Added API Dart_PostCMessage for posting a Dart_CMessage structure

runtime/vm/snapshot_test.cc

 // 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 "include/dart_debugger_api.h"
 #include "platform/assert.h"
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_api_state.h"
@@ skipping 34 matching lines @@
 
 
 static uint8_t* zone_allocator(
     uint8_t* ptr, intptr_t old_size, intptr_t new_size) {
   Zone* zone = Isolate::Current()->current_zone();
   return reinterpret_cast<uint8_t*>(
       zone->Reallocate(reinterpret_cast<uword>(ptr), old_size, new_size));
 }
 
 
-static Dart_CMessage* DecodeMessage(uint8_t* message,
-                                    intptr_t length,
-                                    ReAlloc allocator) {
+static Dart_CObject* DecodeMessage(uint8_t* message,
+                                   intptr_t length,
+                                   ReAlloc allocator) {
   CMessageReader message_reader(message, length, allocator);
   return message_reader.ReadMessage();
 }
 
 
+// Compare two Dart_CObject object graphs rooted in first and
+// second. The second graph will be destroyed by this operation no matter
+// whether the graphs are equal or not.
+static void CompareDartCObjects(Dart_CObject* first, Dart_CObject* second) {
+  // Return immediately if entering a cycle.
+  if (second->type == Dart_CObject::kNumberOfTypes) return;
+
+  EXPECT_NE(first, second);
+  EXPECT_EQ(first->type, second->type);
+  switch (first->type) {
+    case Dart_CObject::kNull:
+      // Nothing more to compare.
+      break;
+    case Dart_CObject::kBool:
+      EXPECT_EQ(first->value.as_bool, second->value.as_bool);
+      break;
+    case Dart_CObject::kInt32:
+      EXPECT_EQ(first->value.as_int32, second->value.as_int32);
+      break;
+    case Dart_CObject::kDouble:
+      EXPECT_EQ(first->value.as_double, second->value.as_double);
+      break;
+    case Dart_CObject::kString:
+      EXPECT_STREQ(first->value.as_string, second->value.as_string);
+      break;
+    case Dart_CObject::kArray:
+      // Use invalid type as a visited marker to avoid infinite
+      // recursion on graphs with cycles.
+      second->type = Dart_CObject::kNumberOfTypes;
+      EXPECT_EQ(first->value.as_array.length, second->value.as_array.length);
+      for (int i = 0; i < first->value.as_array.length; i++) {
+        CompareDartCObjects(first->value.as_array.values[i],
+                            second->value.as_array.values[i]);
+      }
+      break;
+    default:
+      EXPECT(false);
+  }
+}
+
+
+static void CheckEncodeDecodeMessage(Dart_CObject* root) {
+  // Encode and decode the message.
+  uint8_t* buffer = NULL;
+  MessageWriter writer(&buffer, &malloc_allocator);
+  writer.WriteCMessage(root);
+
+  Zone zone(Isolate::Current());
+  Dart_CObject* new_root = DecodeMessage(buffer + Snapshot::kHeaderSize,
+                                         writer.BytesWritten(),
+                                         &zone_allocator);
+
+  // Check that the two messages are the same.
+  CompareDartCObjects(root, new_root);
+}
+
 TEST_CASE(SerializeNull) {
   Zone zone(Isolate::Current());
 
   // Write snapshot with object content.
   uint8_t* buffer;
   SnapshotWriter writer(Snapshot::kMessage, &buffer, &zone_allocator);
   const Object& null_object = Object::Handle();
   writer.WriteObject(null_object.raw());
   writer.FinalizeBuffer();
 
   // Create a snapshot object using the buffer.
   const Snapshot* snapshot = Snapshot::SetupFromBuffer(buffer);
 
   // Read object back from the snapshot.
   SnapshotReader reader(snapshot, Isolate::Current());
   const Object& serialized_object = Object::Handle(reader.ReadObject());
   EXPECT(Equals(null_object, serialized_object));
 
   // Read object back from the snapshot into a C structure.
-  Dart_CMessage* cmessage = DecodeMessage(buffer + Snapshot::kHeaderSize,
-                                          writer.BytesWritten(),
-                                          &zone_allocator);
-  Dart_CObject* cobject = cmessage->root;
-  EXPECT_NOTNULL(cobject);
-  EXPECT_EQ(Dart_CObject::kNull, cobject->type);
+  Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
+                                     writer.BytesWritten(),
+                                     &zone_allocator);
+  EXPECT_NOTNULL(root);
+  EXPECT_EQ(Dart_CObject::kNull, root->type);
+  CheckEncodeDecodeMessage(root);
 }
 
 
 TEST_CASE(SerializeSmi1) {
   Zone zone(Isolate::Current());
 
   // Write snapshot with object content.
   uint8_t* buffer;
   SnapshotWriter writer(Snapshot::kMessage, &buffer, &zone_allocator);
   const Smi& smi = Smi::Handle(Smi::New(124));
   writer.WriteObject(smi.raw());
   writer.FinalizeBuffer();
 
