Decode the Dart message into a Dart_CMessage structure before calling the native port callback

The native port callback is now passed the message as a decodes
Dart_CMessage structure. The Dart_CMessage structure is allocated
in a zone and the callback receiving it should expect the
lifetime to be controlled by the caller.

Added support for zones which do not require a current
isolate. Changed the GrowableArray to support allocating in
aprovided zone instead of the zone for the current isolate.

R=turnidge@google.com, asiva@google.com

BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com//9325022

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@4068 260f80e4-7a28-3924-810f-c04153c831b5

runtime/include/dart_api.h

@@ -535,16 +535,69 @@ DART_EXPORT bool Dart_HasLivePorts();
  */
 DART_EXPORT bool Dart_Post(Dart_Port port_id, Dart_Handle object);
 
+// --- Message sending/receiving from native code ----
+
+/**
+ * A Dart_CObject is used for representing Dart objects as native C
+ * data outside the Dart heap. These objects are totally detached from
+ * the Dart heap. Only a subset of the Dart objects have a
+ * representation as a Dart_CObject.
+ */
+struct Dart_CObject {
+  enum Type {
+    kNull = 0,
+    kBool,
+    kInt32,
+    kDouble,
+    kString,
+    kArray,
+    kNumberOfTypes
+  };
+  Type type;
+  union {
+    bool as_bool;
+    int32_t as_int32;
+    double as_double;
+    char* as_string;
+    struct {
+      int length;
+      Dart_CObject** values;
+    } as_array;
+  } value;
+};
+
+/**
+ * Posts a message on some port. The message will contain the
+ * Dart_CObject object graph rooted in 'message'.
+ *
+ * While the message is being sent the state of the graph of
+ * Dart_CObject structures rooted in 'message' should not be accessed,
+ * as the message generation will make temporary modifications to the
+ * data. When the message has been sent the graph will be fully
+ * restored.
+ *
+ * \param port_id The destination port.
+ * \param message The message to send.
+ *
+ * \return True if the message was posted.
+ */
+DART_EXPORT bool Dart_PostCObject(Dart_Port port_id, Dart_CObject* message);
+
 /**
  * A native message handler.
  *
  * This handler is associated with a native port by calling
  * Dart_NewNativePort.
+ *
+ * The message received is decoded into the message structure. The
+ * lifetime of the message data is controlled by the caller. All the
+ * data references from the message are allocated by the caller and
+ * will be reclaimed when returning to it.
  */
+
 typedef void (*Dart_NativeMessageHandler)(Dart_Port dest_port_id,
                                           Dart_Port reply_port_id,
-                                          uint8_t* data);
-// TODO(turnidge): Make this function take more appropriate arguments.
+                                          Dart_CObject* message);
 
 /**
  * Creates a new native port.  When messages are received on this
@@ -1414,52 +1467,4 @@ DART_EXPORT Dart_Handle Dart_SetNativeResolver(
 DART_EXPORT void Dart_InitPprofSupport();
 DART_EXPORT void Dart_GetPprofSymbolInfo(void** buffer, int* buffer_size);
 
-// --- Message sending/receiving from native code ----
-
-/**
- * A Dart_CObject is used for representing Dart objects as native C
- * data outside the Dart heap. These objects are totally detached from
- * the Dart heap. Only a subset of the Dart objects have a
- * representation as a Dart_CObject.
- */
-struct Dart_CObject {
-  enum Type {
-    kNull = 0,
-    kBool,
-    kInt32,
-    kDouble,
-    kString,
-    kArray,
-    kNumberOfTypes
-  };
-  Type type;
-  union {
-    bool as_bool;
-    int32_t as_int32;
-    double as_double;
-    char* as_string;
-    struct {
-      int length;
-      Dart_CObject** values;
-    } as_array;
-  } value;
-};
-
-/**
- * Posts a message on some port. The message will contain the
- * Dart_CObject object graph rooted in 'message'.
- *
- * While the message is being sent the state of the graph of
- * Dart_CObject structures rooted in 'message' should not be accessed,
- * as the message generation will make temporary modifications to the
- * data. When the message has been sent the graph will be fully
- * restored.
- *
- * \param port_id The destination port.
- * \param message The message to send.
- *
- * \return True if the message was posted.
- */
-DART_EXPORT bool Dart_PostCObject(Dart_Port port_id, Dart_CObject* message);
-
 #endif  // INCLUDE_DART_API_H_

runtime/vm/dart.cc

@@ -1,10 +1,11 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/dart.h"
 
 #include "vm/code_index_table.h"
+#include "vm/dart_api_state.h"
 #include "vm/flags.h"
 #include "vm/freelist.h"
 #include "vm/handles.h"
@@ -34,6 +35,7 @@ bool Dart::InitOnce(Dart_IsolateCreateCallback create,
   Isolate::InitOnce();
   PortMap::InitOnce();
   FreeListElement::InitOnce();
+  Api::InitOnce();
   // Create the VM isolate and finish the VM initialization.
   {
     ASSERT(vm_isolate_ == NULL);

runtime/vm/dart_api_impl.cc

@@ -28,6 +28,8 @@
 
 namespace dart {
 
+ThreadLocalKey Api::api_native_key_ = Thread::kUnsetThreadLocalKey;
+
 const char* CanonicalFunction(const char* func) {
   if (strncmp(func, "dart::", 6) == 0) {
     return func + 6;
@@ -237,6 +239,13 @@ uword Api::Reallocate(uword ptr, intptr_t old_size, intptr_t new_size) {
 }
 
 
+void Api::InitOnce() {
+  ASSERT(api_native_key_ == Thread::kUnsetThreadLocalKey);
+  api_native_key_ = Thread::CreateThreadLocal();
+  ASSERT(api_native_key_ != Thread::kUnsetThreadLocalKey);
+}
+
+
 // --- Handles ---
 
 
@@ -2437,5 +2446,4 @@ DART_EXPORT void Dart_GetPprofSymbolInfo(void** buffer, int* buffer_size) {
   }
 }
 
