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0672317bec10248262da17070627fa8f01736788
sdk/runtime/vm/snapshot.cc
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regis@google.com feb7329e2f Resubmitting r18013. 
Review URL: https://codereview.chromium.org//12084120

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@18018 260f80e4-7a28-3924-810f-c04153c831b5
2013-02-02 00:18:37 +00:00

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// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/snapshot.h"
#include "platform/assert.h"
#include "vm/bigint_operations.h"
#include "vm/bootstrap.h"
#include "vm/class_finalizer.h"
#include "vm/exceptions.h"
#include "vm/heap.h"
#include "vm/longjump.h"
#include "vm/object.h"
#include "vm/object_store.h"
#include "vm/snapshot_ids.h"
#include "vm/symbols.h"
namespace dart {
static const int kNumInitialReferencesInFullSnapshot = 160 * KB;
static const int kNumInitialReferences = 4;
static bool IsSingletonClassId(intptr_t class_id) {
// Check if this is a singleton object class which is shared by all isolates.
return ((class_id >= kClassCid && class_id <= kUnwindErrorCid) ||
(class_id >= kNullCid && class_id <= kVoidCid));
}
static bool IsObjectStoreClassId(intptr_t class_id) {
// Check if this is a class which is stored in the object store.
return (class_id == kObjectCid ||
(class_id >= kInstanceCid && class_id <= kWeakPropertyCid) ||
RawObject::IsStringClassId(class_id));
}
static bool IsObjectStoreTypeId(intptr_t index) {
// Check if this is a type which is stored in the object store.
return (index >= kObjectType && index <= kArrayType);
}
static intptr_t ClassIdFromObjectId(intptr_t object_id) {
ASSERT(object_id > kClassIdsOffset);
intptr_t class_id = (object_id - kClassIdsOffset);
return class_id;
}
static intptr_t ObjectIdFromClassId(intptr_t class_id) {
ASSERT((class_id > kIllegalCid) && (class_id < kNumPredefinedCids));
return (class_id + kClassIdsOffset);
}
static RawType* GetType(ObjectStore* object_store, int index) {
switch (index) {
case kObjectType: return object_store->object_type();
case kNullType: return object_store->null_type();
case kDynamicType: return object_store->dynamic_type();
case kVoidType: return object_store->void_type();
case kFunctionType: return object_store->function_type();
case kNumberType: return object_store->number_type();
case kSmiType: return object_store->smi_type();
case kMintType: return object_store->mint_type();
case kDoubleType: return object_store->double_type();
case kIntType: return object_store->int_type();
case kBoolType: return object_store->bool_type();
case kStringType: return object_store->string_type();
case kArrayType: return object_store->array_type();
default: break;
}
UNREACHABLE();
return Type::null();
}
static int GetTypeIndex(ObjectStore* object_store, const RawType* raw_type) {
ASSERT(raw_type->IsHeapObject());
if (raw_type == object_store->object_type()) {
return kObjectType;
} else if (raw_type == object_store->null_type()) {
return kNullType;
} else if (raw_type == object_store->dynamic_type()) {
return kDynamicType;
} else if (raw_type == object_store->void_type()) {
return kVoidType;
} else if (raw_type == object_store->function_type()) {
return kFunctionType;
} else if (raw_type == object_store->number_type()) {
return kNumberType;
} else if (raw_type == object_store->smi_type()) {
return kSmiType;
} else if (raw_type == object_store->mint_type()) {
return kMintType;
} else if (raw_type == object_store->double_type()) {
return kDoubleType;
} else if (raw_type == object_store->int_type()) {
return kIntType;
} else if (raw_type == object_store->bool_type()) {
return kBoolType;
} else if (raw_type == object_store->string_type()) {
return kStringType;
} else if (raw_type == object_store->array_type()) {
return kArrayType;
}
return kInvalidIndex;
}
// TODO(5411462): Temporary setup of snapshot for testing purposes,
// the actual creation of a snapshot maybe done differently.
const Snapshot* Snapshot::SetupFromBuffer(const void* raw_memory) {
ASSERT(raw_memory != NULL);
ASSERT(kHeaderSize == sizeof(Snapshot));
ASSERT(kLengthIndex == length_offset());
ASSERT((kSnapshotFlagIndex * sizeof(int32_t)) == kind_offset());
ASSERT((kHeapObjectTag & kInlined));
// No object can have kFreeBit and kMarkBit set simultaneously. If kFreeBit
// is set then the rest of tags is a pointer to the next FreeListElement which
// is kObjectAlignment aligned and has at least 2 lower bits set to zero.
ASSERT(kObjectId ==
((1 << RawObject::kFreeBit) | (1 << RawObject::kMarkBit)));
ASSERT((kObjectAlignmentMask & kObjectId) == kObjectId);
const Snapshot* snapshot = reinterpret_cast<const Snapshot*>(raw_memory);
return snapshot;
}
RawSmi* BaseReader::ReadAsSmi() {
intptr_t value = ReadIntptrValue();
ASSERT((value & kSmiTagMask) == kSmiTag);
return reinterpret_cast<RawSmi*>(value);
}
intptr_t BaseReader::ReadSmiValue() {
return Smi::Value(ReadAsSmi());
}
SnapshotReader::SnapshotReader(const uint8_t* buffer,
intptr_t size,
Snapshot::Kind kind,
Isolate* isolate)
: BaseReader(buffer, size),
kind_(kind),
isolate_(isolate),
cls_(Class::Handle()),
obj_(Object::Handle()),
str_(String::Handle()),
library_(Library::Handle()),
type_(AbstractType::Handle()),
type_arguments_(AbstractTypeArguments::Handle()),
tokens_(Array::Handle()),
stream_(TokenStream::Handle()),
data_(ExternalUint8Array::Handle()),
error_(UnhandledException::Handle()),
backward_references_((kind == Snapshot::kFull) ?
kNumInitialReferencesInFullSnapshot :
kNumInitialReferences) {
}
RawObject* SnapshotReader::ReadObject() {
// Setup for long jump in case there is an exception while reading.