   // Create a snapshot object using the buffer.
   const Snapshot* snapshot = Snapshot::SetupFromBuffer(buffer);
 
   // Read object back from the snapshot.
   SnapshotReader reader(snapshot, Isolate::Current());
   const Object& serialized_object = Object::Handle(reader.ReadObject());
   EXPECT(Equals(smi, serialized_object));
 
   // Read object back from the snapshot into a C structure.
-  Dart_CMessage* cmessage = DecodeMessage(buffer + Snapshot::kHeaderSize,
-                                          writer.BytesWritten(),
-                                          &zone_allocator);
-  Dart_CObject* cobject = cmessage->root;
-  EXPECT_NOTNULL(cobject);
-  EXPECT_EQ(Dart_CObject::kInt32, cobject->type);
-  EXPECT_EQ(smi.Value(), cobject->value.as_int32);
+  Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
+                                     writer.BytesWritten(),
+                                     &zone_allocator);
+  EXPECT_NOTNULL(root);
+  EXPECT_EQ(Dart_CObject::kInt32, root->type);
+  EXPECT_EQ(smi.Value(), root->value.as_int32);
+  CheckEncodeDecodeMessage(root);
 }
 
 
 TEST_CASE(SerializeSmi2) {
   Zone zone(Isolate::Current());
 
   // Write snapshot with object content.
   uint8_t* buffer;
   SnapshotWriter writer(Snapshot::kMessage, &buffer, &zone_allocator);
   const Smi& smi = Smi::Handle(Smi::New(-1));
   writer.WriteObject(smi.raw());
   writer.FinalizeBuffer();
 
   // Create a snapshot object using the buffer.
   const Snapshot* snapshot = Snapshot::SetupFromBuffer(buffer);
 
   // Read object back from the snapshot.
   SnapshotReader reader(snapshot, Isolate::Current());
   const Object& serialized_object = Object::Handle(reader.ReadObject());
   EXPECT(Equals(smi, serialized_object));
 
   // Read object back from the snapshot into a C structure.
-  Dart_CMessage* cmessage = DecodeMessage(buffer + Snapshot::kHeaderSize,
-                                          writer.BytesWritten(),
-                                          &zone_allocator);
-  Dart_CObject* cobject = cmessage->root;
-  EXPECT_NOTNULL(cobject);
-  EXPECT_EQ(Dart_CObject::kInt32, cobject->type);
-  EXPECT_EQ(smi.Value(), cobject->value.as_int32);
+  Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
+                                     writer.BytesWritten(),
+                                     &zone_allocator);
+  EXPECT_NOTNULL(root);
+  EXPECT_EQ(Dart_CObject::kInt32, root->type);
+  EXPECT_EQ(smi.Value(), root->value.as_int32);
+  CheckEncodeDecodeMessage(root);
 }
 
 
 TEST_CASE(SerializeDouble) {
   Zone zone(Isolate::Current());
 
   // Write snapshot with object content.
   uint8_t* buffer;
   SnapshotWriter writer(Snapshot::kMessage, &buffer, &zone_allocator);
   const Double& dbl = Double::Handle(Double::New(101.29));
   writer.WriteObject(dbl.raw());
   writer.FinalizeBuffer();
 
   // Create a snapshot object using the buffer.
   const Snapshot* snapshot = Snapshot::SetupFromBuffer(buffer);
 
   // Read object back from the snapshot.
   SnapshotReader reader(snapshot, Isolate::Current());
   const Object& serialized_object = Object::Handle(reader.ReadObject());
   EXPECT(Equals(dbl, serialized_object));
 
   // Read object back from the snapshot into a C structure.
-  Dart_CMessage* cmessage = DecodeMessage(buffer + Snapshot::kHeaderSize,
-                                          writer.BytesWritten(),
-                                          &zone_allocator);
-  Dart_CObject* cobject = cmessage->root;
-  EXPECT_NOTNULL(cobject);
-  EXPECT_EQ(Dart_CObject::kDouble, cobject->type);
-  EXPECT_EQ(dbl.value(), cobject->value.as_double);
+  Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
+                                     writer.BytesWritten(),
+                                     &zone_allocator);
+  EXPECT_NOTNULL(root);
+  EXPECT_EQ(Dart_CObject::kDouble, root->type);
+  EXPECT_EQ(dbl.value(), root->value.as_double);
+  CheckEncodeDecodeMessage(root);
 }
 
 
 TEST_CASE(SerializeBool) {
   Zone zone(Isolate::Current());
 
   // Write snapshot with object content.
   uint8_t* buffer;
   SnapshotWriter writer(Snapshot::kMessage, &buffer, &zone_allocator);
   const Bool& bool1 = Bool::Handle(Bool::True());
@@ skipping 19 matching lines @@
   uint8_t* buffer;
   SnapshotWriter writer(Snapshot::kMessage, &buffer, &zone_allocator);
   const Bool& bl = Bool::Handle(Bool::True());
   writer.WriteObject(bl.raw());
   writer.FinalizeBuffer();
 