-
 }  // namespace dart

runtime/vm/dart_api_impl.h

@@ -121,6 +121,16 @@ class Api : AllStatic {
 
   // Reallocates space in the local zone.
   static uword Reallocate(uword ptr, intptr_t old_size, intptr_t new_size);
+
+  // Performs one-time initialization needed by the API.
+  static void InitOnce();
+
+ private:
+  // Thread local key used by the API. Currently holds the current
+  // ApiNativeScope if any.
+  static ThreadLocalKey api_native_key_;
+
+  friend class ApiNativeScope;
 };
 
 class IsolateSaver {

runtime/vm/dart_api_impl_test.cc

@@ -2890,23 +2890,31 @@ TEST_CASE(ImportLibrary5) {
 
 void NewNativePort_send123(Dart_Port dest_port_id,
                            Dart_Port reply_port_id,
-                           uint8_t* data) {
+                           Dart_CObject *message) {
+  // Gets a null message.
+  EXPECT_NOTNULL(message);
+  EXPECT_EQ(Dart_CObject::kNull, message->type);
+
   // Post integer value.
-  Dart_CObject object;
-  object.type = Dart_CObject::kInt32;
-  object.value.as_int32 = 123;
-  Dart_PostCObject(reply_port_id, &object);
+  Dart_CObject response;
+  response.type = Dart_CObject::kInt32;
+  response.value.as_int32 = 123;
+  Dart_PostCObject(reply_port_id, &response);
 }
 
 
 void NewNativePort_send321(Dart_Port dest_port_id,
                            Dart_Port reply_port_id,
-                           uint8_t* data) {
+                           Dart_CObject* message) {
+  // Gets a null message.
+  EXPECT_NOTNULL(message);
+  EXPECT_EQ(Dart_CObject::kNull, message->type);
+
   // Post integer value.
-  Dart_CObject object;
-  object.type = Dart_CObject::kInt32;
-  object.value.as_int32 = 321;
-  Dart_PostCObject(reply_port_id, &object);
+  Dart_CObject response;
+  response.type = Dart_CObject::kInt32;
+  response.value.as_int32 = 321;
+  Dart_PostCObject(reply_port_id, &response);
 }
 
 

