sd_event_exit
systemd
sd_event_exit
3
sd_event_exit
sd_event_get_exit_code
Ask the event loop to exit
#include <systemd/sd-event.h>
int sd_event_exit
sd_event *event
int code
int sd_event_get_exit_code
sd_event *event
int *ret
Description
sd_event_exit() requests the event loop
specified in the event event loop object to
exit. The code parameter may be any integer
value and is returned as-is by
sd_event_loop3
after the last event loop iteration. It may also be queried
using sd_event_get_exit_code(), see
below.
When exiting is requested the event loop will stop listening
for and dispatching regular event sources. Instead it will proceed
with executing only event sources registered with
sd_event_add_exit3
in the order defined by their priority. After all exit event
sources have been dispatched the event loop is terminated.
If sd_event_exit() is invoked a second
time while the event loop is still processing exit event sources,
the exit code stored in the event loop object is updated, but
otherwise no further operation is executed.
sd_event_get_exit_code() may be used to query the exit code passed to an
earlier call of sd_event_exit(). The return parameter ret
may be set to NULL, in order to simply check if sd_event_exit()
has been called before (as sd_event_get_exit_code() fails with
-ENODATA if that's not the case, see below).
While the full positive and negative integer ranges may be used
for the exit code, care should be taken not pick exit codes that
conflict with regular exit codes returned by
sd_event_loop(), if these exit codes shall be
distinguishable.
Note that for most event source types passing the callback pointer as NULL in
the respective constructor call (i.e. in
sd_event_add_time3,
sd_event_add_signal3,
…) has the effect of sd_event_exit() being invoked once the event source triggers,
with the specified userdata pointer cast to an integer as the exit code parameter. This is useful to
automatically terminate an event loop after some condition, such as a timeout or reception of
SIGTERM or similar. See the documentation for the respective constructor call for
details.
Return Value
On success, sd_event_exit() and sd_event_get_exit_code()
return 0 or a positive integer. On failure, they return a negative errno-style error code.
Errors
Returned errors may indicate the following problems:
-EINVAL
The event loop object or error code pointer are invalid.
-ECHILD
The event loop was created in a different process, library or module instance.
-ESTALE
The event loop has exited already and all exit handlers are already processed.
-ENODATA
Returned by sd_event_get_exit_code() in case the event loop has not
been requested to exit yet.
History
sd_event_exit() and
sd_event_get_exit_code() were added in version 229.
See Also
systemd1
sd-event3
sd_event_new3
sd_event_add_exit3
sd_event_add_time3
sd_event_add_signal3
sd_event_add_io3
sd_event_add_defer3
sd_event_add_inotify3