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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | HISTORY | SEE ALSO | COLOPHON |
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SD_EVENT_EXIT(3) sd_event_exit 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 *code);
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 to an earlier call of sd_event_exit(). The return
parameter code 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_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.
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.
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.
sd_event_exit() and sd_event_get_exit_code() were added in
version 229.
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)
This page is part of the systemd (systemd system and service
manager) project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have
a bug report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
This page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2024-06-13.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
systemd 257~devel SD_EVENT_EXIT(3)
Pages that refer to this page: sd_bus_set_exit_on_disconnect(3), sd-event(3), sd_event_add_child(3), sd_event_add_defer(3), sd_event_add_inotify(3), sd_event_add_io(3), sd_event_add_signal(3), sd_event_add_time(3), sd_event_run(3), sd_event_source_set_exit_on_failure(3), sd_event_wait(3), systemd.directives(7), systemd.index(7)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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