core/dbus: rework creating numbered D-Bus export path by putting counter into class

I dislike the static hash table to cache the integer counter for
numbered paths. Let's instead cache the counter at the class instance
itself -- since the class contains the information how the export
path should be exported.

However, we cannot use a plain integer field inside the class structure,
because the class is copied between derived classes. For example,
NMDeviceEthernet and NMDeviceBridge both get a copy of the NMDeviceClass
instance. Hence, the class doesn't contain the counter directly, but
a pointer to one counter that can be shared between sibling classes.

src/devices/nm-device.c

@@ -15269,7 +15269,7 @@ nm_device_class_init (NMDeviceClass *klass)
 
 	g_type_class_add_private (object_class, sizeof (NMDevicePrivate));
 
-	dbus_object_class->export_path = NM_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/Devices");
+	dbus_object_class->export_path = NM_DBUS_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/Devices");
 	dbus_object_class->interface_infos = NM_DBUS_INTERFACE_INFOS (&interface_info_device,
 	                                                              &nm_interface_info_device_statistics);
 

src/devices/wifi/nm-wifi-ap.c

@@ -1391,7 +1391,7 @@ nm_wifi_ap_class_init (NMWifiAPClass *ap_class)
 	GObjectClass *object_class = G_OBJECT_CLASS (ap_class);
 	NMDBusObjectClass *dbus_object_class = NM_DBUS_OBJECT_CLASS (ap_class);
 
-	dbus_object_class->export_path = NM_EXPORT_PATH_NUMBERED (NM_DBUS_PATH_ACCESS_POINT);
+	dbus_object_class->export_path = NM_DBUS_EXPORT_PATH_NUMBERED (NM_DBUS_PATH_ACCESS_POINT);
 	dbus_object_class->interface_infos = NM_DBUS_INTERFACE_INFOS (&interface_info_access_point);
 
 	object_class->get_property = get_property;

src/dns/nm-dns-manager.c

@@ -2127,7 +2127,7 @@ nm_dns_manager_class_init (NMDnsManagerClass *klass)
 	object_class->finalize = finalize;
 	object_class->get_property = get_property;
 
-	dbus_object_class->export_path = NM_DBUS_PATH "/DnsManager";
+	dbus_object_class->export_path = NM_DBUS_EXPORT_PATH_STATIC (NM_DBUS_PATH "/DnsManager");
 	dbus_object_class->interface_infos = NM_DBUS_INTERFACE_INFOS (&interface_info_dns_manager);
 	dbus_object_class->export_on_construction = TRUE;
 

src/nm-active-connection.c

@@ -1447,7 +1447,7 @@ nm_active_connection_class_init (NMActiveConnectionClass *ac_class)
 
 	g_type_class_add_private (ac_class, sizeof (NMActiveConnectionPrivate));
 
-	dbus_object_class->export_path = NM_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/ActiveConnection");
+	dbus_object_class->export_path = NM_DBUS_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/ActiveConnection");
 	dbus_object_class->interface_infos = NM_DBUS_INTERFACE_INFOS (&interface_info_active_connection);
 
 	object_class->get_property = get_property;

src/nm-checkpoint.c

@@ -558,7 +558,7 @@ nm_checkpoint_class_init (NMCheckpointClass *checkpoint_class)
 	GObjectClass *object_class = G_OBJECT_CLASS (checkpoint_class);
 	NMDBusObjectClass *dbus_object_class = NM_DBUS_OBJECT_CLASS (checkpoint_class);
 
-	dbus_object_class->export_path = NM_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/Checkpoint");
+	dbus_object_class->export_path = NM_DBUS_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/Checkpoint");
 	dbus_object_class->interface_infos = NM_DBUS_INTERFACE_INFOS (&interface_info_checkpoint);
 
 	object_class->dispose = dispose;

src/nm-dbus-object.c

@@ -56,36 +56,32 @@ G_DEFINE_ABSTRACT_TYPE (NMDBusObject, nm_dbus_object, G_TYPE_OBJECT);
 static char *
 _create_export_path (NMDBusObjectClass *klass)
 {
-	const char *class_export_path, *p;
+	nm_assert (NM_IS_DBUS_OBJECT_CLASS (klass));
-	static GHashTable *prefix_counters;
+	nm_assert (klass->export_path.path);
-	guint64 *counter;
 
-	class_export_path = klass->export_path;
+#if NM_MORE_ASSERTS
+	{
+		const char *p;
 