runtime/vm/dart_api_message.cc

@@ -0,0 +1,259 @@
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include "vm/dart_api_message.h"
+#include "vm/object.h"
+#include "vm/object_store.h"
+
+namespace dart {
+
+// TODO(sgjesse): When the external message format is done these
+// duplicate constants from snapshot.cc should be removed.
+enum {
+  kInstanceId = ObjectStore::kMaxId,
+  kMaxPredefinedObjectIds,
+};
+static const int kNumInitialReferences = 4;
+
+ApiMessageReader::ApiMessageReader(const uint8_t* buffer,
+                               intptr_t length,
+                               ReAlloc alloc)
+    : BaseReader(buffer, length),
+      alloc_(alloc),
+      backward_references_(kNumInitialReferences) {
+  Init();
+}
+
+
+void ApiMessageReader::Init() {
+  // Initialize marker objects used to handle Lists.
+  // TODO(sjesse): Remove this when message serialization format is
+  // updated.
+  memset(&type_arguments_marker, 0, sizeof(type_arguments_marker));
+  memset(&dynamic_type_marker, 0, sizeof(dynamic_type_marker));
+  type_arguments_marker.type =
+      static_cast<Dart_CObject::Type>(Dart_CObject_Internal::kTypeArguments);
+  dynamic_type_marker.type =
+      static_cast<Dart_CObject::Type>(Dart_CObject_Internal::kDynamicType);
+}
+
+
+Dart_CObject* ApiMessageReader::ReadMessage() {
+  // Read the object out of the message.
+  return ReadObject();
+}
+
+
+intptr_t ApiMessageReader::LookupInternalClass(intptr_t class_header) {
+  SerializedHeaderType header_type = SerializedHeaderTag::decode(class_header);
+  ASSERT(header_type == kObjectId);
+  intptr_t header_value = SerializedHeaderData::decode(class_header);
+  return header_value;
+}
+
+
+Dart_CObject* ApiMessageReader::AllocateDartCObject(Dart_CObject::Type type) {
+  Dart_CObject* value =
+      reinterpret_cast<Dart_CObject*>(alloc_(NULL, 0, sizeof(Dart_CObject)));
+  value->type = type;
+  return value;
+}
+
+
+Dart_CObject* ApiMessageReader::AllocateDartCObjectNull() {
+  return AllocateDartCObject(Dart_CObject::kNull);
+}
+
+
+Dart_CObject* ApiMessageReader::AllocateDartCObjectBool(bool val) {
+  Dart_CObject* value = AllocateDartCObject(Dart_CObject::kBool);
+  value->value.as_bool = val;
+  return value;
+}
+
+
+Dart_CObject* ApiMessageReader::AllocateDartCObjectInt32(int32_t val) {
+  Dart_CObject* value = AllocateDartCObject(Dart_CObject::kInt32);
+  value->value.as_int32 = val;
+  return value;
+}
+
+
+Dart_CObject* ApiMessageReader::AllocateDartCObjectDouble(double val) {
+  Dart_CObject* value = AllocateDartCObject(Dart_CObject::kDouble);
+  value->value.as_double = val;
+  return value;
+}
+
+
+Dart_CObject* ApiMessageReader::AllocateDartCObjectString(intptr_t length) {
+  // Allocate a Dart_CObject structure followed by an array of chars
+  // for the string content. The pointer to the string content is set
+  // up to this area.
+  Dart_CObject* value =
+      reinterpret_cast<Dart_CObject*>(
+          alloc_(NULL, 0, sizeof(Dart_CObject) + length + 1));
+  value->value.as_string = reinterpret_cast<char*>(value) + sizeof(*value);
+  value->type = Dart_CObject::kString;
+  return value;
+}
+
+
+Dart_CObject* ApiMessageReader::AllocateDartCObjectArray(intptr_t length) {
+  // Allocate a Dart_CObject structure followed by an array of
+  // pointers to Dart_CObject structures. The pointer to the array
+  // content is set up to this area.
+  Dart_CObject* value =
+      reinterpret_cast<Dart_CObject*>(
+          alloc_(NULL, 0, sizeof(Dart_CObject) + length * sizeof(value)));
+  value->type = Dart_CObject::kArray;
+  value->value.as_array.length = length;
+  if (length > 0) {
+    value->value.as_array.values = reinterpret_cast<Dart_CObject**>(value + 1);
+  } else {
+    value->value.as_array.values = NULL;
+  }
+  return value;
+}
+
+
+Dart_CObject* ApiMessageReader::ReadInlinedObject(intptr_t object_id) {
+  // Read the class header information and lookup the class.
+  intptr_t class_header = ReadIntptrValue();
+  intptr_t tags = ReadIntptrValue();
+  USE(tags);
+  intptr_t class_id;
+
+  // Reading of regular dart instances is not supported.
+  if (SerializedHeaderData::decode(class_header) == kInstanceId) {
+    return NULL;
+  }
+
+  ASSERT((class_header & kSmiTagMask) != 0);
+  class_id = LookupInternalClass(class_header);
+  switch (class_id) {
+    case Object::kClassClass: {
+      return NULL;
+    }
+    case Object::kTypeArgumentsClass: {
+      // TODO(sjesse): Remove this when message serialization format is
+      // updated (currently length is leaked).
+      AddBackwardReference(object_id, NULL);
+      Dart_CObject* length = ReadObject();
+      ASSERT(length->type == Dart_CObject::kInt32);
+      for (int i = 0; i < length->value.as_int32; i++) {
+        Dart_CObject* type = ReadObject();
+        if (type != &dynamic_type_marker) return NULL;
+      }
+      return &type_arguments_marker;
+      break;
+    }
+    case ObjectStore::kArrayClass: {
+      intptr_t len = ReadSmiValue();
+      Dart_CObject* value = AllocateDartCObjectArray(len);
+      AddBackwardReference(object_id, value);
+      // Skip type arguments.
+      // TODO(sjesse): Remove this when message serialization format is
+      // updated (currently type_arguments is leaked).
+      Dart_CObject* type_arguments = ReadObject();
+      if (type_arguments != &type_arguments_marker &&
+          type_arguments->type != Dart_CObject::kNull) {
+        return NULL;
+      }
+      for (int i = 0; i < len; i++) {
+        value->value.as_array.values[i] = ReadObject();
+      }
+      return value;
+      break;
+    }
+    case ObjectStore::kDoubleClass: {
+      // Read the double value for the object.
+      Dart_CObject* object = AllocateDartCObjectDouble(Read<double>());
+      AddBackwardReference(object_id, object);
+      return object;
+      break;
+    }
+    case ObjectStore::kOneByteStringClass: {
+      intptr_t len = ReadSmiValue();
+      intptr_t hash = ReadSmiValue();
+      USE(hash);
+      Dart_CObject* object = AllocateDartCObjectString(len);
+      AddBackwardReference(object_id, object);
+      char* p = object->value.as_string;
+      for (intptr_t i = 0; i < len; i++) {
+        *p = Read<uint8_t>();
+        p++;
+      }
+      *p = '\0';
+      return object;
+      break;
+    }
+    case ObjectStore::kTwoByteStringClass:
+      // Two byte strings not supported.
+      return NULL;
+      break;
+    case ObjectStore::kFourByteStringClass:
+      // Four byte strings not supported.
+      return NULL;
+      break;
+    default:
+      // Everything else not supported.
+      return NULL;
+  }
+}
+
+
+Dart_CObject* ApiMessageReader::ReadIndexedObject(intptr_t object_id) {
+  if (object_id == Object::kNullObject) {
+    return AllocateDartCObjectNull();
+  } else if (object_id == ObjectStore::kTrueValue) {
+    return AllocateDartCObjectBool(true);
+  } else if (object_id == ObjectStore::kFalseValue) {
+    return AllocateDartCObjectBool(false);
+  } else if (object_id == ObjectStore::kDynamicType ||
+             object_id == ObjectStore::kDoubleInterface ||
+             object_id == ObjectStore::kIntInterface ||
+             object_id == ObjectStore::kBoolInterface ||
+             object_id == ObjectStore::kStringInterface) {
+    // Always return dynamic type (this is only a marker).
+    return &dynamic_type_marker;
+  } else {
+    intptr_t index = object_id - kMaxPredefinedObjectIds;
+    ASSERT(index < backward_references_.length());
+    ASSERT(backward_references_[index] != NULL);
+    return backward_references_[index];
+  }
+  return NULL;
+}
+
+
+Dart_CObject* ApiMessageReader::ReadObjectImpl(intptr_t header) {
+  SerializedHeaderType header_type = SerializedHeaderTag::decode(header);
+  intptr_t header_value = SerializedHeaderData::decode(header);
+
+  if (header_type == kObjectId) {
+    return ReadIndexedObject(header_value);
+  }
+  ASSERT(header_type == kInlined);
+  return ReadInlinedObject(header_value);
+}
+
+
+Dart_CObject* ApiMessageReader::ReadObject() {
+  int64_t value = Read<int64_t>();
+  if ((value & kSmiTagMask) == 0) {
+    Dart_CObject* dart_value = AllocateDartCObjectInt32(value >> kSmiTagShift);
+    return dart_value;
+  }
+  ASSERT((value <= kIntptrMax) && (value >= kIntptrMin));
+  return ReadObjectImpl(value);
+}
+
+
+void ApiMessageReader::AddBackwardReference(intptr_t id, Dart_CObject* obj) {
+  ASSERT((id - kMaxPredefinedObjectIds) == backward_references_.length());
+  backward_references_.Add(obj);
+}
+
+}  // namespace dart

