[serializer] split up src/snapshot/serialize.*

src/snapshot/code-serializer.cc

+// 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.
+
+#include "src/snapshot/code-serializer.h"
+
+#include "src/code-stubs.h"
+#include "src/log.h"
+#include "src/macro-assembler.h"
+#include "src/profiler/cpu-profiler.h"
+#include "src/snapshot/deserializer.h"
+#include "src/version.h"
+
+namespace v8 {
+namespace internal {
+
+ScriptData* CodeSerializer::Serialize(Isolate* isolate,
+                                      Handle<SharedFunctionInfo> info,
+                                      Handle<String> source) {
+  base::ElapsedTimer timer;
+  if (FLAG_profile_deserialization) timer.Start();
+  if (FLAG_trace_serializer) {
+    PrintF("[Serializing from");
+    Object* script = info->script();
+    if (script->IsScript()) Script::cast(script)->name()->ShortPrint();
+    PrintF("]\n");
+  }
+
+  // Serialize code object.
+  SnapshotByteSink sink(info->code()->CodeSize() * 2);
+  CodeSerializer cs(isolate, &sink, *source);
+  DisallowHeapAllocation no_gc;
+  Object** location = Handle<Object>::cast(info).location();
+  cs.VisitPointer(location);
+  cs.SerializeDeferredObjects();
+  cs.Pad();
+
+  SerializedCodeData data(sink.data(), cs);
+  ScriptData* script_data = data.GetScriptData();
+
+  if (FLAG_profile_deserialization) {
+    double ms = timer.Elapsed().InMillisecondsF();
+    int length = script_data->length();
+    PrintF("[Serializing to %d bytes took %0.3f ms]\n", length, ms);
+  }
+
+  return script_data;
+}
+
+void CodeSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
+                                     WhereToPoint where_to_point, int skip) {
+  int root_index = root_index_map_.Lookup(obj);
+  if (root_index != RootIndexMap::kInvalidRootIndex) {
+    PutRoot(root_index, obj, how_to_code, where_to_point, skip);
+    return;
+  }
+
+  if (SerializeKnownObject(obj, how_to_code, where_to_point, skip)) return;
+
+  FlushSkip(skip);
+
+  if (obj->IsCode()) {
+    Code* code_object = Code::cast(obj);
+    switch (code_object->kind()) {
+      case Code::OPTIMIZED_FUNCTION:  // No optimized code compiled yet.
+      case Code::HANDLER:             // No handlers patched in yet.
+      case Code::REGEXP:              // No regexp literals initialized yet.
+      case Code::NUMBER_OF_KINDS:     // Pseudo enum value.
+        CHECK(false);
+      case Code::BUILTIN:
+        SerializeBuiltin(code_object->builtin_index(), how_to_code,
+                         where_to_point);
+        return;
+      case Code::STUB:
+        SerializeCodeStub(code_object->stub_key(), how_to_code, where_to_point);
+        return;
+#define IC_KIND_CASE(KIND) case Code::KIND:
+        IC_KIND_LIST(IC_KIND_CASE)
+#undef IC_KIND_CASE
+        SerializeIC(code_object, how_to_code, where_to_point);
+        return;
+      case Code::FUNCTION:
+        DCHECK(code_object->has_reloc_info_for_serialization());
+        SerializeGeneric(code_object, how_to_code, where_to_point);
+        return;
+      case Code::WASM_FUNCTION:
+        UNREACHABLE();
+    }
+    UNREACHABLE();
+  }
+
+  // Past this point we should not see any (context-specific) maps anymore.
+  CHECK(!obj->IsMap());
+  // There should be no references to the global object embedded.
+  CHECK(!obj->IsJSGlobalProxy() && !obj->IsJSGlobalObject());
+  // There should be no hash table embedded. They would require rehashing.
+  CHECK(!obj->IsHashTable());
+  // We expect no instantiated function objects or contexts.
+  CHECK(!obj->IsJSFunction() && !obj->IsContext());
+
+  SerializeGeneric(obj, how_to_code, where_to_point);
+}
+
+void CodeSerializer::SerializeGeneric(HeapObject* heap_object,
+                                      HowToCode how_to_code,
+                                      WhereToPoint where_to_point) {
+  // Object has not yet been serialized.  Serialize it here.