   // Create a snapshot object using the buffer.
   Snapshot::SetupFromBuffer(buffer);
 
   // Read object back from the snapshot into a C structure.
-  Dart_CMessage* cmessage = DecodeMessage(buffer + Snapshot::kHeaderSize,
-                                          writer.BytesWritten(),
-                                          &zone_allocator);
-  Dart_CObject* cobject = cmessage->root;
-  EXPECT_NOTNULL(cobject);
-  EXPECT_EQ(Dart_CObject::kBool, cobject->type);
-  EXPECT_EQ(true, cobject->value.as_bool);
+  Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
+                                     writer.BytesWritten(),
+                                     &zone_allocator);
+  EXPECT_NOTNULL(root);
+  EXPECT_EQ(Dart_CObject::kBool, root->type);
+  EXPECT_EQ(true, root->value.as_bool);
+  CheckEncodeDecodeMessage(root);
 }
 
 
 TEST_CASE(SerializeFalse) {
   Zone zone(Isolate::Current());
 
   // Write snapshot with false object.
   uint8_t* buffer;
   SnapshotWriter writer(Snapshot::kMessage, &buffer, &zone_allocator);
   const Bool& bl = Bool::Handle(Bool::False());
   writer.WriteObject(bl.raw());
   writer.FinalizeBuffer();
 
   // Create a snapshot object using the buffer.
   Snapshot::SetupFromBuffer(buffer);
 
   // Read object back from the snapshot into a C structure.
-  Dart_CMessage* cmessage = DecodeMessage(buffer + Snapshot::kHeaderSize,
-                                          writer.BytesWritten(),
-                                          &zone_allocator);
-  Dart_CObject* cobject = cmessage->root;
-  EXPECT_NOTNULL(cobject);
-  EXPECT_EQ(Dart_CObject::kBool, cobject->type);
-  EXPECT_EQ(false, cobject->value.as_bool);
+  Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
+                                     writer.BytesWritten(),
+                                     &zone_allocator);
+  EXPECT_NOTNULL(root);
+  EXPECT_EQ(Dart_CObject::kBool, root->type);
+  EXPECT_EQ(false, root->value.as_bool);
+  CheckEncodeDecodeMessage(root);
 }
 
 
 TEST_CASE(SerializeBigint) {
   Zone zone(Isolate::Current());
 
   // Write snapshot with object content.
   uint8_t* buffer;
   SnapshotWriter writer(Snapshot::kMessage, &buffer, &zone_allocator);
   const Bigint& bigint = Bigint::Handle(Bigint::New(0xfffffffffLL));
   writer.WriteObject(bigint.raw());
   writer.FinalizeBuffer();
 
   // Create a snapshot object using the buffer.
   const Snapshot* snapshot = Snapshot::SetupFromBuffer(buffer);
 
   // Read object back from the snapshot.
   SnapshotReader reader(snapshot, Isolate::Current());
   Bigint& obj = Bigint::Handle();
   obj ^= reader.ReadObject();
   OS::Print("%lld", BigintOperations::ToInt64(obj));
   EXPECT_EQ(BigintOperations::ToInt64(bigint), BigintOperations::ToInt64(obj));
 
   // Read object back from the snapshot into a C structure.
-  Dart_CMessage* cmessage = DecodeMessage(buffer + Snapshot::kHeaderSize,
-                                          writer.BytesWritten(),
-                                          &zone_allocator);
-  Dart_CObject* cobject = cmessage->root;
+  Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
+                                     writer.BytesWritten(),
+                                     &zone_allocator);
   // Bigint not supported.
-  EXPECT(cobject == NULL);
+  EXPECT(root == NULL);
 }
 
 
 TEST_CASE(SerializeSingletons) {
   // Write snapshot with object content.
   uint8_t* buffer;
   SnapshotWriter writer(Snapshot::kMessage, &buffer, &malloc_allocator);
   writer.WriteObject(Object::class_class());
   writer.WriteObject(Object::null_class());
   writer.WriteObject(Object::type_class());
@@ skipping 58 matching lines @@
   // Create a snapshot object using the buffer.
   const Snapshot* snapshot = Snapshot::SetupFromBuffer(buffer);
 
   // Read object back from the snapshot.
   SnapshotReader reader(snapshot, Isolate::Current());
   String& serialized_str = String::Handle();
   serialized_str ^= reader.ReadObject();
   EXPECT(str.Equals(serialized_str));
 
   // Read object back from the snapshot into a C structure.
-  Dart_CMessage* cmessage = DecodeMessage(buffer + Snapshot::kHeaderSize,
-                                          writer.BytesWritten(),
-                                          &zone_allocator);
-  Dart_CObject* cobject = cmessage->root;
-  EXPECT_EQ(Dart_CObject::kString, cobject->type);
-  EXPECT_STREQ(cstr, cobject->value.as_string);
+  Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
+                                     writer.BytesWritten(),
+                                     &zone_allocator);
+  EXPECT_EQ(Dart_CObject::kString, root->type);
+  EXPECT_STREQ(cstr, root->value.as_string);
+  CheckEncodeDecodeMessage(root);
 }
 
