oracular (3) sd_event_set_signal_exit.3.gz

Provided by: libsystemd-dev_256.5-2ubuntu3.1_amd64 bug

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)