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// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_SNAPSHOT_SERIALIZER_H_
#define V8_SNAPSHOT_SERIALIZER_H_
#include <map>
#include "src/instruction-stream.h"
#include "src/isolate.h"
#include "src/log.h"
#include "src/objects.h"
#include "src/snapshot/default-serializer-allocator.h"
#include "src/snapshot/serializer-common.h"
#include "src/snapshot/snapshot-source-sink.h"
namespace v8 {
namespace internal {
class CodeAddressMap : public CodeEventLogger {
public:
explicit CodeAddressMap(Isolate* isolate) : CodeEventLogger(isolate) {
isolate->logger()->AddCodeEventListener(this);
}
~CodeAddressMap() override {
isolate_->logger()->RemoveCodeEventListener(this);
}
void CodeMoveEvent(AbstractCode* from, AbstractCode* to) override {
address_to_name_map_.Move(from->address(), to->address());
}
void CodeDisableOptEvent(AbstractCode* code,
SharedFunctionInfo* shared) override {}
const char* Lookup(Address address) {
return address_to_name_map_.Lookup(address);
}
private:
class NameMap {
public:
NameMap() : impl_() {}
~NameMap() {
for (base::HashMap::Entry* p = impl_.Start(); p != nullptr;
p = impl_.Next(p)) {
DeleteArray(static_cast<const char*>(p->value));
}
}
void Insert(Address code_address, const char* name, int name_size) {
base::HashMap::Entry* entry = FindOrCreateEntry(code_address);
if (entry->value == nullptr) {
entry->value = CopyName(name, name_size);
}
}
const char* Lookup(Address code_address) {
base::HashMap::Entry* entry = FindEntry(code_address);
return (entry != nullptr) ? static_cast<const char*>(entry->value)
: nullptr;
}
void Remove(Address code_address) {
base::HashMap::Entry* entry = FindEntry(code_address);
if (entry != nullptr) {
DeleteArray(static_cast<char*>(entry->value));
RemoveEntry(entry);
}
}
void Move(Address from, Address to) {
if (from == to) return;
base::HashMap::Entry* from_entry = FindEntry(from);
DCHECK_NOT_NULL(from_entry);
void* value = from_entry->value;
RemoveEntry(from_entry);
base::HashMap::Entry* to_entry = FindOrCreateEntry(to);
DCHECK_NULL(to_entry->value);
to_entry->value = value;
}
private:
static char* CopyName(const char* name, int name_size) {
char* result = NewArray<char>(name_size + 1);
for (int i = 0; i < name_size; ++i) {
char c = name[i];
if (c == '\0') c = ' ';
result[i] = c;
}
result[name_size] = '\0';
return result;
}
base::HashMap::Entry* FindOrCreateEntry(Address code_address) {
return impl_.LookupOrInsert(reinterpret_cast<void*>(code_address),
ComputeAddressHash(code_address));
}
base::HashMap::Entry* FindEntry(Address code_address) {
return impl_.Lookup(reinterpret_cast<void*>(code_address),
ComputeAddressHash(code_address));
}
void RemoveEntry(base::HashMap::Entry* entry) {
impl_.Remove(entry->key, entry->hash);
}
base::HashMap impl_;
DISALLOW_COPY_AND_ASSIGN(NameMap);
};
void LogRecordedBuffer(AbstractCode* code, SharedFunctionInfo*,
const char* name, int length) override {
address_to_name_map_.Insert(code->address(), name, length);
}
void LogRecordedBuffer(const wasm::WasmCode* code, const char* name,
int length) override {
UNREACHABLE();
}
NameMap address_to_name_map_;
};
template <class AllocatorT = DefaultSerializerAllocator>
class Serializer : public SerializerDeserializer {
public:
explicit Serializer(Isolate* isolate);
~Serializer() override;
std::vector<SerializedData::Reservation> EncodeReservations() const {
return allocator_.EncodeReservations();
}
const std::vector<byte>* Payload() const { return sink_.data(); }
bool ReferenceMapContains(HeapObject* o) {
return reference_map()->LookupReference(o).is_valid();
}
Isolate* isolate() const { return isolate_; }
protected:
class ObjectSerializer;
class RecursionScope {
public:
explicit RecursionScope(Serializer* serializer) : serializer_(serializer) {
serializer_->recursion_depth_++;
}
~RecursionScope() { serializer_->recursion_depth_--; }
bool ExceedsMaximum() {
return serializer_->recursion_depth_ >= kMaxRecursionDepth;
}
private:
static const int kMaxRecursionDepth = 32;
Serializer* serializer_;
};
void SerializeDeferredObjects();
virtual void SerializeObject(HeapObject* o, HowToCode how_to_code,
WhereToPoint where_to_point, int skip) = 0;
virtual bool MustBeDeferred(HeapObject* object);
void VisitRootPointers(Root root, const char* description, Object** start,
Object** end) override;
void SerializeRootObject(Object* object);
void PutRoot(int index, HeapObject* object, HowToCode how, WhereToPoint where,
int skip);
void PutSmi(Smi* smi);
void PutBackReference(HeapObject* object, SerializerReference reference);
void PutAttachedReference(SerializerReference reference,
HowToCode how_to_code, WhereToPoint where_to_point);
// Emit alignment prefix if necessary, return required padding space in bytes.
