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

runtime/vm/snapshot.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 "vm/snapshot.h"
 
 #include "platform/assert.h"
 #include "vm/bootstrap.h"
 #include "vm/exceptions.h"
 #include "vm/heap.h"
@@ skipping 423 matching lines @@
     obj_.SetCreatedFromSnapshot();
   }
   return obj_.raw();
 }
 
 
 CMessageReader::CMessageReader(const uint8_t* buffer,
                                intptr_t length,
                                ReAlloc alloc)
     : BaseReader(buffer, length),
+      zone_(NULL),
       alloc_(alloc),
       backward_references_(kNumInitialReferences) {
+  // When no explicit zone is used ensure that there is a current
+  // isolate zone as backward_references_ needs an isolate zone for
+  // allocation.
+  ASSERT(Isolate::Current() != NULL);
+  ASSERT(Isolate::Current()->current_zone() != NULL);
+  Init();
+}
+
+
+CMessageReader::CMessageReader(const uint8_t* buffer,
+                               intptr_t length,
+                               Zone* zone)
+    : BaseReader(buffer, length),
+      zone_(zone),
+      alloc_(NULL),
+      backward_references_(kNumInitialReferences, zone) {
+  ASSERT(zone != NULL);
+  Init();
+}
+
+
+void CMessageReader::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_CMessage* CMessageReader::ReadMessage() {
   // Read the object out of the message.
   Dart_CObject* object = ReadObject();
 
   Dart_CMessage* message =
-      reinterpret_cast<Dart_CMessage*>(alloc_(NULL, 0, sizeof(Dart_CMessage)));
+      reinterpret_cast<Dart_CMessage*>(
+          Allocate(NULL, 0, sizeof(Dart_CMessage)));
   if (message == NULL) return NULL;
   message->root = object;
   return message;
 }
 
 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;
 }
 
+uint8_t* CMessageReader::Allocate(uint8_t* ptr,
+                                  intptr_t old_size,
+                                  intptr_t new_size) {
+  if (alloc_ != NULL) {
+    return alloc_(ptr, old_size, new_size);
+  } else {
+    return reinterpret_cast<uint8_t*>(
+        zone_->Reallocate(reinterpret_cast<uword>(ptr), old_size, new_size));
+  }
+}
 
 Dart_CObject* CMessageReader::AllocateDartCObject(Dart_CObject::Type type) {
   Dart_CObject* value =
       reinterpret_cast<Dart_CObject*>(
-          alloc_(NULL, 0, sizeof(Dart_CObject)));
+          Allocate(NULL, 0, sizeof(Dart_CObject)));
   value->type = type;
   return value;
 }
 
 
 Dart_CObject* CMessageReader::AllocateDartCObjectNull() {
   return AllocateDartCObject(Dart_CObject::kNull);
 }
 
 
@@ skipping 17 matching lines @@
   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));
+          Allocate(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)));
+          Allocate(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;
 }
 
@@ skipping 362 matching lines @@
 
 
 void SnapshotWriterVisitor::VisitPointers(RawObject** first, RawObject** last) {
   for (RawObject** current = first; current <= last; current++) {
     RawObject* raw_obj = *current;
     writer_->WriteObject(raw_obj);
   }
 }
 
 }  // namespace dart