From 718d006a63f773c42106494e823250c48942cf08 Mon Sep 17 00:00:00 2001 From: David Herrmann Date: Tue, 17 Sep 2013 17:39:54 +0200 Subject: logind: listen actively for session devices Session compositors need access to fbdev, DRM and evdev devices if they control a session. To make logind pass them to sessions, we need to listen for them actively. However, we avoid creating new seats for non master-of-seat devices. Only once a seat is created, we start remembering all other session devices. If the last master-device is removed (even if there are other non-master devices still available), we destroy the seat. This is the current behavior, but we need to explicitly implement it now as there may be non-master devices in the seat->devices list. Unlike master devices, we don't care whether our list of non-master devices is complete. We don't export this list but use it only as cache if sessions request these devices. Hence, if a session requests a device that is not in the list, we will simply look it up. However, once a session requested a device, we must be notified of "remove" udev events. So we must link the devices somehow into the device-list. Regarding the implementation, we now sort the device list by the "master" flag. This guarantees that master devices are at the front and non-master devices at the tail of the list. Thus, we can easily test whether a seat has a master device attached. --- src/login/logind-seat.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'src/login/logind-seat.c') diff --git a/src/login/logind-seat.c b/src/login/logind-seat.c index 470d08bc05..2c60b8ae51 100644 --- a/src/login/logind-seat.c +++ b/src/login/logind-seat.c @@ -448,10 +448,17 @@ bool seat_can_tty(Seat *s) { return seat_is_vtconsole(s); } +bool seat_has_master_device(Seat *s) { + assert(s); + + /* device list is ordered by "master" flag */ + return !!s->devices && s->devices->master; +} + bool seat_can_graphical(Seat *s) { assert(s); - return !!s->devices; + return seat_has_master_device(s); } int seat_get_idle_hint(Seat *s, dual_timestamp *t) { @@ -499,7 +506,7 @@ int seat_check_gc(Seat *s, bool drop_not_started) { if (seat_is_vtconsole(s)) return 1; - return !!s->devices; + return seat_has_master_device(s); } void seat_add_to_gc_queue(Seat *s) { -- cgit v1.2.3-54-g00ecf