \
case (base_tag) + CODE_SPACE: /* NOLINT */ \
case (base_tag) + MAP_SPACE: /* NOLINT */ \
case (base_tag) + CELL_SPACE: /* NOLINT */ \
case (base_tag) + kLargeData: /* NOLINT */ \
case (base_tag) + kLargeCode: /* NOLINT */ \
case (base_tag) + kLargeFixedArray: /* NOLINT */
void Deserializer::ReadChunk(Object** current,
Object** limit,
int space,
Address address) {
while (current < limit) {
int data = source_->Get();
switch (data) {
#define RAW_CASE(index, size) \
case RAW_DATA_SERIALIZATION + 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
case RAW_DATA_SERIALIZATION: {
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;
}
case OBJECT_SERIALIZATION + NEW_SPACE: {
ReadObject(NEW_SPACE, Heap::new_space(), current);
if (space != NEW_SPACE) {
Heap::RecordWrite(address, static_cast<int>(
reinterpret_cast<Address>(current) - address));
}
current++;
break;
}
case OBJECT_SERIALIZATION + OLD_DATA_SPACE:
ReadObject(OLD_DATA_SPACE, Heap::old_data_space(), current++);
break;
case OBJECT_SERIALIZATION + OLD_POINTER_SPACE:
ReadObject(OLD_POINTER_SPACE, Heap::old_pointer_space(), current++);
break;
case OBJECT_SERIALIZATION + MAP_SPACE:
ReadObject(MAP_SPACE, Heap::map_space(), current++);
break;
case OBJECT_SERIALIZATION + CODE_SPACE:
ReadObject(CODE_SPACE, Heap::code_space(), current++);
LOG(LogCodeObject(current[-1]));
break;
case OBJECT_SERIALIZATION + CELL_SPACE:
ReadObject(CELL_SPACE, Heap::cell_space(), current++);
break;
case OBJECT_SERIALIZATION + kLargeData:
ReadObject(kLargeData, Heap::lo_space(), current++);
break;
case OBJECT_SERIALIZATION + kLargeCode:
ReadObject(kLargeCode, Heap::lo_space(), current++);
LOG(LogCodeObject(current[-1]));
break;
case OBJECT_SERIALIZATION + kLargeFixedArray:
ReadObject(kLargeFixedArray, Heap::lo_space(), current++);
break;
case CODE_OBJECT_SERIALIZATION + kLargeCode: {
Object* new_code_object = NULL;
ReadObject(kLargeCode, Heap::lo_space(), &new_code_object);
Code* code_object = reinterpret_cast<Code*>(new_code_object);
LOG(LogCodeObject(code_object));
// Setting a branch/call to another code object from code.
Address location_of_branch_data = reinterpret_cast<Address>(current);
Assembler::set_target_at(location_of_branch_data,
code_object->instruction_start());
location_of_branch_data += Assembler::kCallTargetSize;
current = reinterpret_cast<Object**>(location_of_branch_data);
break;
}
case CODE_OBJECT_SERIALIZATION + CODE_SPACE: {
Object* new_code_object = NULL;
ReadObject(CODE_SPACE, Heap::code_space(), &new_code_object);
Code* code_object = reinterpret_cast<Code*>(new_code_object);
LOG(LogCodeObject(code_object));
// Setting a branch/call to another code object from code.
Address location_of_branch_data = reinterpret_cast<Address>(current);
Assembler::set_target_at(location_of_branch_data,
code_object->instruction_start());
location_of_branch_data += Assembler::kCallTargetSize;
current = reinterpret_cast<Object**>(location_of_branch_data);
break;
}
ONE_CASE_PER_SPACE(BACKREF_SERIALIZATION) {
// Write a backreference to an object we unpacked earlier.
int backref_space = (data & kSpaceMask);
if (backref_space == NEW_SPACE && space != NEW_SPACE) {
Heap::RecordWrite(address, static_cast<int>(
reinterpret_cast<Address>(current) - address));
}
*current++ = GetAddressFromEnd(backref_space);
break;
}
ONE_CASE_PER_SPACE(REFERENCE_SERIALIZATION) {
// Write a reference to an object we unpacked earlier.
