runtime/vm/clustered_snapshot.cc

// Copyright (c) 2016, 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/clustered_snapshot.h"

#include "platform/assert.h"
#include "vm/bootstrap.h"
#include "vm/class_finalizer.h"
#include "vm/dart.h"
#include "vm/dart_entry.h"
#include "vm/exceptions.h"
#include "vm/heap.h"
#include "vm/lockers.h"
#include "vm/longjump.h"
#include "vm/native_entry.h"
#include "vm/object.h"
#include "vm/object_store.h"
#include "vm/stub_code.h"
#include "vm/symbols.h"
#include "vm/timeline.h"
#include "vm/version.h"

namespace dart {

static RawObject* AllocateUninitialized(PageSpace* old_space, intptr_t size) {
  ASSERT(Utils::IsAligned(size, kObjectAlignment));
  uword address =
      old_space->TryAllocateDataBumpLocked(size, PageSpace::kForceGrowth);
  if (address == 0) {
    OUT_OF_MEMORY();
  }
  return reinterpret_cast<RawObject*>(address + kHeapObjectTag);
}


void Deserializer::InitializeHeader(RawObject* raw,
                                    intptr_t class_id,
                                    intptr_t size,
                                    bool is_vm_isolate,
                                    bool is_canonical) {
  ASSERT(Utils::IsAligned(size, kObjectAlignment));
  uword tags = 0;
  tags = RawObject::ClassIdTag::update(class_id, tags);
  tags = RawObject::SizeTag::update(size, tags);
  tags = RawObject::VMHeapObjectTag::update(is_vm_isolate, tags);
  tags = RawObject::CanonicalObjectTag::update(is_canonical, tags);
  raw->ptr()->tags_ = tags;
}


#if !defined(DART_PRECOMPILED_RUNTIME)
class ClassSerializationCluster : public SerializationCluster {
 public:
  explicit ClassSerializationCluster(intptr_t num_cids)
      : predefined_(kNumPredefinedCids), objects_(num_cids) {}
  virtual ~ClassSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawClass* cls = Class::RawCast(object);
    intptr_t class_id = cls->ptr()->id_;

    if (class_id < kNumPredefinedCids) {
      // These classes are allocated by Object::Init or Object::InitOnce, so the
      // deserializer must find them in the class table instead of allocating
      // them.
      predefined_.Add(cls);
    } else {
      objects_.Add(cls);
    }

    RawObject** from = cls->from();
    RawObject** to = cls->to_snapshot(s->kind());
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kClassCid);
    intptr_t count = predefined_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawClass* cls = predefined_[i];
      intptr_t class_id = cls->ptr()->id_;
      s->WriteCid(class_id);
      s->AssignRef(cls);
    }
    count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawClass* cls = objects_[i];
      s->AssignRef(cls);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = predefined_.length();
    for (intptr_t i = 0; i < count; i++) {
      WriteClass(s, predefined_[i]);
    }
    count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      WriteClass(s, objects_[i]);
    }
  }

  void WriteClass(Serializer* s, RawClass* cls) {
    Snapshot::Kind kind = s->kind();
    RawObject** from = cls->from();
    RawObject** to = cls->to_snapshot(kind);
    for (RawObject** p = from; p <= to; p++) {
      s->WriteRef(*p);
    }
    intptr_t class_id = cls->ptr()->id_;
    if (class_id == kIllegalCid) {
      FATAL1("Attempting to serialize class with illegal cid: %s\n",
             Class::Handle(cls).ToCString());
    }
    s->WriteCid(class_id);
    s->Write<int32_t>(cls->ptr()->instance_size_in_words_);
    s->Write<int32_t>(cls->ptr()->next_field_offset_in_words_);
    s->Write<int32_t>(cls->ptr()->type_arguments_field_offset_in_words_);
    s->Write<uint16_t>(cls->ptr()->num_type_arguments_);
    s->Write<uint16_t>(cls->ptr()->num_own_type_arguments_);
    s->Write<uint16_t>(cls->ptr()->num_native_fields_);
    s->WriteTokenPosition(cls->ptr()->token_pos_);
    s->Write<uint16_t>(cls->ptr()->state_bits_);
  }

 private:
  GrowableArray<RawClass*> predefined_;
  GrowableArray<RawClass*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class ClassDeserializationCluster : public DeserializationCluster {
 public:
  ClassDeserializationCluster() {}
  virtual ~ClassDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    predefined_start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    ClassTable* table = d->isolate()->class_table();
    for (intptr_t i = 0; i < count; i++) {
      intptr_t class_id = d->ReadCid();
      ASSERT(table->HasValidClassAt(class_id));
      RawClass* cls = table->At(class_id);
      ASSERT(cls != NULL);
      d->AssignRef(cls);
    }
    predefined_stop_index_ = d->next_index();

    start_index_ = d->next_index();
    count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(AllocateUninitialized(old_space, Class::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    Snapshot::Kind kind = d->kind();
    bool is_vm_object = d->isolate() == Dart::vm_isolate();
    ClassTable* table = d->isolate()->class_table();

    for (intptr_t id = predefined_start_index_; id < predefined_stop_index_;
         id++) {
      RawClass* cls = reinterpret_cast<RawClass*>(d->Ref(id));
      RawObject** from = cls->from();
      RawObject** to_snapshot = cls->to_snapshot(kind);
      for (RawObject** p = from; p <= to_snapshot; p++) {
        *p = d->ReadRef();
      }

      intptr_t class_id = d->ReadCid();
      cls->ptr()->id_ = class_id;
      if (!RawObject::IsInternalVMdefinedClassId(class_id)) {
        cls->ptr()->instance_size_in_words_ = d->Read<int32_t>();
        cls->ptr()->next_field_offset_in_words_ = d->Read<int32_t>();
      } else {
        d->Read<int32_t>();  // Skip.
        d->Read<int32_t>();  // Skip.
      }
      cls->ptr()->type_arguments_field_offset_in_words_ = d->Read<int32_t>();
      cls->ptr()->num_type_arguments_ = d->Read<uint16_t>();
      cls->ptr()->num_own_type_arguments_ = d->Read<uint16_t>();
      cls->ptr()->num_native_fields_ = d->Read<uint16_t>();
      cls->ptr()->token_pos_ = d->ReadTokenPosition();
      cls->ptr()->state_bits_ = d->Read<uint16_t>();
    }

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawClass* cls = reinterpret_cast<RawClass*>(d->Ref(id));
      Deserializer::InitializeHeader(cls, kClassCid, Class::InstanceSize(),
                                     is_vm_object);
      RawObject** from = cls->from();
      RawObject** to_snapshot = cls->to_snapshot(kind);
      RawObject** to = cls->to();
      for (RawObject** p = from; p <= to_snapshot; p++) {
        *p = d->ReadRef();
      }
      for (RawObject** p = to_snapshot + 1; p <= to; p++) {
        *p = Object::null();
      }

      intptr_t class_id = d->ReadCid();

      ASSERT(class_id >= kNumPredefinedCids);
      Instance fake;
      cls->ptr()->handle_vtable_ = fake.vtable();

      cls->ptr()->id_ = class_id;
      cls->ptr()->instance_size_in_words_ = d->Read<int32_t>();
      cls->ptr()->next_field_offset_in_words_ = d->Read<int32_t>();
      cls->ptr()->type_arguments_field_offset_in_words_ = d->Read<int32_t>();
      cls->ptr()->num_type_arguments_ = d->Read<uint16_t>();
      cls->ptr()->num_own_type_arguments_ = d->Read<uint16_t>();
      cls->ptr()->num_native_fields_ = d->Read<uint16_t>();
      cls->ptr()->token_pos_ = d->ReadTokenPosition();
      cls->ptr()->state_bits_ = d->Read<uint16_t>();

      table->AllocateIndex(class_id);
      table->SetAt(class_id, cls);
    }
  }

  void PostLoad(const Array& refs, Snapshot::Kind kind, Zone* zone) {
    NOT_IN_PRODUCT(TimelineDurationScope tds(
        Thread::Current(), Timeline::GetIsolateStream(), "PostLoadClass"));

    Class& cls = Class::Handle(zone);
    for (intptr_t i = predefined_start_index_; i < predefined_stop_index_;
         i++) {
      cls ^= refs.At(i);
      cls.RehashConstants(zone);
    }
    for (intptr_t i = start_index_; i < stop_index_; i++) {
      cls ^= refs.At(i);
      cls.RehashConstants(zone);
    }
  }

 private:
  intptr_t predefined_start_index_;
  intptr_t predefined_stop_index_;
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class UnresolvedClassSerializationCluster : public SerializationCluster {
 public:
  UnresolvedClassSerializationCluster() {}
  virtual ~UnresolvedClassSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawUnresolvedClass* cls = UnresolvedClass::RawCast(object);
    objects_.Add(cls);