 
 TEST_CASE(SerializeArray) {
   Zone zone(Isolate::Current());
 
   // Write snapshot with object content.
   uint8_t* buffer;
   SnapshotWriter writer(Snapshot::kMessage, &buffer, &zone_allocator);
   const int kArrayLength = 10;
   Array& array = Array::Handle(Array::New(kArrayLength));
   Smi& smi = Smi::Handle();
   for (int i = 0; i < kArrayLength; i++) {
     smi ^= Smi::New(i);
     array.SetAt(i, smi);
   }
   writer.WriteObject(array.raw());
   writer.FinalizeBuffer();
 
   // Create a snapshot object using the buffer.
   const Snapshot* snapshot = Snapshot::SetupFromBuffer(buffer);
 
   // Read object back from the snapshot.
   SnapshotReader reader(snapshot, Isolate::Current());
   Array& serialized_array = Array::Handle();
   serialized_array ^= reader.ReadObject();
   EXPECT(array.Equals(serialized_array));
 
   // Read object back from the snapshot into a C structure.
-  Dart_CMessage* cmessage = DecodeMessage(buffer + Snapshot::kHeaderSize,
-                                          writer.BytesWritten(),
-                                          &zone_allocator);
-  Dart_CObject* cobject = cmessage->root;
-  EXPECT_EQ(Dart_CObject::kArray, cobject->type);
-  EXPECT_EQ(kArrayLength, cobject->value.as_array.length);
+  Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
+                                     writer.BytesWritten(),
+                                     &zone_allocator);
+  EXPECT_EQ(Dart_CObject::kArray, root->type);
+  EXPECT_EQ(kArrayLength, root->value.as_array.length);
   for (int i = 0; i < kArrayLength; i++) {
-    Dart_CObject* element = cobject->value.as_array.values[i];
+    Dart_CObject* element = root->value.as_array.values[i];
     EXPECT_EQ(Dart_CObject::kInt32, element->type);
     EXPECT_EQ(i, element->value.as_int32);
   }
+  CheckEncodeDecodeMessage(root);
 }
 
 
 TEST_CASE(SerializeEmptyArray) {
   Zone zone(Isolate::Current());
 
   // Write snapshot with object content.
   uint8_t* buffer;
   SnapshotWriter writer(Snapshot::kMessage, &buffer, &zone_allocator);
   const int kArrayLength = 0;
   Array& array = Array::Handle(Array::New(kArrayLength));
   writer.WriteObject(array.raw());
   writer.FinalizeBuffer();
 
   // Create a snapshot object using the buffer.
   const Snapshot* snapshot = Snapshot::SetupFromBuffer(buffer);
 
   // Read object back from the snapshot.
   SnapshotReader reader(snapshot, Isolate::Current());
   Array& serialized_array = Array::Handle();
   serialized_array ^= reader.ReadObject();
   EXPECT(array.Equals(serialized_array));
 
   // Read object back from the snapshot into a C structure.
-  Dart_CMessage* cmessage = DecodeMessage(buffer + Snapshot::kHeaderSize,
-                                          writer.BytesWritten(),
-                                          &zone_allocator);
-  Dart_CObject* cobject = cmessage->root;
-  EXPECT_EQ(Dart_CObject::kArray, cobject->type);
-  EXPECT_EQ(kArrayLength, cobject->value.as_array.length);
-  EXPECT(cobject->value.as_array.values == NULL);
+  Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
+                                     writer.BytesWritten(),
+                                     &zone_allocator);
+  EXPECT_EQ(Dart_CObject::kArray, root->type);
+  EXPECT_EQ(kArrayLength, root->value.as_array.length);
+  EXPECT(root->value.as_array.values == NULL);
+  CheckEncodeDecodeMessage(root);
 }
 
 
 TEST_CASE(SerializeScript) {
   const char* kScriptChars =
       "class A {\n"
       "  static bar() { return 42; }\n"
       "  static fly() { return 5; }\n"
       "}\n";
 
@@ skipping 301 matching lines @@
   Zone zone(Isolate::Current());
   uint8_t* buffer = NULL;
   MessageWriter writer(&buffer, &zone_allocator);
 
   static const int kArrayLength = 2;
   intptr_t data[kArrayLength] = {1, 2};
   int len = kArrayLength;
   writer.WriteMessage(len, data);
 
