Extend DebugAgent API with AsyncDebugRunner

include/v8-debug.h

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 62 matching lines @@
 enum DebugEvent {
   Break = 1,
   Exception = 2,
   NewFunction = 3,
   BeforeCompile = 4,
   AfterCompile  = 5,
   ScriptCollected = 6
 };
 
 
+/**
+ * Function helps debug agent to start V8 whenever there are debug requests
+ * pending. This makes V8 responsive to remote debugger even when no script
+ * is being running.
+ * Should cause an empty cycle to be run in V8 (e.g. evaluate "void(0)")
+ * either synchronously or asynchronously.
+ * Should return false if embedder for some reason is not going to start V8
+ * in any reasonable future.
+ */
+typedef bool (*AsyncDebugRunner)();
+
+
 class EXPORT Debug {
  public:
   /**
    * A client object passed to the v8 debugger whose ownership will be taken by
    * it. v8 is always responsible for deleting the object.
    */
   class ClientData {
    public:
     virtual ~ClientData() {}
   };
@@ skipping 158 matching lines @@
   /**
    * Returns a mirror object for the given object.
    */
   static Local<Value> GetMirror(v8::Handle<v8::Value> obj);
 
  /**
   * Enable the V8 builtin debug agent. The debugger agent will listen on the
   * supplied TCP/IP port for remote debugger connection.
   * \param name the name of the embedding application
   * \param port the TCP/IP port to listen on
+  * \param debug_runner helps V8 respond when idle; may be NULL
   */
-  static bool EnableAgent(const char* name, int port);
+  static bool EnableAgent(const char* name, int port,
+                          AsyncDebugRunner async_debug_runner = NULL);
 };
 
 
 }  // namespace v8
 
 
 #undef EXPORT
 
 
 #endif  // V8_V8_DEBUG_H_