NAME

       sd_bus_set_connected_signal, sd_bus_get_connected_signal - Control emission of local
       connection establishment signal on bus connections

SYNOPSIS

       #include <systemd/sd-bus.h>

       int sd_bus_set_connected_signal(sd_bus *bus, int b);

       int sd_bus_get_connected_signal(sd_bus *bus);

DESCRIPTION

       sd_bus_set_connected_signal() may be used to control whether a local, synthetic
       Connected() signal message shall be generated and enqueued for dispatching when the
       connection is fully established. If the b parameter is zero the message is not generated
       (the default), otherwise it is generated.

       sd_bus_get_connected_signal() may be used to query whether this feature is enabled. It
       returns zero if not, positive otherwise.

       The Connected() signal message is generated from the "org.freedesktop.DBus.Local" service
       and interface, and "/org/freedesktop/DBus/Local" object path. Use
       sd_bus_match_signal_async(3) to match on this signal.

       This message is particularly useful on slow transports where connections take a long time
       to be established. This is especially the case when sd_bus_set_watch_bind(3) is used. The
       signal is generated when the sd_bus_is_ready(3) returns positive for the first time.

       The Connected() signal corresponds with the Disconnected() signal that is synthesized
       locally when the connection is terminated. The latter is generated unconditionally
       however, unlike the former which needs to be enabled explicitly before it is generated,
       with sd_bus_set_connected_signal().

RETURN VALUE

       On success, these functions return 0 or a positive integer. On failure, they return a
       negative errno-style error code.

   Errors
       Returned errors may indicate the following problems:

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

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_bus_set_connected_signal() and sd_bus_get_connected_signal() were added in version 237.

SEE ALSO

       systemd(1), sd-bus(3), sd_bus_match_signal_async(3), sd_bus_set_watch_bind(3),
       sd_bus_is_ready(3)