Attachment 29445 Details for Bug 23297 – Support duplicate object registrations

[patch] Support duplicate object registrations

Support-duplicate-object-registrations.patch (text/plain), 12.56 KB, created by Will Thompson on 2009-09-12 04:02:18 UTC

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Creator: Will Thompson

Created: 2009-09-12 04:02:18 UTC

Size: 12.56 KB

patch

obsolete

>From 0263b72669de710e0adda419a520ae9f123a1be9 Mon Sep 17 00:00:00 2001
>From: Colin Walters <walters@verbum.org>
>Date: Wed, 19 Aug 2009 13:27:53 -0400
>Subject: [PATCH] Support duplicate object registrations
>
>Before commit e869fda4, we semi-supported registering the
>same object multiple times.  We'd accept messages for both paths,
>however when signals were emitted, they'd both use the first object
>path.
>
>That commit simply disallowed multiple registrations, which broke
>backwards compatibility with some projects like PolicyKit which
>had the same object registered with different paths.
>
>With this commit, explicitly allow and support multiple registrations.
>The primary change is that signals are now emitted once for each
>registration path of an object, using the correct path.
>---
> dbus/dbus-gobject.c           |  159 ++++++++++++++++++++++++++++-------------
> test/core/test-dbus-glib.c    |   41 +++++++++++
> test/core/test-service-glib.c |    4 +
> 3 files changed, 154 insertions(+), 50 deletions(-)
>
>diff --git a/dbus/dbus-gobject.c b/dbus/dbus-gobject.c
>index f0c4df8..fb41168 100644
>--- a/dbus/dbus-gobject.c
>+++ b/dbus/dbus-gobject.c
>@@ -407,9 +407,16 @@ object_registration_free (ObjectRegistration *o)
> {
>   if (o->object != NULL)
>     {
>+      GSList *registrations;
>+
>+      /* Ok, the object is still around; clear out this particular registration
>+       * from the registrations list.
>+       */
>+      registrations = g_object_steal_data (o->object, "dbus_glib_object_registrations");
>+      registrations = g_slist_remove (registrations, o);
>+      g_object_set_data (o->object, "dbus_glib_object_registrations", registrations);
>+
>       g_object_weak_unref (o->object, object_registration_object_died, o);
>-      g_object_steal_data (o->object, "dbus_glib_object_registration");
>-      o->object = NULL;
>     }
> 
>   g_free (o->object_path);
>@@ -1741,30 +1748,19 @@ dbus_g_signal_closure_finalize (gpointer data,
> }
> 
> static void
>-signal_emitter_marshaller (GClosure        *closure,
>-			   GValue          *retval,
>-			   guint            n_param_values,
>-			   const GValue    *param_values,
>-			   gpointer         invocation_hint,
>-			   gpointer         marshal_data)
>+emit_signal_for_registration (ObjectRegistration *o,
>+                              DBusGSignalClosure *sigclosure,
>+                              GValue             *retval,
>+                              guint               n_param_values,
>+                              const GValue       *param_values)
> {
>-  DBusGSignalClosure *sigclosure;
>   DBusMessage *signal;
>   DBusMessageIter iter;
>   guint i;
>-  const char *path;
>-
>-  sigclosure = (DBusGSignalClosure *) closure;
>-  
>-  g_assert (retval == NULL);
>-
>-  path = _dbus_gobject_get_path (sigclosure->object);
> 
>-  g_assert (path != NULL);
>-
>-  signal = dbus_message_new_signal (path,
>-				    sigclosure->sigiface,
>-				    sigclosure->signame);
>+  signal = dbus_message_new_signal (o->object_path,
>+                                    sigclosure->sigiface,
>+                                    sigclosure->signame);
>   if (!signal)
>     {
>       g_error ("out of memory");
>@@ -1777,20 +1773,45 @@ signal_emitter_marshaller (GClosure        *closure,
>   for (i = 1; i < n_param_values; i++)
>     {
>       if (!_dbus_gvalue_marshal (&iter,
>-				(GValue *) (&(param_values[i]))))
>-	{
>-	  g_warning ("failed to marshal parameter %d for signal %s",
>-		     i, sigclosure->signame);
>-	  goto out;
>-	}
>+                                (GValue *) (&(param_values[i]))))
>+        {
>+          g_warning ("failed to marshal parameter %d for signal %s",
>+                     i, sigclosure->signame);
>+          goto out;
>+        }
>     }
>   dbus_connection_send (DBUS_CONNECTION_FROM_G_CONNECTION (sigclosure->connection),
>-			signal, NULL);
>- out:
>+                        signal, NULL);
>+out:
>   dbus_message_unref (signal);
> }
> 
> static void
>+signal_emitter_marshaller (GClosure        *closure,
>+			   GValue          *retval,
>+			   guint            n_param_values,
>+			   const GValue    *param_values,