    RawObject** from = cls->from();
    RawObject** to = cls->to();
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kUnresolvedClassCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawUnresolvedClass* cls = objects_[i];
      s->AssignRef(cls);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawUnresolvedClass* cls = objects_[i];
      RawObject** from = cls->from();
      RawObject** to = cls->to();
      for (RawObject** p = from; p <= to; p++) {
        s->WriteRef(*p);
      }
      s->WriteTokenPosition(cls->ptr()->token_pos_);
    }
  }

 private:
  GrowableArray<RawUnresolvedClass*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class UnresolvedClassDeserializationCluster : public DeserializationCluster {
 public:
  UnresolvedClassDeserializationCluster() {}
  virtual ~UnresolvedClassDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(
          AllocateUninitialized(old_space, UnresolvedClass::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawUnresolvedClass* cls =
          reinterpret_cast<RawUnresolvedClass*>(d->Ref(id));
      Deserializer::InitializeHeader(cls, kUnresolvedClassCid,
                                     UnresolvedClass::InstanceSize(),
                                     is_vm_object);
      RawObject** from = cls->from();
      RawObject** to = cls->to();
      for (RawObject** p = from; p <= to; p++) {
        *p = d->ReadRef();
      }
      cls->ptr()->token_pos_ = d->ReadTokenPosition();
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class TypeArgumentsSerializationCluster : public SerializationCluster {
 public:
  TypeArgumentsSerializationCluster() {}
  virtual ~TypeArgumentsSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawTypeArguments* type_args = TypeArguments::RawCast(object);
    objects_.Add(type_args);

    s->Push(type_args->ptr()->instantiations_);
    intptr_t length = Smi::Value(type_args->ptr()->length_);
    for (intptr_t i = 0; i < length; i++) {
      s->Push(type_args->ptr()->types()[i]);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kTypeArgumentsCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawTypeArguments* type_args = objects_[i];
      intptr_t length = Smi::Value(type_args->ptr()->length_);
      s->Write<int32_t>(length);
      s->AssignRef(type_args);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawTypeArguments* type_args = objects_[i];
      intptr_t length = Smi::Value(type_args->ptr()->length_);
      s->Write<int32_t>(length);
      s->Write<bool>(type_args->IsCanonical());
      intptr_t hash = Smi::Value(type_args->ptr()->hash_);
      s->Write<int32_t>(hash);
      s->WriteRef(type_args->ptr()->instantiations_);
      for (intptr_t j = 0; j < length; j++) {
        s->WriteRef(type_args->ptr()->types()[j]);
      }
    }
  }

 private:
  GrowableArray<RawTypeArguments*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class TypeArgumentsDeserializationCluster : public DeserializationCluster {
 public:
  TypeArgumentsDeserializationCluster() {}
  virtual ~TypeArgumentsDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      intptr_t length = d->Read<int32_t>();
      d->AssignRef(AllocateUninitialized(old_space,
                                         TypeArguments::InstanceSize(length)));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawTypeArguments* type_args =
          reinterpret_cast<RawTypeArguments*>(d->Ref(id));
      intptr_t length = d->Read<int32_t>();
      bool is_canonical = d->Read<bool>();
      Deserializer::InitializeHeader(type_args, kTypeArgumentsCid,
                                     TypeArguments::InstanceSize(length),
                                     is_vm_object, is_canonical);
      type_args->ptr()->length_ = Smi::New(length);
      type_args->ptr()->hash_ = Smi::New(d->Read<int32_t>());
      type_args->ptr()->instantiations_ =
          reinterpret_cast<RawArray*>(d->ReadRef());
      for (intptr_t j = 0; j < length; j++) {
        type_args->ptr()->types()[j] =
            reinterpret_cast<RawAbstractType*>(d->ReadRef());
      }
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class PatchClassSerializationCluster : public SerializationCluster {
 public:
  PatchClassSerializationCluster() {}
  virtual ~PatchClassSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawPatchClass* cls = PatchClass::RawCast(object);
    objects_.Add(cls);

    RawObject** from = cls->from();
    RawObject** to = cls->to();
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kPatchClassCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawPatchClass* cls = objects_[i];
      s->AssignRef(cls);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawPatchClass* cls = objects_[i];
      RawObject** from = cls->from();
      RawObject** to = cls->to();
      for (RawObject** p = from; p <= to; p++) {
        s->WriteRef(*p);
      }
    }
  }

 private:
  GrowableArray<RawPatchClass*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class PatchClassDeserializationCluster : public DeserializationCluster {
 public:
  PatchClassDeserializationCluster() {}
  virtual ~PatchClassDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(
          AllocateUninitialized(old_space, PatchClass::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawPatchClass* cls = reinterpret_cast<RawPatchClass*>(d->Ref(id));
      Deserializer::InitializeHeader(cls, kPatchClassCid,
                                     PatchClass::InstanceSize(), is_vm_object);
      RawObject** from = cls->from();
      RawObject** to = cls->to();
      for (RawObject** p = from; p <= to; p++) {
        *p = d->ReadRef();
      }
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class FunctionSerializationCluster : public SerializationCluster {
 public:
  FunctionSerializationCluster() {}
  virtual ~FunctionSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawFunction* func = Function::RawCast(object);
    objects_.Add(func);

    RawObject** from = func->from();
    RawObject** to = func->to_snapshot();
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
    if (s->kind() == Snapshot::kAppAOT) {
      s->Push(func->ptr()->code_);
    } else if (s->kind() == Snapshot::kAppJIT) {
      NOT_IN_PRECOMPILED(s->Push(func->ptr()->unoptimized_code_));
      s->Push(func->ptr()->code_);
      s->Push(func->ptr()->ic_data_array_);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kFunctionCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawFunction* func = objects_[i];
      s->AssignRef(func);
    }
  }

  void WriteFill(Serializer* s) {
    Snapshot::Kind kind = s->kind();
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawFunction* func = objects_[i];
      RawObject** from = func->from();
      RawObject** to = func->to_snapshot();
      for (RawObject** p = from; p <= to; p++) {
        s->WriteRef(*p);
      }
      if (kind == Snapshot::kAppAOT) {
        s->WriteRef(func->ptr()->code_);
      } else if (s->kind() == Snapshot::kAppJIT) {
        NOT_IN_PRECOMPILED(s->WriteRef(func->ptr()->unoptimized_code_));
        s->WriteRef(func->ptr()->code_);
        s->WriteRef(func->ptr()->ic_data_array_);
      }

#if !defined(DART_PRECOMPILED_RUNTIME)
      if (kind != Snapshot::kAppAOT) {
        s->WriteTokenPosition(func->ptr()->token_pos_);
        s->WriteTokenPosition(func->ptr()->end_token_pos_);
      }
#endif
      s->Write<int16_t>(func->ptr()->num_fixed_parameters_);
      s->Write<int16_t>(func->ptr()->num_optional_parameters_);
      s->Write<uint32_t>(func->ptr()->kind_tag_);
      if (kind == Snapshot::kAppAOT) {
        // Omit fields used to support de/reoptimization.
      } else if (!Snapshot::IncludesCode(kind)) {
#if !defined(DART_PRECOMPILED_RUNTIME)
        bool is_optimized = Code::IsOptimized(func->ptr()->code_);
        if (is_optimized) {
          s->Write<int32_t>(FLAG_optimization_counter_threshold);
        } else {
          s->Write<int32_t>(0);
        }
#endif
      }
    }
  }

 private:
  GrowableArray<RawFunction*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class FunctionDeserializationCluster : public DeserializationCluster {
 public:
  FunctionDeserializationCluster() {}
  virtual ~FunctionDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(AllocateUninitialized(old_space, Function::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    Snapshot::Kind kind = d->kind();
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawFunction* func = reinterpret_cast<RawFunction*>(d->Ref(id));
      Deserializer::InitializeHeader(func, kFunctionCid,
                                     Function::InstanceSize(), is_vm_object);
      RawObject** from = func->from();
      RawObject** to_snapshot = func->to_snapshot();
      RawObject** to = func->to();
      for (RawObject** p = from; p <= to_snapshot; p++) {
        *p = d->ReadRef();
      }
      for (RawObject** p = to_snapshot + 1; p <= to; p++) {
        *p = Object::null();
      }
      if (kind == Snapshot::kAppAOT) {
        func->ptr()->code_ = reinterpret_cast<RawCode*>(d->ReadRef());
      } else if (kind == Snapshot::kAppJIT) {
        NOT_IN_PRECOMPILED(func->ptr()->unoptimized_code_ =
                               reinterpret_cast<RawCode*>(d->ReadRef()));
        func->ptr()->code_ = reinterpret_cast<RawCode*>(d->ReadRef());
        func->ptr()->ic_data_array_ = reinterpret_cast<RawArray*>(d->ReadRef());
      }

