sd_event_source_set_exit_on_failure, sd_event_source_get_exit_on_failure — Set or retrieve the exit-on-failure feature of event sources
#include <systemd/sd-event.h>
int sd_event_source_set_exit_on_failure( | sd_event_source *source, |
int b); |
int sd_event_source_get_exit_on_failure( | sd_event_source *source); |
sd_event_source_set_exit_on_failure() may be used to set/unset the
exit-on-failure flag of the event source object specified as source. The flag
defaults to off. If on and the callback function set for the event source returns a failure code (i.e. a
negative value) the event loop is exited too, using the callback return code as the exit code for
sd_event_exit(3). If
off, the event source is disabled but the event loop continues to run. Setting this flag is useful for
"dominant" event sources that define the purpose and reason for the event loop, and whose failure hence
should propagate to the event loop itself — as opposed to "auxiliary" event sources whose failures should
remain local and affect the event source, but not propagate further.
sd_event_source_get_exit_on_failure() may be used to query the flag currently
set for the event source object source.
On success, sd_event_source_set_exit_on_failure() returns a non-negative
integer. sd_event_source_get_exit_on_failure() returns 0 if the flag is off, > 0
if the flag is on. On failure, both return a negative errno-style error code.
Returned errors may indicate the following problems:
-EINVAL¶source is not a valid pointer to an
sd_event_source object.
-EDOM¶The event source refers to an exit event source (as created with sd_event_add_exit(3)), for which this functionality is not supported.
Functions described here are available as a shared
library, which can be compiled against and linked to with the
libsystemd pkg-config(1)
file.
The code described here uses
getenv(3),
which is declared to be not multi-thread-safe. This means that the code calling the functions described
here must not call
setenv(3)
from a parallel thread. It is recommended to only do calls to setenv()
from an early phase of the program when no other threads have been started.