runtime/vm/dart_api_message.h

@@ -0,0 +1,81 @@
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#ifndef VM_DART_API_MESSAGE_H_
+#define VM_DART_API_MESSAGE_H_
+
+#include "vm/dart_api_state.h"
+#include "vm/snapshot.h"
+
+namespace dart {
+
+// Use this C structure for reading internal objects in the serialized
+// data. These are objects that we need to process in order to
+// generate the Dart_CObject graph but that we don't want to expose in
+// that graph.
+// TODO(sjesse): Remove this when message serialization format is
+// updated.
+struct Dart_CObject_Internal : public Dart_CObject {
+  enum Type {
+    kTypeArguments = Dart_CObject::kNumberOfTypes,
+    kDynamicType,
+  };
+};
+
+
+// Reads a message snapshot into a C structure.
+class ApiMessageReader : public BaseReader {
+ public:
+  ApiMessageReader(const uint8_t* buffer, intptr_t length, ReAlloc alloc);
+  ~ApiMessageReader() { }
+
+  Dart_CObject* ReadMessage();
+
+ private:
+  // Allocates a Dart_CObject object.
+  Dart_CObject* AllocateDartCObject();
+  // Allocates a Dart_CObject object with the specified type.
+  Dart_CObject* AllocateDartCObject(Dart_CObject::Type type);
+  // Allocates a Dart_CObject object for the null object.
+  Dart_CObject* AllocateDartCObjectNull();
+  // Allocates a Dart_CObject object for a boolean object.
+  Dart_CObject* AllocateDartCObjectBool(bool value);
+  // Allocates a Dart_CObject object for for a 32-bit integer.
+  Dart_CObject* AllocateDartCObjectInt32(int32_t value);
+  // Allocates a Dart_CObject object for a double.
+  Dart_CObject* AllocateDartCObjectDouble(double value);
+  // Allocates a Dart_CObject object for string data.
+  Dart_CObject* AllocateDartCObjectString(intptr_t length);
+  // Allocates a C array of Dart_CObject objects.
+  Dart_CObject* AllocateDartCObjectArray(intptr_t length);
+
+  void Init();
+
+  intptr_t LookupInternalClass(intptr_t class_header);
+  Dart_CObject* ReadInlinedObject(intptr_t object_id);
+  Dart_CObject* ReadObjectImpl(intptr_t header);
+  Dart_CObject* ReadIndexedObject(intptr_t object_id);
+  Dart_CObject* ReadObject();
+
+  // Add object to backward references.
+  void AddBackwardReference(intptr_t id, Dart_CObject* obj);
+
+  Dart_CObject_Internal* AsInternal(Dart_CObject* object) {
+    ASSERT(object->type >= Dart_CObject::kNumberOfTypes);
+    return reinterpret_cast<Dart_CObject_Internal*>(object);
+  }
+
+  // Allocation of the structures for the decoded message happens
+  // either in the supplied zone or using the supplied allocation
+  // function.
+  ReAlloc alloc_;
+  ApiGrowableArray<Dart_CObject*> backward_references_;
+
+  Dart_CObject type_arguments_marker;
+  Dart_CObject dynamic_type_marker;
+};
+
+}  // namespace dart
+
+#endif  // VM_DART_API_MESSAGE_H_

runtime/vm/dart_api_state.h

@@ -1,4 +1,4 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
@@ -7,8 +7,10 @@
 
 #include "include/dart_api.h"
 
+#include "platform/thread.h"
 #include "vm/dart_api_impl.h"
 #include "vm/flags.h"
+#include "vm/growable_array.h"
 #include "vm/handles.h"
 #include "vm/object.h"
 #include "vm/os.h"
@@ -46,8 +48,11 @@ class ApiZone {
   intptr_t SizeInBytes() const { return zone_.SizeInBytes(); }
 
  private:
+  BaseZone* GetBaseZone() { return &zone_; }
+
   BaseZone zone_;
 
+  template<typename T> friend class ApiGrowableArray;
   DISALLOW_COPY_AND_ASSIGN(ApiZone);
 };
 
@@ -507,6 +512,49 @@ class ApiState {
   DISALLOW_COPY_AND_ASSIGN(ApiState);
 };
 
+
+class ApiNativeScope {
+ public:
+  ApiNativeScope() {
+    // Currently no support for nesting native scopes.
+    ASSERT(Current() == NULL);
+    Thread::SetThreadLocal(Api::api_native_key_, reinterpret_cast<uword>(this));
+  }
+
+  ~ApiNativeScope() {
+    ASSERT(Current() == this);
+    Thread::SetThreadLocal(Api::api_native_key_, NULL);
+  }
+
+  static inline ApiNativeScope* Current() {
+    return reinterpret_cast<ApiNativeScope*>(
+        Thread::GetThreadLocal(Api::api_native_key_));
+  }
+
+  ApiZone* zone() { return &zone_; }
+
+ private:
+  ApiZone zone_;
+};
+
+
+// Api growable arrays use a zone for allocation. The constructor
+// picks the zone from the current isolate if in an isolate
+// environment. When outside an isolate environment it picks the zone
+// from the current native scope.
+template<typename T>
+class ApiGrowableArray : public BaseGrowableArray<T, ValueObject> {
+ public:
+  explicit ApiGrowableArray(int initial_capacity)
+      : BaseGrowableArray<T, ValueObject>(
+          initial_capacity,
+          ApiNativeScope::Current()->zone()->GetBaseZone()) {}
+  ApiGrowableArray()
+      : BaseGrowableArray<T, ValueObject>(
+          ApiNativeScope::Current()->zone()->GetBaseZone()) {}
+};
+
+
 }  // namespace dart
 
 #endif  // VM_DART_API_STATE_H_

runtime/vm/growable_array.h

@@ -18,15 +18,14 @@ namespace dart {
 template<typename T, typename B>
 class BaseGrowableArray : public B {
  public:
-  BaseGrowableArray() : length_(0), capacity_(0), data_(NULL), zone_(NULL) {
-    ASSERT(Isolate::Current() != NULL);
-    zone_ = Isolate::Current()->current_zone();
+  explicit BaseGrowableArray(BaseZone* zone)
+      : length_(0), capacity_(0), data_(NULL), zone_(zone) {
+    ASSERT(zone_ != NULL);
   }
 
-  explicit BaseGrowableArray(int initial_capacity)
-      : length_(0), capacity_(0), data_(NULL), zone_(NULL) {
-    ASSERT(Isolate::Current() != NULL);
-    zone_ = Isolate::Current()->current_zone();
+  BaseGrowableArray(int initial_capacity, BaseZone* zone)
+      : length_(0), capacity_(0), data_(NULL), zone_(zone) {
+    ASSERT(zone_ != NULL);
     if (initial_capacity > 0) {
       capacity_ = Utils::RoundUpToPowerOfTwo(initial_capacity);
       data_ = reinterpret_cast<T*>(zone_->Allocate(capacity_ * sizeof(T)));
@@ -76,7 +75,7 @@ class BaseGrowableArray : public B {
   int length_;
   int capacity_;
   T* data_;
-  Zone* zone_;  // Zone in which we are allocating the array.
+  BaseZone* zone_;  // Zone in which we are allocating the array.
 
   void Resize(int new_length);
 