#if defined(DEBUG)
      func->ptr()->entry_point_ = 0;
#endif

#if !defined(DART_PRECOMPILED_RUNTIME)
      if (kind != Snapshot::kAppAOT) {
        func->ptr()->token_pos_ = d->ReadTokenPosition();
        func->ptr()->end_token_pos_ = d->ReadTokenPosition();
      }
#endif
      func->ptr()->num_fixed_parameters_ = d->Read<int16_t>();
      func->ptr()->num_optional_parameters_ = d->Read<int16_t>();
      func->ptr()->kind_tag_ = d->Read<uint32_t>();
      if (kind == Snapshot::kAppAOT) {
        // Omit fields used to support de/reoptimization.
      } else {
#if !defined(DART_PRECOMPILED_RUNTIME)
        if (Snapshot::IncludesCode(kind)) {
          func->ptr()->usage_counter_ = 0;
        } else {
          func->ptr()->usage_counter_ = d->Read<int32_t>();
        }
        func->ptr()->deoptimization_counter_ = 0;
        func->ptr()->optimized_instruction_count_ = 0;
        func->ptr()->optimized_call_site_count_ = 0;
#endif
      }
    }
  }

  void PostLoad(const Array& refs, Snapshot::Kind kind, Zone* zone) {
    NOT_IN_PRODUCT(TimelineDurationScope tds(
        Thread::Current(), Timeline::GetIsolateStream(), "PostLoadFunction"));

    if (kind == Snapshot::kAppAOT) {
      Function& func = Function::Handle(zone);
      for (intptr_t i = start_index_; i < stop_index_; i++) {
        func ^= refs.At(i);
        ASSERT(func.raw()->ptr()->code_->IsCode());
        uword entry_point = func.raw()->ptr()->code_->ptr()->entry_point_;
        ASSERT(entry_point != 0);
        func.raw()->ptr()->entry_point_ = entry_point;
      }
    } else if (kind == Snapshot::kAppJIT) {
      Function& func = Function::Handle(zone);
      Code& code = Code::Handle(zone);
      for (intptr_t i = start_index_; i < stop_index_; i++) {
        func ^= refs.At(i);
        code ^= func.CurrentCode();
        if (func.HasCode() && !code.IsDisabled()) {
          func.SetInstructions(code);
          func.set_was_compiled(true);
        } else {
          func.ClearCode();
          func.set_was_compiled(false);
        }
      }
    } else {
      Function& func = Function::Handle(zone);
      for (intptr_t i = start_index_; i < stop_index_; i++) {
        func ^= refs.At(i);
        func.ClearICDataArray();
        func.ClearCode();
        func.set_was_compiled(false);
      }
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class ClosureDataSerializationCluster : public SerializationCluster {
 public:
  ClosureDataSerializationCluster() {}
  virtual ~ClosureDataSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawClosureData* data = ClosureData::RawCast(object);
    objects_.Add(data);

    if (s->kind() != Snapshot::kAppAOT) {
      s->Push(data->ptr()->context_scope_);
    }
    s->Push(data->ptr()->parent_function_);
    s->Push(data->ptr()->signature_type_);
    s->Push(data->ptr()->closure_);
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kClosureDataCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawClosureData* data = objects_[i];
      s->AssignRef(data);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawClosureData* data = objects_[i];
      if (s->kind() != Snapshot::kAppAOT) {
        s->WriteRef(data->ptr()->context_scope_);
      }
      s->WriteRef(data->ptr()->parent_function_);
      s->WriteRef(data->ptr()->signature_type_);
      s->WriteRef(data->ptr()->closure_);
    }
  }

 private:
  GrowableArray<RawClosureData*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class ClosureDataDeserializationCluster : public DeserializationCluster {
 public:
  ClosureDataDeserializationCluster() {}
  virtual ~ClosureDataDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(
          AllocateUninitialized(old_space, ClosureData::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawClosureData* data = reinterpret_cast<RawClosureData*>(d->Ref(id));
      Deserializer::InitializeHeader(data, kClosureDataCid,
                                     ClosureData::InstanceSize(), is_vm_object);
      if (d->kind() == Snapshot::kAppAOT) {
        data->ptr()->context_scope_ = ContextScope::null();
      } else {
        data->ptr()->context_scope_ =
            static_cast<RawContextScope*>(d->ReadRef());
      }
      data->ptr()->parent_function_ = static_cast<RawFunction*>(d->ReadRef());
      data->ptr()->signature_type_ = static_cast<RawType*>(d->ReadRef());
      data->ptr()->closure_ = static_cast<RawInstance*>(d->ReadRef());
      data->ptr()->hash_ = Object::null();
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class SignatureDataSerializationCluster : public SerializationCluster {
 public:
  SignatureDataSerializationCluster() {}
  virtual ~SignatureDataSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawSignatureData* data = SignatureData::RawCast(object);
    objects_.Add(data);

    RawObject** from = data->from();
    RawObject** to = data->to();
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kSignatureDataCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawSignatureData* data = objects_[i];
      s->AssignRef(data);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawSignatureData* data = objects_[i];
      RawObject** from = data->from();
      RawObject** to = data->to();
      for (RawObject** p = from; p <= to; p++) {
        s->WriteRef(*p);
      }
    }
  }

 private:
  GrowableArray<RawSignatureData*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class SignatureDataDeserializationCluster : public DeserializationCluster {
 public:
  SignatureDataDeserializationCluster() {}
  virtual ~SignatureDataDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(
          AllocateUninitialized(old_space, SignatureData::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawSignatureData* data = reinterpret_cast<RawSignatureData*>(d->Ref(id));
      Deserializer::InitializeHeader(
          data, kSignatureDataCid, SignatureData::InstanceSize(), is_vm_object);
      RawObject** from = data->from();
      RawObject** to = data->to();
      for (RawObject** p = from; p <= to; p++) {
        *p = d->ReadRef();
      }
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class RedirectionDataSerializationCluster : public SerializationCluster {
 public:
  RedirectionDataSerializationCluster() {}
  virtual ~RedirectionDataSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawRedirectionData* data = RedirectionData::RawCast(object);
    objects_.Add(data);

    RawObject** from = data->from();
    RawObject** to = data->to();
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kRedirectionDataCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawRedirectionData* data = objects_[i];
      s->AssignRef(data);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawRedirectionData* data = objects_[i];
      RawObject** from = data->from();
      RawObject** to = data->to();
      for (RawObject** p = from; p <= to; p++) {
        s->WriteRef(*p);
      }
    }
  }

 private:
  GrowableArray<RawRedirectionData*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class RedirectionDataDeserializationCluster : public DeserializationCluster {
 public:
  RedirectionDataDeserializationCluster() {}
  virtual ~RedirectionDataDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(
          AllocateUninitialized(old_space, RedirectionData::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawRedirectionData* data =
          reinterpret_cast<RawRedirectionData*>(d->Ref(id));
      Deserializer::InitializeHeader(data, kRedirectionDataCid,
                                     RedirectionData::InstanceSize(),
                                     is_vm_object);
      RawObject** from = data->from();
      RawObject** to = data->to();
      for (RawObject** p = from; p <= to; p++) {
        *p = d->ReadRef();
      }
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class FieldSerializationCluster : public SerializationCluster {
 public:
  FieldSerializationCluster() {}
  virtual ~FieldSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawField* field = Field::RawCast(object);
    objects_.Add(field);

