|
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | SEE ALSO | COLOPHON |
SD_BUS_ATTACH_EVENT(3) sd_bus_attach_event SD_BUS_ATTACH_EVENT(3)
sd_bus_attach_event, sd_bus_detach_event, sd_bus_get_event - Attach a
bus connection object to an event loop
#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);
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.
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.
These APIs are implemented as a shared library, which can be compiled
and linked to with the libsystemd pkg-config(1) file.
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)
This page is part of the systemd (systemd system and service manager)
project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug
report for this manual page, see
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page was obtained from the project's upstream Git repository
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of the original manual page), send a mail to man-pages@man7.org
systemd 246 SD_BUS_ATTACH_EVENT(3)
Pages that refer to this page: sd-bus(3) , sd_bus_get_close_on_exit(3) , sd_bus_get_events(3) , sd_bus_get_exit_on_disconnect(3) , sd_bus_get_fd(3) , sd_bus_get_timeout(3) , sd_bus_process(3) , sd_bus_set_close_on_exit(3) , sd_bus_set_exit_on_disconnect(3) , sd_bus_set_fd(3) , sd_bus_wait(3) , 30-systemd-environment-d-generator(7) , systemd.directives(7) , systemd.index(7)