From ed3a9f6a30958ef90a24bc60aec86493974101d3 Mon Sep 17 00:00:00 2001
From: David Herrmann <dh.herrmann@gmail.com>
Date: Mon, 22 Sep 2014 17:55:31 +0200
Subject: [PATCH] terminal: handle callback errors in sysview instead of
propagating them
We cannot sanely propagate error codes if we call into user-callbacks
multiple times for multiple objects. There is no way to merge those errors
or somehow propagate them.
However, we can just act similar to sd-event and print a log-message while
discarding the values. This way, we allow error-returns, but can properly
continue working on our objects.
---
src/libsystemd-terminal/sysview.c | 175 +++++++++++++++++---------------------
1 file changed, 76 insertions(+), 99 deletions(-)
diff --git a/src/libsystemd-terminal/sysview.c b/src/libsystemd-terminal/sysview.c
index 208c6ce25c..969514ad9d 100644
--- a/src/libsystemd-terminal/sysview.c
+++ b/src/libsystemd-terminal/sysview.c
@@ -272,7 +272,7 @@ static int session_take_control_fn(sd_bus *bus,
void *userdata,
sd_bus_error *ret_error) {
sysview_session *session = userdata;
- int error;
+ int r, error;
session->slot_take_control = sd_bus_slot_unref(session->slot_take_control);
@@ -287,7 +287,12 @@ static int session_take_control_fn(sd_bus *bus,
error = 0;
}
- return context_raise_session_control(session->seat->context, session, error);
+ r = context_raise_session_control(session->seat->context, session, error);
+ if (r < 0)
+ log_debug("sysview: callback failed while signalling session control '%d' on session '%s': %s",
+ error, session->name, strerror(-r));
+
+ return 0;
}
int sysview_session_take_control(sysview_session *session) {
@@ -548,10 +553,10 @@ static int context_raise_session_refresh(sysview_context *c, sysview_session *se
return context_raise(c, &event, 0);
}
-static int context_add_device(sysview_context *c, sysview_device *device) {
+static void context_add_device(sysview_context *c, sysview_device *device) {
sysview_session *session;
- int r, error = 0;
Iterator i;
+ int r;
assert(c);
assert(device);
@@ -564,20 +569,16 @@ static int context_add_device(sysview_context *c, sysview_device *device) {
continue;
r = context_raise_session_attach(c, session, device);
- if (r != 0)
- error = r;
+ if (r < 0)
+ log_debug("sysview: callback failed while attaching device '%s' to session '%s': %s",
+ device->name, session->name, strerror(-r));
}
-
- if (error < 0)
- log_debug("sysview: error while adding device '%s': %s",
- device->name, strerror(-r));
- return error;
}
-static int context_remove_device(sysview_context *c, sysview_device *device) {
+static void context_remove_device(sysview_context *c, sysview_device *device) {
sysview_session *session;
- int r, error = 0;
Iterator i;
+ int r;
assert(c);
assert(device);
@@ -589,21 +590,18 @@ static int context_remove_device(sysview_context *c, sysview_device *device) {
continue;
r = context_raise_session_detach(c, session, device);
- if (r != 0)
- error = r;
+ if (r < 0)
+ log_debug("sysview: callback failed while detaching device '%s' from session '%s': %s",
+ device->name, session->name, strerror(-r));
}
- if (error < 0)
- log_debug("sysview: error while removing device '%s': %s",
- device->name, strerror(-r));
sysview_device_free(device);
- return error;
}
-static int context_change_device(sysview_context *c, sysview_device *device, struct udev_device *ud) {
+static void context_change_device(sysview_context *c, sysview_device *device, struct udev_device *ud) {
sysview_session *session;
- int r, error = 0;
Iterator i;
+ int r;
assert(c);
assert(device);
@@ -615,21 +613,17 @@ static int context_change_device(sysview_context *c, sysview_device *device, str
continue;
r = context_raise_session_refresh(c, session, device, ud);
- if (r != 0)
- error = r;
+ if (r < 0)
