struct BusService
{
+ int refcount;
+
BusRegistry *registry;
char *name;
DBusList *owners;
}
service->registry = registry;
-
+ service->refcount = 1;
+
if (!_dbus_string_copy_data (service_name, &service->name))
{
_dbus_mem_pool_dealloc (registry->service_pool, service);
if (!bus_driver_send_service_created (service->name, transaction, error))
{
- dbus_free (service->name);
- _dbus_mem_pool_dealloc (registry->service_pool, service);
+ bus_service_unref (service);
return NULL;
}
if (!bus_activation_service_created (bus_context_get_activation (registry->context),
service->name, transaction, error))
{
- dbus_free (service->name);
- _dbus_mem_pool_dealloc (registry->service_pool, service);
+ bus_service_unref (service);
return NULL;
}
if (!bus_service_add_owner (service, owner_if_created,
transaction, error))
{
- dbus_free (service->name);
- _dbus_mem_pool_dealloc (registry->service_pool, service);
+ bus_service_unref (service);
return NULL;
}
service->name,
service))
{
- bus_connection_remove_owned_service (owner_if_created,
- service);
- _dbus_list_clear (&service->owners);
- dbus_free (service->name);
- _dbus_mem_pool_dealloc (registry->service_pool, service);
+ /* The add_owner gets reverted on transaction cancel */
BUS_SET_OOM (error);
return NULL;
}
}
dbus_bool_t
+bus_registry_acquire_service (BusRegistry *registry,
+ DBusConnection *connection,
+ const DBusString *service_name,
+ dbus_uint32_t flags,
+ dbus_uint32_t *result,
+ BusTransaction *transaction,
+ DBusError *error)
+{
+ dbus_bool_t retval;
+ DBusConnection *old_owner;
+ DBusConnection *current_owner;
+ BusService *service;
+
+ retval = FALSE;
+
+ if (_dbus_string_get_length (service_name) == 0)
+ {
+ dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
+ "Zero-length service name is not allowed");
+
+ _dbus_verbose ("Attempt to acquire zero-length service name\n");
+
+ goto out;
+ }
+
+ if (_dbus_string_get_byte (service_name, 0) == ':')
+ {
+ /* Not allowed; only base services can start with ':' */
+ dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
+ "Cannot acquire a service starting with ':' such as \"%s\"",
+ _dbus_string_get_const_data (service_name));
+
+ _dbus_verbose ("Attempt to acquire invalid base service name \"%s\"",
+ _dbus_string_get_const_data (service_name));
+
+ goto out;
+ }
+
+ service = bus_registry_lookup (registry, service_name);
+
+ if (service != NULL)
+ old_owner = bus_service_get_primary_owner (service);
+ else
+ old_owner = NULL;
+
+ if (service == NULL)
+ {
+ service = bus_registry_ensure (registry,
+ service_name, connection, transaction, error);
+ if (service == NULL)
+ goto out;
+ }
+
+ current_owner = bus_service_get_primary_owner (service);
+
+ if (old_owner == NULL)
+ {
+ _dbus_assert (current_owner == connection);
+
+ bus_service_set_prohibit_replacement (service,
+ (flags & DBUS_SERVICE_FLAG_PROHIBIT_REPLACEMENT));
+
+ *result = DBUS_SERVICE_REPLY_PRIMARY_OWNER;
+ }
+ else if (old_owner == connection)
+ *result = DBUS_SERVICE_REPLY_ALREADY_OWNER;
+ else if (!((flags & DBUS_SERVICE_FLAG_REPLACE_EXISTING)))
+ *result = DBUS_SERVICE_REPLY_SERVICE_EXISTS;
+ else if (bus_service_get_prohibit_replacement (service))
+ {
+ /* Queue the connection */
+ if (!bus_service_add_owner (service, connection,
+ transaction, error))
+ goto out;
+
+ *result = DBUS_SERVICE_REPLY_IN_QUEUE;
+ }
+ else
+ {
+ /* Replace the current owner */
+
+ /* We enqueue the new owner and remove the first one because
+ * that will cause ServiceAcquired and ServiceLost messages to
+ * be sent.