int PutAlignmentPrefix(HeapObject* object);
void PutNextChunk(int space);
// Returns true if the object was successfully serialized as hot object.
bool SerializeHotObject(HeapObject* obj, HowToCode how_to_code,
WhereToPoint where_to_point, int skip);
// Returns true if the object was successfully serialized as back reference.
bool SerializeBackReference(HeapObject* obj, HowToCode how_to_code,
WhereToPoint where_to_point, int skip);
// Returns true if the object was successfully serialized as a builtin
// reference.
bool SerializeBuiltinReference(HeapObject* obj, HowToCode how_to_code,
WhereToPoint where_to_point, int skip);
// Returns true if the given heap object is a bytecode handler code object.
bool ObjectIsBytecodeHandler(HeapObject* obj) const;
inline void FlushSkip(int skip) {
if (skip != 0) {
sink_.Put(kSkip, "SkipFromSerializeObject");
sink_.PutInt(skip, "SkipDistanceFromSerializeObject");
}
}
ExternalReferenceEncoder::Value EncodeExternalReference(Address addr) {
return external_reference_encoder_.Encode(addr);
}
// GetInt reads 4 bytes at once, requiring padding at the end.
void Pad();
// We may not need the code address map for logging for every instance
// of the serializer. Initialize it on demand.
void InitializeCodeAddressMap();
Code* CopyCode(Code* code);
void QueueDeferredObject(HeapObject* obj) {
DCHECK(reference_map_.LookupReference(obj).is_back_reference());
deferred_objects_.push_back(obj);
}
void OutputStatistics(const char* name);
#ifdef OBJECT_PRINT
void CountInstanceType(Map* map, int size, AllocationSpace space);
#endif // OBJECT_PRINT
#ifdef DEBUG
void PushStack(HeapObject* o) { stack_.push_back(o); }
void PopStack() { stack_.pop_back(); }
void PrintStack();
#endif // DEBUG
SerializerReferenceMap* reference_map() { return &reference_map_; }
RootIndexMap* root_index_map() { return &root_index_map_; }
AllocatorT* allocator() { return &allocator_; }
SnapshotByteSink sink_; // Used directly by subclasses.
private:
Isolate* isolate_;
SerializerReferenceMap reference_map_;
ExternalReferenceEncoder external_reference_encoder_;
RootIndexMap root_index_map_;
CodeAddressMap* code_address_map_ = nullptr;
std::vector<byte> code_buffer_;
std::vector<HeapObject*> deferred_objects_; // To handle stack overflow.
int recursion_depth_ = 0;
AllocatorT allocator_;
#ifdef OBJECT_PRINT
static const int kInstanceTypes = LAST_TYPE + 1;
int* instance_type_count_[LAST_SPACE];
size_t* instance_type_size_[LAST_SPACE];
#endif // OBJECT_PRINT
#ifdef DEBUG
std::vector<HeapObject*> stack_;
#endif // DEBUG
friend class DefaultSerializerAllocator;
DISALLOW_COPY_AND_ASSIGN(Serializer);
};
class RelocInfoIterator;
template <class AllocatorT>
class Serializer<AllocatorT>::ObjectSerializer : public ObjectVisitor {
public:
ObjectSerializer(Serializer* serializer, HeapObject* obj,
SnapshotByteSink* sink, HowToCode how_to_code,
WhereToPoint where_to_point)
: serializer_(serializer),
object_(obj),
sink_(sink),
reference_representation_(how_to_code + where_to_point),
bytes_processed_so_far_(0) {
#ifdef DEBUG
serializer_->PushStack(obj);
#endif // DEBUG
}
~ObjectSerializer() override {
#ifdef DEBUG
serializer_->PopStack();
#endif // DEBUG
}
void Serialize();
void SerializeObject();
void SerializeDeferred();
void VisitPointers(HeapObject* host, Object** start, Object** end) override;
void VisitPointers(HeapObject* host, MaybeObject** start,
MaybeObject** end) override;
void VisitEmbeddedPointer(Code* host, RelocInfo* target) override;
void VisitExternalReference(Foreign* host, Address* p) override;
void VisitExternalReference(Code* host, RelocInfo* rinfo) override;
void VisitInternalReference(Code* host, RelocInfo* rinfo) override;
void VisitCodeTarget(Code* host, RelocInfo* target) override;
void VisitRuntimeEntry(Code* host, RelocInfo* reloc) override;
void VisitOffHeapTarget(Code* host, RelocInfo* target) override;
// Relocation info needs to be visited sorted by target_address_address.
void VisitRelocInfo(RelocIterator* it) override;
private:
void SerializePrologue(AllocationSpace space, int size, Map* map);
// This function outputs or skips the raw data between the last pointer and
// up to the current position.
void SerializeContent(Map* map, int size);
void OutputRawData(Address up_to);
void OutputCode(int size);
int SkipTo(Address to);
int32_t SerializeBackingStore(void* backing_store, int32_t byte_length);
void SerializeJSTypedArray();
void SerializeJSArrayBuffer();
void SerializeExternalString();
void SerializeExternalStringAsSequentialString();
Serializer* serializer_;
HeapObject* object_;
SnapshotByteSink* sink_;
std::map<void*, Smi*> backing_stores;
int reference_representation_;
int bytes_processed_so_far_;
};
} // namespace internal
} // namespace v8
#endif // V8_SNAPSHOT_SERIALIZER_H_
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