+ log_debug("sysview: callback failed while changing device '%s' on session '%s': %s",
+ device->name, session->name, strerror(-r));
}
-
- if (error < 0)
- log_debug("sysview: error while changing device '%s': %s",
- device->name, strerror(-r));
- return error;
}
-static int context_add_session(sysview_context *c, sysview_seat *seat, const char *id) {
+static void context_add_session(sysview_context *c, sysview_seat *seat, const char *id) {
sysview_session *session;
sysview_device *device;
- int r, error = 0;
Iterator i;
+ int r;
assert(c);
assert(seat);
@@ -637,7 +631,7 @@ static int context_add_session(sysview_context *c, sysview_seat *seat, const cha
session = sysview_find_session(c, id);
if (session)
- return 0;
+ return;
log_debug("sysview: add session '%s' on seat '%s'", id, seat->name);
@@ -654,35 +648,33 @@ static int context_add_session(sysview_context *c, sysview_seat *seat, const cha
if (seat->public) {
session->public = true;
r = context_raise_session_add(c, session);
- if (r != 0) {
+ if (r < 0) {
+ log_debug("sysview: callback failed while adding session '%s': %s",
+ session->name, strerror(-r));
session->public = false;
goto error;
}
HASHMAP_FOREACH(device, seat->device_map, i) {
r = context_raise_session_attach(c, session, device);
- if (r != 0)
- error = r;
+ if (r < 0)
+ log_debug("sysview: callback failed while attaching device '%s' to new session '%s': %s",
+ device->name, session->name, strerror(-r));
}
-
- r = error;
- if (r != 0)
- goto error;
}
- return 0;
+ return;
error:
if (r < 0)
log_debug("sysview: error while adding session '%s': %s",
id, strerror(-r));
- return r;
}
-static int context_remove_session(sysview_context *c, sysview_session *session) {
+static void context_remove_session(sysview_context *c, sysview_session *session) {
sysview_device *device;
- int r, error = 0;
Iterator i;
+ int r;
assert(c);
assert(session);
@@ -692,27 +684,25 @@ static int context_remove_session(sysview_context *c, sysview_session *session)
if (session->public) {
HASHMAP_FOREACH(device, session->seat->device_map, i) {
r = context_raise_session_detach(c, session, device);
- if (r != 0)
- error = r;
+ if (r < 0)
+ log_debug("sysview: callback failed while detaching device '%s' from old session '%s': %s",
+ device->name, session->name, strerror(-r));
}
session->public = false;
r = context_raise_session_remove(c, session);
- if (r != 0)
- error = r;
+ if (r < 0)
+ log_debug("sysview: callback failed while removing session '%s': %s",
+ session->name, strerror(-r));
}
if (!session->custom)
sysview_session_release_control(session);
- if (error < 0)
- log_debug("sysview: error while removing session '%s': %s",
- session->name, strerror(-error));
sysview_session_free(session);
- return error;
}
-static int context_add_seat(sysview_context *c, const char *id) {
+static void context_add_seat(sysview_context *c, const char *id) {
sysview_seat *seat;
int r;
@@ -721,7 +711,7 @@ static int context_add_seat(sysview_context *c, const char *id) {
seat = sysview_find_seat(c, id);
if (seat)
- return 0;
+ return;
log_debug("sysview: add seat '%s'", id);
@@ -731,54 +721,45 @@ static int context_add_seat(sysview_context *c, const char *id) {
seat->public = true;
r = context_raise_seat_add(c, seat);
- if (r != 0) {
+ if (r < 0) {
+ log_debug("sysview: callback failed while adding seat '%s': %s",
+ seat->name, strerror(-r));
seat->public = false;
- goto error;
}
- return 0;
+ return;
error:
if (r < 0)
log_debug("sysview: error while adding seat '%s': %s",
id, strerror(-r));
- return r;
}
-static int context_remove_seat(sysview_context *c, sysview_seat *seat) {
+static void context_remove_seat(sysview_context *c, sysview_seat *seat) {
sysview_session *session;
sysview_device *device;
- int r, error = 0;
+ int r;
assert(c);
assert(seat);
log_debug("sysview: remove seat '%s'", seat->name);