+  ObjectSerializer serializer(this, heap_object, sink_, how_to_code,
+                              where_to_point);
+  serializer.Serialize();
+}
+
+void CodeSerializer::SerializeBuiltin(int builtin_index, HowToCode how_to_code,
+                                      WhereToPoint where_to_point) {
+  DCHECK((how_to_code == kPlain && where_to_point == kStartOfObject) ||
+         (how_to_code == kPlain && where_to_point == kInnerPointer) ||
+         (how_to_code == kFromCode && where_to_point == kInnerPointer));
+  DCHECK_LT(builtin_index, Builtins::builtin_count);
+  DCHECK_LE(0, builtin_index);
+
+  if (FLAG_trace_serializer) {
+    PrintF(" Encoding builtin: %s\n",
+           isolate()->builtins()->name(builtin_index));
+  }
+
+  sink_->Put(kBuiltin + how_to_code + where_to_point, "Builtin");
+  sink_->PutInt(builtin_index, "builtin_index");
+}
+
+void CodeSerializer::SerializeCodeStub(uint32_t stub_key, HowToCode how_to_code,
+                                       WhereToPoint where_to_point) {
+  DCHECK((how_to_code == kPlain && where_to_point == kStartOfObject) ||
+         (how_to_code == kPlain && where_to_point == kInnerPointer) ||
+         (how_to_code == kFromCode && where_to_point == kInnerPointer));
+  DCHECK(CodeStub::MajorKeyFromKey(stub_key) != CodeStub::NoCache);
+  DCHECK(!CodeStub::GetCode(isolate(), stub_key).is_null());
+
+  int index = AddCodeStubKey(stub_key) + kCodeStubsBaseIndex;
+
+  if (FLAG_trace_serializer) {
+    PrintF(" Encoding code stub %s as %d\n",
+           CodeStub::MajorName(CodeStub::MajorKeyFromKey(stub_key)), index);
+  }
+
+  sink_->Put(kAttachedReference + how_to_code + where_to_point, "CodeStub");
+  sink_->PutInt(index, "CodeStub key");
+}
+
+void CodeSerializer::SerializeIC(Code* ic, HowToCode how_to_code,
+                                 WhereToPoint where_to_point) {
+  // The IC may be implemented as a stub.
+  uint32_t stub_key = ic->stub_key();
+  if (stub_key != CodeStub::NoCacheKey()) {
+    if (FLAG_trace_serializer) {
+      PrintF(" %s is a code stub\n", Code::Kind2String(ic->kind()));
+    }
+    SerializeCodeStub(stub_key, how_to_code, where_to_point);
+    return;
+  }
+  // The IC may be implemented as builtin. Only real builtins have an
+  // actual builtin_index value attached (otherwise it's just garbage).
+  // Compare to make sure we are really dealing with a builtin.
+  int builtin_index = ic->builtin_index();
+  if (builtin_index < Builtins::builtin_count) {
+    Builtins::Name name = static_cast<Builtins::Name>(builtin_index);
+    Code* builtin = isolate()->builtins()->builtin(name);
+    if (builtin == ic) {
+      if (FLAG_trace_serializer) {
+        PrintF(" %s is a builtin\n", Code::Kind2String(ic->kind()));
+      }
+      DCHECK(ic->kind() == Code::KEYED_LOAD_IC ||
+             ic->kind() == Code::KEYED_STORE_IC);
+      SerializeBuiltin(builtin_index, how_to_code, where_to_point);
+      return;
+    }
+  }
+  // The IC may also just be a piece of code kept in the non_monomorphic_cache.
+  // In that case, just serialize as a normal code object.
+  if (FLAG_trace_serializer) {
+    PrintF(" %s has no special handling\n", Code::Kind2String(ic->kind()));
+  }
+  DCHECK(ic->kind() == Code::LOAD_IC || ic->kind() == Code::STORE_IC);
+  SerializeGeneric(ic, how_to_code, where_to_point);
+}
+
+int CodeSerializer::AddCodeStubKey(uint32_t stub_key) {
+  // TODO(yangguo) Maybe we need a hash table for a faster lookup than O(n^2).
+  int index = 0;
+  while (index < stub_keys_.length()) {
+    if (stub_keys_[index] == stub_key) return index;
+    index++;
+  }
+  stub_keys_.Add(stub_key);
+  return index;
+}
+
+MaybeHandle<SharedFunctionInfo> CodeSerializer::Deserialize(
+    Isolate* isolate, ScriptData* cached_data, Handle<String> source) {
+  base::ElapsedTimer timer;
+  if (FLAG_profile_deserialization) timer.Start();
+
+  HandleScope scope(isolate);
+
+  base::SmartPointer<SerializedCodeData> scd(
+      SerializedCodeData::FromCachedData(isolate, cached_data, *source));
+  if (scd.is_empty()) {
+    if (FLAG_profile_deserialization) PrintF("[Cached code failed check]\n");
+    DCHECK(cached_data->rejected());
+    return MaybeHandle<SharedFunctionInfo>();
+  }
+
+  // Prepare and register list of attached objects.
