config: if we can't connect to HAL, listen for a startup notification.

If HAL isn't available when we try to connect, the registered NameOwnerChanged
signal handler waits until HAL is available. Once we connected to HAL, we
unregister the signal handler again.
This allows HAL to be started in parallel or after the server has started.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
This commit is contained in:
Peter Hutterer 2009-02-04 11:50:18 +10:00
parent 5b2bbffc12
commit 4844bff58f

View File

@ -467,11 +467,10 @@ disconnect_hook(void *data)
info->system_bus = NULL;
}
static void
connect_hook(DBusConnection *connection, void *data)
static BOOL
connect_and_register(DBusConnection *connection, struct config_hal_info *info)
{
DBusError error;
struct config_hal_info *info = data;
char **devices;
int num_devices, i;
@ -479,8 +478,10 @@ connect_hook(DBusConnection *connection, void *data)
dbus_error_init(&error);
if (!info->hal_ctx)
info->hal_ctx = libhal_ctx_new();
if (info->hal_ctx)
return TRUE; /* already registered, pretend we did something */
info->hal_ctx = libhal_ctx_new();
if (!info->hal_ctx) {
LogMessage(X_ERROR, "config/hal: couldn't create HAL context\n");
goto out_err;
@ -512,7 +513,7 @@ connect_hook(DBusConnection *connection, void *data)
dbus_error_free(&error);
return;
return TRUE;
out_ctx2:
if (!libhal_ctx_shutdown(info->hal_ctx, &error))
@ -526,6 +527,104 @@ out_err:
info->hal_ctx = NULL;
info->system_bus = NULL;
return FALSE;
}
/**
* Handle NewOwnerChanged signals to deal with HAL startup at X server runtime.
*
* NewOwnerChanged is send once when HAL shuts down, and once again when it
* comes back up. Message has three arguments, first is the name
* (org.freedesktop.Hal), the second one is the old owner, third one is new
* owner.
*/
static DBusHandlerResult
ownerchanged_handler(DBusConnection *connection, DBusMessage *message, void *data)
{
int ret = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
if (dbus_message_is_signal(message,
"org.freedesktop.DBus",
"NameOwnerChanged")) {
DBusError error;
char *name, *old_owner, *new_owner;
dbus_error_init(&error);
dbus_message_get_args(message, &error,
DBUS_TYPE_STRING, &name,
DBUS_TYPE_STRING, &old_owner,
DBUS_TYPE_STRING, &new_owner,
DBUS_TYPE_INVALID);
if (dbus_error_is_set(&error)) {
ErrorF("[config/hal] failed to get NameOwnerChanged args: %s (%s)\n",
error.name, error.message);
} else if (name && strcmp(name, "org.freedesktop.Hal") == 0) {
if (!old_owner || !strlen(old_owner)) {
DebugF("[config/hal] HAL startup detected.\n");
if (connect_and_register(connection, (struct config_hal_info*)data))
dbus_connection_unregister_object_path(connection,
"/org/freedesktop/DBus");
else
ErrorF("[config/hal] Failed to connect to HAL bus.\n");
}
ret = DBUS_HANDLER_RESULT_HANDLED;
}
dbus_error_free(&error);
}
return ret;
}
/**
* Register a handler for the NameOwnerChanged signal.
*/
static BOOL
listen_for_startup(DBusConnection *connection, void *data)
{
DBusObjectPathVTable vtable = { .message_function = ownerchanged_handler, };
DBusError error;
const char MATCH_RULE[] = "sender='org.freedesktop.DBus',"
"interface='org.freedesktop.DBus',"
"type='signal',"
"path='/org/freedesktop/DBus',"
"member='NameOwnerChanged'";
int rc = FALSE;
dbus_error_init(&error);
dbus_bus_add_match(connection, MATCH_RULE, &error);
if (!dbus_error_is_set(&error)) {
if (dbus_connection_register_object_path(connection,
"/org/freedesktop/DBus",
&vtable,
data))
rc = TRUE;
else
ErrorF("[config/hal] cannot register object path.\n");
} else {
ErrorF("[config/hal] couldn't add match rule: %s (%s)\n", error.name,
error.message);
ErrorF("[config/hal] cannot detect a HAL startup.\n");
}
dbus_error_free(&error);
return rc;
}
static void
connect_hook(DBusConnection *connection, void *data)
{
struct config_hal_info *info = data;
if (listen_for_startup(connection, data) &&
connect_and_register(connection, info))
dbus_connection_unregister_object_path(connection,
"/org/freedesktop/DBus");
return;
}