    Snapshot::Kind kind = s->kind();

    s->Push(field->ptr()->name_);
    s->Push(field->ptr()->owner_);
    s->Push(field->ptr()->type_);
    // Write out the initial static value or field offset.
    if (Field::StaticBit::decode(field->ptr()->kind_bits_)) {
      if (kind == Snapshot::kAppAOT) {
        // For precompiled static fields, the value was already reset and
        // initializer_ now contains a Function.
        s->Push(field->ptr()->value_.static_value_);
      } else if (Field::ConstBit::decode(field->ptr()->kind_bits_)) {
        // Do not reset const fields.
        s->Push(field->ptr()->value_.static_value_);
      } else {
        // Otherwise, for static fields we write out the initial static value.
        s->Push(field->ptr()->initializer_.saved_value_);
      }
    } else {
      s->Push(field->ptr()->value_.offset_);
    }
    // Write out the initializer function or saved initial value.
    if (kind == Snapshot::kAppAOT) {
      s->Push(field->ptr()->initializer_.precompiled_);
    } else {
      s->Push(field->ptr()->initializer_.saved_value_);
    }
    if (kind != Snapshot::kAppAOT) {
      // Write out the guarded list length.
      s->Push(field->ptr()->guarded_list_length_);
    }
    if (kind == Snapshot::kAppJIT) {
      s->Push(field->ptr()->dependent_code_);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kFieldCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawField* field = objects_[i];
      s->AssignRef(field);
    }
  }

  void WriteFill(Serializer* s) {
    Snapshot::Kind kind = s->kind();
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawField* field = objects_[i];

      s->WriteRef(field->ptr()->name_);
      s->WriteRef(field->ptr()->owner_);
      s->WriteRef(field->ptr()->type_);
      // Write out the initial static value or field offset.
      if (Field::StaticBit::decode(field->ptr()->kind_bits_)) {
        if (kind == Snapshot::kAppAOT) {
          // For precompiled static fields, the value was already reset and
          // initializer_ now contains a Function.
          s->WriteRef(field->ptr()->value_.static_value_);
        } else if (Field::ConstBit::decode(field->ptr()->kind_bits_)) {
          // Do not reset const fields.
          s->WriteRef(field->ptr()->value_.static_value_);
        } else {
          // Otherwise, for static fields we write out the initial static value.
          s->WriteRef(field->ptr()->initializer_.saved_value_);
        }
      } else {
        s->WriteRef(field->ptr()->value_.offset_);
      }
      // Write out the initializer function or saved initial value.
      if (kind == Snapshot::kAppAOT) {
        s->WriteRef(field->ptr()->initializer_.precompiled_);
      } else {
        s->WriteRef(field->ptr()->initializer_.saved_value_);
      }
      if (kind != Snapshot::kAppAOT) {
        // Write out the guarded list length.
        s->WriteRef(field->ptr()->guarded_list_length_);
      }
      if (kind == Snapshot::kAppJIT) {
        s->WriteRef(field->ptr()->dependent_code_);
      }

      if (kind != Snapshot::kAppAOT) {
        s->WriteTokenPosition(field->ptr()->token_pos_);
        s->WriteCid(field->ptr()->guarded_cid_);
        s->WriteCid(field->ptr()->is_nullable_);
      }
      s->Write<uint8_t>(field->ptr()->kind_bits_);
    }
  }

 private:
  GrowableArray<RawField*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class FieldDeserializationCluster : public DeserializationCluster {
 public:
  FieldDeserializationCluster() {}
  virtual ~FieldDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(AllocateUninitialized(old_space, Field::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    Snapshot::Kind kind = d->kind();
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawField* field = reinterpret_cast<RawField*>(d->Ref(id));
      Deserializer::InitializeHeader(field, kFieldCid, Field::InstanceSize(),
                                     is_vm_object);
      RawObject** from = field->from();
      RawObject** to_snapshot = field->to_snapshot(kind);
      RawObject** to = field->to();
      for (RawObject** p = from; p <= to_snapshot; p++) {
        *p = d->ReadRef();
      }
      for (RawObject** p = to_snapshot + 1; p <= to; p++) {
        *p = Object::null();
      }

      if (kind != Snapshot::kAppAOT) {
        field->ptr()->token_pos_ = d->ReadTokenPosition();
        field->ptr()->guarded_cid_ = d->ReadCid();
        field->ptr()->is_nullable_ = d->ReadCid();
      }
      field->ptr()->kind_bits_ = d->Read<uint8_t>();
    }
  }

  void PostLoad(const Array& refs, Snapshot::Kind kind, Zone* zone) {
    NOT_IN_PRODUCT(TimelineDurationScope tds(
        Thread::Current(), Timeline::GetIsolateStream(), "PostLoadField"));

    Field& field = Field::Handle(zone);
    if (!Isolate::Current()->use_field_guards()) {
      for (intptr_t i = start_index_; i < stop_index_; i++) {
        field ^= refs.At(i);
        field.set_guarded_cid(kDynamicCid);
        field.set_is_nullable(true);
        field.set_guarded_list_length(Field::kNoFixedLength);
        field.set_guarded_list_length_in_object_offset(
            Field::kUnknownLengthOffset);
      }
    } else {
      for (intptr_t i = start_index_; i < stop_index_; i++) {
        field ^= refs.At(i);
        field.InitializeGuardedListLengthInObjectOffset();
      }
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class LiteralTokenSerializationCluster : public SerializationCluster {
 public:
  LiteralTokenSerializationCluster() {}
  virtual ~LiteralTokenSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawLiteralToken* token = LiteralToken::RawCast(object);
    objects_.Add(token);

    RawObject** from = token->from();
    RawObject** to = token->to();
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kLiteralTokenCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawLiteralToken* token = objects_[i];
      s->AssignRef(token);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawLiteralToken* token = objects_[i];
      RawObject** from = token->from();
      RawObject** to = token->to();
      for (RawObject** p = from; p <= to; p++) {
        s->WriteRef(*p);
      }
      s->Write<int32_t>(token->ptr()->kind_);
    }
  }

 private:
  GrowableArray<RawLiteralToken*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class LiteralTokenDeserializationCluster : public DeserializationCluster {
 public:
  LiteralTokenDeserializationCluster() {}
  virtual ~LiteralTokenDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(
          AllocateUninitialized(old_space, LiteralToken::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawLiteralToken* token = reinterpret_cast<RawLiteralToken*>(d->Ref(id));
      Deserializer::InitializeHeader(
          token, kLiteralTokenCid, LiteralToken::InstanceSize(), is_vm_object);
      RawObject** from = token->from();
      RawObject** to = token->to();
      for (RawObject** p = from; p <= to; p++) {
        *p = d->ReadRef();
      }
      token->ptr()->kind_ = static_cast<Token::Kind>(d->Read<int32_t>());
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class TokenStreamSerializationCluster : public SerializationCluster {
 public:
  TokenStreamSerializationCluster() {}
  virtual ~TokenStreamSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawTokenStream* stream = TokenStream::RawCast(object);
    objects_.Add(stream);

    RawObject** from = stream->from();
    RawObject** to = stream->to();
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kTokenStreamCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawTokenStream* stream = objects_[i];
      s->AssignRef(stream);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawTokenStream* stream = objects_[i];
      RawObject** from = stream->from();
      RawObject** to = stream->to();
      for (RawObject** p = from; p <= to; p++) {
        s->WriteRef(*p);
      }
    }
  }

 private:
  GrowableArray<RawTokenStream*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class TokenStreamDeserializationCluster : public DeserializationCluster {
 public:
  TokenStreamDeserializationCluster() {}
  virtual ~TokenStreamDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(
          AllocateUninitialized(old_space, TokenStream::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawTokenStream* stream = reinterpret_cast<RawTokenStream*>(d->Ref(id));
      Deserializer::InitializeHeader(stream, kTokenStreamCid,
                                     TokenStream::InstanceSize(), is_vm_object);
      RawObject** from = stream->from();
      RawObject** to = stream->to();
      for (RawObject** p = from; p <= to; p++) {
        *p = d->ReadRef();
      }
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class ScriptSerializationCluster : public SerializationCluster {
 public:
  ScriptSerializationCluster() {}
  virtual ~ScriptSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawScript* script = Script::RawCast(object);
    objects_.Add(script);

    RawObject** from = script->from();
    RawObject** to = script->to_snapshot(s->kind());
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kScriptCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawScript* script = objects_[i];
      s->AssignRef(script);
    }
  }

  void WriteFill(Serializer* s) {
    Snapshot::Kind kind = s->kind();
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawScript* script = objects_[i];
      RawObject** from = script->from();
      RawObject** to = script->to_snapshot(kind);
      for (RawObject** p = from; p <= to; p++) {
        s->WriteRef(*p);
      }

      s->Write<int32_t>(script->ptr()->line_offset_);
      s->Write<int32_t>(script->ptr()->col_offset_);
      s->Write<int8_t>(script->ptr()->kind_);
    }
  }

 private:
  GrowableArray<RawScript*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class ScriptDeserializationCluster : public DeserializationCluster {
 public:
  ScriptDeserializationCluster() {}
  virtual ~ScriptDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(AllocateUninitialized(old_space, Script::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    Snapshot::Kind kind = d->kind();
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawScript* script = reinterpret_cast<RawScript*>(d->Ref(id));
      Deserializer::InitializeHeader(script, kScriptCid, Script::InstanceSize(),
                                     is_vm_object);
      RawObject** from = script->from();
      RawObject** to_snapshot = script->to_snapshot(kind);
      RawObject** to = script->to();
      for (RawObject** p = from; p <= to_snapshot; p++) {
        *p = d->ReadRef();
      }
      for (RawObject** p = to_snapshot + 1; p <= to; p++) {
        *p = Object::null();
      }

      script->ptr()->line_offset_ = d->Read<int32_t>();
      script->ptr()->col_offset_ = d->Read<int32_t>();
      script->ptr()->kind_ = d->Read<int8_t>();
      script->ptr()->load_timestamp_ = 0;
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class LibrarySerializationCluster : public SerializationCluster {
 public:
  LibrarySerializationCluster() {}
  virtual ~LibrarySerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawLibrary* lib = Library::RawCast(object);
    objects_.Add(lib);