@@ -95,9 +94,6 @@ inline void BaseGrowableArray<T, B>::Sort(
 template<typename T, typename B>
 void BaseGrowableArray<T, B>::Resize(int new_length) {
   if (new_length > capacity_) {
-    ASSERT(Isolate::Current() != NULL);
-    // Check that we allocating in the array's zone.
-    ASSERT(zone_ == Isolate::Current()->current_zone());
     int new_capacity = Utils::RoundUpToPowerOfTwo(new_length);
     T* new_data = reinterpret_cast<T*>(
         zone_->Reallocate(reinterpret_cast<uword>(data_),
@@ -115,8 +111,12 @@ template<typename T>
 class GrowableArray : public BaseGrowableArray<T, ValueObject> {
  public:
   explicit GrowableArray(int initial_capacity)
-      : BaseGrowableArray<T, ValueObject>(initial_capacity) {}
-  GrowableArray() : BaseGrowableArray<T, ValueObject>() {}
+      : BaseGrowableArray<T, ValueObject>(
+          initial_capacity,
+          Isolate::Current()->current_zone()->GetBaseZone()) {}
+  GrowableArray()
+      : BaseGrowableArray<T, ValueObject>(
+          Isolate::Current()->current_zone()->GetBaseZone()) {}
 };
 
 
@@ -124,8 +124,12 @@ template<typename T>
 class ZoneGrowableArray : public BaseGrowableArray<T, ZoneAllocated> {
  public:
   explicit ZoneGrowableArray(int initial_capacity)
-      : BaseGrowableArray<T, ZoneAllocated>(initial_capacity) {}
-  ZoneGrowableArray() : BaseGrowableArray<T, ZoneAllocated>() {}
+      : BaseGrowableArray<T, ZoneAllocated>(
+          initial_capacity,
+          Isolate::Current()->current_zone()->GetBaseZone()) {}
+  ZoneGrowableArray() :
+      BaseGrowableArray<T, ZoneAllocated>(
+          Isolate::Current()->current_zone()->GetBaseZone()) {}
 };
 
 }  // namespace dart

runtime/vm/native_message_handler.cc

@@ -4,8 +4,10 @@
 
 #include "vm/native_message_handler.h"
 
+#include "vm/dart_api_message.h"
 #include "vm/isolate.h"
 #include "vm/message.h"
+#include "vm/snapshot.h"
 #include "vm/thread.h"
 
 namespace dart {
@@ -31,6 +33,14 @@ void NativeMessageHandler::CheckAccess() {
 #endif
 
 
+static uint8_t* zone_allocator(
+    uint8_t* ptr, intptr_t old_size, intptr_t new_size) {
+  ApiZone* zone = ApiNativeScope::Current()->zone();
+  return reinterpret_cast<uint8_t*>(
+      zone->Reallocate(reinterpret_cast<uword>(ptr), old_size, new_size));
+}
+
+
 static void RunWorker(uword parameter) {
   NativeMessageHandler* handler =
       reinterpret_cast<NativeMessageHandler*>(parameter);
@@ -47,12 +57,19 @@ static void RunWorker(uword parameter) {
         // dispatched to special vm code.  Implement.
         UNIMPLEMENTED();
       }
-      // TODO(sgjesse): Once CMessageReader::ReadObject is committed,
-      // use that here and pass the resulting data object to the
-      // handler instead.
+      // Enter a native scope for handling the message. This will create a
+      // zone for allocating the objects for decoding the message.
+      ApiNativeScope scope;
+
+      int32_t length = reinterpret_cast<int32_t*>(
+          message->data())[Snapshot::kLengthIndex];
+      ApiMessageReader reader(message->data() + Snapshot::kHeaderSize,
+                              length,
+                              zone_allocator);
+      Dart_CObject* object = reader.ReadMessage();
       (*handler->func())(message->dest_port(),
                          message->reply_port(),
-                         message->data());
+                         object);
       delete message;
     }
   }

runtime/vm/snapshot.cc

@@ -437,242 +437,6 @@ RawObject* SnapshotReader::ReadInlinedObject(intptr_t object_id) {
 }
 