+ */
+
+ if (!bus_service_add_owner (service, connection,
+ transaction, error))
+ goto out;
+
+ if (!bus_service_remove_owner (service, old_owner,
+ transaction, error))
+ goto out;
+
+ _dbus_assert (connection == bus_service_get_primary_owner (service));
+ *result = DBUS_SERVICE_REPLY_PRIMARY_OWNER;
+ }
+
+ retval = TRUE;
+
+ out:
+ return retval;
+}
+
+static void
+bus_service_unlink_owner (BusService *service,
+ DBusConnection *owner)
+{
+ _dbus_list_remove_last (&service->owners, owner);
+ bus_connection_remove_owned_service (owner, service);
+}
+
+static void
+bus_service_unlink (BusService *service)
+{
+ _dbus_assert (service->owners == NULL);
+
+ /* the service may not be in the hash, if
+ * the failure causing transaction cancel
+ * was in the right place, but that's OK
+ */
+ _dbus_hash_table_remove_string (service->registry->service_hash,
+ service->name);
+
+ bus_service_unref (service);
+}
+
+static void
+bus_service_relink (BusService *service,
+ DBusPreallocatedHash *preallocated)
+{
+ _dbus_assert (service->owners == NULL);
+ _dbus_assert (preallocated != NULL);
+
+ _dbus_hash_table_insert_string_preallocated (service->registry->service_hash,
+ preallocated,
+ service->name,
+ service);
+
+ bus_service_ref (service);
+}
+
+typedef struct
+{
+ DBusConnection *connection;
+ BusService *service;
+} OwnershipCancelData;
+
+static void
+cancel_ownership (void *data)
+{
+ OwnershipCancelData *d = data;
+
+ /* We don't need to send messages notifying of these
+ * changes, since we're reverting something that was
+ * cancelled (effectively never really happened)
+ */
+ bus_service_unlink_owner (d->service, d->connection);
+
+ if (d->service->owners == NULL)
+ bus_service_unlink (d->service);
+}
+
+static void
+free_ownership_cancel_data (void *data)
+{
+ OwnershipCancelData *d = data;
+
+ dbus_connection_unref (d->connection);
+ bus_service_unref (d->service);
+
+ dbus_free (d);
+}
+
+static dbus_bool_t
+add_cancel_ownership_to_transaction (BusTransaction *transaction,
+ BusService *service,
+ DBusConnection *connection)
+{
+ OwnershipCancelData *d;
+
+ d = dbus_new (OwnershipCancelData, 1);
+ if (d == NULL)
+ return FALSE;
+
+ d->service = service;
+ d->connection = connection;
+
+ if (!bus_transaction_add_cancel_hook (transaction, cancel_ownership, d,
+ free_ownership_cancel_data))
+ {
+ dbus_free (d);
+ return FALSE;
+ }
+
+ bus_service_ref (d->service);
+ dbus_connection_ref (d->connection);
+
+ return TRUE;
+}
+
+/* this function is self-cancelling if you cancel the transaction */
+dbus_bool_t
bus_service_add_owner (BusService *service,
DBusConnection *owner,
BusTransaction *transaction,
BUS_SET_OOM (error);
return FALSE;
}
+
+ if (!add_cancel_ownership_to_transaction (transaction,
+ service,
+ owner))
+ {
+ bus_service_unlink_owner (service, owner);
+ BUS_SET_OOM (error);
+ return FALSE;
+ }
return TRUE;
}
+typedef struct
+{
+ DBusConnection *connection;
+ BusService *service;
+ DBusConnection *before_connection; /* restore to position before this connection in owners list */
+ DBusList *connection_link;
+ DBusList *service_link;
+ DBusPreallocatedHash *hash_entry;
+} OwnershipRestoreData;
+
+static void
+restore_ownership (void *data)
+{
+ OwnershipRestoreData *d = data;
+ DBusList *link;
+
+ _dbus_assert (d->service_link != NULL);
+ _dbus_assert (d->connection_link != NULL);
+
+ if (d->service->owners == NULL)
+ {
+ _dbus_assert (d->hash_entry != NULL);
+ bus_service_relink (d->service, d->hash_entry);
+ }
+ else
+ {
+ _dbus_assert (d->hash_entry == NULL);
+ }
+
+ /* We don't need to send messages notifying of these
+ * changes, since we're reverting something that was
+ * cancelled (effectively never really happened)
+ */
+ link = _dbus_list_get_first_link (&d->service->owners);
+ while (link != NULL)
+ {
+ if (link->data == d->before_connection)
+ break;
+
+ link = _dbus_list_get_next_link (&d->service->owners, link);
+ }
+
+ _dbus_list_insert_before_link (&d->service->owners, link, d->connection_link);
+
+ /* Note that removing then restoring this changes the order in which
+ * ServiceDeleted messages are sent on destruction of the
+ * connection. This should be OK as the only guarantee there is
+ * that the base service is destroyed last, and we never even
+ * tentatively remove the base service.
