sd_bus_set_connected_signal
systemd
Developer
Lennart
Poettering
lennart@poettering.net
sd_bus_set_connected_signal
3
sd_bus_set_connected_signal
sd_bus_get_connected_signal
Control emmission of local connection establishment signal on bus connections
#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_async3 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_bind3 is
used. The signal is generated when the
sd_bus_is_ready3 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.
Notes
sd_bus_set_connected_signal() and sd_bus_get_connected_signal() are available as
a shared library, which can be compiled and linked to with the libsystemd pkg-config1 file.
See Also
systemd1,
sd-bus3,
sd_bus_match_signal_async3,
sd_bus_set_watch_bind3,
sd_bus_is_ready3