    RawObject** from = lib->from();
    RawObject** to = lib->to_snapshot();
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kLibraryCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawLibrary* lib = objects_[i];
      s->AssignRef(lib);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawLibrary* lib = objects_[i];
      RawObject** from = lib->from();
      RawObject** to = lib->to_snapshot();
      for (RawObject** p = from; p <= to; p++) {
        s->WriteRef(*p);
      }

      s->Write<int32_t>(lib->ptr()->index_);
      s->Write<uint16_t>(lib->ptr()->num_imports_);
      s->Write<int8_t>(lib->ptr()->load_state_);
      s->Write<bool>(lib->ptr()->corelib_imported_);
      s->Write<bool>(lib->ptr()->is_dart_scheme_);
      s->Write<bool>(lib->ptr()->debuggable_);
    }
  }

 private:
  GrowableArray<RawLibrary*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class LibraryDeserializationCluster : public DeserializationCluster {
 public:
  LibraryDeserializationCluster() {}
  virtual ~LibraryDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(AllocateUninitialized(old_space, Library::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawLibrary* lib = reinterpret_cast<RawLibrary*>(d->Ref(id));
      Deserializer::InitializeHeader(lib, kLibraryCid, Library::InstanceSize(),
                                     is_vm_object);
      RawObject** from = lib->from();
      RawObject** to_snapshot = lib->to_snapshot();
      RawObject** to = lib->to();
      for (RawObject** p = from; p <= to_snapshot; p++) {
        *p = d->ReadRef();
      }
      for (RawObject** p = to_snapshot + 1; p <= to; p++) {
        *p = Object::null();
      }

      lib->ptr()->native_entry_resolver_ = NULL;
      lib->ptr()->native_entry_symbol_resolver_ = NULL;
      lib->ptr()->index_ = d->Read<int32_t>();
      lib->ptr()->num_imports_ = d->Read<uint16_t>();
      lib->ptr()->load_state_ = d->Read<int8_t>();
      lib->ptr()->corelib_imported_ = d->Read<bool>();
      lib->ptr()->is_dart_scheme_ = d->Read<bool>();
      lib->ptr()->debuggable_ = d->Read<bool>();
      lib->ptr()->is_in_fullsnapshot_ = true;
    }
  }

  void PostLoad(const Array& refs, Snapshot::Kind kind, Zone* zone) {
    // TODO(rmacnak): This is surprisingly slow, roughly 20% of deserialization
    // time for the JIT. Maybe make the lookups happy with a null?

    NOT_IN_PRODUCT(TimelineDurationScope tds(
        Thread::Current(), Timeline::GetIsolateStream(), "PostLoadLibrary"));

    Library& lib = Library::Handle(zone);
    for (intptr_t i = start_index_; i < stop_index_; i++) {
      lib ^= refs.At(i);
      const intptr_t kInitialNameCacheSize = 64;
      lib.InitResolvedNamesCache(kInitialNameCacheSize);
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class NamespaceSerializationCluster : public SerializationCluster {
 public:
  NamespaceSerializationCluster() {}
  virtual ~NamespaceSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawNamespace* ns = Namespace::RawCast(object);
    objects_.Add(ns);

    RawObject** from = ns->from();
    RawObject** to = ns->to();
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kNamespaceCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawNamespace* ns = objects_[i];
      s->AssignRef(ns);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawNamespace* ns = objects_[i];
      RawObject** from = ns->from();
      RawObject** to = ns->to();
      for (RawObject** p = from; p <= to; p++) {
        s->WriteRef(*p);
      }
    }
  }

 private:
  GrowableArray<RawNamespace*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class NamespaceDeserializationCluster : public DeserializationCluster {
 public:
  NamespaceDeserializationCluster() {}
  virtual ~NamespaceDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(AllocateUninitialized(old_space, Namespace::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawNamespace* ns = reinterpret_cast<RawNamespace*>(d->Ref(id));
      Deserializer::InitializeHeader(ns, kNamespaceCid,
                                     Namespace::InstanceSize(), is_vm_object);
      RawObject** from = ns->from();
      RawObject** to = ns->to();
      for (RawObject** p = from; p <= to; p++) {
        *p = d->ReadRef();
      }
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class CodeSerializationCluster : public SerializationCluster {
 public:
  CodeSerializationCluster() {}
  virtual ~CodeSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawCode* code = Code::RawCast(object);
    objects_.Add(code);

    s->Push(code->ptr()->object_pool_);
    s->Push(code->ptr()->owner_);
    s->Push(code->ptr()->exception_handlers_);
    s->Push(code->ptr()->pc_descriptors_);
#if defined(DART_PRECOMPILED_RUNTIME) || defined(DART_PRECOMPILER)
    s->Push(code->ptr()->catch_entry_.catch_entry_state_maps_);
#else
    s->Push(code->ptr()->catch_entry_.variables_);
#endif
    s->Push(code->ptr()->stackmaps_);
    if (!FLAG_dwarf_stack_traces) {
      s->Push(code->ptr()->inlined_id_to_function_);
      s->Push(code->ptr()->code_source_map_);
    }
    if (s->kind() != Snapshot::kAppAOT) {
      s->Push(code->ptr()->await_token_positions_);
    }

    if (s->kind() == Snapshot::kAppJIT) {
      s->Push(code->ptr()->deopt_info_array_);
      s->Push(code->ptr()->static_calls_target_table_);
      NOT_IN_PRODUCT(s->Push(code->ptr()->return_address_metadata_));
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kCodeCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawCode* code = objects_[i];
      s->AssignRef(code);
    }
  }

  void WriteFill(Serializer* s) {
    Snapshot::Kind kind = s->kind();
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawCode* code = objects_[i];

      intptr_t pointer_offsets_length =
          Code::PtrOffBits::decode(code->ptr()->state_bits_);
      if (pointer_offsets_length != 0) {
        FATAL("Cannot serialize code with embedded pointers");
      }
      if (kind == Snapshot::kAppAOT) {
        // No disabled code in precompilation.
        NOT_IN_PRECOMPILED(ASSERT(code->ptr()->instructions_ ==
                                  code->ptr()->active_instructions_));
      }

      RawInstructions* instr = code->ptr()->instructions_;
      int32_t text_offset = s->GetTextOffset(instr, code);
      s->Write<int32_t>(text_offset);
      if (s->kind() == Snapshot::kAppJIT) {
        // TODO(rmacnak): Fix references to disabled code before serializing.
        if (code->ptr()->active_instructions_ != code->ptr()->instructions_) {
          instr = code->ptr()->active_instructions_;
          text_offset = s->GetTextOffset(instr, code);
        }
        s->Write<int32_t>(text_offset);
      }

      s->WriteRef(code->ptr()->object_pool_);
      s->WriteRef(code->ptr()->owner_);
      s->WriteRef(code->ptr()->exception_handlers_);
      s->WriteRef(code->ptr()->pc_descriptors_);
#if defined(DART_PRECOMPILED_RUNTIME) || defined(DART_PRECOMPILER)
      s->WriteRef(code->ptr()->catch_entry_.catch_entry_state_maps_);
#else
      s->WriteRef(code->ptr()->catch_entry_.variables_);
#endif
      s->WriteRef(code->ptr()->stackmaps_);
      if (FLAG_dwarf_stack_traces) {
        s->WriteRef(Array::null());
        s->WriteRef(CodeSourceMap::null());
      } else {
        s->WriteRef(code->ptr()->inlined_id_to_function_);
        s->WriteRef(code->ptr()->code_source_map_);
      }
      if (s->kind() != Snapshot::kAppAOT) {
        s->WriteRef(code->ptr()->await_token_positions_);
      }
      if (s->kind() == Snapshot::kAppJIT) {
        s->WriteRef(code->ptr()->deopt_info_array_);
        s->WriteRef(code->ptr()->static_calls_target_table_);
        NOT_IN_PRODUCT(s->WriteRef(code->ptr()->return_address_metadata_));
      }

      s->Write<int32_t>(code->ptr()->state_bits_);
    }
  }

 private:
  GrowableArray<RawCode*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class CodeDeserializationCluster : public DeserializationCluster {
 public:
  CodeDeserializationCluster() {}
  virtual ~CodeDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(AllocateUninitialized(old_space, Code::InstanceSize(0)));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawCode* code = reinterpret_cast<RawCode*>(d->Ref(id));
      Deserializer::InitializeHeader(code, kCodeCid, Code::InstanceSize(0),
                                     is_vm_object);

      int32_t text_offset = d->Read<int32_t>();
      RawInstructions* instr = d->GetInstructionsAt(text_offset);

      code->ptr()->entry_point_ = Instructions::UncheckedEntryPoint(instr);
      code->ptr()->checked_entry_point_ =
          Instructions::CheckedEntryPoint(instr);
      NOT_IN_PRECOMPILED(code->ptr()->active_instructions_ = instr);
      code->ptr()->instructions_ = instr;