+  Vector<const uint32_t> code_stub_keys = scd->CodeStubKeys();
+  Vector<Handle<Object> > attached_objects = Vector<Handle<Object> >::New(
+      code_stub_keys.length() + kCodeStubsBaseIndex);
+  attached_objects[kSourceObjectIndex] = source;
+  for (int i = 0; i < code_stub_keys.length(); i++) {
+    attached_objects[i + kCodeStubsBaseIndex] =
+        CodeStub::GetCode(isolate, code_stub_keys[i]).ToHandleChecked();
+  }
+
+  Deserializer deserializer(scd.get());
+  deserializer.SetAttachedObjects(attached_objects);
+
+  // Deserialize.
+  Handle<SharedFunctionInfo> result;
+  if (!deserializer.DeserializeCode(isolate).ToHandle(&result)) {
+    // Deserializing may fail if the reservations cannot be fulfilled.
+    if (FLAG_profile_deserialization) PrintF("[Deserializing failed]\n");
+    return MaybeHandle<SharedFunctionInfo>();
+  }
+
+  if (FLAG_profile_deserialization) {
+    double ms = timer.Elapsed().InMillisecondsF();
+    int length = cached_data->length();
+    PrintF("[Deserializing from %d bytes took %0.3f ms]\n", length, ms);
+  }
+  result->set_deserialized(true);
+
+  if (isolate->logger()->is_logging_code_events() ||
+      isolate->cpu_profiler()->is_profiling()) {
+    String* name = isolate->heap()->empty_string();
+    if (result->script()->IsScript()) {
+      Script* script = Script::cast(result->script());
+      if (script->name()->IsString()) name = String::cast(script->name());
+    }
+    isolate->logger()->CodeCreateEvent(
+        Logger::SCRIPT_TAG, result->abstract_code(), *result, NULL, name);
+  }
+  return scope.CloseAndEscape(result);
+}
+
+class Checksum {
+ public:
+  explicit Checksum(Vector<const byte> payload) {
+#ifdef MEMORY_SANITIZER
+    // Computing the checksum includes padding bytes for objects like strings.
+    // Mark every object as initialized in the code serializer.
+    MSAN_MEMORY_IS_INITIALIZED(payload.start(), payload.length());
+#endif  // MEMORY_SANITIZER
+    // Fletcher's checksum. Modified to reduce 64-bit sums to 32-bit.
+    uintptr_t a = 1;
+    uintptr_t b = 0;
+    const uintptr_t* cur = reinterpret_cast<const uintptr_t*>(payload.start());
+    DCHECK(IsAligned(payload.length(), kIntptrSize));
+    const uintptr_t* end = cur + payload.length() / kIntptrSize;
+    while (cur < end) {
+      // Unsigned overflow expected and intended.
+      a += *cur++;
+      b += a;
+    }
+#if V8_HOST_ARCH_64_BIT
+    a ^= a >> 32;
+    b ^= b >> 32;
+#endif  // V8_HOST_ARCH_64_BIT
+    a_ = static_cast<uint32_t>(a);
+    b_ = static_cast<uint32_t>(b);
+  }
+
+  bool Check(uint32_t a, uint32_t b) const { return a == a_ && b == b_; }
+
+  uint32_t a() const { return a_; }
+  uint32_t b() const { return b_; }
+
+ private:
+  uint32_t a_;
+  uint32_t b_;
+
+  DISALLOW_COPY_AND_ASSIGN(Checksum);
+};
+
+SerializedCodeData::SerializedCodeData(const List<byte>& payload,
+                                       const CodeSerializer& cs) {
+  DisallowHeapAllocation no_gc;
+  const List<uint32_t>* stub_keys = cs.stub_keys();
+
+  List<Reservation> reservations;
+  cs.EncodeReservations(&reservations);
+
+  // Calculate sizes.
+  int reservation_size = reservations.length() * kInt32Size;
+  int num_stub_keys = stub_keys->length();
+  int stub_keys_size = stub_keys->length() * kInt32Size;
+  int payload_offset = kHeaderSize + reservation_size + stub_keys_size;
+  int padded_payload_offset = POINTER_SIZE_ALIGN(payload_offset);
+  int size = padded_payload_offset + payload.length();
+
+  // Allocate backing store and create result data.
+  AllocateData(size);
+
+  // Set header values.
+  SetMagicNumber(cs.isolate());
+  SetHeaderValue(kVersionHashOffset, Version::Hash());
+  SetHeaderValue(kSourceHashOffset, SourceHash(cs.source()));
+  SetHeaderValue(kCpuFeaturesOffset,
+                 static_cast<uint32_t>(CpuFeatures::SupportedFeatures()));
+  SetHeaderValue(kFlagHashOffset, FlagList::Hash());
+  SetHeaderValue(kNumReservationsOffset, reservations.length());
+  SetHeaderValue(kNumCodeStubKeysOffset, num_stub_keys);
+  SetHeaderValue(kPayloadLengthOffset, payload.length());
+
+  Checksum checksum(payload.ToConstVector());
+  SetHeaderValue(kChecksum1Offset, checksum.a());
+  SetHeaderValue(kChecksum2Offset, checksum.b());
+
+  // Copy reservation chunk sizes.