LongJump* base = isolate()->long_jump_base();
LongJump jump;
isolate()->set_long_jump_base(&jump);
const Instance& null_object = Instance::Handle();
*ErrorHandle() = UnhandledException::New(null_object, null_object);
if (setjmp(*jump.Set()) == 0) {
Object& obj = Object::Handle(ReadObjectImpl());
for (intptr_t i = 0; i < backward_references_.length(); i++) {
if (!backward_references_[i]->is_deserialized()) {
ReadObjectImpl();
backward_references_[i]->set_state(kIsDeserialized);
}
}
isolate()->set_long_jump_base(base);
return obj.raw();
} else {
// An error occurred while reading, return the error object.
const Error& err = Error::Handle(isolate()->object_store()->sticky_error());
isolate()->object_store()->clear_sticky_error();
isolate()->set_long_jump_base(base);
return err.raw();
}
}
RawClass* SnapshotReader::ReadClassId(intptr_t object_id) {
ASSERT(kind_ != Snapshot::kFull);
// Read the class header information and lookup the class.
intptr_t class_header = ReadIntptrValue();
ASSERT((class_header & kSmiTagMask) != kSmiTag);
Class& cls = Class::ZoneHandle(isolate(), Class::null());
cls = LookupInternalClass(class_header);
AddBackRef(object_id, &cls, kIsDeserialized);
if (cls.IsNull()) {
// Read the library/class information and lookup the class.
str_ ^= ReadObjectImpl(class_header);
library_ = Library::LookupLibrary(str_);
ASSERT(!library_.IsNull());
str_ ^= ReadObjectImpl();
cls = library_.LookupClass(str_);
}
ASSERT(!cls.IsNull());
return cls.raw();
}
RawObject* SnapshotReader::ReadObjectImpl() {
int64_t value = Read<int64_t>();
if ((value & kSmiTagMask) == kSmiTag) {
return NewInteger(value);
}
return ReadObjectImpl(value);
}
RawObject* SnapshotReader::ReadObjectImpl(intptr_t header_value) {
ASSERT((header_value <= kIntptrMax) && (header_value >= kIntptrMin));
if (IsVMIsolateObject(header_value)) {
return ReadVMIsolateObject(header_value);
} else {
if (SerializedHeaderTag::decode(header_value) == kObjectId) {
return ReadIndexedObject(SerializedHeaderData::decode(header_value));
}
ASSERT(SerializedHeaderTag::decode(header_value) == kInlined);
return ReadInlinedObject(SerializedHeaderData::decode(header_value));
}
}
RawObject* SnapshotReader::ReadObjectRef() {
int64_t header_value = Read<int64_t>();
if ((header_value & kSmiTagMask) == kSmiTag) {
return NewInteger(header_value);
}
ASSERT((header_value <= kIntptrMax) && (header_value >= kIntptrMin));
if (IsVMIsolateObject(header_value)) {
return ReadVMIsolateObject(header_value);
} else if (SerializedHeaderTag::decode(header_value) == kObjectId) {
return ReadIndexedObject(SerializedHeaderData::decode(header_value));
}
ASSERT(SerializedHeaderTag::decode(header_value) == kInlined);
intptr_t object_id = SerializedHeaderData::decode(header_value);
ASSERT(GetBackRef(object_id) == NULL);
// Read the class header information and lookup the class.
intptr_t class_header = ReadIntptrValue();
// Since we are only reading an object reference, If it is an instance kind
// then we only need to figure out the class of the object and allocate an
// instance of it. The individual fields will be read later.
if (SerializedHeaderData::decode(class_header) == kInstanceObjectId) {
Instance& result = Instance::ZoneHandle(isolate(), Instance::null());
AddBackRef(object_id, &result, kIsNotDeserialized);
cls_ ^= ReadObjectImpl(); // Read class information.
ASSERT(!cls_.IsNull());
intptr_t instance_size = cls_.instance_size();
ASSERT(instance_size > 0);
if (kind_ == Snapshot::kFull) {
result ^= AllocateUninitialized(cls_, instance_size);
} else {
result ^= Object::Allocate(cls_.id(), instance_size, HEAP_SPACE(kind_));
}
return result.raw();
}
ASSERT((class_header & kSmiTagMask) != kSmiTag);
cls_ = LookupInternalClass(class_header);
ASSERT(!cls_.IsNull());
// Similarly Array and ImmutableArray objects are also similarly only
// allocated here, the individual array elements are read later.
intptr_t class_id = cls_.id();
if (class_id == kArrayCid) {
// Read the length and allocate an object based on the len.
intptr_t len = ReadSmiValue();
Array& array = Array::ZoneHandle(
isolate(),
((kind_ == Snapshot::kFull) ?
NewArray(len) : Array::New(len, HEAP_SPACE(kind_))));
AddBackRef(object_id, &array, kIsNotDeserialized);
return array.raw();
}
if (class_id == kImmutableArrayCid) {
// Read the length and allocate an object based on the len.
intptr_t len = ReadSmiValue();
ImmutableArray& array = ImmutableArray::ZoneHandle(
isolate(),
(kind_ == Snapshot::kFull) ?