   // Read object back from the snapshot into a C structure.
-  Dart_CMessage* cmessage = DecodeMessage(buffer + Snapshot::kHeaderSize,
-                                          writer.BytesWritten(),
-                                          &zone_allocator);
-  Dart_CObject* cobject = cmessage->root;
-  EXPECT_EQ(Dart_CObject::kArray, cobject->type);
-  EXPECT_EQ(kArrayLength, cobject->value.as_array.length);
+  Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
+                                     writer.BytesWritten(),
+                                     &zone_allocator);
+  EXPECT_EQ(Dart_CObject::kArray, root->type);
+  EXPECT_EQ(kArrayLength, root->value.as_array.length);
   for (int i = 0; i < kArrayLength; i++) {
-    Dart_CObject* element = cobject->value.as_array.values[i];
+    Dart_CObject* element = root->value.as_array.values[i];
     EXPECT_EQ(Dart_CObject::kInt32, element->type);
     EXPECT_EQ(i + 1, element->value.as_int32);
   }
+  CheckEncodeDecodeMessage(root);
 }
 
 
 // Helper function to call a top level Dart function, serialize the
 // result and deserialize the result into a Dart_CObject structure.
-static Dart_CMessage* GetDeserializedDartMessage(Dart_Handle lib,
-                                                 const char* dart_function) {
+static Dart_CObject* GetDeserializedDartMessage(Dart_Handle lib,
+                                                const char* dart_function) {
   Dart_Handle result;
   result = Dart_InvokeStatic(lib,
                              Dart_NewString(""),
                              Dart_NewString(dart_function),
                              0,
                              NULL);
   EXPECT_VALID(result);
 
   // Serialize the list into a message.
   uint8_t* buffer;
   SnapshotWriter writer(Snapshot::kMessage, &buffer, &zone_allocator);
   const Object& list = Object::Handle(Api::UnwrapHandle(result));
   writer.WriteObject(list.raw());
   writer.FinalizeBuffer();
 
   // Read object back from the snapshot into a C structure.
-  Dart_CMessage* cmessage = DecodeMessage(buffer + Snapshot::kHeaderSize,
-                                          writer.BytesWritten(),
-                                          &zone_allocator);
-  return cmessage;
+  return DecodeMessage(buffer + Snapshot::kHeaderSize,
+                       writer.BytesWritten(),
+                       &zone_allocator);
 }
 
 
 UNIT_TEST_CASE(DartGeneratedMessages) {
   static const char* kCustomIsolateScriptChars =
       "getSmi() {\n"
       "  return 42;\n"
       "}\n"
       "getString() {\n"
       "  return \"Hello, world!\";\n"
@@ skipping 32 matching lines @@
     {
       Zone zone(Isolate::Current());
       uint8_t* buffer;
       SnapshotWriter writer(Snapshot::kMessage, &buffer, &zone_allocator);
       Smi& smi = Smi::Handle();
       smi ^= Api::UnwrapHandle(smi_result);
       writer.WriteObject(smi.raw());
       writer.FinalizeBuffer();
 
       // Read object back from the snapshot into a C structure.
-      Dart_CMessage* cmessage = DecodeMessage(buffer + Snapshot::kHeaderSize,
-                                              writer.BytesWritten(),
-                                              &zone_allocator);
-      Dart_CObject* cobject = cmessage->root;
-      EXPECT_NOTNULL(cobject);
-      EXPECT_EQ(Dart_CObject::kInt32, cobject->type);
-      EXPECT_EQ(42, cobject->value.as_int32);
+      Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
+                                         writer.BytesWritten(),
+                                         &zone_allocator);
+      EXPECT_NOTNULL(root);
+      EXPECT_EQ(Dart_CObject::kInt32, root->type);
+      EXPECT_EQ(42, root->value.as_int32);
+      CheckEncodeDecodeMessage(root);
     }
     {
       Zone zone(Isolate::Current());
       uint8_t* buffer;
       SnapshotWriter writer(Snapshot::kMessage, &buffer, &zone_allocator);
       String& str = String::Handle();
       str ^= Api::UnwrapHandle(string_result);
       writer.WriteObject(str.raw());
       writer.FinalizeBuffer();
 
       // Read object back from the snapshot into a C structure.
-      Dart_CMessage* cmessage = DecodeMessage(buffer + Snapshot::kHeaderSize,
-                                              writer.BytesWritten(),
-                                              &zone_allocator);
-      Dart_CObject* cobject = cmessage->root;
-      EXPECT_NOTNULL(cobject);
-      EXPECT_EQ(Dart_CObject::kString, cobject->type);
-      EXPECT_STREQ("Hello, world!", cobject->value.as_string);
+      Dart_CObject* root = DecodeMessage(buffer + Snapshot::kHeaderSize,
+                                         writer.BytesWritten(),
+                                         &zone_allocator);
+      EXPECT_NOTNULL(root);
+      EXPECT_EQ(Dart_CObject::kString, root->type);
+      EXPECT_STREQ("Hello, world!", root->value.as_string);
+      CheckEncodeDecodeMessage(root);
     }
   }
   Dart_ExitScope();
   Dart_ShutdownIsolate();
 }
 
 
 UNIT_TEST_CASE(DartGeneratedListMessages) {
   const int kArrayLength = 10;
   static const char* kScriptChars =
@@ skipping 23 matching lines @@
   TestCase::CreateTestIsolate();
   Isolate* isolate = Isolate::Current();
   EXPECT(isolate != NULL);
   Dart_EnterScope();
 
