sd_bus_enqueue_for_read — Re-enqueue a bus message on a bus connection, for reading
#include <systemd/sd-bus.h>
int sd_bus_enqueue_for_read( | sd_bus *bus, |
sd_bus_message *message); |
sd_bus_enqueue_for_read() may be used to re-enqueue an incoming bus message on
the local read queue, so that it is processed and dispatched locally again, similarly to how an incoming
message from the peer is processed. Takes a bus connection object and the message to enqueue. A reference
is taken of the message and the caller's reference thus remains in possession of the caller. The message
is enqueued at the end of the queue, thus will be dispatched after all other already queued messages are
dispatched.
This call is primarily useful for dealing with incoming method calls that may be processed only after an additional asynchronous operation completes. One example are PolicyKit authorization requests that are determined to be necessary to authorize a newly incoming method call: when the PolicyKit response is received the original method call may be re-enqueued to process it again, this time with the authorization result known.
On success, this function return 0 or a positive integer. On failure, it returns a negative errno-style 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.