Handle vmservice messages while at breakpoint.

runtime/bin/dbg_message.h

 // 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.
 
 #ifndef BIN_DBG_MESSAGE_H_
 #define BIN_DBG_MESSAGE_H_
 
 #include "bin/builtin.h"
 #include "bin/utils.h"
 
@@ skipping 143 matching lines @@
   Dart_IsolateId isolate_id() const { return isolate_id_; }
   DbgMsgQueue* next() const { return next_; }
   void set_next(DbgMsgQueue* next) { next_ = next; }
 
   // Add specified debug command message to the queue.
   void AddMessage(int32_t cmd_idx,
                   const char* start,
                   const char* end,
                   int debug_fd);
 
-  // Handle all debug command messages in the queue.
-  void HandleMessages();
+  // Notify an isolate of a pending vmservice message.
+  void Notify();
+
+  // Run a message loop which handles messages as they arrive until
+  // normal program execution resumes.
+  void MessageLoop();
+
+  // Handle any pending debug command messages in the queue.  Return
+  // value indicates whether a resume has been requested.
+  bool HandlePendingMessages();
 
   // Interrupt Isolate.
   void InterruptIsolate();
 
   // Queue output messages, these are sent out when we hit an event.
   void QueueOutputMsg(dart::TextBuffer* msg);
 
   // Send all queued messages over to the debugger.
   void SendQueuedMsgs();
 
@@ skipping 42 matching lines @@
   // It returns kInvalidCommand otherwise.
   static int32_t LookupIsolateCommand(const char* buf, int32_t buflen);
 
   // Queue debugger message targetted for the isolate.
   static bool AddIsolateMessage(Dart_IsolateId isolate_id,
                                 int32_t cmd_idx,
                                 const char* start,
                                 const char* end,
                                 int debug_fd);
 
+  // Notify an isolate of a pending vmservice message.
+  static void NotifyIsolate(Dart_Isolate isolate);
+
   // Interrupt isolate.
   static bool InterruptIsolate(Dart_IsolateId isolate_id);
 
   // Add Debugger Message Queue corresponding to the Isolate.
   static DbgMsgQueue* AddIsolateMsgQueue(Dart_IsolateId isolate_id);
 
   // Get Debugger Message Queue corresponding to the Isolate.
   static DbgMsgQueue* GetIsolateMsgQueue(Dart_IsolateId isolate_id);
 
   // Remove Debugger Message Queue corresponding to the Isolate.
@@ skipping 23 matching lines @@
   static dart::Mutex* msg_queue_list_lock_;
 
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(DbgMsgQueueList);
 };
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // BIN_DBG_MESSAGE_H_