#if !defined(DART_PRECOMPILED_RUNTIME)
      if (d->kind() == Snapshot::kAppJIT) {
        int32_t text_offset = d->Read<int32_t>();
        RawInstructions* instr = d->GetInstructionsAt(text_offset);
        code->ptr()->active_instructions_ = instr;
        code->ptr()->entry_point_ = Instructions::UncheckedEntryPoint(instr);
        code->ptr()->checked_entry_point_ =
            Instructions::CheckedEntryPoint(instr);
      }
#endif  // !DART_PRECOMPILED_RUNTIME

      code->ptr()->object_pool_ =
          reinterpret_cast<RawObjectPool*>(d->ReadRef());
      code->ptr()->owner_ = d->ReadRef();
      code->ptr()->exception_handlers_ =
          reinterpret_cast<RawExceptionHandlers*>(d->ReadRef());
      code->ptr()->pc_descriptors_ =
          reinterpret_cast<RawPcDescriptors*>(d->ReadRef());
#if defined(DART_PRECOMPILED_RUNTIME) || defined(DART_PRECOMPILER)
      code->ptr()->catch_entry_.catch_entry_state_maps_ =
          reinterpret_cast<RawTypedData*>(d->ReadRef());
#else
      code->ptr()->catch_entry_.variables_ =
          reinterpret_cast<RawSmi*>(d->ReadRef());
#endif
      code->ptr()->stackmaps_ = reinterpret_cast<RawArray*>(d->ReadRef());
      code->ptr()->inlined_id_to_function_ =
          reinterpret_cast<RawArray*>(d->ReadRef());
      code->ptr()->code_source_map_ =
          reinterpret_cast<RawCodeSourceMap*>(d->ReadRef());

#if !defined(DART_PRECOMPILED_RUNTIME)
      code->ptr()->await_token_positions_ =
          reinterpret_cast<RawArray*>(d->ReadRef());

      if (d->kind() == Snapshot::kAppJIT) {
        code->ptr()->deopt_info_array_ =
            reinterpret_cast<RawArray*>(d->ReadRef());
        code->ptr()->static_calls_target_table_ =
            reinterpret_cast<RawArray*>(d->ReadRef());
#if defined(PRODUCT)
        code->ptr()->return_address_metadata_ = Object::null();
#else
        code->ptr()->return_address_metadata_ = d->ReadRef();
#endif
      } else {
        code->ptr()->deopt_info_array_ = Array::null();
        code->ptr()->static_calls_target_table_ = Array::null();
        code->ptr()->return_address_metadata_ = Object::null();
      }

      code->ptr()->var_descriptors_ = LocalVarDescriptors::null();
      code->ptr()->comments_ = Array::null();

      code->ptr()->compile_timestamp_ = 0;
#endif  // !DART_PRECOMPILED_RUNTIME

      code->ptr()->state_bits_ = d->Read<int32_t>();
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class ObjectPoolSerializationCluster : public SerializationCluster {
 public:
  ObjectPoolSerializationCluster() {}
  virtual ~ObjectPoolSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawObjectPool* pool = ObjectPool::RawCast(object);
    objects_.Add(pool);

    intptr_t length = pool->ptr()->length_;
    RawTypedData* info_array = pool->ptr()->info_array_;

    for (intptr_t i = 0; i < length; i++) {
      ObjectPool::EntryType entry_type =
          static_cast<ObjectPool::EntryType>(info_array->ptr()->data()[i]);
      if (entry_type == ObjectPool::kTaggedObject) {
        s->Push(pool->ptr()->data()[i].raw_obj_);
      }
    }

    // TODO(rmacnak): Allocate the object pool and its info array together.
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kObjectPoolCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawObjectPool* pool = objects_[i];
      intptr_t length = pool->ptr()->length_;
      s->Write<int32_t>(length);
      s->AssignRef(pool);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawObjectPool* pool = objects_[i];
      RawTypedData* info_array = pool->ptr()->info_array_;
      intptr_t length = pool->ptr()->length_;
      s->Write<int32_t>(length);
      for (intptr_t j = 0; j < length; j++) {
        ObjectPool::EntryType entry_type =
            static_cast<ObjectPool::EntryType>(info_array->ptr()->data()[j]);
        s->Write<int8_t>(entry_type);
        RawObjectPool::Entry& entry = pool->ptr()->data()[j];
        switch (entry_type) {
          case ObjectPool::kTaggedObject: {
#if !defined(TARGET_ARCH_DBC)
            if (entry.raw_obj_ ==
                StubCode::CallNativeCFunction_entry()->code()) {
              // Natives can run while precompiling, becoming linked and
              // switching their stub. Reset to the initial stub used for
              // lazy-linking.
              s->WriteRef(StubCode::CallBootstrapCFunction_entry()->code());
              break;
            }
#endif
            s->WriteRef(entry.raw_obj_);
            break;
          }
          case ObjectPool::kImmediate: {
            s->Write<intptr_t>(entry.raw_value_);
            break;
          }
          case ObjectPool::kNativeEntry: {
// Write nothing. Will initialize with the lazy link entry.
#if defined(TARGET_ARCH_DBC)
            UNREACHABLE();  // DBC does not support lazy native call linking.
#endif
            break;
          }
          default:
            UNREACHABLE();
        }
      }
    }
  }

 private:
  GrowableArray<RawObjectPool*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class ObjectPoolDeserializationCluster : public DeserializationCluster {
 public:
  ObjectPoolDeserializationCluster() {}
  virtual ~ObjectPoolDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      intptr_t length = d->Read<int32_t>();
      d->AssignRef(
          AllocateUninitialized(old_space, ObjectPool::InstanceSize(length)));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();
    PageSpace* old_space = d->heap()->old_space();
    for (intptr_t id = start_index_; id < stop_index_; id += 1) {
      intptr_t length = d->Read<int32_t>();
      RawTypedData* info_array = reinterpret_cast<RawTypedData*>(
          AllocateUninitialized(old_space, TypedData::InstanceSize(length)));
      Deserializer::InitializeHeader(info_array, kTypedDataUint8ArrayCid,
                                     TypedData::InstanceSize(length),
                                     is_vm_object);
      info_array->ptr()->length_ = Smi::New(length);
      RawObjectPool* pool = reinterpret_cast<RawObjectPool*>(d->Ref(id + 0));
      Deserializer::InitializeHeader(
          pool, kObjectPoolCid, ObjectPool::InstanceSize(length), is_vm_object);
      pool->ptr()->length_ = length;
      pool->ptr()->info_array_ = info_array;
      for (intptr_t j = 0; j < length; j++) {
        ObjectPool::EntryType entry_type =
            static_cast<ObjectPool::EntryType>(d->Read<int8_t>());
        info_array->ptr()->data()[j] = entry_type;
        RawObjectPool::Entry& entry = pool->ptr()->data()[j];
        switch (entry_type) {
          case ObjectPool::kTaggedObject:
            entry.raw_obj_ = d->ReadRef();
            break;
          case ObjectPool::kImmediate:
            entry.raw_value_ = d->Read<intptr_t>();
            break;
          case ObjectPool::kNativeEntry: {
#if !defined(TARGET_ARCH_DBC)
            // Read nothing. Initialize with the lazy link entry.
            uword new_entry = NativeEntry::LinkNativeCallEntry();
            entry.raw_value_ = static_cast<intptr_t>(new_entry);
#else
            UNREACHABLE();  // DBC does not support lazy native call linking.
#endif
            break;
          }
          default:
            UNREACHABLE();
        }
      }
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
// PcDescriptor, StackMap, OneByteString, TwoByteString
class RODataSerializationCluster : public SerializationCluster {
 public:
  explicit RODataSerializationCluster(intptr_t cid) : cid_(cid) {}
  virtual ~RODataSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    objects_.Add(object);

