x SuSE Linux 13.1-RELEASE x
x SuSE Linux 13.1-RELEASEx
SD_BUS_IS_OPEN(3) sd_bus_is_open SD_BUS_IS_OPEN(3)
NAME
sd_bus_is_open, sd_bus_is_ready - Check whether the bus connection is
open or ready
SYNOPSIS
#include <systemd/sd-bus.h>
int sd_bus_is_open(sd_bus *bus);
int sd_bus_is_ready(sd_bus *bus);
DESCRIPTION
sd_bus_is_open() checks whether the specified bus connection is open,
i.e. in the process of being established, already established or in the
process of being torn down. It returns zero when the connection has not
been started yet (i.e. sd_bus_start(3) or some equivalent call has not
been invoked yet), or is fully terminated again (for example after
sd_bus_close(3)), it returns positive otherwise.
sd_bus_is_ready() checks whether the specified connection is fully
established, i.e. completed the connection and authentication phases of
the protocol and received the Hello() method call response, and is not
in the process of being torn down again. It returns zero outside of
this state, and positive otherwise. Effectively, this function returns
positive while regular messages can be sent or received on the
connection.
The bus argument may be NULL, zero is also returned in that case.
To be notified when the connection is fully established, use
sd_bus_set_connected_signal(3) and install a match for the Connected()
signal on the "org.freedesktop.DBus.Local" interface. To be notified
when the connection is torn down again, install a match for the
Disconnected() signal on the "org.freedesktop.DBus.Local" interface.
RETURN VALUE
Those functions return 0 if the bus is not in the given state, and a
positive integer when it is. On failure, a negative errno-style error
code is returned.
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.
SEE ALSO
systemd(1), sd-bus(3), sd_bus_start(3), sd_bus_close(3),
sd_bus_set_connected_signal(3)
systemd 254 SD_BUS_IS_OPEN(3)
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