NewImmutableArray(len) : ImmutableArray::New(len, HEAP_SPACE(kind_)));
AddBackRef(object_id, &array, kIsNotDeserialized);
return array.raw();
}
// For all other internal VM classes we read the object inline.
intptr_t tags = ReadIntptrValue();
switch (class_id) {
#define SNAPSHOT_READ(clazz) \
case clazz::kClassId: { \
obj_ = clazz::ReadFrom(this, object_id, tags, kind_); \
break; \
}
CLASS_LIST_NO_OBJECT(SNAPSHOT_READ)
#undef SNAPSHOT_READ
default: UNREACHABLE(); break;
}
if (kind_ == Snapshot::kFull) {
obj_.SetCreatedFromSnapshot();
}
return obj_.raw();
}
void SnapshotReader::AddBackRef(intptr_t id,
Object* obj,
DeserializeState state) {
intptr_t index = (id - kMaxPredefinedObjectIds);
ASSERT(index == backward_references_.length());
BackRefNode* node = new BackRefNode(obj, state);
ASSERT(node != NULL);
backward_references_.Add(node);
}
Object* SnapshotReader::GetBackRef(intptr_t id) {
ASSERT(id >= kMaxPredefinedObjectIds);
intptr_t index = (id - kMaxPredefinedObjectIds);
if (index < backward_references_.length()) {
return backward_references_[index]->reference();
}
return NULL;
}
void SnapshotReader::ReadFullSnapshot() {
ASSERT(kind_ == Snapshot::kFull);
Isolate* isolate = Isolate::Current();
ASSERT(isolate != NULL);
ObjectStore* object_store = isolate->object_store();
ASSERT(object_store != NULL);
NoGCScope no_gc;
// TODO(asiva): Add a check here to ensure we have the right heap
// size for the full snapshot being read.
// Read in all the objects stored in the object store.
intptr_t num_flds = (object_store->to() - object_store->from());
for (intptr_t i = 0; i <= num_flds; i++) {
*(object_store->from() + i) = ReadObjectImpl();
}
for (intptr_t i = 0; i < backward_references_.length(); i++) {
if (!backward_references_[i]->is_deserialized()) {
ReadObjectImpl();
backward_references_[i]->set_state(kIsDeserialized);
}
}
// Setup native resolver for bootstrap impl.
Bootstrap::SetupNativeResolver();
}
#define ALLOC_NEW_OBJECT_WITH_LEN(type, class_obj, length) \
ASSERT(kind_ == Snapshot::kFull); \
ASSERT(isolate()->no_gc_scope_depth() != 0); \
cls_ = class_obj; \
Raw##type* obj = reinterpret_cast<Raw##type*>( \
AllocateUninitialized(cls_, type::InstanceSize(length))); \
obj->ptr()->length_ = Smi::New(length); \
return obj; \
RawArray* SnapshotReader::NewArray(intptr_t len) {
ALLOC_NEW_OBJECT_WITH_LEN(Array, object_store()->array_class(), len);
}
RawImmutableArray* SnapshotReader::NewImmutableArray(intptr_t len) {
ALLOC_NEW_OBJECT_WITH_LEN(ImmutableArray,
object_store()->immutable_array_class(),
len);
}
RawOneByteString* SnapshotReader::NewOneByteString(intptr_t len) {
ALLOC_NEW_OBJECT_WITH_LEN(OneByteString,
object_store()->one_byte_string_class(),
len);
}
RawTwoByteString* SnapshotReader::NewTwoByteString(intptr_t len) {
ALLOC_NEW_OBJECT_WITH_LEN(TwoByteString,
object_store()->two_byte_string_class(),
len);
}
RawTypeArguments* SnapshotReader::NewTypeArguments(intptr_t len) {
ALLOC_NEW_OBJECT_WITH_LEN(TypeArguments,
Object::type_arguments_class(),
len);
}
RawTokenStream* SnapshotReader::NewTokenStream(intptr_t len) {
ASSERT(kind_ == Snapshot::kFull);
ASSERT(isolate()->no_gc_scope_depth() != 0);
cls_ = Object::token_stream_class();
stream_ = reinterpret_cast<RawTokenStream*>(
AllocateUninitialized(cls_, TokenStream::InstanceSize()));
cls_ = object_store()->external_uint8_array_class();
uint8_t* array = const_cast<uint8_t*>(CurrentBufferAddress());
ASSERT(array != NULL);
Advance(len);
data_ = reinterpret_cast<RawExternalUint8Array*>(
AllocateUninitialized(cls_, ExternalUint8Array::InstanceSize()));
data_.SetData(array);
data_.SetLength(len);
stream_.SetStream(data_);
return stream_.raw();
}
RawContext* SnapshotReader::NewContext(intptr_t num_variables) {
ASSERT(kind_ == Snapshot::kFull);
ASSERT(isolate()->no_gc_scope_depth() != 0);
cls_ = Object::context_class();
RawContext* obj = reinterpret_cast<RawContext*>(
AllocateUninitialized(cls_, Context::InstanceSize(num_variables)));
obj->ptr()->num_variables_ = num_variables;
return obj;
}
RawClass* SnapshotReader::NewClass(intptr_t class_id) {
ASSERT(kind_ == Snapshot::kFull);
ASSERT(isolate()->no_gc_scope_depth() != 0);
if (class_id < kNumPredefinedCids) {
ASSERT((class_id >= kInstanceCid) &&
(class_id <= kExternalTwoByteStringCid));
return isolate()->class_table()->At(class_id);
}
cls_ = Object::class_class();
RawClass* obj = reinterpret_cast<RawClass*>(
AllocateUninitialized(cls_, Class::InstanceSize()));
Instance fake;
obj->ptr()->handle_vtable_ = fake.vtable();
cls_ = obj;
cls_.set_id(kIllegalCid);
isolate()->class_table()->Register(cls_);