    // A string's hash must already be computed when we write it because it
    // will be loaded into read-only memory.
    if (cid_ == kOneByteStringCid) {
      RawOneByteString* str = static_cast<RawOneByteString*>(object);
      if (str->ptr()->hash_ == Smi::New(0)) {
        intptr_t hash =
            String::Hash(str->ptr()->data(), Smi::Value(str->ptr()->length_));
        str->ptr()->hash_ = Smi::New(hash);
      }
      ASSERT(str->ptr()->hash_ != Smi::New(0));
    } else if (cid_ == kTwoByteStringCid) {
      RawTwoByteString* str = static_cast<RawTwoByteString*>(object);
      if (str->ptr()->hash_ == Smi::New(0)) {
        intptr_t hash = String::Hash(str->ptr()->data(),
                                     Smi::Value(str->ptr()->length_) * 2);
        str->ptr()->hash_ = Smi::New(hash);
      }
      ASSERT(str->ptr()->hash_ != Smi::New(0));
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(cid_);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawObject* object = objects_[i];
      int32_t rodata_offset = s->GetRODataOffset(object);
      s->Write<int32_t>(rodata_offset);
      s->AssignRef(object);
    }
  }

  void WriteFill(Serializer* s) {
    // No-op.
  }

 private:
  const intptr_t cid_;
  GrowableArray<RawObject*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class RODataDeserializationCluster : public DeserializationCluster {
 public:
  RODataDeserializationCluster() {}
  virtual ~RODataDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      int32_t rodata_offset = d->Read<int32_t>();
      d->AssignRef(d->GetObjectAt(rodata_offset));
    }
  }

  void ReadFill(Deserializer* d) {
    // No-op.
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class ExceptionHandlersSerializationCluster : public SerializationCluster {
 public:
  ExceptionHandlersSerializationCluster() {}
  virtual ~ExceptionHandlersSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawExceptionHandlers* handlers = ExceptionHandlers::RawCast(object);
    objects_.Add(handlers);

    s->Push(handlers->ptr()->handled_types_data_);
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kExceptionHandlersCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawExceptionHandlers* handlers = objects_[i];
      intptr_t length = handlers->ptr()->num_entries_;
      s->Write<int32_t>(length);
      s->AssignRef(handlers);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawExceptionHandlers* handlers = objects_[i];
      intptr_t length = handlers->ptr()->num_entries_;
      s->Write<int32_t>(length);
      s->WriteRef(handlers->ptr()->handled_types_data_);

      uint8_t* data = reinterpret_cast<uint8_t*>(handlers->ptr()->data());
      intptr_t length_in_bytes = length * sizeof(ExceptionHandlerInfo);
      s->WriteBytes(data, length_in_bytes);
    }
  }

 private:
  GrowableArray<RawExceptionHandlers*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class ExceptionHandlersDeserializationCluster : public DeserializationCluster {
 public:
  ExceptionHandlersDeserializationCluster() {}
  virtual ~ExceptionHandlersDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      intptr_t length = d->Read<int32_t>();
      d->AssignRef(AllocateUninitialized(
          old_space, ExceptionHandlers::InstanceSize(length)));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawExceptionHandlers* handlers =
          reinterpret_cast<RawExceptionHandlers*>(d->Ref(id));
      intptr_t length = d->Read<int32_t>();
      Deserializer::InitializeHeader(handlers, kExceptionHandlersCid,
                                     ExceptionHandlers::InstanceSize(length),
                                     is_vm_object);
      handlers->ptr()->num_entries_ = length;
      handlers->ptr()->handled_types_data_ =
          reinterpret_cast<RawArray*>(d->ReadRef());

      uint8_t* data = reinterpret_cast<uint8_t*>(handlers->ptr()->data());
      intptr_t length_in_bytes = length * sizeof(ExceptionHandlerInfo);
      d->ReadBytes(data, length_in_bytes);
    }
  }
};

#if !defined(DART_PRECOMPILED_RUNTIME)
class ContextSerializationCluster : public SerializationCluster {
 public:
  ContextSerializationCluster() {}
  virtual ~ContextSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawContext* context = Context::RawCast(object);
    objects_.Add(context);

    s->Push(context->ptr()->parent_);
    intptr_t length = context->ptr()->num_variables_;
    for (intptr_t i = 0; i < length; i++) {
      s->Push(context->ptr()->data()[i]);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kContextCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawContext* context = objects_[i];
      intptr_t length = context->ptr()->num_variables_;
      s->Write<int32_t>(length);
      s->AssignRef(context);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawContext* context = objects_[i];
      intptr_t length = context->ptr()->num_variables_;
      s->Write<int32_t>(length);
      s->WriteRef(context->ptr()->parent_);
      for (intptr_t j = 0; j < length; j++) {
        s->WriteRef(context->ptr()->data()[j]);
      }
    }
  }

 private:
  GrowableArray<RawContext*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class ContextDeserializationCluster : public DeserializationCluster {
 public:
  ContextDeserializationCluster() {}
  virtual ~ContextDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      intptr_t length = d->Read<int32_t>();
      d->AssignRef(
          AllocateUninitialized(old_space, Context::InstanceSize(length)));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawContext* context = reinterpret_cast<RawContext*>(d->Ref(id));
      intptr_t length = d->Read<int32_t>();
      Deserializer::InitializeHeader(
          context, kContextCid, Context::InstanceSize(length), is_vm_object);
      context->ptr()->num_variables_ = length;
      context->ptr()->parent_ = reinterpret_cast<RawContext*>(d->ReadRef());
      for (intptr_t j = 0; j < length; j++) {
        context->ptr()->data()[j] = d->ReadRef();
      }
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class ContextScopeSerializationCluster : public SerializationCluster {
 public:
  ContextScopeSerializationCluster() {}
  virtual ~ContextScopeSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawContextScope* scope = ContextScope::RawCast(object);
    objects_.Add(scope);

    intptr_t length = scope->ptr()->num_variables_;
    RawObject** from = scope->from();
    RawObject** to = scope->to(length);
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kContextScopeCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawContextScope* scope = objects_[i];
      intptr_t length = scope->ptr()->num_variables_;
      s->Write<int32_t>(length);
      s->AssignRef(scope);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawContextScope* scope = objects_[i];
      intptr_t length = scope->ptr()->num_variables_;
      s->Write<int32_t>(length);
      s->Write<bool>(scope->ptr()->is_implicit_);
      RawObject** from = scope->from();
      RawObject** to = scope->to(length);
      for (RawObject** p = from; p <= to; p++) {
        s->WriteRef(*p);
      }
    }
  }

 private:
  GrowableArray<RawContextScope*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class ContextScopeDeserializationCluster : public DeserializationCluster {
 public:
  ContextScopeDeserializationCluster() {}
  virtual ~ContextScopeDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      intptr_t length = d->Read<int32_t>();
      d->AssignRef(
          AllocateUninitialized(old_space, ContextScope::InstanceSize(length)));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawContextScope* scope = reinterpret_cast<RawContextScope*>(d->Ref(id));
      intptr_t length = d->Read<int32_t>();
      Deserializer::InitializeHeader(scope, kContextScopeCid,
                                     ContextScope::InstanceSize(length),
                                     is_vm_object);
      scope->ptr()->num_variables_ = length;
      scope->ptr()->is_implicit_ = d->Read<bool>();
      RawObject** from = scope->from();
      RawObject** to = scope->to(length);
      for (RawObject** p = from; p <= to; p++) {
        *p = d->ReadRef();
      }
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class UnlinkedCallSerializationCluster : public SerializationCluster {
 public:
  UnlinkedCallSerializationCluster() {}
  virtual ~UnlinkedCallSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawUnlinkedCall* unlinked = UnlinkedCall::RawCast(object);
    objects_.Add(unlinked);

    RawObject** from = unlinked->from();
    RawObject** to = unlinked->to();
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kUnlinkedCallCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawUnlinkedCall* unlinked = objects_[i];
      s->AssignRef(unlinked);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawUnlinkedCall* unlinked = objects_[i];
      RawObject** from = unlinked->from();
      RawObject** to = unlinked->to();
      for (RawObject** p = from; p <= to; p++) {
        s->WriteRef(*p);
      }
    }
  }

 private:
  GrowableArray<RawUnlinkedCall*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class UnlinkedCallDeserializationCluster : public DeserializationCluster {
 public:
  UnlinkedCallDeserializationCluster() {}
  virtual ~UnlinkedCallDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(
          AllocateUninitialized(old_space, UnlinkedCall::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawUnlinkedCall* unlinked =
          reinterpret_cast<RawUnlinkedCall*>(d->Ref(id));
      Deserializer::InitializeHeader(unlinked, kUnlinkedCallCid,
                                     UnlinkedCall::InstanceSize(),
                                     is_vm_object);
      RawObject** from = unlinked->from();
      RawObject** to = unlinked->to();
      for (RawObject** p = from; p <= to; p++) {
        *p = d->ReadRef();
      }
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class ICDataSerializationCluster : public SerializationCluster {
 public:
  ICDataSerializationCluster() {}
  virtual ~ICDataSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawICData* ic = ICData::RawCast(object);
    objects_.Add(ic);