   Dart_Handle lib = TestCase::LoadTestScript(kScriptChars, NULL);
   EXPECT_VALID(lib);
 
   {
     DARTSCOPE_NOCHECKS(isolate);
-
     {
       // Generate a list of nulls from Dart code.
       Zone zone(Isolate::Current());
-      Dart_CMessage* cmessage = GetDeserializedDartMessage(lib, "getList");
-      Dart_CObject* value = cmessage->root;
-      EXPECT_NOTNULL(value);
-      EXPECT_EQ(Dart_CObject::kArray, value->type);
-      EXPECT_EQ(kArrayLength, value->value.as_array.length);
+      Dart_CObject* root = GetDeserializedDartMessage(lib, "getList");
+      EXPECT_NOTNULL(root);
+      EXPECT_EQ(Dart_CObject::kArray, root->type);
+      EXPECT_EQ(kArrayLength, root->value.as_array.length);
       for (int i = 0; i < kArrayLength; i++) {
-        EXPECT_EQ(Dart_CObject::kNull, value->value.as_array.values[i]->type);
+        EXPECT_EQ(Dart_CObject::kNull, root->value.as_array.values[i]->type);
       }
+      CheckEncodeDecodeMessage(root);
     }
     {
       // Generate a list of ints from Dart code.
       Zone zone(Isolate::Current());
-      Dart_CMessage* cmessage = GetDeserializedDartMessage(lib, "getIntList");
-      Dart_CObject* value = cmessage->root;
-      EXPECT_NOTNULL(value);
-      EXPECT_EQ(Dart_CObject::kArray, value->type);
-      EXPECT_EQ(kArrayLength, value->value.as_array.length);
+      Dart_CObject* root = GetDeserializedDartMessage(lib, "getIntList");
+      EXPECT_NOTNULL(root);
+      EXPECT_EQ(Dart_CObject::kArray, root->type);
+      EXPECT_EQ(kArrayLength, root->value.as_array.length);
       for (int i = 0; i < kArrayLength; i++) {
-        EXPECT_EQ(Dart_CObject::kInt32, value->value.as_array.values[i]->type);
-        EXPECT_EQ(i, value->value.as_array.values[i]->value.as_int32);
+        EXPECT_EQ(Dart_CObject::kInt32, root->value.as_array.values[i]->type);
+        EXPECT_EQ(i, root->value.as_array.values[i]->value.as_int32);
       }
+      CheckEncodeDecodeMessage(root);
     }
     {
       // Generate a list of strings from Dart code.
       Zone zone(Isolate::Current());
-      Dart_CMessage* cmessage =
-          GetDeserializedDartMessage(lib, "getStringList");
-      Dart_CObject* value = cmessage->root;
-      EXPECT_NOTNULL(value);
-      EXPECT_EQ(Dart_CObject::kArray, value->type);
-      EXPECT_EQ(kArrayLength, value->value.as_array.length);
+      Dart_CObject* root = GetDeserializedDartMessage(lib, "getStringList");
+      EXPECT_NOTNULL(root);
+      EXPECT_EQ(Dart_CObject::kArray, root->type);
+      EXPECT_EQ(kArrayLength, root->value.as_array.length);
       for (int i = 0; i < kArrayLength; i++) {
-        EXPECT_EQ(Dart_CObject::kString, value->value.as_array.values[i]->type);
+        EXPECT_EQ(Dart_CObject::kString, root->value.as_array.values[i]->type);
         char buffer[3];
         snprintf(buffer, sizeof(buffer), "%d", i);
-        EXPECT_STREQ(buffer, value->value.as_array.values[i]->value.as_string);
+        EXPECT_STREQ(buffer, root->value.as_array.values[i]->value.as_string);
       }
     }
     {
       // Generate a list of objects of different types from Dart code.
       Zone zone(Isolate::Current());
-      Dart_CMessage* cmessage = GetDeserializedDartMessage(lib, "getMixedList");
-      Dart_CObject* value = cmessage->root;
-      EXPECT_NOTNULL(value);
-      EXPECT_EQ(Dart_CObject::kArray, value->type);
-      EXPECT_EQ(kArrayLength, value->value.as_array.length);
+      Dart_CObject* root = GetDeserializedDartMessage(lib, "getMixedList");
+      EXPECT_NOTNULL(root);
+      EXPECT_EQ(Dart_CObject::kArray, root->type);
+      EXPECT_EQ(kArrayLength, root->value.as_array.length);
 