return cls_.raw();
}
RawMint* SnapshotReader::NewMint(int64_t value) {
ASSERT(kind_ == Snapshot::kFull);
ASSERT(isolate()->no_gc_scope_depth() != 0);
cls_ = object_store()->mint_class();
RawMint* obj = reinterpret_cast<RawMint*>(
AllocateUninitialized(cls_, Mint::InstanceSize()));
obj->ptr()->value_ = value;
return obj;
}
RawBigint* SnapshotReader::NewBigint(const char* hex_string) {
ASSERT(kind_ == Snapshot::kFull);
ASSERT(isolate()->no_gc_scope_depth() != 0);
cls_ = object_store()->bigint_class();
intptr_t bigint_length = BigintOperations::ComputeChunkLength(hex_string);
RawBigint* obj = reinterpret_cast<RawBigint*>(
AllocateUninitialized(cls_, Bigint::InstanceSize(bigint_length)));
obj->ptr()->allocated_length_ = bigint_length;
obj->ptr()->signed_length_ = bigint_length;
BigintOperations::FromHexCString(hex_string, Bigint::Handle(obj));
return obj;
}
RawDouble* SnapshotReader::NewDouble(double value) {
ASSERT(kind_ == Snapshot::kFull);
ASSERT(isolate()->no_gc_scope_depth() != 0);
cls_ = object_store()->double_class();
RawDouble* obj = reinterpret_cast<RawDouble*>(
AllocateUninitialized(cls_, Double::InstanceSize()));
obj->ptr()->value_ = value;
return obj;
}
#define ALLOC_NEW_OBJECT(type, class_obj) \
ASSERT(kind_ == Snapshot::kFull); \
ASSERT(isolate()->no_gc_scope_depth() != 0); \
cls_ = class_obj; \
return reinterpret_cast<Raw##type*>( \
AllocateUninitialized(cls_, type::InstanceSize())); \
RawUnresolvedClass* SnapshotReader::NewUnresolvedClass() {
ALLOC_NEW_OBJECT(UnresolvedClass, Object::unresolved_class_class());
}
RawType* SnapshotReader::NewType() {
ALLOC_NEW_OBJECT(Type, object_store()->type_class());
}
RawTypeParameter* SnapshotReader::NewTypeParameter() {
ALLOC_NEW_OBJECT(TypeParameter, object_store()->type_parameter_class());
}
RawPatchClass* SnapshotReader::NewPatchClass() {
ALLOC_NEW_OBJECT(PatchClass, Object::patch_class_class());
}
RawClosureData* SnapshotReader::NewClosureData() {
ALLOC_NEW_OBJECT(ClosureData, Object::closure_data_class());
}
RawRedirectionData* SnapshotReader::NewRedirectionData() {
ALLOC_NEW_OBJECT(RedirectionData, Object::redirection_data_class());
}
RawFunction* SnapshotReader::NewFunction() {
ALLOC_NEW_OBJECT(Function, Object::function_class());
}
RawField* SnapshotReader::NewField() {
ALLOC_NEW_OBJECT(Field, Object::field_class());
}
RawLibrary* SnapshotReader::NewLibrary() {
ALLOC_NEW_OBJECT(Library, Object::library_class());
}
RawLibraryPrefix* SnapshotReader::NewLibraryPrefix() {
ALLOC_NEW_OBJECT(LibraryPrefix, Object::library_prefix_class());
}
RawNamespace* SnapshotReader::NewNamespace() {
ALLOC_NEW_OBJECT(Namespace, Object::namespace_class());
}
RawScript* SnapshotReader::NewScript() {
ALLOC_NEW_OBJECT(Script, Object::script_class());
}
RawLiteralToken* SnapshotReader::NewLiteralToken() {
ALLOC_NEW_OBJECT(LiteralToken, Object::literal_token_class());
}
RawGrowableObjectArray* SnapshotReader::NewGrowableObjectArray() {
ALLOC_NEW_OBJECT(GrowableObjectArray,
object_store()->growable_object_array_class());
}
RawApiError* SnapshotReader::NewApiError() {
ALLOC_NEW_OBJECT(ApiError, Object::api_error_class());
}
RawLanguageError* SnapshotReader::NewLanguageError() {
ALLOC_NEW_OBJECT(LanguageError, Object::language_error_class());
}
RawObject* SnapshotReader::NewInteger(int64_t value) {
ASSERT((value & kSmiTagMask) == kSmiTag);
value = value >> kSmiTagShift;
if ((value <= Smi::kMaxValue) && (value >= Smi::kMinValue)) {
return Smi::New(value);
}
if (kind_ == Snapshot::kFull) {
return NewMint(value);
}
return Mint::NewCanonical(value);
}
RawClass* SnapshotReader::LookupInternalClass(intptr_t class_header) {
// If the header is an object Id, lookup singleton VM classes or classes
// stored in the object store.
if (IsVMIsolateObject(class_header)) {
intptr_t class_id = GetVMIsolateObjectId(class_header);
if (IsSingletonClassId(class_id)) {
return isolate()->class_table()->At(class_id); // get singleton class.
}
} else if (SerializedHeaderTag::decode(class_header) == kObjectId) {
intptr_t class_id = SerializedHeaderData::decode(class_header);
if (IsObjectStoreClassId(class_id)) {
return isolate()->class_table()->At(class_id); // get singleton class.
}
}
return Class::null();
}
RawObject* SnapshotReader::AllocateUninitialized(const Class& cls,
intptr_t size) {
ASSERT(isolate()->no_gc_scope_depth() != 0);
ASSERT(Utils::IsAligned(size, kObjectAlignment));
Heap* heap = isolate()->heap();
uword address = heap->TryAllocate(size, Heap::kOld);
if (address == 0) {
// Use the preallocated out of memory exception to avoid calling
// into dart code or allocating any code.
