попросите цикл событий выйти (Ask the event loop to exit)
Имя (Name)
sd_event_exit, sd_event_get_exit_code - Ask the event loop to
exit
Синопсис (Synopsis)
#include <systemd/sd-event.h>
int sd_event_exit(sd_event *
event, int
code);
int sd_event_get_exit_code(sd_event *
event, int *
code);
Описание (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_loop(3) 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_exit(3) 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 into sd_event_exit()
earlier.
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_time(3), sd_event_add_signal(3), ...) 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 time-out or reception
of SIGTERM
or similar. See the documentation for the respective
constructor call for details.
Возвращаемое значение (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.
-ESTALE
The event loop has exited already and all exit handlers are
already processed.
-ENODATA
The event loop has not been requested to exit yet.
Примечание (Note)
These APIs are implemented as a shared library, which can be
compiled and linked to with the libsystemd pkg-config
(1) file.
Смотри также (See also)
systemd(1), sd-event(3), sd_event_new(3), sd_event_add_exit(3),
sd_event_add_time(3), sd_event_add_signal(3), sd_event_add_io(3),
sd_event_add_defer(3), sd_event_add_inotify(3)