 
-CMessageReader::CMessageReader(const uint8_t* buffer,
-                               intptr_t length,
-                               ReAlloc alloc)
-    : BaseReader(buffer, length),
-      alloc_(alloc),
-      backward_references_(kNumInitialReferences) {
-  // Initialize marker objects used to handle Lists.
-  // TODO(sjesse): Remove this when message serialization format is
-  // updated.
-  memset(&type_arguments_marker, 0, sizeof(type_arguments_marker));
-  memset(&dynamic_type_marker, 0, sizeof(dynamic_type_marker));
-  type_arguments_marker.type =
-      static_cast<Dart_CObject::Type>(Dart_CObject_Internal::kTypeArguments);
-  dynamic_type_marker.type =
-      static_cast<Dart_CObject::Type>(Dart_CObject_Internal::kDynamicType);
-}
-
-
-Dart_CObject* CMessageReader::ReadMessage() {
-  // Read the object out of the message.
-  return ReadObject();
-}
-
-intptr_t CMessageReader::LookupInternalClass(intptr_t class_header) {
-  SerializedHeaderType header_type = SerializedHeaderTag::decode(class_header);
-  ASSERT(header_type == kObjectId);
-  intptr_t header_value = SerializedHeaderData::decode(class_header);
-  return header_value;
-}
-
-
-Dart_CObject* CMessageReader::AllocateDartCObject(Dart_CObject::Type type) {
-  Dart_CObject* value =
-      reinterpret_cast<Dart_CObject*>(
-          alloc_(NULL, 0, sizeof(Dart_CObject)));
-  value->type = type;
-  return value;
-}
-
-
-Dart_CObject* CMessageReader::AllocateDartCObjectNull() {
-  return AllocateDartCObject(Dart_CObject::kNull);
-}
-
-
-Dart_CObject* CMessageReader::AllocateDartCObjectBool(bool val) {
-  Dart_CObject* value = AllocateDartCObject(Dart_CObject::kBool);
-  value->value.as_bool = val;
-  return value;
-}
-
-
-Dart_CObject* CMessageReader::AllocateDartCObjectInt32(int32_t val) {
-  Dart_CObject* value = AllocateDartCObject(Dart_CObject::kInt32);
-  value->value.as_int32 = val;
-  return value;
-}
-
-
-Dart_CObject* CMessageReader::AllocateDartCObjectDouble(double val) {
-  Dart_CObject* value = AllocateDartCObject(Dart_CObject::kDouble);
-  value->value.as_double = val;
-  return value;
-}
-
-
-Dart_CObject* CMessageReader::AllocateDartCObjectString(intptr_t length) {
-  // Allocate a Dart_CObject structure followed by an array of chars
-  // for the string content. The pointer to the string content is set
-  // up to this area.
-  Dart_CObject* value =
-      reinterpret_cast<Dart_CObject*>(
-          alloc_(NULL, 0, sizeof(Dart_CObject) + length + 1));
-  value->value.as_string = reinterpret_cast<char*>(value) + sizeof(*value);
-  value->type = Dart_CObject::kString;
-  return value;
-}
-
-
-Dart_CObject* CMessageReader::AllocateDartCObjectArray(intptr_t length) {
-  // Allocate a Dart_CObject structure followed by an array of
-  // pointers to Dart_CObject structures. The pointer to the array
-  // content is set up to this area.
-  Dart_CObject* value =
-      reinterpret_cast<Dart_CObject*>(
-          alloc_(NULL, 0, sizeof(Dart_CObject) + length * sizeof(value)));
-  value->type = Dart_CObject::kArray;
-  value->value.as_array.length = length;
-  if (length > 0) {
-    value->value.as_array.values = reinterpret_cast<Dart_CObject**>(value + 1);
-  } else {
-    value->value.as_array.values = NULL;
-  }
-  return value;
-}
-
-
-Dart_CObject* CMessageReader::ReadInlinedObject(intptr_t object_id) {
-  // Read the class header information and lookup the class.
-  intptr_t class_header = ReadIntptrValue();
-  intptr_t tags = ReadIntptrValue();
-  USE(tags);
-  intptr_t class_id;
-
-  // Reading of regular dart instances is not supported.
-  if (SerializedHeaderData::decode(class_header) == kInstanceId) {
-    return NULL;
-  }
-
-  ASSERT((class_header & kSmiTagMask) != 0);
-  class_id = LookupInternalClass(class_header);
-  switch (class_id) {
-    case Object::kClassClass: {
-      return NULL;
-    }
-    case Object::kTypeArgumentsClass: {
-      // TODO(sjesse): Remove this when message serialization format is
-      // updated (currently length is leaked).
-      AddBackwardReference(object_id, NULL);
-      Dart_CObject* length = ReadObject();
-      ASSERT(length->type == Dart_CObject::kInt32);
-      for (int i = 0; i < length->value.as_int32; i++) {
-        Dart_CObject* type = ReadObject();
-        if (type != &dynamic_type_marker) return NULL;
-      }
-      return &type_arguments_marker;
-      break;
-    }
-    case ObjectStore::kArrayClass: {
-      intptr_t len = ReadSmiValue();
-      Dart_CObject* value = AllocateDartCObjectArray(len);
-      AddBackwardReference(object_id, value);
-      // Skip type arguments.
-      // TODO(sjesse): Remove this when message serialization format is
-      // updated (currently type_arguments is leaked).
-      Dart_CObject* type_arguments = ReadObject();
-      if (type_arguments != &type_arguments_marker &&
-          type_arguments->type != Dart_CObject::kNull) {
-        return NULL;
-      }
-      for (int i = 0; i < len; i++) {
-        value->value.as_array.values[i] = ReadObject();
-      }
-      return value;
-      break;
-    }
-    case ObjectStore::kDoubleClass: {
-      // Read the double value for the object.
-      Dart_CObject* object = AllocateDartCObjectDouble(Read<double>());
-      AddBackwardReference(object_id, object);
-      return object;
-      break;
-    }
-    case ObjectStore::kOneByteStringClass: {
-      intptr_t len = ReadSmiValue();
-      intptr_t hash = ReadSmiValue();
-      USE(hash);
-      Dart_CObject* object = AllocateDartCObjectString(len);
-      AddBackwardReference(object_id, object);
-      char* p = object->value.as_string;
-      for (intptr_t i = 0; i < len; i++) {
-        *p = Read<uint8_t>();
-        p++;
-      }
-      *p = '\0';
-      return object;
-      break;
-    }
-    case ObjectStore::kTwoByteStringClass:
-      // Two byte strings not supported.
-      return NULL;
-      break;
-    case ObjectStore::kFourByteStringClass:
-      // Four byte strings not supported.
-      return NULL;
-      break;
-    default:
-      // Everything else not supported.
-      return NULL;
-  }
-}
-
-
-Dart_CObject* CMessageReader::ReadIndexedObject(intptr_t object_id) {
-  if (object_id == Object::kNullObject) {
-    return AllocateDartCObjectNull();
-  } else if (object_id == ObjectStore::kTrueValue) {
-    return AllocateDartCObjectBool(true);
-  } else if (object_id == ObjectStore::kFalseValue) {
-    return AllocateDartCObjectBool(false);
-  } else if (object_id == ObjectStore::kDynamicType ||
-             object_id == ObjectStore::kDoubleInterface ||
-             object_id == ObjectStore::kIntInterface ||
-             object_id == ObjectStore::kBoolInterface ||
-             object_id == ObjectStore::kStringInterface) {
-    // Always return dynamic type (this is only a marker).
-    return &dynamic_type_marker;
-  } else {
-    intptr_t index = object_id - kMaxPredefinedObjectIds;
-    ASSERT(index < backward_references_.length());
-    ASSERT(backward_references_[index] != NULL);
-    return backward_references_[index];
-  }
-  return NULL;
-}
-
-
-Dart_CObject* CMessageReader::ReadObjectImpl(intptr_t header) {
-  SerializedHeaderType header_type = SerializedHeaderTag::decode(header);
-  intptr_t header_value = SerializedHeaderData::decode(header);
-
-  if (header_type == kObjectId) {
-    return ReadIndexedObject(header_value);
-  }
-  ASSERT(header_type == kInlined);
-  return ReadInlinedObject(header_value);
-}
-
-
-Dart_CObject* CMessageReader::ReadObject() {
-  int64_t value = Read<int64_t>();
-  if ((value & kSmiTagMask) == 0) {
-    Dart_CObject* dart_value = AllocateDartCObjectInt32(value >> kSmiTagShift);
-    return dart_value;
-  }
-  ASSERT((value <= kIntptrMax) && (value >= kIntptrMin));
-  return ReadObjectImpl(value);
-}
-
-
-void CMessageReader::AddBackwardReference(intptr_t id, Dart_CObject* obj) {
-  ASSERT((id - kMaxPredefinedObjectIds) == backward_references_.length());
-  backward_references_.Add(obj);
-}
-
-
 void MessageWriter::WriteMessage(intptr_t field_count, intptr_t *data) {
   // Write out the serialization header value for this object.
   WriteSerializationMarker(kInlined, kMaxPredefinedObjectIds);

runtime/vm/snapshot.h

@@ -404,68 +404,6 @@ class SnapshotReader : public BaseReader {
 };
 
