sd_event_set_signal_exit(3) — Linux manual page

SD_EVENT...NAL_EXIT(3)  sd_event_set_signal_exit  SD_EVENT...NAL_EXIT(3)

NAME

       sd_event_set_signal_exit - Automatically leave event loop on
       SIGINT and SIGTERM

SYNOPSIS

       #include <systemd/sd-event.h>

       int sd_event_set_signal_exit(sd_event *event, int b);

DESCRIPTION

       sd_event_set_signal_exit() may be used to ensure the event loop
       terminates once a SIGINT or SIGTERM signal is received. It is a
       convenience wrapper around invocations of sd_event_add_signal(3)
       for both signals. The two signals are automatically added to the
       calling thread's signal mask (if a program is multi-threaded care
       should be taken to either invoke this function before the first
       thread is started or to manually block the two signals
       process-wide first).

       If the parameter b is specified as true, the event loop will
       terminate on SIGINT and SIGTERM. If specified as false, it will
       no longer. When this functionality is turned off the calling
       thread's signal mask is restored to match the state before it was
       turned on, for the two signals. By default the two signals are
       not handled by the event loop, and Linux' default signal handling
       for them is in effect.

       It's customary for UNIX programs to exit on either of these two
       signals, hence it's typically a good idea to enable this
       functionality for the main event loop of a program.

RETURN VALUE

       sd_event_set_signal_exit() returns a positive non-zero value when
       the setting was successfully changed. It returns a zero when the
       specified setting was already in effect. On failure, it returns a
       negative errno-style error code.

   Errors
       Returned errors may indicate the following problems:

       -ECHILD
           The event loop has been created in a different process,
           library or module instance.

           Added in version 252.

       -EINVAL
           The passed event loop object was invalid.

           Added in version 252.

NOTES

       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

       sd_event_set_signal_exit() was added in version 252.

SEE ALSO

       systemd(1), sd-event(3), sd_event_new(3), sd_event_add_signal(3)

COLOPHON

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       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have
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       ⟨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
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systemd 257~devel                                 SD_EVENT...NAL_EXIT(3)

Pages that refer to this page: systemd.directives(7), systemd.index(7)

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