- while ((device = hashmap_first(seat->device_map))) {
- r = context_remove_device(c, device);
- if (r != 0)
- error = r;
- }
+ while ((device = hashmap_first(seat->device_map)))
+ context_remove_device(c, device);
- while ((session = hashmap_first(seat->session_map))) {
- r = context_remove_session(c, session);
- if (r != 0)
- error = r;
- }
+ while ((session = hashmap_first(seat->session_map)))
+ context_remove_session(c, session);
if (seat->public) {
seat->public = false;
r = context_raise_seat_remove(c, seat);
- if (r != 0)
- error = r;
+ if (r < 0)
+ log_debug("sysview: callback failed while removing seat '%s': %s",
+ seat->name, strerror(-r));
}
- if (error < 0)
- log_debug("sysview: error while removing seat '%s': %s",
- seat->name, strerror(-error));
sysview_seat_free(seat);
- return error;
}
int sysview_context_new(sysview_context **out,
@@ -923,12 +904,12 @@ static int context_ud_hotplug(sysview_context *c, struct udev_device *d) {
if (!device)
return 0;
- return context_remove_device(c, device);
+ context_remove_device(c, device);
} else if (streq_ptr(action, "change")) {
if (!device)
return 0;
- return context_change_device(c, device, d);
+ context_change_device(c, device, d);
} else if (!action || streq_ptr(action, "add")) {
struct udev_device *p;
unsigned int type, t;
@@ -966,7 +947,7 @@ static int context_ud_hotplug(sysview_context *c, struct udev_device *d) {
return r;
}
- return context_add_device(c, device);
+ context_add_device(c, device);
}
return 0;
@@ -1093,7 +1074,8 @@ static int context_ld_seat_new(sysview_context *c, sd_bus_message *signal) {
return r;
}
- return context_add_seat(c, id);
+ context_add_seat(c, id);
+ return 0;
}
static int context_ld_seat_removed(sysview_context *c, sd_bus_message *signal) {
@@ -1112,7 +1094,8 @@ static int context_ld_seat_removed(sysview_context *c, sd_bus_message *signal) {
if (!seat)
return 0;
- return context_remove_seat(c, seat);
+ context_remove_seat(c, seat);
+ return 0;
}
static int context_ld_session_new(sysview_context *c, sd_bus_message *signal) {
@@ -1159,14 +1142,13 @@ static int context_ld_session_new(sysview_context *c, sd_bus_message *signal) {
}
r = context_raise_session_filter(c, id, seatid, username, uid);
- if (r <= 0) {
- if (r < 0)
- log_debug("sysview: cannot filter new session '%s' on seat '%s': %s",
- id, seatid, strerror(-r));
- return r;
- }
+ if (r < 0)
+ log_debug("sysview: callback failed while filtering session '%s': %s",
+ id, strerror(-r));
+ else if (r > 0)
+ context_add_session(c, seat, id);
- return context_add_session(c, seat, id);
+ return 0;
error:
log_debug("sysview: failed retrieving information for new session '%s': %s",
@@ -1190,7 +1172,8 @@ static int context_ld_session_removed(sysview_context *c, sd_bus_message *signal
if (!session)
return 0;
- return context_remove_session(c, session);
+ context_remove_session(c, session);
+ return 0;
}
static int context_ld_manager_signal_fn(sd_bus *bus,
@@ -1265,9 +1248,7 @@ static int context_ld_list_seats_fn(sd_bus *bus,
if (r < 0)
goto error;
- r = context_add_seat(c, id);
- if (r != 0)
- return r;
+ context_add_seat(c, id);
r = sd_bus_message_exit_container(reply);
if (r < 0)
@@ -1328,15 +1309,11 @@ static int context_ld_list_sessions_fn(sd_bus *bus,
seat = sysview_find_seat(c, seatid);
if (seat) {
r = context_raise_session_filter(c, id, seatid, username, uid);
- if (r < 0) {
- log_debug("sysview: cannot filter listed session '%s' on seat '%s': %s",
- id, seatid, strerror(-r));
- return r;
- } else if (r > 0) {
- r = context_add_session(c, seat, id);
- if (r != 0)
- return r;
- }
+ if (r < 0)
+ log_debug("sysview: callback failed while filtering session '%s': %s",
+ id, strerror(-r));
+ else if (r > 0)
+ context_add_session(c, seat, id);
}
r = sd_bus_message_exit_container(reply);