+ */
+ bus_connection_add_owned_service_link (d->connection, d->service_link);
+
+ d->hash_entry = NULL;
+ d->service_link = NULL;
+ d->connection_link = NULL;
+}
+
+static void
+free_ownership_restore_data (void *data)
+{
+ OwnershipRestoreData *d = data;
+
+ if (d->service_link)
+ _dbus_list_free_link (d->service_link);
+ if (d->connection_link)
+ _dbus_list_free_link (d->connection_link);
+ if (d->hash_entry)
+ _dbus_hash_table_free_preallocated_entry (d->service->registry->service_hash,
+ d->hash_entry);
+
+ dbus_connection_unref (d->connection);
+ bus_service_unref (d->service);
+
+ dbus_free (d);
+}
+
+static dbus_bool_t
+add_restore_ownership_to_transaction (BusTransaction *transaction,
+ BusService *service,
+ DBusConnection *connection)
+{
+ OwnershipRestoreData *d;
+ DBusList *link;
+
+ d = dbus_new (OwnershipRestoreData, 1);
+ if (d == NULL)
+ return FALSE;
+
+ d->service = service;
+ d->connection = connection;
+ d->service_link = _dbus_list_alloc_link (service);
+ d->connection_link = _dbus_list_alloc_link (connection);
+ d->hash_entry = _dbus_hash_table_preallocate_entry (service->registry->service_hash);
+
+ bus_service_ref (d->service);
+ dbus_connection_ref (d->connection);
+
+ d->before_connection = NULL;
+ link = _dbus_list_get_first_link (&service->owners);
+ while (link != NULL)
+ {
+ if (link->data == connection)
+ {
+ link = _dbus_list_get_next_link (&service->owners, link);
+
+ if (link)
+ d->before_connection = link->data;
+
+ break;
+ }
+
+ link = _dbus_list_get_next_link (&service->owners, link);
+ }
+
+ if (d->service_link == NULL ||
+ d->connection_link == NULL ||
+ d->hash_entry == NULL ||
+ !bus_transaction_add_cancel_hook (transaction, restore_ownership, d,
+ free_ownership_restore_data))
+ {
+ free_ownership_restore_data (d);
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/* this function is self-cancelling if you cancel the transaction */
dbus_bool_t
bus_service_remove_owner (BusService *service,
DBusConnection *owner,
}
else if (_dbus_list_length_is_one (&service->owners))
{
- /* We are the only owner - send service deleted */
if (!bus_driver_send_service_deleted (service->name,
transaction, error))
return FALSE;
_dbus_assert (link != NULL);
link = _dbus_list_get_next_link (&service->owners, link);
- if (link != NULL)
- {
- /* This will be our new owner */
- if (!bus_driver_send_service_acquired (link->data,
- service->name,
- transaction,
- error))
- return FALSE;
- }
+ _dbus_assert (link != NULL);
+
+ /* This will be our new owner */
+ if (!bus_driver_send_service_acquired (link->data,
+ service->name,
+ transaction,
+ error))
+ return FALSE;
+ }
+
+ if (!add_restore_ownership_to_transaction (transaction, service, owner))
+ {
+ BUS_SET_OOM (error);
+ return FALSE;
}
- _dbus_list_remove_last (&service->owners, owner);
- bus_connection_remove_owned_service (owner, service);
+ bus_service_unlink_owner (service, owner);
if (service->owners == NULL)
+ bus_service_unlink (service);
+
+ return TRUE;
+}
+
+void
+bus_service_ref (BusService *service)
+{
+ _dbus_assert (service->refcount > 0);
+
+ service->refcount += 1;
+}
+
+void
+bus_service_unref (BusService *service)
+{
+ _dbus_assert (service->refcount > 0);
+
+ service->refcount -= 1;
+
+ if (service->refcount == 0)
{
- /* Delete service (already sent message that it was deleted above) */
- _dbus_hash_table_remove_string (service->registry->service_hash,
- service->name);
+ _dbus_assert (service->owners == NULL);
dbus_free (service->name);
_dbus_mem_pool_dealloc (service->registry->service_pool, service);
}
-
- return TRUE;
}
DBusConnection*
projects / platform / upstream / dbus.git / blobdiff