int reference_space = (data & kSpaceMask);
if (reference_space == NEW_SPACE && space != NEW_SPACE) {
Heap::RecordWrite(address, static_cast<int>(
reinterpret_cast<Address>(current) - address));
}
*current++ = GetAddressFromStart(reference_space);
break;
}
#define COMMON_REFS_CASE(index, reference_space, address) \
case REFERENCE_SERIALIZATION + index: { \
ASSERT(SpaceIsPaged(reference_space)); \
Address object_address = \
pages_[reference_space][0] + (address << kObjectAlignmentBits); \
*current++ = HeapObject::FromAddress(object_address); \
break; \
}
COMMON_REFERENCE_PATTERNS(COMMON_REFS_CASE)
#undef COMMON_REFS_CASE
ONE_CASE_PER_SPACE(CODE_BACKREF_SERIALIZATION) {
int backref_space = (data & kSpaceMask);
// Can't use Code::cast because heap is not set up yet and assertions
// will fail.
Code* code_object =
reinterpret_cast<Code*>(GetAddressFromEnd(backref_space));
// Setting a branch/call to previously decoded code object from code.
Address location_of_branch_data = reinterpret_cast<Address>(current);
Assembler::set_target_at(location_of_branch_data,
code_object->instruction_start());
location_of_branch_data += Assembler::kCallTargetSize;
current = reinterpret_cast<Object**>(location_of_branch_data);
break;
}
ONE_CASE_PER_SPACE(CODE_REFERENCE_SERIALIZATION) {
int backref_space = (data & kSpaceMask);
// Can't use Code::cast because heap is not set up yet and assertions
// will fail.
Code* code_object =
reinterpret_cast<Code*>(GetAddressFromStart(backref_space));
// Setting a branch/call to previously decoded code object from code.
Address location_of_branch_data = reinterpret_cast<Address>(current);
Assembler::set_target_at(location_of_branch_data,
code_object->instruction_start());
location_of_branch_data += Assembler::kCallTargetSize;
current = reinterpret_cast<Object**>(location_of_branch_data);
break;
}
case EXTERNAL_REFERENCE_SERIALIZATION: {
int reference_id = source_->GetInt();
Address address = external_reference_decoder_->Decode(reference_id);
*current++ = reinterpret_cast<Object*>(address);
break;
}
case EXTERNAL_BRANCH_TARGET_SERIALIZATION: {
int reference_id = source_->GetInt();
Address address = external_reference_decoder_->Decode(reference_id);
Address location_of_branch_data = reinterpret_cast<Address>(current);
Assembler::set_external_target_at(location_of_branch_data, address);
location_of_branch_data += Assembler::kExternalTargetSize;
current = reinterpret_cast<Object**>(location_of_branch_data);
break;
}
case START_NEW_PAGE_SERIALIZATION: {
int space = source_->Get();
pages_[space].Add(last_object_address_);
break;
}
case NATIVES_STRING_RESOURCE: {
int index = source_->Get();
Vector<const char> source_vector = Natives::GetScriptSource(index);
NativesExternalStringResource* resource =
new NativesExternalStringResource(source_vector.start());
*current++ = reinterpret_cast<Object*>(resource);
break;
}
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(((integer >> shift) & 0x7f) | 0x80, "IntPart");
}
}
PutSection(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(SYNCHRONIZE, 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(SYNCHRONIZE, 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_(NULL) {
for (int i = 0; i <= LAST_SPACE; i++) {
fullness_[i] = 0;
}
}
void Serializer::Serialize() {
// No active threads.
CHECK_EQ(NULL, ThreadState::FirstInUse());
// No active or weak handles.
CHECK(HandleScopeImplementer::instance()->blocks()->is_empty());
CHECK_EQ(0, GlobalHandles::NumberOfWeakHandles());
CHECK_EQ(NULL, external_reference_encoder_);
// We don't support serializing installed extensions.