    RawObject** from = ic->from();
    RawObject** to = ic->to_snapshot(s->kind());
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kICDataCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawICData* ic = objects_[i];
      s->AssignRef(ic);
    }
  }

  void WriteFill(Serializer* s) {
    Snapshot::Kind kind = s->kind();
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawICData* ic = objects_[i];
      RawObject** from = ic->from();
      RawObject** to = ic->to_snapshot(kind);
      for (RawObject** p = from; p <= to; p++) {
        s->WriteRef(*p);
      }
      if (kind != Snapshot::kAppAOT) {
        NOT_IN_PRECOMPILED(s->Write<int32_t>(ic->ptr()->deopt_id_));
      }
      s->Write<uint32_t>(ic->ptr()->state_bits_);
#if defined(TAG_IC_DATA)
      s->Write<int32_t>(ic->ptr()->tag_);
#endif
    }
  }

 private:
  GrowableArray<RawICData*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class ICDataDeserializationCluster : public DeserializationCluster {
 public:
  ICDataDeserializationCluster() {}
  virtual ~ICDataDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(AllocateUninitialized(old_space, ICData::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    Snapshot::Kind kind = d->kind();
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawICData* ic = reinterpret_cast<RawICData*>(d->Ref(id));
      Deserializer::InitializeHeader(ic, kICDataCid, ICData::InstanceSize(),
                                     is_vm_object);
      RawObject** from = ic->from();
      RawObject** to_snapshot = ic->to_snapshot(kind);
      RawObject** to = ic->to();
      for (RawObject** p = from; p <= to_snapshot; p++) {
        *p = d->ReadRef();
      }
      for (RawObject** p = to_snapshot + 1; p <= to; p++) {
        *p = Object::null();
      }
      NOT_IN_PRECOMPILED(ic->ptr()->deopt_id_ = d->Read<int32_t>());
      ic->ptr()->state_bits_ = d->Read<int32_t>();
#if defined(TAG_IC_DATA)
      ic->ptr()->tag_ = d->Read<int32_t>();
#endif
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class MegamorphicCacheSerializationCluster : public SerializationCluster {
 public:
  MegamorphicCacheSerializationCluster() {}
  virtual ~MegamorphicCacheSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawMegamorphicCache* cache = MegamorphicCache::RawCast(object);
    objects_.Add(cache);

    RawObject** from = cache->from();
    RawObject** to = cache->to();
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kMegamorphicCacheCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawMegamorphicCache* cache = objects_[i];
      s->AssignRef(cache);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawMegamorphicCache* cache = objects_[i];
      RawObject** from = cache->from();
      RawObject** to = cache->to();
      for (RawObject** p = from; p <= to; p++) {
        s->WriteRef(*p);
      }
      s->Write<int32_t>(cache->ptr()->filled_entry_count_);
    }
  }

 private:
  GrowableArray<RawMegamorphicCache*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class MegamorphicCacheDeserializationCluster : public DeserializationCluster {
 public:
  MegamorphicCacheDeserializationCluster() {}
  virtual ~MegamorphicCacheDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(
          AllocateUninitialized(old_space, MegamorphicCache::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawMegamorphicCache* cache =
          reinterpret_cast<RawMegamorphicCache*>(d->Ref(id));
      Deserializer::InitializeHeader(cache, kMegamorphicCacheCid,
                                     MegamorphicCache::InstanceSize(),
                                     is_vm_object);
      RawObject** from = cache->from();
      RawObject** to = cache->to();
      for (RawObject** p = from; p <= to; p++) {
        *p = d->ReadRef();
      }
      cache->ptr()->filled_entry_count_ = d->Read<int32_t>();
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class SubtypeTestCacheSerializationCluster : public SerializationCluster {
 public:
  SubtypeTestCacheSerializationCluster() {}
  virtual ~SubtypeTestCacheSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawSubtypeTestCache* cache = SubtypeTestCache::RawCast(object);
    objects_.Add(cache);
    s->Push(cache->ptr()->cache_);
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kSubtypeTestCacheCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawSubtypeTestCache* cache = objects_[i];
      s->AssignRef(cache);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawSubtypeTestCache* cache = objects_[i];
      s->WriteRef(cache->ptr()->cache_);
    }
  }

 private:
  GrowableArray<RawSubtypeTestCache*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class SubtypeTestCacheDeserializationCluster : public DeserializationCluster {
 public:
  SubtypeTestCacheDeserializationCluster() {}
  virtual ~SubtypeTestCacheDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(
          AllocateUninitialized(old_space, SubtypeTestCache::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawSubtypeTestCache* cache =
          reinterpret_cast<RawSubtypeTestCache*>(d->Ref(id));
      Deserializer::InitializeHeader(cache, kSubtypeTestCacheCid,
                                     SubtypeTestCache::InstanceSize(),
                                     is_vm_object);
      cache->ptr()->cache_ = reinterpret_cast<RawArray*>(d->ReadRef());
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class LanguageErrorSerializationCluster : public SerializationCluster {
 public:
  LanguageErrorSerializationCluster() {}
  virtual ~LanguageErrorSerializationCluster() {}

  void Trace(Serializer* s, RawObject* object) {
    RawLanguageError* error = LanguageError::RawCast(object);
    objects_.Add(error);

    RawObject** from = error->from();
    RawObject** to = error->to();
    for (RawObject** p = from; p <= to; p++) {
      s->Push(*p);
    }
  }

  void WriteAlloc(Serializer* s) {
    s->WriteCid(kLanguageErrorCid);
    intptr_t count = objects_.length();
    s->Write<int32_t>(count);
    for (intptr_t i = 0; i < count; i++) {
      RawLanguageError* error = objects_[i];
      s->AssignRef(error);
    }
  }

  void WriteFill(Serializer* s) {
    intptr_t count = objects_.length();
    for (intptr_t i = 0; i < count; i++) {
      RawLanguageError* error = objects_[i];
      RawObject** from = error->from();
      RawObject** to = error->to();
      for (RawObject** p = from; p <= to; p++) {
        s->WriteRef(*p);
      }
      s->WriteTokenPosition(error->ptr()->token_pos_);
      s->Write<bool>(error->ptr()->report_after_token_);
      s->Write<int8_t>(error->ptr()->kind_);
    }
  }

 private:
  GrowableArray<RawLanguageError*> objects_;
};
#endif  // !DART_PRECOMPILED_RUNTIME


class LanguageErrorDeserializationCluster : public DeserializationCluster {
 public:
  LanguageErrorDeserializationCluster() {}
  virtual ~LanguageErrorDeserializationCluster() {}

  void ReadAlloc(Deserializer* d) {
    start_index_ = d->next_index();
    PageSpace* old_space = d->heap()->old_space();
    intptr_t count = d->Read<int32_t>();
    for (intptr_t i = 0; i < count; i++) {
      d->AssignRef(
          AllocateUninitialized(old_space, LanguageError::InstanceSize()));
    }
    stop_index_ = d->next_index();
  }

  void ReadFill(Deserializer* d) {
    bool is_vm_object = d->isolate() == Dart::vm_isolate();

    for (intptr_t id = start_index_; id < stop_index_; id++) {
      RawLanguageError* error = reinterpret_cast<RawLanguageError*>(d->Ref(id));
      Deserializer::InitializeHeader(error, kLanguageErrorCid,
                                     LanguageError::InstanceSize(),
                                     is_vm_object);
      RawObject** from = error->from();
      RawObject** to = error->to();
      for (RawObject** p = from; p <= to; p++) {
        *p = d->ReadRef();
      }
      error->ptr()->token_pos_ = d->ReadTokenPosition();
      error->ptr()->report_after_token_ = d->Read<bool>();
      error->ptr()->kind_ = d->Read<int8_t>();
    }
  }
};


#if !defined(DART_PRECOMPILED_RUNTIME)
class UnhandledExceptionSerializationCluster : public SerializationCluster {
 public:
  UnhandledExceptionSerializationCluster() {}
  virtual ~UnhandledExceptionSerializationCluster() {}

  void Trace(Serializer*