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.TH "SD_BUS_ENQUEUE_FOR_READ" "3" "" "systemd 256.7" "sd_bus_enqueue_for_read"
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.SH "NAME"
sd_bus_enqueue_for_read \- Re\-enqueue a bus message on a bus connection, for reading
.SH "SYNOPSIS"
.sp
.ft B
.nf
#include <systemd/sd\-bus\&.h>
.fi
.ft
.HP \w'int\ sd_bus_enqueue_for_read('u
.BI "int sd_bus_enqueue_for_read(sd_bus\ *" "bus" ", sd_bus_message\ *" "message" ");"
.SH "DESCRIPTION"
.PP
\fBsd_bus_enqueue_for_read()\fR
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\*(Aqs 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\&.
.PP
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\&.
.SH "RETURN VALUE"
.PP
On success, this function return 0 or a positive integer\&. On failure, it returns a negative errno\-style error code\&.
.SS "Errors"
.PP
Returned errors may indicate the following problems:
.PP
\fB\-ECHILD\fR
.RS 4
The bus connection has been created in a different process, library or module instance\&.
.RE
.SH "NOTES"
.PP
Functions described here are available as a shared library, which can be compiled against and linked to with the
\fBlibsystemd\fR\ \&\fBpkg-config\fR(1)
file\&.
.PP
The code described here uses
\fBgetenv\fR(3), which is declared to be not multi\-thread\-safe\&. This means that the code calling the functions described here must not call
\fBsetenv\fR(3)
from a parallel thread\&. It is recommended to only do calls to
\fBsetenv()\fR
from an early phase of the program when no other threads have been started\&.
.SH "HISTORY"
.PP
\fBsd_bus_enqueue_for_read()\fR
was added in version 245\&.
.SH "SEE ALSO"
.PP
\fBsystemd\fR(1), \fBsd-bus\fR(3), \fBsd_bus_send\fR(3)