>+			   gpointer         invocation_hint,
>+			   gpointer         marshal_data)
>+{
>+  DBusGSignalClosure *sigclosure;
>+  GSList *registrations, *iter;
>+
>+  sigclosure = (DBusGSignalClosure *) closure;
>+
>+  g_assert (retval == NULL);
>+
>+  registrations = g_object_get_data (sigclosure->object, "dbus_glib_object_registrations");
>+
>+  for (iter = registrations; iter; iter = iter->next)
>+    {
>+      ObjectRegistration *o = iter->data;
>+
>+      emit_signal_for_registration (o, sigclosure, retval, n_param_values, param_values);
>+    }
>+}
>+
>+static void
> export_signals (DBusGConnection *connection, const GList *info_list, GObject *object)
> {
>   GType gtype;
>@@ -2092,14 +2113,18 @@ void
> dbus_g_connection_unregister_g_object (DBusGConnection *connection,
>                                        GObject *object)
> {
>-  ObjectRegistration *o;
>+  GList *registrations, *iter;
> 
>-  o = g_object_get_data (object, "dbus_glib_object_registration");
>+  registrations = g_object_get_data (object, "dbus_glib_object_registrations");
> 
>-  g_return_if_fail (o != NULL);
>+  g_return_if_fail (registrations != NULL);
> 
>-  dbus_connection_unregister_object_path (DBUS_CONNECTION_FROM_G_CONNECTION (o->connection),
>-      o->object_path);
>+  for (iter = registrations; iter; iter = iter->next)
>+    {
>+      ObjectRegistration *o = iter->data;
>+      dbus_connection_unregister_object_path (DBUS_CONNECTION_FROM_G_CONNECTION (o->connection),
>+          o->object_path);
>+    }
> }
> 
> /**
>@@ -2116,6 +2141,9 @@ dbus_g_connection_unregister_g_object (DBusGConnection *connection,
>  * The registration will be cancelled if either the #DBusConnection or
>  * the #GObject gets finalized, or if dbus_g_connection_unregister_g_object()
>  * is used.
>+ *
>+ * Note: If an object is registered multiple times, the first registration
>+ * takes priority for cases such as turning an object into an object path.
>  */
> void
> dbus_g_connection_register_g_object (DBusGConnection       *connection,
>@@ -2123,28 +2151,44 @@ dbus_g_connection_register_g_object (DBusGConnection       *connection,
>                                      GObject               *object)
> {
>   GList *info_list;
>+  GSList *registrations, *iter;
>   ObjectRegistration *o;
>+  gboolean is_first_registration;
> 
>   g_return_if_fail (connection != NULL);
>   g_return_if_fail (at_path != NULL);
>   g_return_if_fail (G_IS_OBJECT (object));
> 
>-  info_list = lookup_object_info (object);
>-  if (info_list == NULL)
>+  /* This is a GSList of ObjectRegistration*  */
>+  registrations = g_object_steal_data (object, "dbus_glib_object_registrations");
>+
>+  for (iter = registrations; iter; iter = iter->next)
>     {
>-      g_warning ("No introspection data registered for object class \"%s\"",
>-		 g_type_name (G_TYPE_FROM_INSTANCE (object)));
>-      return;
>+      o = iter->data;
>+
>+      /* Silently ignore duplicate registrations */
>+      if (strcmp (o->object_path, at_path) == 0)
>+        return;
>     }
> 
>-  o = g_object_get_data (object, "dbus_glib_object_registration");
>+  is_first_registration = registrations == NULL;
> 
>-  if (o != NULL)
>+  /* This is used to hook up signals below, but we do this check
>+   * before trying to register the object to make sure we have
>+   * introspection data for it.
>+   */
>+  if (is_first_registration)
>     {
>-      g_warning ("Object already registered at %s, can't re-register at %s",
>-          o->object_path, at_path);
>-      return;
>+      info_list = lookup_object_info (object);
>+      if (info_list == NULL)
>+        {
>+          g_warning ("No introspection data registered for object class \"%s\"",
>+                     g_type_name (G_TYPE_FROM_INSTANCE (object)));
>+          return;
>+        }
>     }
>+  else
>+    info_list = NULL;
> 
>   o = object_registration_new (connection, at_path, object);
> 
>@@ -2155,12 +2199,22 @@ dbus_g_connection_register_g_object (DBusGConnection       *connection,
>     {
>       g_error ("Failed to register GObject with DBusConnection");
>       object_registration_free (o);
>+      g_list_free (info_list);
>       return;
>     }
> 
>-  export_signals (connection, info_list, object);
>-  g_list_free (info_list);
>-  g_object_set_data (object, "dbus_glib_object_registration", o);
>+  if (is_first_registration)
>+    {
>+      /* This adds a hook into every signal for the object.  Only do this
>+       * on the first registration, because inside the signal marshaller
>+       * we emit a signal for each registration.