-      EXPECT_EQ(Dart_CObject::kInt32, value->value.as_array.values[0]->type);
-      EXPECT_EQ(0, value->value.as_array.values[0]->value.as_int32);
-      EXPECT_EQ(Dart_CObject::kString, value->value.as_array.values[1]->type);
-      EXPECT_STREQ("1", value->value.as_array.values[1]->value.as_string);
-      EXPECT_EQ(Dart_CObject::kDouble, value->value.as_array.values[2]->type);
-      EXPECT_EQ(2.2, value->value.as_array.values[2]->value.as_double);
-      EXPECT_EQ(Dart_CObject::kBool, value->value.as_array.values[3]->type);
-      EXPECT_EQ(true, value->value.as_array.values[3]->value.as_bool);
+      EXPECT_EQ(Dart_CObject::kInt32, root->value.as_array.values[0]->type);
+      EXPECT_EQ(0, root->value.as_array.values[0]->value.as_int32);
+      EXPECT_EQ(Dart_CObject::kString, root->value.as_array.values[1]->type);
+      EXPECT_STREQ("1", root->value.as_array.values[1]->value.as_string);
+      EXPECT_EQ(Dart_CObject::kDouble, root->value.as_array.values[2]->type);
+      EXPECT_EQ(2.2, root->value.as_array.values[2]->value.as_double);
+      EXPECT_EQ(Dart_CObject::kBool, root->value.as_array.values[3]->type);
+      EXPECT_EQ(true, root->value.as_array.values[3]->value.as_bool);
 
       for (int i = 0; i < kArrayLength; i++) {
         if (i > 3) {
-          EXPECT_EQ(Dart_CObject::kNull, value->value.as_array.values[i]->type);
+          EXPECT_EQ(Dart_CObject::kNull, root->value.as_array.values[i]->type);
         }
       }
     }
   }
   Dart_ExitScope();
   Dart_ShutdownIsolate();
 }
 
 
 UNIT_TEST_CASE(DartGeneratedListMessagesWithBackref) {
@@ skipping 34 matching lines @@
 
   Dart_Handle lib = TestCase::LoadTestScript(kScriptChars, NULL);
   EXPECT_VALID(lib);
 
   {
     DARTSCOPE_NOCHECKS(isolate);
 
     {
       // Generate a list of strings from Dart code.
       Zone zone(Isolate::Current());
-      Dart_CMessage* cmessage =
-          GetDeserializedDartMessage(lib, "getStringList");
-      Dart_CObject* object = cmessage->root;
-      EXPECT_NOTNULL(object);
-      EXPECT_EQ(Dart_CObject::kArray, object->type);
-      EXPECT_EQ(kArrayLength, object->value.as_array.length);
+      Dart_CObject* root = GetDeserializedDartMessage(lib, "getStringList");
+      EXPECT_NOTNULL(root);
+      EXPECT_EQ(Dart_CObject::kArray, root->type);
+      EXPECT_EQ(kArrayLength, root->value.as_array.length);
       for (int i = 0; i < kArrayLength; i++) {
-        Dart_CObject* element = object->value.as_array.values[i];
-        EXPECT_EQ(object->value.as_array.values[0], element);
+        Dart_CObject* element = root->value.as_array.values[i];
+        EXPECT_EQ(root->value.as_array.values[0], element);
         EXPECT_EQ(Dart_CObject::kString, element->type);
         EXPECT_STREQ("Hello, world!", element->value.as_string);
       }
     }
     {
       // Generate a list of doubles from Dart code.
       Zone zone(Isolate::Current());
-      Dart_CMessage* cmessage =
-          GetDeserializedDartMessage(lib, "getDoubleList");
-      Dart_CObject* object = cmessage->root;
-      EXPECT_NOTNULL(object);
-      EXPECT_EQ(Dart_CObject::kArray, object->type);
-      EXPECT_EQ(kArrayLength, object->value.as_array.length);
+      Dart_CObject* root = GetDeserializedDartMessage(lib, "getDoubleList");
+      EXPECT_NOTNULL(root);
+      EXPECT_EQ(Dart_CObject::kArray, root->type);
+      EXPECT_EQ(kArrayLength, root->value.as_array.length);
       for (int i = 0; i < kArrayLength; i++) {
-        Dart_CObject* element = object->value.as_array.values[i];
-        EXPECT_EQ(object->value.as_array.values[0], element);
+        Dart_CObject* element = root->value.as_array.values[i];
+        EXPECT_EQ(root->value.as_array.values[0], element);
         EXPECT_EQ(Dart_CObject::kDouble, element->type);
         EXPECT_EQ(3.14, element->value.as_double);
       }
     }
     {
       // Generate a list of objects of different types from Dart code.
       Zone zone(Isolate::Current());
-      Dart_CMessage* cmessage = GetDeserializedDartMessage(lib, "getMixedList");
-      Dart_CObject* object = cmessage->root;
-      EXPECT_NOTNULL(object);
-      EXPECT_EQ(Dart_CObject::kArray, object->type);
-      EXPECT_EQ(kArrayLength, object->value.as_array.length);
+      Dart_CObject* root = GetDeserializedDartMessage(lib, "getMixedList");
+      EXPECT_NOTNULL(root);
+      EXPECT_EQ(Dart_CObject::kArray, root->type);
+      EXPECT_EQ(kArrayLength, root->value.as_array.length);
       for (int i = 0; i < kArrayLength; i++) {
-        Dart_CObject* element = object->value.as_array.values[i];
+        Dart_CObject* element = root->value.as_array.values[i];
         if ((i % 2) == 0) {
-          EXPECT_EQ(object->value.as_array.values[0], element);
+          EXPECT_EQ(root->value.as_array.values[0], element);
           EXPECT_EQ(Dart_CObject::kString, element->type);
           EXPECT_STREQ("A", element->value.as_string);
         } else {
-          EXPECT_EQ(object->value.as_array.values[1], element);
+          EXPECT_EQ(root->value.as_array.values[1], element);
           EXPECT_EQ(Dart_CObject::kDouble, element->type);
           EXPECT_STREQ(2.72, element->value.as_double);
         }
       }
     }
     {
       // Generate a list of objects of different types from Dart code.
       Zone zone(Isolate::Current());
-      Dart_CMessage* cmessage =
-          GetDeserializedDartMessage(lib, "getSelfRefList");
-      Dart_CObject* object = cmessage->root;
-      EXPECT_NOTNULL(object);
-      EXPECT_EQ(Dart_CObject::kArray, object->type);
-      EXPECT_EQ(kArrayLength, object->value.as_array.length);
+      Dart_CObject* root = GetDeserializedDartMessage(lib, "getSelfRefList");
+      EXPECT_NOTNULL(root);
+      EXPECT_EQ(Dart_CObject::kArray, root->type);
+      EXPECT_EQ(kArrayLength, root->value.as_array.length);
       for (int i = 0; i < kArrayLength; i++) {
-        Dart_CObject* element = object->value.as_array.values[i];
+        Dart_CObject* element = root->value.as_array.values[i];
         EXPECT_EQ(Dart_CObject::kArray, element->type);
-        EXPECT_EQ(object, element);
+        EXPECT_EQ(root, element);
       }
     }
   }
   Dart_ExitScope();
   Dart_ShutdownIsolate();
 }
 