+  CopyBytes(data_ + kHeaderSize, reinterpret_cast<byte*>(reservations.begin()),
+            reservation_size);
+
+  // Copy code stub keys.
+  CopyBytes(data_ + kHeaderSize + reservation_size,
+            reinterpret_cast<byte*>(stub_keys->begin()), stub_keys_size);
+
+  memset(data_ + payload_offset, 0, padded_payload_offset - payload_offset);
+
+  // Copy serialized data.
+  CopyBytes(data_ + padded_payload_offset, payload.begin(),
+            static_cast<size_t>(payload.length()));
+}
+
+SerializedCodeData::SanityCheckResult SerializedCodeData::SanityCheck(
+    Isolate* isolate, String* source) const {
+  uint32_t magic_number = GetMagicNumber();
+  if (magic_number != ComputeMagicNumber(isolate)) return MAGIC_NUMBER_MISMATCH;
+  uint32_t version_hash = GetHeaderValue(kVersionHashOffset);
+  uint32_t source_hash = GetHeaderValue(kSourceHashOffset);
+  uint32_t cpu_features = GetHeaderValue(kCpuFeaturesOffset);
+  uint32_t flags_hash = GetHeaderValue(kFlagHashOffset);
+  uint32_t c1 = GetHeaderValue(kChecksum1Offset);
+  uint32_t c2 = GetHeaderValue(kChecksum2Offset);
+  if (version_hash != Version::Hash()) return VERSION_MISMATCH;
+  if (source_hash != SourceHash(source)) return SOURCE_MISMATCH;
+  if (cpu_features != static_cast<uint32_t>(CpuFeatures::SupportedFeatures())) {
+    return CPU_FEATURES_MISMATCH;
+  }
+  if (flags_hash != FlagList::Hash()) return FLAGS_MISMATCH;
+  if (!Checksum(Payload()).Check(c1, c2)) return CHECKSUM_MISMATCH;
+  return CHECK_SUCCESS;
+}
+
+uint32_t SerializedCodeData::SourceHash(String* source) const {
+  return source->length();
+}
+
+// Return ScriptData object and relinquish ownership over it to the caller.
+ScriptData* SerializedCodeData::GetScriptData() {
+  DCHECK(owns_data_);
+  ScriptData* result = new ScriptData(data_, size_);
+  result->AcquireDataOwnership();
+  owns_data_ = false;
+  data_ = NULL;
+  return result;
+}
+
+Vector<const SerializedData::Reservation> SerializedCodeData::Reservations()
+    const {
+  return Vector<const Reservation>(
+      reinterpret_cast<const Reservation*>(data_ + kHeaderSize),
+      GetHeaderValue(kNumReservationsOffset));
+}
+
+Vector<const byte> SerializedCodeData::Payload() const {
+  int reservations_size = GetHeaderValue(kNumReservationsOffset) * kInt32Size;
+  int code_stubs_size = GetHeaderValue(kNumCodeStubKeysOffset) * kInt32Size;
+  int payload_offset = kHeaderSize + reservations_size + code_stubs_size;
+  int padded_payload_offset = POINTER_SIZE_ALIGN(payload_offset);
+  const byte* payload = data_ + padded_payload_offset;
+  DCHECK(IsAligned(reinterpret_cast<intptr_t>(payload), kPointerAlignment));
+  int length = GetHeaderValue(kPayloadLengthOffset);
+  DCHECK_EQ(data_ + size_, payload + length);
+  return Vector<const byte>(payload, length);
+}
+
+Vector<const uint32_t> SerializedCodeData::CodeStubKeys() const {
+  int reservations_size = GetHeaderValue(kNumReservationsOffset) * kInt32Size;
+  const byte* start = data_ + kHeaderSize + reservations_size;
+  return Vector<const uint32_t>(reinterpret_cast<const uint32_t*>(start),
+                                GetHeaderValue(kNumCodeStubKeysOffset));
+}
+
+SerializedCodeData::SerializedCodeData(ScriptData* data)
+    : SerializedData(const_cast<byte*>(data->data()), data->length()) {}
+
+SerializedCodeData* SerializedCodeData::FromCachedData(Isolate* isolate,
+                                                       ScriptData* cached_data,
+                                                       String* source) {
+  DisallowHeapAllocation no_gc;
+  SerializedCodeData* scd = new SerializedCodeData(cached_data);
+  SanityCheckResult r = scd->SanityCheck(isolate, source);
+  if (r == CHECK_SUCCESS) return scd;
+  cached_data->Reject();
+  source->GetIsolate()->counters()->code_cache_reject_reason()->AddSample(r);
+  delete scd;
+  return NULL;
+}
+
+}  // namespace internal
+}  // namespace v8