>+       */
>+      export_signals (connection, info_list, object);
>+      g_list_free (info_list);
>+    }
>+
>+  registrations = g_slist_append (registrations, o);
>+  g_object_set_data (object, "dbus_glib_object_registrations", registrations);
> }
> 
> /**
>@@ -2539,15 +2593,20 @@ dbus_g_method_return_error (DBusGMethodInvocation *context, const GError *error)
>   g_free (context);
> }
> 
>-const char * _dbus_gobject_get_path (GObject *obj)
>+const char *
>+_dbus_gobject_get_path (GObject *obj)
> {
>+  GSList *registrations;
>   ObjectRegistration *o;
> 
>-  o = g_object_get_data (obj, "dbus_glib_object_registration");
>+  registrations = g_object_get_data (obj, "dbus_glib_object_registrations");
> 
>-  if (o == NULL)
>+  if (registrations == NULL)
>     return NULL;
> 
>+  /* First one to have been registered wins */
>+  o = registrations->data;
>+
>   return o->object_path;
> }
> 
>diff --git a/test/core/test-dbus-glib.c b/test/core/test-dbus-glib.c
>index c6071a7..288606f 100644
>--- a/test/core/test-dbus-glib.c
>+++ b/test/core/test-dbus-glib.c
>@@ -15,6 +15,7 @@ static const char *await_terminating_service = NULL;
> static int n_times_foo_received = 0;
> static int n_times_frobnicate_received = 0;
> static int n_times_frobnicate_received_2 = 0;
>+static int n_times_compat_frobnicate_received = 0;
> static int n_times_sig0_received = 0;
> static int n_times_sig1_received = 0;
> static int n_times_sig2_received = 0;
>@@ -139,6 +140,20 @@ frobnicate_signal_handler_2 (DBusGProxy  *proxy,
> }
> 
> static void
>+frobnicate_signal_handler_compat (DBusGProxy  *proxy,
>+                                  int          val,
>+                                  void        *user_data)
>+{
>+  n_times_compat_frobnicate_received += 1;
>+
>+  g_assert (val == 42);
>+  g_print ("Got Frobnicate signal (compat)\n");
>+
>+  g_main_loop_quit (loop);
>+  g_source_remove (exit_timeout);
>+}
>+
>+static void
> sig0_signal_handler (DBusGProxy  *proxy,
> 		     const char  *str0,
> 		     int          val,
>@@ -1886,6 +1901,32 @@ main (int argc, char **argv)
> 
>   run_mainloop ();
> 
>+  /* Tests for a "compatibilty" object path.  This is the same object as above, just
>+   * at a different path.
>+   */
>+  proxy = dbus_g_proxy_new_for_name_owner (connection,
>+                                           "org.freedesktop.DBus.GLib.TestService",
>+                                           "/org/freedesktop/DBus/GLib/Tests/Compat/MyTestObjectCompat",
>+                                           "org.freedesktop.DBus.GLib.Tests.MyObject",
>+                                           &error);
>+  dbus_g_proxy_add_signal (proxy, "Frobnicate", G_TYPE_INT, G_TYPE_INVALID);
>+
>+  dbus_g_proxy_connect_signal (proxy, "Frobnicate",
>+                               G_CALLBACK (frobnicate_signal_handler_compat),
>+                               NULL, NULL);
>+
>+  g_print ("Calling EmitFrobnicate (compat)\n");
>+  if (!dbus_g_proxy_call (proxy, "EmitFrobnicate", &error,
>+                          G_TYPE_INVALID, G_TYPE_INVALID))
>+    lose_gerror ("Failed to complete EmitFrobnicate call on compat proxy", error);
>+
>+  g_main_loop_run (loop);
>+
>+  if (n_times_compat_frobnicate_received != 1)
>+    lose ("Frobnicate signal received %d times for compat proxy, should have been 1", n_times_compat_frobnicate_received);
>+
>+  g_object_unref (proxy);
>+
>   /* Test introspection */
>   proxy = dbus_g_proxy_new_for_name_owner (connection,
>                                            "org.freedesktop.DBus.GLib.TestService",
>diff --git a/test/core/test-service-glib.c b/test/core/test-service-glib.c
>index 1cdb0ac..fad2473 100644
>--- a/test/core/test-service-glib.c
>+++ b/test/core/test-service-glib.c
>@@ -66,6 +66,10 @@ main (int argc, char **argv)
>   dbus_g_connection_register_g_object (connection,
>                                        "/org/freedesktop/DBus/GLib/Tests/MyTestObject",
>                                        obj);
>+  /* Register a second time; we want the object to also be reachable through this interface */
>+  dbus_g_connection_register_g_object (connection,
>+                                       "/org/freedesktop/DBus/GLib/Tests/Compat/MyTestObjectCompat",
>+                                       obj);
>   dbus_g_connection_register_g_object (connection,
>                                        "/org/freedesktop/DBus/GLib/Tests/MyTestObject2",
>                                        obj2);
>-- 
>1.6.3.3

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