dbus: allow unregistering of exported objects

dbus/bus.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef DBUS_BUS_H_
 #define DBUS_BUS_H_
 #pragma once
 
 #include <map>
 #include <set>
@@ skipping 208 matching lines @@
   // The bus will own all exported objects created by the bus, to ensure
   // that the exported objects are unregistered at the shutdown time of
   // the bus.
   //
   // The exported object is used to export methods of local objects, and
   // send signal from them.
   //
   // Must be called in the origin thread.
   virtual ExportedObject* GetExportedObject(const ObjectPath& object_path);
 
+  // Unregisters the exported object for the given object path |object_path|.
+  //
+  // Getting an exported object for the same object path after this call
+  // will return a new object, method calls on any remaining copies of the
+  // previous object will not be called.
+  //
+  // Must be called in the origin thread.
+  virtual void UnregisterExportedObject(const ObjectPath& object_path);

[satorux1, 2012/03/13 06:07:06]

This doesn't take a callback, so clients don't know when the object is
unregistered. is it ok?

[keybuk, 2012/03/13 16:01:05]

The most likely place for this to be called is from a service provider
destructor, so a callback doesn't make sense. Though you make a point that this
introduces potentials for races, I'll adjust it a little so it doesn't have that

+
   // Shuts down the bus and blocks until it's done. More specifically, this
   // function does the following:
   //
   // - Unregisters the object paths
   // - Releases the service names
   // - Closes the connection to dbus-daemon.
   //
   // BLOCKING CALL.
   virtual void ShutdownAndBlock();
 
@@ skipping 174 matching lines @@
   // Returns true if the bus is connected to D-Bus.
   bool is_connected() { return connection_ != NULL; }
 
  protected:
   // This is protected, so we can define sub classes.
   virtual ~Bus();
 
  private:
   friend class base::RefCountedThreadSafe<Bus>;
 
+  // Helper function used for UnregisterExportedObject().
+  void UnregisterExportedObjectInternal(const ObjectPath& object_path);
+
   // Helper function used for ShutdownOnDBusThreadAndBlock().
   void ShutdownOnDBusThreadAndBlockInternal();
 
   // Helper function used for RequestOwnership().
   void RequestOwnershipInternal(const std::string& service_name,
                                 OnOwnershipCallback on_ownership_callback);
 
   // Called when the ownership request is completed.
   void OnOwnership(OnOwnershipCallback on_ownership_callback,
                    const std::string& service_name,
@@ skipping 79 matching lines @@
   // OnAddTimeout()/OnRemoveTimeou() are balanced.
   int num_pending_watches_;
   int num_pending_timeouts_;
 
   DISALLOW_COPY_AND_ASSIGN(Bus);
 };
 
 }  // namespace dbus
 
 #endif  // DBUS_BUS_H_