seatd: shut down builtin server when seat is closed v1 PROPOSED

Lucas Stach: 1
 seatd: shut down builtin server when seat is closed

 1 files changed, 11 insertions(+), 3 deletions(-)

Am Montag, dem 23.01.2023 um 23:40 +0100 schrieb Kenny Levinsen:

[PATCH] seatd: shut down builtin server when seat is closed Export this patch

This shuts down the spawned builtin server process by sending it a
SIGTERM when the seat is closed.
---
This is probably trying to fix the same issue as 795cf169e779
("seatd: Shut down on client disconnect in builtin"), but I can't see
how this is supposed to work. AFAICS nothing defines LIBSEAT and I
don't see any way to distinguish between a real seatd server and the
builtin one at that spot in the code.

Kenny Levinsen <kl@kl.wtf>

1 year, 7 months ago

Did you experience issues with the shutdown procedure?

Lucas Stach <l.stach@pengutronix.de>

1 year, 7 months ago

Yes, this is fixing an issue where stopping a weston instance using the
builtin server isn't properly shutting down the server process.

Next

LIBSEAT is defined by meson when building libseat, see meson.build line 
132:

    libseat_c_args = ['-DLIBSEAT=1']

The libseat builtin server is included directly into libseat itself 
with that define set, while the seatd binary is built without that 
define set.

Lucas Stach <l.stach@pengutronix.de>

1 year, 7 months ago

Yea, I found that after I sent the patch and apparently 795cf169e779 is
even required for the subject patch to work as intended. I guess I need
to take a closer look again, except you might have some ideas on why
the shutdown isn't working as intended in my use case.

Regards,
Lucas

This is all separate from the newer seatd-launch procedure, which just 
uses the seatd binary rather than building seatd into libseat itself.

---
 libseat/backend/seatd.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/libseat/backend/seatd.c b/libseat/backend/seatd.c
index abcd2a5bf5cf..dd7977391950 100644
--- a/libseat/backend/seatd.c
+++ b/libseat/backend/seatd.c
@@ -2,6 +2,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <poll.h>
+#include <signal.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -38,6 +39,7 @@ struct backend_seatd {
 	struct linked_list pending_events;
 	bool awaiting_pong;
 	bool error;
+	pid_t builtin_server_pid;
 
 	char seat_name[MAX_SEAT_LEN];
 };
@@ -354,7 +356,8 @@ static int dispatch_and_execute(struct libseat *base, int timeout) {
 	return predispatch + postdispatch;
 }
 
-static struct libseat *_open_seat(const struct libseat_seat_listener *listener, void *data, int fd) {
+static struct libseat *_open_seat(const struct libseat_seat_listener *listener, void *data,
+				  int fd, pid_t server_pid) {
 	assert(listener != NULL);
 	assert(listener->enable_seat != NULL && listener->disable_seat != NULL);
 	struct backend_seatd *backend = calloc(1, sizeof(struct backend_seatd));
@@ -366,6 +369,7 @@ static struct libseat *_open_seat(const struct libseat_seat_listener *listener,
 	backend->seat_listener = listener;
 	backend->seat_listener_data = data;
 	backend->connection.fd = fd;
+	backend->builtin_server_pid = server_pid;
 	backend->base.impl = &seatd_impl;
 	linked_list_init(&backend->pending_events);
 
@@ -408,7 +412,7 @@ static struct libseat *open_seat(const struct libseat_seat_listener *listener, v
 		return NULL;
 	}
 
-	return _open_seat(listener, data, fd);
+	return _open_seat(listener, data, fd, -1);
 }
 
 static int close_seat(struct libseat *base) {
@@ -427,6 +431,10 @@ static int close_seat(struct libseat *base) {
 	}
 
 	execute_events(backend);
+
+	if (backend->builtin_server_pid != -1)
+		kill(backend->builtin_server_pid, SIGTERM);
+
 	destroy(backend);
 	return 0;
 
@@ -647,7 +655,7 @@ static struct libseat *builtin_open_seat(const struct libseat_seat_listener *lis
 	} else {
 		close(fds[0]);
 		int fd = fds[1];
-		return _open_seat(listener, data, fd);
+		return _open_seat(listener, data, fd, pid);
 	}
 }
 
-- 
2.39.0

Kenny Levinsen <kl@kl.wtf>

1 year, 7 months ago

On Thu, Jan 19 2023 at 07:14:17 PM +01:00:00, Lucas Stach 
<l.stach@pengutronix.de> wrote: