cashew: do not delete DBus::ObjectProxy objects from D-Bus callbacks

src/service_manager.h

 // Copyright (c) 2010 The Chromium OS 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 SRC_SERVICE_MANAGER_H_
 #define SRC_SERVICE_MANAGER_H_
 
+#include <glib.h>
+
 #include <map>
 #include <string>
 #include <vector>
 
 #include <base/basictypes.h>  // NOLINT
 #include <dbus-c++/dbus.h>  // NOLINT
 
 #include "src/flimflam_manager_client_glue.h"
 #include "src/service.h"
 
 namespace cashew {
 
 class CashewServer;
 
 // map of service path names to Service objects
 typedef std::map<std::string, Service*> ServiceMap;
 
+// vector of Service objects
+typedef std::vector<Service*> ServiceList;
+
 // vector of DBus::Path objects (strings) representing service path names
 typedef std::vector<DBus::Path> ServicePathList;
 
 // monitors Flimflam and maintains a collection of cellular service objects
 class ServiceManager : public org::chromium::flimflam::Manager_proxy,
                        public DBus::IntrospectableProxy,
                        public DBus::ObjectProxy {
   public:
-    explicit ServiceManager(DBus::Connection& connection);  // NOLINT
+    explicit ServiceManager(DBus::Connection& connection,  // NOLINT
+                            GMainLoop * const main_loop);
     virtual ~ServiceManager();
 
     // look up a service by its path name
     // returns NULL if service is not found
     virtual const Service* GetService(const std::string& service_path) const;
 
     // set Cashew server
     // we'll talk to it when we want to emit updates to the world on behalf of
     // our child Services.
     // it's ok to clear this by setting it to NULL, in which case our updates
@@ skipping 41 matching lines @@
 
     // set idle/timer source id
     virtual void SetGetPropertiesSourceId(guint source_id);
 
     // are we in the process of retrying our GetProperties call?
     virtual bool RetryingGetProperties() const;
 
     // set the retrying flag
     virtual void OnRetryingGetProperties(bool retrying);
 
+    // get deferred service deletion source id
+    virtual guint GetDeferredServiceDeletionSourceId() const;
+
+    // set deferred service deletion source id
+    virtual void SetDeferredServiceDeletionSourceId(guint source_id);
+
   private:
     // D-Bus connection owned by our creator
     // shared with Service objs that we create
     DBus::Connection& connection_;
 
+    // glib main loop
+    GMainLoop * const main_loop_;
+
     // collection of Service objs representing cellular services
     ServiceMap services_;
 
     // Cashew server implementing our front-end interface
     CashewServer *cashew_server_;
 
     // default technology most recently reported by Flimflam
     Service::Type default_technology_;
 
     // the cellular service, if any, that we think is the default service
     // can be NULL if we don't know the default service or a non-cellular
     // service is the default
     Service *default_cellular_service_;
 
     // global connectivity state most recently reported by Flimflam
     ConnectivityState connectivity_state_;
 
     // GetProperties timer glib source id
     // 0 means no source
     guint get_properties_source_id_;
 
     // are we in the process of retrying our GetProperties call?
     // this flag exists to distinguish between our initial g_idle_add call
     // and our subsequent timer calls
     bool retrying_get_properties_;
 
-    // delete a collection of services
-    void DeleteServices(ServiceMap *service_map);
+    // Service objects pending deletion from the main loop
+    // we need to do this to work around a dbus-c++ deadlock issue that arises
+    // when we send a D-Bus message from a D-Bus callback
+    ServiceList services_pending_deletion_;
+
+    // glib source id for deferred service deletion
+    guint deferred_service_deletion_source_id_;
+
+    // delete a collection of services as soon as possible
+    // calls DeleteServiceOrScheduleForLaterDeletion (below) for each service
+    void DeleteServicesWhenPossible(ServiceMap *service_map);
+
+    // deletes members of |services_pending_deletion_| immediately
+    void DeletePendingServices();
+
+    // delete a service as soon as possible
+    // the service is deleted immediately if the main loop is not running
+    // otherwise, it is scheduled for deletion from the main loop
+    void DeleteServiceOrScheduleForLaterDeletion(Service *service);
+
+    // glib integration: static wrapper for DeletePendingServices
+    // takes object ptr as data and invokes object->DeletePendingServices()
+    // does not reschedule itself to run again
+    static gboolean StaticDeletePendingServicesCallback(gpointer data);
 
     // glib integration: static wrapper for GetFlimflamProperties
     // takes object ptr as data and invokes object->GetFlimflamProperties()
     static gboolean StaticGetFlimflamPropertiesCallback(gpointer data);
 
     // get interesting properties from Flimflam such as Services and
     // DefaultTechnology
     // returns true on success and false on failure
     bool GetFlimflamProperties();
 
@@ skipping 30 matching lines @@
 
     // Flimflam has told us that it has gone offline
     void OnFlimflamOffline();
 
     DISALLOW_COPY_AND_ASSIGN(ServiceManager);
 };
 
 }  // namespace cashew
 
 #endif  // SRC_SERVICE_MANAGER_H_