Display isolate message queue in Observatory debugger

runtime/vm/message_handler.cc

Index: runtime/vm/message_handler.cc
diff --git a/runtime/vm/message_handler.cc b/runtime/vm/message_handler.cc
index 68344cb35db67ad979f96ade6edb381ee91f2d2d..58018858076d468e1f29470d79abc0a4ed21a7b6 100644
--- a/runtime/vm/message_handler.cc
+++ b/runtime/vm/message_handler.cc
@@ -34,6 +34,7 @@ class MessageHandlerTask : public ThreadPool::Task {
 MessageHandler::MessageHandler()
     : queue_(new MessageQueue()),
       oob_queue_(new MessageQueue()),
+      oob_message_handling_allowed_(true),
       live_ports_(0),
       paused_(0),
       pause_on_start_(false),
@@ -208,6 +209,9 @@ bool MessageHandler::HandleNextMessage() {
 
 
 bool MessageHandler::HandleOOBMessages() {
+  if (!oob_message_handling_allowed_) {
+    return true;
+  }
   MonitorLocker ml(&monitor_);
 #if defined(DEBUG)
   CheckAccess();
@@ -333,4 +337,39 @@ void MessageHandler::decrement_live_ports() {
   live_ports_--;
 }
 
+
+MessageHandler::AcquiredQueues::AcquiredQueues()
+    : handler_(NULL) {
+}
+
+
+MessageHandler::AcquiredQueues::~AcquiredQueues() {
+  if (handler_ != NULL) {
+    // Release ownership.
+    handler_->oob_message_handling_allowed_ = true;
+    handler_->monitor_.Exit();
+  }

[turnidge, 2015/05/04 17:47:13]

Move the bulk of this into Reset.

[Cutch, 2015/05/04 19:56:51]

Done.

+  Reset(NULL);
+}
+
+
+void MessageHandler::AcquiredQueues::Reset(MessageHandler* handler) {
+  handler_ = handler;
+  if (handler_ == NULL) {
+    return;
+  }
+  ASSERT(handler_ != NULL);
+  // Take ownership.
+  handler_->monitor_.Enter();
+  handler_->oob_message_handling_allowed_ = false;

[turnidge, 2015/05/04 17:47:13]

Does this need to be done under the monitor here?

[Cutch, 2015/05/04 19:56:51]

Done.

+}
+
+
+void MessageHandler::AcquireQueues(AcquiredQueues* acquired_queues) {
+  ASSERT(acquired_queues != NULL);
+  // No double dipping.
+  ASSERT(acquired_queues->handler_ == NULL);
+  acquired_queues->Reset(this);
+}
+
 }  // namespace dart