x SuSE Linux 13.1-RELEASE x
x SuSE Linux 13.1-RELEASEx
SD_BUS_ATTACH_EVENT(3) sd_bus_attach_event SD_BUS_ATTACH_EVENT(3)
NAME
sd_bus_attach_event, sd_bus_detach_event, sd_bus_get_event - Attach a
bus connection object to an event loop
SYNOPSIS
#include <systemd/sd-bus.h>
int sd_bus_attach_event(sd_bus *bus, sd_event *e, int priority);
int sd_bus_detach_event(sd_bus *bus);
sd_event *sd_bus_get_event(sd_bus *bus);
DESCRIPTION
sd_bus_attach_event() attaches the specified bus connection object to
an sd-event(3) event loop object at the specified priority (see
sd_event_source_set_priority(3) for details on event loop priorities).
When a bus connection object is attached to an event loop incoming
messages will be automatically read and processed, and outgoing
messages written, whenever the event loop is run. When the event loop
is about to terminate, the bus connection is automatically flushed and
closed (see sd_bus_set_close_on_exit(3) for details on this). By
default bus connection objects are not attached to any event loop. When
a bus connection object is attached to one it is not necessary to
invoke sd_bus_wait(3) or sd_bus_process(3) as this functionality is
handled automatically by the event loop.
sd_bus_detach_event() detaches a bus object from its event loop.
The sd_bus_get_event() returns the event loop object the specified bus
object is currently attached to, or NULL if it is currently not
attached to any.
Note that sd_bus_attach_event() is only one of three supported ways to
implement I/O event handling for bus connections. Alternatively use
sd_bus_get_fd(3) for hooking up a bus connection object with external
or manual event loops. Or use sd_bus_wait(3) as a simple synchronous,
blocking I/O waiting call.
RETURN VALUE
On success, sd_bus_attach_event() and sd_bus_detach_event() return 0 or
a positive integer. On failure, they return a negative errno-style
error code.
sd_bus_get_event() returns an event loop object or NULL.
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-event(3), sd_event_source_set_priority(3),
sd_bus_set_close_on_exit(3), sd_bus_wait(3), sd_bus_get_fd(3)
systemd 254 SD_BUS_ATTACH_EVENT(3)
Want to link to this manual page? Use this URL:
<http://star2.abcm.com/cgi-bin/bsdi-man?query=sd_bus_attach_event&sektion=3&manpath=>