sd_varlink_is_connected, sd_varlink_is_idle — Query if a Varlink connection object is currently connected or idle
#include <systemd/sd-varlink.h>
int sd_varlink_is_connected( | sd_varlink *link); |
int sd_varlink_is_idle( | sd_varlink *link); |
sd_varlink_is_connected() checks whether the specified Varlink connection
object is currently connected or whether it has been fully disconnected already.
sd_varlink_is_idle() checks whether the specified Varlink connection object is
currently connected but idle, i.e. may accept a method call for enqueuing (if client side of a Varlink
connection) or is waiting for more incoming method calls to arrive (if server side of a Varlink
connection).
If the connection is currently connected sd_varlink_is_connected() returns a
positive non-zero value. If disconnected it returns 0. If the connection currently is idle
sd_varlink_is_idle() returns a positive non-zero integer. If not, returns 0. On
failure, both functions return a negative errno error code.
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.
sd_varlink_is_connected() was added in version 259.
sd_varlink_is_idle() was added in version 257.