Keep track of current "pause" event in the debugger.

runtime/vm/debugger.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 VM_DEBUGGER_H_
 #define VM_DEBUGGER_H_
 
 #include "include/dart_debugger_api.h"
 
 #include "vm/object.h"
@@ skipping 286 matching lines @@
   void OneTimeBreakAtEntry(const Function& target_function);
 
   void RemoveBreakpoint(intptr_t bp_id);
   SourceBreakpoint* GetBreakpointById(intptr_t id);
 
   void SetStepOver();
   void SetSingleStep();
   void SetStepOut();
   bool IsStepping() const { return resume_action_ != kContinue; }
 
+  bool IsPaused() const { return pause_event_ != NULL; }
+
+  // Indicates why the debugger is currently paused.  If the debugger
+  // is not paused, this returns NULL.  Note that the debugger can be
+  // paused for breakpoints, isolate interruption, and (sometimes)
+  // exceptions.
+  const DebuggerEvent* PauseEvent() const { return pause_event_; }
+
   void SetExceptionPauseInfo(Dart_ExceptionPauseInfo pause_info);
   Dart_ExceptionPauseInfo GetExceptionPauseInfo();
 
   void VisitObjectPointers(ObjectPointerVisitor* visitor);
 
   // Called from Runtime when a breakpoint in Dart code is reached.
   void BreakpointCallback();
 
   // Returns true if there is at least one breakpoint set in func.
   // Checks for both user-defined and internal temporary breakpoints.
@@ skipping 95 matching lines @@
   intptr_t nextId() { return next_id_++; }
 
   bool ShouldPauseOnException(DebuggerStackTrace* stack_trace,
                               const Instance& exc);
 
   void CollectLibraryFields(const GrowableObjectArray& field_list,
                             const Library& lib,
                             const String& prefix,
                             bool include_private_fields);
 
+  // Handles any events which pause vm execution.  Breakpoints,
+  // interrupts, etc.
+  void Pause(DebuggerEvent* event);
+
   Isolate* isolate_;
   Dart_Port isolate_id_;  // A unique ID for the isolate in the debugger.
   bool initialized_;
 
   // ID number generator.
   intptr_t next_id_;
 
-  // Current stack trace. Valid while executing breakpoint callback code.
-  DebuggerStackTrace* stack_trace_;
-
-  RemoteObjectCache* obj_cache_;
 
   SourceBreakpoint* src_breakpoints_;
   CodeBreakpoint* code_breakpoints_;
 
   // Tells debugger what to do when resuming execution after a breakpoint.
   ResumeAction resume_action_;
 
   // Do not call back to breakpoint handler if this flag is set.
   // Effectively this means ignoring breakpoints. Set when Dart code may
   // be run as a side effect of getting values of fields.
   bool ignore_breakpoints_;
 
-  // True while debugger calls event_handler_. Used to prevent recursive
-  // debugger events.
-  bool in_event_notification_;
+  // Indicates why the debugger is currently paused.  If the debugger
+  // is not paused, this is NULL.  Note that the debugger can be
+  // paused for breakpoints, isolate interruption, and (sometimes)
+  // exceptions.
+  DebuggerEvent* pause_event_;
+
+  // An id -> object map.  Valid only while IsPaused().
+  RemoteObjectCache* obj_cache_;
+
+  // Current stack trace. Valid only while IsPaused().
+  DebuggerStackTrace* stack_trace_;
 
   Dart_ExceptionPauseInfo exc_pause_info_;
 
   static EventHandler* event_handler_;
 
   friend class Isolate;
   friend class SourceBreakpoint;
   DISALLOW_COPY_AND_ASSIGN(Debugger);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_DEBUGGER_H_