-	nm_assert (class_export_path);
+		p = strchr (klass->export_path.path, '%');
-
+		if (klass->export_path.int_counter) {
-	p = strchr (class_export_path, '%');
+			nm_assert (p);
-	if (p) {
+			nm_assert (p[1] == 'l');
-		if (G_UNLIKELY (!prefix_counters))
+			nm_assert (p[2] == 'l');
-			prefix_counters = g_hash_table_new (nm_str_hash, g_str_equal);
+			nm_assert (p[3] == 'u');
-
+			nm_assert (p[4] == '\0');
-		nm_assert (p[1] == 'l');
+		} else
-		nm_assert (p[2] == 'l');
+			nm_assert (!p);
-		nm_assert (p[3] == 'u');
+	}
-		nm_assert (p[4] == '\0');
+#endif
-
-		counter = g_hash_table_lookup (prefix_counters, class_export_path);
-		if (!counter) {
-			counter = g_slice_new0 (guint64);
-			g_hash_table_insert (prefix_counters, (char *) class_export_path, counter);
-		}
 
+	if (klass->export_path.int_counter) {
 		NM_PRAGMA_WARNING_DISABLE("-Wformat-nonliteral")
-		return g_strdup_printf (class_export_path, (unsigned long long) (++(*counter)));
+		return g_strdup_printf (klass->export_path.path,
+		                        ++(*klass->export_path.int_counter));
 		NM_PRAGMA_WARNING_REENABLE
 	}
-
+	return g_strdup (klass->export_path.path);
-	return g_strdup (class_export_path);
 }
 
 /**

src/nm-dbus-object.h

@@ -32,6 +32,38 @@ void nm_dbus_object_set_quitting (void);
 
 /*****************************************************************************/
 
+typedef struct {
+	const char *path;
+
+	/* if path is of type NM_DBUS_EXPORT_PATH_NUMBERED(), we need a
+	 * per-class counter when generating a new numbered path.
+	 *
+	 * Each NMDBusObjectClass instance has a shallow clone of the NMDBusObjectClass parent
+	 * instance in every derived type. Hence we cannot embed the counter there directly,
+	 * because it must be shared, e.g. between NMDeviceBond and NMDeviceEthernet.
+	 * Make int_counter a pointer to the actual counter that is used by ever sibling
+	 * class. */
+	long long unsigned *int_counter;
+} NMDBusExportPath;
+
+#define NM_DBUS_EXPORT_PATH_STATIC(basepath) \
+	({ \
+		((NMDBusExportPath) { \
+			.path = ""basepath"", \
+		}); \
+	})
+
+#define NM_DBUS_EXPORT_PATH_NUMBERED(basepath) \
+	({ \
+		static long long unsigned _int_counter = 0; \
+		((NMDBusExportPath) { \
+			.path = ""basepath"/%llu", \
+			.int_counter = &_int_counter, \
+		}); \
+	})
+
+/*****************************************************************************/
+
 /* "org.freedesktop.NetworkManager.Device.Statistics" is a special interface,
  * because although it has a legacy PropertiesChanged signal, it only notifies
  * about properties that actually exist on that interface. That is, because it
@@ -82,7 +114,7 @@ struct _NMDBusObject {
 typedef struct {
 	GObjectClass parent;
 
-	const char *export_path;
+	NMDBusExportPath export_path;
 
 	const NMDBusInterfaceInfoExtended *const*interface_infos;
 

src/nm-dbus-utils.h

@@ -23,10 +23,6 @@
 
 /*****************************************************************************/
 
-#define NM_EXPORT_PATH_NUMBERED(basepath) ""basepath"/%llu"
-
-/*****************************************************************************/
-
 struct _NMDBusInterfaceInfoExtended;
 struct _NMDBusMethodInfoExtended;
 

src/nm-dhcp4-config.c

@@ -167,7 +167,7 @@ nm_dhcp4_config_class_init (NMDhcp4ConfigClass *config_class)
 	object_class->get_property = get_property;
 	object_class->finalize = finalize;
 
-	dbus_object_class->export_path = NM_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/DHCP4Config");
+	dbus_object_class->export_path = NM_DBUS_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/DHCP4Config");
 	dbus_object_class->interface_infos = NM_DBUS_INTERFACE_INFOS (&interface_info_dhcp4_config);
 	dbus_object_class->export_on_construction = TRUE;
 

src/nm-dhcp6-config.c

@@ -165,7 +165,7 @@ nm_dhcp6_config_class_init (NMDhcp6ConfigClass *config_class)
 	object_class->get_property = get_property;
 	object_class->finalize = finalize;
 
-	dbus_object_class->export_path = NM_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/DHCP6Config");
+	dbus_object_class->export_path = NM_DBUS_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/DHCP6Config");
 	dbus_object_class->interface_infos = NM_DBUS_INTERFACE_INFOS (&interface_info_dhcp6_config);
 	dbus_object_class->export_on_construction = TRUE;
 

src/nm-ip4-config.c

@@ -3240,7 +3240,7 @@ nm_ip4_config_class_init (NMIP4ConfigClass *config_class)
 	GObjectClass *object_class = G_OBJECT_CLASS (config_class);
 	NMDBusObjectClass *dbus_object_class = NM_DBUS_OBJECT_CLASS (config_class);
 