+
+UNIT_TEST_CASE(PostCObject) {
+  // Create a native port for posting from C to Dart
+  TestIsolateScope __test_isolate__;
+  const char* kScriptChars =
+      "void main() {\n"
+      "  var messageCount = 0;\n"
+      "  var exception = '';\n"
+      "  var port = new ReceivePort();\n"
+      "  port.receive((message, replyTo) {\n"
+      "    exception += message.toString();\n"
+      "    messageCount++;\n"
+      "    if (messageCount == 7) throw new Exception(exception);\n"
+      "  });\n"
+      "  return port.toSendPort();\n"
+      "}\n";
+  Dart_Handle lib = TestCase::LoadTestScript(kScriptChars, NULL);
+  Dart_EnterScope();
+
+  // xxx
+  Dart_Handle send_port = Dart_InvokeStatic(lib,
+                                            Dart_NewString(""),
+                                            Dart_NewString("main"),
+                                            0,
+                                            NULL);
+  EXPECT_VALID(send_port);
+  Dart_Handle result =
+      Dart_GetInstanceField(send_port, Dart_NewString("_id"));
+  ASSERT(!Dart_IsError(result));
+  ASSERT(Dart_IsInteger(result));
+  int64_t send_port_id;
+  Dart_Handle result2 = Dart_IntegerToInt64(result, &send_port_id);
+  ASSERT(!Dart_IsError(result2));
+
+  // Setup single object message.
+  Dart_CObject object;
+
+  object.type = Dart_CObject::kNull;
+  EXPECT(Dart_PostCObject(send_port_id, &object));
+
+  object.type = Dart_CObject::kBool;
+  object.value.as_bool = true;
+  EXPECT(Dart_PostCObject(send_port_id, &object));
+
+  object.type = Dart_CObject::kBool;
+  object.value.as_bool = false;
+  EXPECT(Dart_PostCObject(send_port_id, &object));
+
+  object.type = Dart_CObject::kInt32;
+  object.value.as_int32 = 123;
+  EXPECT(Dart_PostCObject(send_port_id, &object));
+
+  object.type = Dart_CObject::kString;
+  object.value.as_string = const_cast<char*>("456");
+  EXPECT(Dart_PostCObject(send_port_id, &object));
+
+  object.type = Dart_CObject::kDouble;
+  object.value.as_double = 3.14;
+  EXPECT(Dart_PostCObject(send_port_id, &object));
+
+  object.type = Dart_CObject::kArray;
+  object.value.as_array.length = 0;
+  EXPECT(Dart_PostCObject(send_port_id, &object));
+
+  result = Dart_RunLoop();
+  EXPECT(Dart_IsError(result));
+  EXPECT(Dart_ErrorHasException(result));
+  EXPECT_SUBSTRING("Exception: nulltruefalse1234563.14[]\n",
+                   Dart_GetError(result));
+
+  Dart_ExitScope();
+}
+
 #endif  // defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_X64).
 
 }  // namespace dart