// We do a longjmp at this point to unwind out of the entire
// read part and return the error object back.
const Instance& exception =
Instance::Handle(object_store()->out_of_memory());
ErrorHandle()->set_exception(exception);
Isolate::Current()->long_jump_base()->Jump(1, *ErrorHandle());
}
RawObject* raw_obj = reinterpret_cast<RawObject*>(address + kHeapObjectTag);
uword tags = 0;
intptr_t index = cls.id();
ASSERT(index != kIllegalCid);
tags = RawObject::ClassIdTag::update(index, tags);
tags = RawObject::SizeTag::update(size, tags);
raw_obj->ptr()->tags_ = tags;
return raw_obj;
}
RawObject* SnapshotReader::ReadVMIsolateObject(intptr_t header_value) {
intptr_t object_id = GetVMIsolateObjectId(header_value);
if (object_id == kNullObject) {
// This is a singleton null object, return it.
return Object::null();
}
if (object_id == kSentinelObject) {
return Object::sentinel().raw();
}
if (object_id == kEmptyArrayObject) {
return Object::empty_array().raw();
}
if (object_id == kTrueValue) {
return Bool::True().raw();
}
if (object_id == kFalseValue) {
return Bool::False().raw();
}
intptr_t class_id = ClassIdFromObjectId(object_id);
if (IsSingletonClassId(class_id)) {
return isolate()->class_table()->At(class_id); // get singleton class.
} else {
ASSERT(Symbols::IsVMSymbolId(object_id));
return Symbols::GetVMSymbol(object_id); // return VM symbol.
}
UNREACHABLE();
return Object::null();
}
RawObject* SnapshotReader::ReadIndexedObject(intptr_t object_id) {
intptr_t class_id = ClassIdFromObjectId(object_id);
if (IsObjectStoreClassId(class_id)) {
return isolate()->class_table()->At(class_id); // get singleton class.
}
if (kind_ != Snapshot::kFull) {
if (IsObjectStoreTypeId(object_id)) {
return GetType(object_store(), object_id); // return type obj.
}
}
Object* object = GetBackRef(object_id);
return object->raw();
}
RawObject* SnapshotReader::ReadInlinedObject(intptr_t object_id) {
// Read the class header information and lookup the class.
intptr_t class_header = ReadIntptrValue();
intptr_t tags = ReadIntptrValue();
if (SerializedHeaderData::decode(class_header) == kInstanceObjectId) {
// Object is regular dart instance.
Instance* result = reinterpret_cast<Instance*>(GetBackRef(object_id));
intptr_t instance_size = 0;
if (result == NULL) {
result = &(Instance::ZoneHandle(isolate(), Instance::null()));
AddBackRef(object_id, result, kIsDeserialized);
cls_ ^= ReadObjectImpl();
ASSERT(!cls_.IsNull());
instance_size = cls_.instance_size();
ASSERT(instance_size > 0);
// Allocate the instance and read in all the fields for the object.
if (kind_ == Snapshot::kFull) {
*result ^= AllocateUninitialized(cls_, instance_size);
} else {
*result ^= Object::Allocate(cls_.id(),
instance_size,
HEAP_SPACE(kind_));
}
} else {
cls_ ^= ReadObjectImpl();
ASSERT(!cls_.IsNull());
instance_size = cls_.instance_size();
}
intptr_t offset = Object::InstanceSize();
while (offset < instance_size) {
obj_ = ReadObjectRef();
result->SetFieldAtOffset(offset, obj_);
offset += kWordSize;
}
if (kind_ == Snapshot::kFull) {
result->SetCreatedFromSnapshot();
} else if (result->IsCanonical()) {
*result = result->Canonicalize();
}
return result->raw();
}
ASSERT((class_header & kSmiTagMask) != kSmiTag);
cls_ = LookupInternalClass(class_header);
ASSERT(!cls_.IsNull());
switch (cls_.id()) {
#define SNAPSHOT_READ(clazz) \
case clazz::kClassId: { \
obj_ = clazz::ReadFrom(this, object_id, tags, kind_); \
break; \
}
CLASS_LIST_NO_OBJECT(SNAPSHOT_READ)
#undef SNAPSHOT_READ
default: UNREACHABLE(); break;
}
if (kind_ == Snapshot::kFull) {
obj_.SetCreatedFromSnapshot();
}
return obj_.raw();
}
void SnapshotReader::ArrayReadFrom(const Array& result,
intptr_t len,
intptr_t tags) {
// Set the object tags.
result.set_tags(tags);
// Setup the object fields.
*TypeArgumentsHandle() ^= ReadObjectImpl();
result.SetTypeArguments(*TypeArgumentsHandle());
for (intptr_t i = 0; i < len; i++) {
*ObjectHandle() = ReadObjectRef();
result.SetAt(i, *ObjectHandle());
}
}
SnapshotWriter::SnapshotWriter(Snapshot::Kind kind,
uint8_t** buffer,
ReAlloc alloc,
intptr_t increment_size)
: BaseWriter(buffer, alloc, increment_size),
kind_(kind),
object_store_(Isolate::Current()->object_store()),
class_table_(Isolate::Current()->class_table()),
forward_list_(),
exception_type_(Exceptions::kNone),
exception_msg_(NULL),
error_(LanguageError::Handle()) {
}
void SnapshotWriter::WriteObject(RawObject* rawobj) {
WriteObjectImpl(rawobj);
WriteForwardedObjects();
}
void SnapshotWriter::HandleVMIsolateObject(RawObject* rawobj) {
// Check if it is a singleton null object.
if (rawobj == Object::null()) {
WriteVMIsolateObject(kNullObject);
return;
}
// Check if it is a singleton sentinel object.
if (rawobj == Object::sentinel().raw()) {
WriteVMIsolateObject(kSentinelObject);
return;
}
// Check if it is a singleton empty array object.
