Use the ThreadPool for all isolates and native ports. Previously,

runtime/vm/native_message_handler.cc

Index: runtime/vm/native_message_handler.cc
===================================================================
--- runtime/vm/native_message_handler.cc	(revision 5987)
+++ runtime/vm/native_message_handler.cc	(working copy)
@@ -41,47 +41,26 @@
 }
 
 
-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();
-      }
-      // 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(),
-                         object);
-      delete message;
-    }
+bool NativeMessageHandler::HandleMessage(Message* message) {
+  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();

[Ivan Posva, 2012/04/08 22:58:27]

Should OOB messages be accepted by the native message handlers at all?

[turnidge, 2012/04/11 19:37:16]

With the current setup, HandleMessage is virtual, so it seemed to make sense to
me detect oob messages here.  Another option would be to add another virtual
HandleOOBMessage and only implement that for IsolateMessageHandler.  I could do
that if you'd like.

In the future, I could see using a native port to implement port forwarding to
other servers.  In that case, it might make sense to allow oob messages to
forward to other servers.  But there is currently no use for oob messages in
native ports.

[turnidge, 2012/04/17 23:46:55]

Thought about this some more.  Changed the comment and changed the UNIMPLEMENTED
to UNREACHABLE.

On 2012/04/11 19:37:16, turnidge wrote:

   }
-}
+  // Enter a native scope for handling the message. This will create a
+  // zone for allocating the objects for decoding the message.
+  ApiNativeScope scope;
 
-
-void NativeMessageHandler::StartWorker() {
-  int result = Thread::Start(RunWorker, reinterpret_cast<uword>(this));
-  if (result != 0) {
-    FATAL1("Failed to start native message handler worker thread %d", result);
-  }
+  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();
+  (*func())(message->dest_port(), message->reply_port(), object);
+  delete message;
+  return true;
 }
 
-
 }  // namespace dart