-	dbus_object_class->export_path = NM_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/IP4Config");
+	dbus_object_class->export_path = NM_DBUS_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/IP4Config");
 	dbus_object_class->interface_infos = NM_DBUS_INTERFACE_INFOS (&interface_info_ip4_config);
 
 	object_class->get_property = get_property;

src/nm-ip6-config.c

@@ -2800,7 +2800,7 @@ nm_ip6_config_class_init (NMIP6ConfigClass *config_class)
 	GObjectClass *object_class = G_OBJECT_CLASS (config_class);
 	NMDBusObjectClass *dbus_object_class = NM_DBUS_OBJECT_CLASS (config_class);
 
-	dbus_object_class->export_path = NM_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/IP6Config");
+	dbus_object_class->export_path = NM_DBUS_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/IP6Config");
 	dbus_object_class->interface_infos = NM_DBUS_INTERFACE_INFOS (&interface_info_ip6_config);
 
 	object_class->get_property = get_property;

src/nm-manager.c

@@ -7047,7 +7047,7 @@ nm_manager_class_init (NMManagerClass *manager_class)
 	GObjectClass *object_class = G_OBJECT_CLASS (manager_class);
 	NMDBusObjectClass *dbus_object_class = NM_DBUS_OBJECT_CLASS (manager_class);
 
-	dbus_object_class->export_path = NM_DBUS_PATH;
+	dbus_object_class->export_path = NM_DBUS_EXPORT_PATH_STATIC (NM_DBUS_PATH);
 	dbus_object_class->interface_infos = NM_DBUS_INTERFACE_INFOS (&interface_info_manager);
 
 	object_class->constructed = constructed;

src/ppp/nm-ppp-manager.c

@@ -1419,7 +1419,7 @@ nm_ppp_manager_class_init (NMPPPManagerClass *manager_class)
 	object_class->get_property = get_property;
 	object_class->set_property = set_property;
 
-	dbus_object_class->export_path = NM_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/PPP");
+	dbus_object_class->export_path = NM_DBUS_EXPORT_PATH_NUMBERED (NM_DBUS_PATH"/PPP");
 	dbus_object_class->interface_infos = NM_DBUS_INTERFACE_INFOS (&interface_info_ppp);
 
 	obj_properties[PROP_PARENT_IFACE] =

src/settings/nm-agent-manager.c

@@ -1687,7 +1687,7 @@ nm_agent_manager_class_init (NMAgentManagerClass *agent_manager_class)
 	GObjectClass *object_class = G_OBJECT_CLASS (agent_manager_class);
 	NMDBusObjectClass *dbus_object_class = NM_DBUS_OBJECT_CLASS (agent_manager_class);
 
-	dbus_object_class->export_path = NM_DBUS_PATH_AGENT_MANAGER;
+	dbus_object_class->export_path = NM_DBUS_EXPORT_PATH_STATIC (NM_DBUS_PATH_AGENT_MANAGER);
 	dbus_object_class->interface_infos = NM_DBUS_INTERFACE_INFOS (&interface_info_agent_manager);
 
 	object_class->constructed = constructed;

src/settings/nm-settings-connection.c

@@ -3181,7 +3181,7 @@ nm_settings_connection_class_init (NMSettingsConnectionClass *klass)
 
 	g_type_class_add_private (klass, sizeof (NMSettingsConnectionPrivate));
 
-	dbus_object_class->export_path = NM_EXPORT_PATH_NUMBERED (NM_DBUS_PATH_SETTINGS);
+	dbus_object_class->export_path = NM_DBUS_EXPORT_PATH_NUMBERED (NM_DBUS_PATH_SETTINGS);
 	dbus_object_class->interface_infos = NM_DBUS_INTERFACE_INFOS (&interface_info_settings_connection);
 
 	object_class->constructed = constructed;

src/settings/nm-settings.c

@@ -2080,7 +2080,7 @@ nm_settings_class_init (NMSettingsClass *class)
 	GObjectClass *object_class = G_OBJECT_CLASS (class);
 	NMDBusObjectClass *dbus_object_class = NM_DBUS_OBJECT_CLASS (class);
 
-	dbus_object_class->export_path = NM_DBUS_PATH_SETTINGS;
+	dbus_object_class->export_path = NM_DBUS_EXPORT_PATH_STATIC (NM_DBUS_PATH_SETTINGS);
 	dbus_object_class->interface_infos = NM_DBUS_INTERFACE_INFOS (&interface_info_settings);
 
 	object_class->get_property = get_property;