if (rawobj == Object::empty_array().raw()) {
WriteVMIsolateObject(kEmptyArrayObject);
return;
}
// Check if it is a singleton boolean true object.
if (rawobj == Bool::True().raw()) {
WriteVMIsolateObject(kTrueValue);
return;
}
// Check if it is a singleton boolean false object.
if (rawobj == Bool::False().raw()) {
WriteVMIsolateObject(kFalseValue);
return;
}
// Check if it is a singleton class object which is shared by
// all isolates.
intptr_t id = rawobj->GetClassId();
if (id == kClassCid) {
RawClass* raw_class = reinterpret_cast<RawClass*>(rawobj);
intptr_t class_id = raw_class->ptr()->id_;
if (IsSingletonClassId(class_id)) {
intptr_t object_id = ObjectIdFromClassId(class_id);
WriteVMIsolateObject(object_id);
return;
}
}
// Check it is a predefined symbol in the VM isolate.
id = Symbols::LookupVMSymbol(rawobj);
if (id != kInvalidIndex) {
WriteVMIsolateObject(id);
return;
}
UNREACHABLE();
}
void SnapshotWriter::WriteObjectRef(RawObject* raw) {
// First check if object can be written as a simple predefined type.
if (CheckAndWritePredefinedObject(raw)) {
return;
}
NoGCScope no_gc;
RawClass* cls = class_table_->At(raw->GetClassId());
intptr_t class_id = cls->ptr()->id_;
ASSERT(class_id == raw->GetClassId());
if (class_id >= kNumPredefinedCids) {
if (Class::IsSignatureClass(cls)) {
// We do not allow closure objects in an isolate message.
set_exception_type(Exceptions::kArgument);
// TODO(6726): Allocate these constant strings once in the VM isolate.
set_exception_msg("Illegal argument in isolate message"
" : (object is a closure)");
Isolate::Current()->long_jump_base()->Jump(1, *ErrorHandle());
}
// Object is being referenced, add it to the forward ref list and mark
// it so that future references to this object in the snapshot will use
// this object id. Mark it as not having been serialized yet so that we
// will serialize the object when we go through the forward list.
intptr_t object_id = MarkObject(raw, kIsNotSerialized);
// Write out the serialization header value for this object.
WriteInlinedObjectHeader(object_id);
// Indicate this is an instance object.
WriteIntptrValue(SerializedHeaderData::encode(kInstanceObjectId));
// Write out the class information for this object.
WriteObjectImpl(cls);
return;
}
if (class_id == kArrayCid) {
// Object is being referenced, add it to the forward ref list and mark
// it so that future references to this object in the snapshot will use
// this object id. Mark it as not having been serialized yet so that we
// will serialize the object when we go through the forward list.
intptr_t object_id = MarkObject(raw, kIsNotSerialized);
RawArray* rawarray = reinterpret_cast<RawArray*>(raw);
// Write out the serialization header value for this object.
WriteInlinedObjectHeader(object_id);
// Write out the class information.
WriteIndexedObject(kArrayCid);
// Write out the length field.
Write<RawObject*>(rawarray->ptr()->length_);
return;
}
if (class_id == kImmutableArrayCid) {
// Object is being referenced, add it to the forward ref list and mark
// it so that future references to this object in the snapshot will use
// this object id. Mark it as not having been serialized yet so that we
// will serialize the object when we go through the forward list.
intptr_t object_id = MarkObject(raw, kIsNotSerialized);
RawArray* rawarray = reinterpret_cast<RawArray*>(raw);
// Write out the serialization header value for this object.
WriteInlinedObjectHeader(object_id);
// Write out the class information.
WriteIndexedObject(kImmutableArrayCid);
// Write out the length field.
Write<RawObject*>(rawarray->ptr()->length_);
return;
}
// Object is being referenced, add it to the forward ref list and mark
// it so that future references to this object in the snapshot will use
// this object id. Mark it as not having been serialized yet so that we
// will serialize the object when we go through the forward list.
intptr_t object_id = MarkObject(raw, kIsSerialized);
switch (class_id) {
#define SNAPSHOT_WRITE(clazz) \
case clazz::kClassId: { \
Raw##clazz* raw_obj = reinterpret_cast<Raw##clazz*>(raw); \
raw_obj->WriteTo(this, object_id, kind_); \
return; \
} \
CLASS_LIST_NO_OBJECT(SNAPSHOT_WRITE)
#undef SNAPSHOT_WRITE
default: break;
}
UNREACHABLE();
}
void FullSnapshotWriter::WriteFullSnapshot() {
Isolate* isolate = Isolate::Current();
ASSERT(isolate != NULL);
ObjectStore* object_store = isolate->object_store();
ASSERT(object_store != NULL);
ASSERT(ClassFinalizer::AllClassesFinalized());
// Setup for long jump in case there is an exception while writing
// the snapshot.
LongJump* base = isolate->long_jump_base();
LongJump jump;
isolate->set_long_jump_base(&jump);
// TODO(6726): Allocate these constant strings once in the VM isolate.
*ErrorHandle() = LanguageError::New(
String::Handle(String::New("Error while writing full snapshot")));
if (setjmp(*jump.Set()) == 0) {
NoGCScope no_gc;
// Reserve space in the output buffer for a snapshot header.
ReserveHeader();
// Write out all the objects in the object store of the isolate which
// is the root set for all dart allocated objects at this point.
SnapshotWriterVisitor visitor(this, false);
object_store->VisitObjectPointers(&visitor);
// Write out all forwarded objects.