 
-// Use this C structure for reading internal objects in the serialized
-// data. These are objects that we need to process in order to
-// generate the Dart_CObject graph but that we don't want to expose in
-// that graph.
-// TODO(sjesse): Remove this when message serialization format is
-// updated.
-struct Dart_CObject_Internal : public Dart_CObject {
-  enum Type {
-    kTypeArguments = Dart_CObject::kNumberOfTypes,
-    kDynamicType,
-  };
-};
-
-
-// Reads a message snapshot into C structure.
-class CMessageReader : public BaseReader {
- public:
-  CMessageReader(const uint8_t* buffer, intptr_t length, ReAlloc alloc);
-  ~CMessageReader() { }
-
-  Dart_CObject* ReadMessage();
-
- private:
-  // Allocates a Dart_CObject object on the C heap.
-  Dart_CObject* AllocateDartCObject();
-  // Allocates a Dart_CObject object with the specified type on the C heap.
-  Dart_CObject* AllocateDartCObject(Dart_CObject::Type type);
-  // Allocates a Dart_CObject object for the null object on the C heap.
-  Dart_CObject* AllocateDartCObjectNull();
-  // Allocates a Dart_CObject object for a boolean object on the C heap.
-  Dart_CObject* AllocateDartCObjectBool(bool value);
-  // Allocates a Dart_CObject object for for a 32-bit integer on the C heap.
-  Dart_CObject* AllocateDartCObjectInt32(int32_t value);
-  // Allocates a Dart_CObject object for a double on the C heap.
-  Dart_CObject* AllocateDartCObjectDouble(double value);
-  // Allocates a Dart_CObject object for string data on the C heap.
-  Dart_CObject* AllocateDartCObjectString(intptr_t length);
-  // Allocates a C array of Dart_CObject objects on the C heap.
-  Dart_CObject* AllocateDartCObjectArray(intptr_t length);
-
-  intptr_t LookupInternalClass(intptr_t class_header);
-  Dart_CObject* ReadInlinedObject(intptr_t object_id);
-  Dart_CObject* ReadObjectImpl(intptr_t header);
-  Dart_CObject* ReadIndexedObject(intptr_t object_id);
-  Dart_CObject* ReadObject();
-
-  // Add object to backward references.
-  void AddBackwardReference(intptr_t id, Dart_CObject* obj);
-
-  Dart_CObject_Internal* AsInternal(Dart_CObject* object) {
-    ASSERT(object->type >= Dart_CObject::kNumberOfTypes);
-    return reinterpret_cast<Dart_CObject_Internal*>(object);
-  }
-
-  ReAlloc alloc_;
-  GrowableArray<Dart_CObject*> backward_references_;
-
-  Dart_CObject type_arguments_marker;
-  Dart_CObject dynamic_type_marker;
-};
-
-
 class BaseWriter {
  public:
   // Size of the snapshot.

runtime/vm/snapshot_test.cc

@@ -7,6 +7,7 @@
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart_api_impl.h"
+#include "vm/dart_api_message.h"
 #include "vm/dart_api_state.h"
 #include "vm/snapshot.h"
 #include "vm/unit_test.h"
@@ -55,7 +56,7 @@ static uint8_t* zone_allocator(
 static Dart_CObject* DecodeMessage(uint8_t* message,
                                    intptr_t length,
                                    ReAlloc allocator) {
-  CMessageReader message_reader(message, length, allocator);
+  ApiMessageReader message_reader(message, length, allocator);
   return message_reader.ReadMessage();
 }
 
@@ -107,7 +108,6 @@ static void CheckEncodeDecodeMessage(Dart_CObject* root) {
   MessageWriter writer(&buffer, &malloc_allocator);
   writer.WriteCMessage(root);
 
-  Zone zone(Isolate::Current());
   Dart_CObject* new_root = DecodeMessage(buffer + Snapshot::kHeaderSize,
                                          writer.BytesWritten(),
                                          &zone_allocator);
@@ -135,6 +135,7 @@ TEST_CASE(SerializeNull) {
   EXPECT(Equals(null_object, serialized_object));
 
   // Read object back from the snapshot into a C structure.
+  ApiNativeScope scope;
   Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
                                      writer.BytesWritten(),
                                      &zone_allocator);
@@ -163,6 +164,7 @@ TEST_CASE(SerializeSmi1) {
   EXPECT(Equals(smi, serialized_object));
 
   // Read object back from the snapshot into a C structure.
+  ApiNativeScope scope;
   Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
                                      writer.BytesWritten(),
                                      &zone_allocator);
@@ -192,6 +194,7 @@ TEST_CASE(SerializeSmi2) {
   EXPECT(Equals(smi, serialized_object));
 
   // Read object back from the snapshot into a C structure.
+  ApiNativeScope scope;
   Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
                                      writer.BytesWritten(),
                                      &zone_allocator);
@@ -221,6 +224,7 @@ TEST_CASE(SerializeDouble) {
   EXPECT(Equals(dbl, serialized_object));
 
   // Read object back from the snapshot into a C structure.
+  ApiNativeScope scope;
   Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
                                      writer.BytesWritten(),
                                      &zone_allocator);
@@ -267,6 +271,7 @@ TEST_CASE(SerializeTrue) {
   Snapshot::SetupFromBuffer(buffer);
 
   // Read object back from the snapshot into a C structure.
+  ApiNativeScope scope;
   Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
                                      writer.BytesWritten(),
                                      &zone_allocator);
@@ -291,6 +296,7 @@ TEST_CASE(SerializeFalse) {
   Snapshot::SetupFromBuffer(buffer);
 
   // Read object back from the snapshot into a C structure.
+  ApiNativeScope scope;
   Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
                                      writer.BytesWritten(),
                                      &zone_allocator);
@@ -322,6 +328,7 @@ TEST_CASE(SerializeBigint) {
   EXPECT_EQ(BigintOperations::ToInt64(bigint), BigintOperations::ToInt64(obj));
 
   // Read object back from the snapshot into a C structure.
+  ApiNativeScope scope;
   Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
                                      writer.BytesWritten(),
                                      &zone_allocator);
@@ -405,6 +412,7 @@ TEST_CASE(SerializeString) {
   EXPECT(str.Equals(serialized_str));
 
   // Read object back from the snapshot into a C structure.
+  ApiNativeScope scope;
   Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
                                      writer.BytesWritten(),
                                      &zone_allocator);
@@ -440,6 +448,7 @@ TEST_CASE(SerializeArray) {
   EXPECT(array.Equals(serialized_array));
 
