poller: Raise signals through self-pipe

Signal handling relied on poll(2) being interrupted by signals, followed
by a check for signal handlers flagging a signal as received. This only
allowed signals that were received during poll(2) to be handled
correctly.

Implement the usual self-pipe implementation, where signal handlers
write an arbitrary byte to a polled file descriptor to ensure proper
level-triggered signal handling.

1 files changed, 4 insertions, 1 deletions

diff --git a/seatd/server.c b/seatd/server.c
index c31fbba..5abe389 100644
--- a/seatd/server.c
+++ b/seatd/server.c
@@ -23,7 +23,10 @@ static int server_handle_vt_rel(int signal, void *data);
 static int server_handle_kill(int signal, void *data);
 
 int server_init(struct server *server) {
-	poller_init(&server->poller);
+	if (poller_init(&server->poller) == -1) {
+		log_errorf("could not initialize poller: %s", strerror(errno));
+		return -1;
+	}
 
 	linked_list_init(&server->seats);
 	linked_list_init(&server->idle_clients);