sd_event_exit(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | HISTORY | SEE ALSO | COLOPHON

SD_EVENT_EXIT(3)              sd_event_exit             SD_EVENT_EXIT(3)

NAME         top

       sd_event_exit, sd_event_get_exit_code - Ask the event loop to
       exit

SYNOPSIS         top

       #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);

DESCRIPTION         top

       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.

RETURN VALUE         top

       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.

NOTES         top

       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.

HISTORY         top

       sd_event_exit() and sd_event_get_exit_code() were added in
       version 229.

SEE ALSO         top

       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)

COLOPHON         top

       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)