   // Read object back from the snapshot into a C structure.
+  ApiNativeScope scope;
   Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
                                      writer.BytesWritten(),
                                      &zone_allocator);
@@ -475,6 +484,7 @@ TEST_CASE(SerializeEmptyArray) {
   EXPECT(array.Equals(serialized_array));
 
   // Read object back from the snapshot into a C structure.
+  ApiNativeScope scope;
   Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
                                      writer.BytesWritten(),
                                      &zone_allocator);
@@ -803,6 +813,7 @@ TEST_CASE(IntArrayMessage) {
   writer.WriteMessage(len, data);
 
   // Read object back from the snapshot into a C structure.
+  ApiNativeScope scope;
   Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
                                      writer.BytesWritten(),
                                      &zone_allocator);
@@ -892,6 +903,7 @@ UNIT_TEST_CASE(DartGeneratedMessages) {
       writer.FinalizeBuffer();
 
       // Read object back from the snapshot into a C structure.
+      ApiNativeScope scope;
       Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
                                          writer.BytesWritten(),
                                          &zone_allocator);
@@ -910,6 +922,7 @@ UNIT_TEST_CASE(DartGeneratedMessages) {
       writer.FinalizeBuffer();
 
       // Read object back from the snapshot into a C structure.
+      ApiNativeScope scope;
       Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
                                          writer.BytesWritten(),
                                          &zone_allocator);
@@ -962,7 +975,7 @@ UNIT_TEST_CASE(DartGeneratedListMessages) {
     DARTSCOPE_NOCHECKS(isolate);
     {
       // Generate a list of nulls from Dart code.
-      Zone zone(Isolate::Current());
+      ApiNativeScope scope;
       Dart_CObject* root = GetDeserializedDartMessage(lib, "getList");
       EXPECT_NOTNULL(root);
       EXPECT_EQ(Dart_CObject::kArray, root->type);
@@ -974,7 +987,7 @@ UNIT_TEST_CASE(DartGeneratedListMessages) {
     }
     {
       // Generate a list of ints from Dart code.
-      Zone zone(Isolate::Current());
+      ApiNativeScope scope;
       Dart_CObject* root = GetDeserializedDartMessage(lib, "getIntList");
       EXPECT_NOTNULL(root);
       EXPECT_EQ(Dart_CObject::kArray, root->type);
@@ -987,7 +1000,7 @@ UNIT_TEST_CASE(DartGeneratedListMessages) {
     }
     {
       // Generate a list of strings from Dart code.
-      Zone zone(Isolate::Current());
+      ApiNativeScope scope;
       Dart_CObject* root = GetDeserializedDartMessage(lib, "getStringList");
       EXPECT_NOTNULL(root);
       EXPECT_EQ(Dart_CObject::kArray, root->type);
@@ -1001,7 +1014,7 @@ UNIT_TEST_CASE(DartGeneratedListMessages) {
     }
     {
       // Generate a list of objects of different types from Dart code.
-      Zone zone(Isolate::Current());
+      ApiNativeScope scope;
       Dart_CObject* root = GetDeserializedDartMessage(lib, "getMixedList");
       EXPECT_NOTNULL(root);
       EXPECT_EQ(Dart_CObject::kArray, root->type);
@@ -1072,7 +1085,7 @@ UNIT_TEST_CASE(DartGeneratedListMessagesWithBackref) {
 
     {
       // Generate a list of strings from Dart code.
-      Zone zone(Isolate::Current());
+      ApiNativeScope scope;
       Dart_CObject* root = GetDeserializedDartMessage(lib, "getStringList");
       EXPECT_NOTNULL(root);
       EXPECT_EQ(Dart_CObject::kArray, root->type);
@@ -1086,7 +1099,7 @@ UNIT_TEST_CASE(DartGeneratedListMessagesWithBackref) {
     }
     {
       // Generate a list of doubles from Dart code.
-      Zone zone(Isolate::Current());
+      ApiNativeScope scope;
       Dart_CObject* root = GetDeserializedDartMessage(lib, "getDoubleList");
       EXPECT_NOTNULL(root);
       EXPECT_EQ(Dart_CObject::kArray, root->type);
@@ -1100,7 +1113,7 @@ UNIT_TEST_CASE(DartGeneratedListMessagesWithBackref) {
     }
     {
       // Generate a list of objects of different types from Dart code.
-      Zone zone(Isolate::Current());
+      ApiNativeScope scope;
       Dart_CObject* root = GetDeserializedDartMessage(lib, "getMixedList");
       EXPECT_NOTNULL(root);
       EXPECT_EQ(Dart_CObject::kArray, root->type);
@@ -1120,7 +1133,7 @@ UNIT_TEST_CASE(DartGeneratedListMessagesWithBackref) {
     }
     {
       // Generate a list of objects of different types from Dart code.
-      Zone zone(Isolate::Current());
+      ApiNativeScope scope;
       Dart_CObject* root = GetDeserializedDartMessage(lib, "getSelfRefList");
       EXPECT_NOTNULL(root);
       EXPECT_EQ(Dart_CObject::kArray, root->type);

runtime/vm/vm_sources.gypi

@@ -81,6 +81,8 @@
     'dart_api_impl.h',
     'dart_api_state.h',
     'dart_api_impl_test.cc',
+    'dart_api_message.cc',
+    'dart_api_message.h',
     'dart_entry.cc',
     'dart_entry.h',
     'dart_entry_test.cc',

runtime/vm/zone.h

@@ -91,6 +91,7 @@ class BaseZone {
 
   friend class Zone;
   friend class ApiZone;
+  template<typename T, typename B> friend class BaseGrowableArray;
   DISALLOW_COPY_AND_ASSIGN(BaseZone);
 };
 
@@ -127,6 +128,8 @@ class Zone : public StackResource {
   void VisitObjectPointers(ObjectPointerVisitor* visitor);
 
  private:
+  BaseZone* GetBaseZone() { return &zone_; }
+
   BaseZone zone_;
 
   // Structure for managing handles allocation.
@@ -134,6 +137,10 @@ class Zone : public StackResource {
 
   // Used for chaining zones in order to allow unwinding of stacks.
   Zone* previous_;
+
+  template<typename T> friend class GrowableArray;
+  template<typename T> friend class ZoneGrowableArray;
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(Zone);
 };