WriteForwardedObjects();
FillHeader(kind());
UnmarkAll();
isolate->set_long_jump_base(base);
} else {
isolate->set_long_jump_base(base);
ThrowException(exception_type(), exception_msg());
}
}
uword SnapshotWriter::GetObjectTags(RawObject* raw) {
uword tags = raw->ptr()->tags_;
if (SerializedHeaderTag::decode(tags) == kObjectId) {
intptr_t id = SerializedHeaderData::decode(tags);
return forward_list_[id - kMaxPredefinedObjectIds]->tags();
} else {
return tags;
}
}
intptr_t SnapshotWriter::MarkObject(RawObject* raw, SerializeState state) {
NoGCScope no_gc;
intptr_t object_id = forward_list_.length() + kMaxPredefinedObjectIds;
ASSERT(object_id <= kMaxObjectId);
uword value = 0;
value = SerializedHeaderTag::update(kObjectId, value);
value = SerializedHeaderData::update(object_id, value);
uword tags = raw->ptr()->tags_;
raw->ptr()->tags_ = value;
ForwardObjectNode* node = new ForwardObjectNode(raw, tags, state);
ASSERT(node != NULL);
forward_list_.Add(node);
return object_id;
}
void SnapshotWriter::UnmarkAll() {
NoGCScope no_gc;
for (intptr_t i = 0; i < forward_list_.length(); i++) {
RawObject* raw = forward_list_[i]->raw();
raw->ptr()->tags_ = forward_list_[i]->tags(); // Restore original tags.
}
}
bool SnapshotWriter::CheckAndWritePredefinedObject(RawObject* rawobj) {
// Check if object can be written in one of the following ways:
// - Smi: the Smi value is written as is (last bit is not tagged).
// - VM internal class (from VM isolate): (index of class in vm isolate | 0x3)
// - Object that has already been written: (negative id in stream | 0x3)
NoGCScope no_gc;
// First check if it is a Smi (i.e not a heap object).
if (!rawobj->IsHeapObject()) {
Write<int64_t>(reinterpret_cast<intptr_t>(rawobj));
return true;
}
// Check if object has already been serialized, in that case just write
// the object id out.
uword tags = rawobj->ptr()->tags_;
if (SerializedHeaderTag::decode(tags) == kObjectId) {
intptr_t id = SerializedHeaderData::decode(tags);
WriteIndexedObject(id);
return true;
}
// Now check if it is an object from the VM isolate (NOTE: premarked objects
// are considered to be objects in the VM isolate). These objects are shared
// by all isolates.
if (rawobj->IsVMHeapObject()) {
HandleVMIsolateObject(rawobj);
return true;
}
// Check if the object is a Mint and could potentially be a Smi
// on other architectures (64 bit), if so write it out as int64_t value.
if (rawobj->GetClassId() == kMintCid) {
int64_t value = reinterpret_cast<RawMint*>(rawobj)->ptr()->value_;
const intptr_t kSmi64Bits = 62;
const int64_t kSmi64Max = (static_cast<int64_t>(1) << kSmi64Bits) - 1;
const int64_t kSmi64Min = -(static_cast<int64_t>(1) << kSmi64Bits);
if (value <= kSmi64Max && value >= kSmi64Min) {
Write<int64_t>((value << kSmiTagShift) | kSmiTag);
return true;
}
}
// Check if it is a code object in that case just write a Null object
// as we do not want code objects in the snapshot.
if (rawobj->GetClassId() == kCodeCid) {
WriteVMIsolateObject(kNullObject);
return true;
}
// Check if classes are not being serialized and it is preinitialized type.
if (kind_ != Snapshot::kFull) {
RawType* raw_type = reinterpret_cast<RawType*>(rawobj);
intptr_t index = GetTypeIndex(object_store(), raw_type);
if (index != kInvalidIndex) {
WriteIndexedObject(index);
return true;
}
}
return false;
}
void SnapshotWriter::WriteObjectImpl(RawObject* raw) {
// First check if object can be written as a simple predefined type.
if (CheckAndWritePredefinedObject(raw)) {
return;
}
// Object is being serialized, add it to the forward ref list and mark
// it so that future references to this object in the snapshot will use
// an object id, instead of trying to serialize it again.
MarkObject(raw, kIsSerialized);
WriteInlinedObject(raw);
}
void SnapshotWriter::WriteInlinedObject(RawObject* raw) {
// Now write the object out inline in the stream as follows:
// - Object is seen for the first time (inlined as follows):
// (object size in multiples of kObjectAlignment | 0x1)
// serialized fields of the object
// ......
NoGCScope no_gc;
uword tags = raw->ptr()->tags_;
ASSERT(SerializedHeaderTag::decode(tags) == kObjectId);
intptr_t object_id = SerializedHeaderData::decode(tags);
tags = forward_list_[object_id - kMaxPredefinedObjectIds]->tags();
RawClass* cls = class_table_->At(RawObject::ClassIdTag::decode(tags));
intptr_t class_id = cls->ptr()->id_;
if (class_id >= kNumPredefinedCids) {
if (Class::IsSignatureClass(cls)) {
// We do not allow closure objects in an isolate message.
set_exception_type(Exceptions::kArgument);
// TODO(6726): Allocate these constant strings once in the VM isolate.
set_exception_msg("Illegal argument in isolate message"
" : (object is a closure)");
Isolate::Current()->long_jump_base()->Jump(1, *ErrorHandle());
}
if (cls->ptr()->num_native_fields_ != 0) {
// We do not allow objects with native fields in an isolate message.
set_exception_type(Exceptions::kArgument);
// TODO(6726): Allocate these constant strings once in the VM isolate.
set_exception_msg("Illegal argument in isolate message"
" : (object extends NativeWrapper)");
Isolate::Current()->long_jump_base()->Jump(1, *ErrorHandle());
}
// Object is regular dart instance.
intptr_t instance_size =
cls->ptr()->instance_size_in_words_ << kWordSizeLog2;
ASSERT(instance_size != 0);
// Write out the serialization header value for this object.
