Add support for native ports in the vm.

runtime/vm/native_message_handler.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/native_message_handler.h"
+
+#include "vm/isolate.h"
+#include "vm/message.h"
+#include "vm/thread.h"
+
+namespace dart {
+
+NativeMessageHandler::NativeMessageHandler(const char* name,
+                                           Dart_NativeMessageHandler func)
+    : name_(strdup(name)),
+      func_(func) {
+  // A NativeMessageHandler always has one live port.
+  increment_live_ports();
+}
+
+
+NativeMessageHandler::~NativeMessageHandler() {
+  free(name_);
+}
+
+
+#if defined(DEBUG)
+void NativeMessageHandler::CheckAccess() {
+  ASSERT(Isolate::Current() == NULL);
+}
+#endif
+
+
+static void RunWorker(uword parameter) {
+  NativeMessageHandler* handler =
+      reinterpret_cast<NativeMessageHandler*>(parameter);
+#if defined(DEBUG)
+    handler->CheckAccess();
+#endif
+
+  while (handler->HasLivePorts()) {
+    Message* message = handler->queue()->Dequeue(0);
+    if (message != NULL) {
+      if (message->priority() >= Message::kOOBPriority) {
+        // TODO(turnidge): Out of band messages will not go through
+        // the regular message handler.  Instead they will be
+        // dispatched to special vm code.  Implement.
+        UNIMPLEMENTED();
+      }

[siva, 2012/02/01 00:38:56]

I suppose CMessageReader::ReadObject will be called here and the resulting
object will be passed in as data.
Maybe a TODO here will make that clear.

[turnidge, 2012/02/01 18:51:27]

Done.

+      (*handler->func())(message->dest_port(),
+                         message->reply_port(),
+                         message->data());
+      delete message;
+    }
+  }
+}
+
+
+void NativeMessageHandler::StartWorker() {
+  new Thread(RunWorker, reinterpret_cast<uword>(this));
+}
+
+
+}  // namespace dart