for (RegisteredExtension* ext = RegisteredExtension::first_extension();
ext != NULL;
ext = ext->next()) {
CHECK_NE(v8::INSTALLED, ext->state());
}
external_reference_encoder_ = new ExternalReferenceEncoder();
Heap::IterateRoots(this, VISIT_ONLY_STRONG);
delete external_reference_encoder_;
external_reference_encoder_ = NULL;
SerializationAddressMapper::Zap();
}
void Serializer::VisitPointers(Object** start, Object** end) {
for (Object** current = start; current < end; current++) {
if ((*current)->IsSmi()) {
sink_->Put(RAW_DATA_SERIALIZATION, "RawData");
sink_->PutInt(kPointerSize, "length");
for (int i = 0; i < kPointerSize; i++) {
sink_->Put(reinterpret_cast<byte*>(current)[i], "Byte");
}
} else {
SerializeObject(*current, TAGGED_REPRESENTATION);
}
}
}
void Serializer::SerializeObject(
Object* o,
ReferenceRepresentation reference_representation) {
CHECK(o->IsHeapObject());
HeapObject* heap_object = HeapObject::cast(o);
if (SerializationAddressMapper::IsMapped(heap_object)) {
int space = SpaceOfAlreadySerializedObject(heap_object);
int address = SerializationAddressMapper::MappedTo(heap_object);
int offset = CurrentAllocationAddress(space) - address;
bool from_start = true;
if (SpaceIsPaged(space)) {
if ((CurrentAllocationAddress(space) >> kPageSizeBits) ==
(address >> kPageSizeBits)) {
from_start = false;
address = offset;
}
} else if (space == NEW_SPACE) {
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 (reference_representation == CODE_TARGET_REPRESENTATION) {
if (from_start) {
sink_->Put(CODE_REFERENCE_SERIALIZATION + space, "RefCodeSer");
sink_->PutInt(address, "address");
} else {
sink_->Put(CODE_BACKREF_SERIALIZATION + space, "BackRefCodeSer");
sink_->PutInt(address, "address");
}
} else {
CHECK_EQ(TAGGED_REPRESENTATION, reference_representation);
if (from_start) {
#define COMMON_REFS_CASE(tag, common_space, common_offset) \
if (space == common_space && address == common_offset) { \
sink_->PutSection(tag + REFERENCE_SERIALIZATION, "RefSer"); \
} else /* NOLINT */
COMMON_REFERENCE_PATTERNS(COMMON_REFS_CASE)
#undef COMMON_REFS_CASE
{ /* NOLINT */
sink_->Put(REFERENCE_SERIALIZATION + space, "RefSer");
sink_->PutInt(address, "address");
}
} else {
sink_->Put(BACKREF_SERIALIZATION + space, "BackRefSer");
sink_->PutInt(address, "address");
}
}
} else {
// Object has not yet been serialized. Serialize it here.
ObjectSerializer serializer(this,
heap_object,
sink_,
reference_representation);
serializer.Serialize();
}
}
void Serializer::ObjectSerializer::Serialize() {
int space = Serializer::SpaceOfObject(object_);
int size = object_->Size();
if (reference_representation_ == TAGGED_REPRESENTATION) {
sink_->Put(OBJECT_SERIALIZATION + space, "ObjectSerialization");
} else {
CHECK_EQ(CODE_TARGET_REPRESENTATION, reference_representation_);
sink_->Put(CODE_OBJECT_SERIALIZATION + space, "ObjectSerialization");
}
sink_->PutInt(size >> kObjectAlignmentBits, "Size in words");
// Mark this object as already serialized.
bool start_new_page;
SerializationAddressMapper::Map(
object_,
serializer_->Allocate(space, size, &start_new_page));
if (start_new_page) {
sink_->Put(START_NEW_PAGE_SERIALIZATION, "NewPage");
sink_->PutSection(space, "NewPageSpace");
}
// Serialize the map (first word of the object).
serializer_->SerializeObject(object_->map(), TAGGED_REPRESENTATION);
// 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()) {
serializer_->SerializeObject(*current, TAGGED_REPRESENTATION);
bytes_processed_so_far_ += kPointerSize;
current++;
}
}
}
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(EXTERNAL_REFERENCE_SERIALIZATION, "ExternalReference");
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::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);
sink_->Put(EXTERNAL_BRANCH_TARGET_SERIALIZATION, "ExternalReference");
sink_->PutInt(encoding, "reference id");
bytes_processed_so_far_ += Assembler::kExternalTargetSize;
}
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, CODE_TARGET_REPRESENTATION);
bytes_processed_so_far_ += Assembler::kCallTargetSize;
}
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;
Resource* resource = string->resource();
if (resource == *resource_pointer) {
sink_->Put(NATIVES_STRING_RESOURCE, "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(RAW_DATA_SERIALIZATION + index, "RawDataFixed"); \
} else /* NOLINT */
COMMON_RAW_LENGTHS(RAW_CASE)
#undef RAW_CASE
{ /* NOLINT */
sink_->Put(RAW_DATA_SERIALIZATION, "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;
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
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