WriteInlinedObjectHeader(object_id);
// Indicate this is an instance object.
WriteIntptrValue(SerializedHeaderData::encode(kInstanceObjectId));
// Write out the tags.
WriteIntptrValue(tags);
// Write out the class information for this object.
WriteObjectImpl(cls);
// Write out all the fields for the object.
intptr_t offset = Object::InstanceSize();
while (offset < instance_size) {
WriteObjectRef(*reinterpret_cast<RawObject**>(
reinterpret_cast<uword>(raw->ptr()) + offset));
offset += kWordSize;
}
return;
}
switch (class_id) {
#define SNAPSHOT_WRITE(clazz) \
case clazz::kClassId: { \
Raw##clazz* raw_obj = reinterpret_cast<Raw##clazz*>(raw); \
raw_obj->WriteTo(this, object_id, kind_); \
return; \
} \
CLASS_LIST_NO_OBJECT(SNAPSHOT_WRITE)
#undef SNAPSHOT_WRITE
default: break;
}
UNREACHABLE();
}
void SnapshotWriter::WriteForwardedObjects() {
// Write out all objects that were added to the forward list and have
// not been serialized yet. These would typically be fields of instance
// objects, arrays or immutable arrays (this is done in order to avoid
// deep recursive calls to WriteObjectImpl).
// NOTE: The forward list might grow as we process the list.
for (intptr_t i = 0; i < forward_list_.length(); i++) {
if (!forward_list_[i]->is_serialized()) {
// Write the object out in the stream.
RawObject* raw = forward_list_[i]->raw();
WriteInlinedObject(raw);
// Mark object as serialized.
forward_list_[i]->set_state(kIsSerialized);
}
}
}
void SnapshotWriter::WriteClassId(RawClass* cls) {
ASSERT(kind_ != Snapshot::kFull);
int class_id = cls->ptr()->id_;
if (IsSingletonClassId(class_id)) {
intptr_t object_id = ObjectIdFromClassId(class_id);
WriteVMIsolateObject(object_id);
} else if (IsObjectStoreClassId(class_id)) {
intptr_t object_id = ObjectIdFromClassId(class_id);
WriteIndexedObject(object_id);
} else {
// TODO(5411462): Should restrict this to only core-lib classes in this
// case.
// Write out the class and tags information.
WriteVMIsolateObject(kClassCid);
WriteIntptrValue(GetObjectTags(cls));
// Write out the library url and class name.
RawLibrary* library = cls->ptr()->library_;
ASSERT(library != Library::null());
WriteObjectImpl(library->ptr()->url_);
WriteObjectImpl(cls->ptr()->name_);
}
}
void SnapshotWriter::ArrayWriteTo(intptr_t object_id,
intptr_t array_kind,
intptr_t tags,
RawSmi* length,
RawAbstractTypeArguments* type_arguments,
RawObject* data[]) {
intptr_t len = Smi::Value(length);
// Write out the serialization header value for this object.
WriteInlinedObjectHeader(object_id);
// Write out the class and tags information.
WriteIndexedObject(array_kind);
WriteIntptrValue(tags);
// Write out the length field.
Write<RawObject*>(length);
// Write out the type arguments.
WriteObjectImpl(type_arguments);
// Write out the individual object ids.
for (intptr_t i = 0; i < len; i++) {
WriteObjectRef(data[i]);
}
}
void SnapshotWriter::ThrowException(Exceptions::ExceptionType type,
const char* msg) {
Isolate::Current()->object_store()->clear_sticky_error();
UnmarkAll();
const String& msg_obj = String::Handle(String::New(msg));
const Array& args = Array::Handle(Array::New(1));
args.SetAt(0, msg_obj);
Exceptions::ThrowByType(type, args);
UNREACHABLE();
}
void ScriptSnapshotWriter::WriteScriptSnapshot(const Library& lib) {
ASSERT(kind() == Snapshot::kScript);
Isolate* isolate = Isolate::Current();
ASSERT(isolate != NULL);
ASSERT(ClassFinalizer::AllClassesFinalized());
// Setup for long jump in case there is an exception while writing
// the snapshot.
LongJump* base = isolate->long_jump_base();
LongJump jump;
isolate->set_long_jump_base(&jump);
*ErrorHandle() = LanguageError::New(
String::Handle(String::New("Error while writing script snapshot")));
if (setjmp(*jump.Set()) == 0) {
// Write out the library object.
NoGCScope no_gc;
ReserveHeader();
WriteObject(lib.raw());
FillHeader(kind());
UnmarkAll();
isolate->set_long_jump_base(base);
} else {
isolate->set_long_jump_base(base);
ThrowException(exception_type(), exception_msg());
}
}
void SnapshotWriterVisitor::VisitPointers(RawObject** first, RawObject** last) {
for (RawObject** current = first; current <= last; current++) {
RawObject* raw_obj = *current;
if (as_references_) {
writer_->WriteObjectRef(raw_obj);
} else {
writer_->WriteObjectImpl(raw_obj);
}
}
}
void MessageWriter::WriteMessage(const Object& obj) {
ASSERT(kind() == Snapshot::kMessage);
Isolate* isolate = Isolate::Current();
ASSERT(isolate != NULL);
// Setup for long jump in case there is an exception while writing
// the message.
LongJump* base = isolate->long_jump_base();
LongJump jump;
isolate->set_long_jump_base(&jump);
*ErrorHandle() = LanguageError::New(
String::Handle(String::New("Error while writing message")));
if (setjmp(*jump.Set()) == 0) {
NoGCScope no_gc;
WriteObject(obj.raw());
UnmarkAll();
isolate->set_long_jump_base(base);
} else {
isolate->set_long_jump_base(base);
ThrowException(exception_type(), exception_msg());
}
}
} // namespace dart
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