1SD_BUS_SET_WATCH_BIND(3)     sd_bus_set_watch_bind    SD_BUS_SET_WATCH_BIND(3)
2
3
4

NAME

6       sd_bus_set_watch_bind, sd_bus_get_watch_bind - Control socket binding
7       watching on bus connections
8

SYNOPSIS

10       #include <systemd/sd-bus.h>
11
12       int sd_bus_set_watch_bind(sd_bus *bus, int b);
13
14       int sd_bus_get_watch_bind(sd_bus *bus);
15

DESCRIPTION

17       sd_bus_set_watch_bind() may be used to enable or disable client-side
18       watching of server socket binding for a bus connection object. If the b
19       is true, the feature is enabled, otherwise disabled (which is the
20       default). When enabled, and the selected bus address refers to an
21       AF_UNIX socket in the file system which does not exist while the
22       connection attempt is made an inotify(7) watch is installed on it,
23       waiting for the socket to appear. As soon as the socket appears the
24       connection is made. This functionality is useful in particular in
25       early-boot programs that need to run before the system bus is
26       available, but want to connect to it the instant it may be connected
27       to.
28
29       sd_bus_get_watch_bind() may be used to query the current setting of
30       this feature. It returns zero when the feature is disabled, and
31       positive if enabled.
32
33       Note that no timeout is applied while we wait for the socket to appear.
34       This means that any synchronous remote operation (such as
35       sd_bus_call(3), sd_bus_add_match(3) or sd_bus_request_name(3)), that is
36       used on a connection with this feature enabled that hasn't been
37       established yet, might block forever if the socket is never created.
38       However, asynchronous remote operations (such as sd_bus_send(3),
39       sd_bus_call_async(3), sd_bus_add_match_async(3)) do not block in this
40       case, and safely enqueue the requested operations to be dispatched the
41       instant the connection is set up.
42
43       Use sd_bus_is_ready(3) to determine whether the connection is fully
44       established, i.e. whether the peer socket has been bound, connected to
45       and authenticated. Use sd_bus_set_connected_signal(3) to be notified
46       when the connection is fully established.
47

RETURN VALUE

49       On success, these functions return 0 or a positive integer. On failure,
50       they return a negative errno-style error code.
51
52   Errors
53       Returned errors may indicate the following problems:
54
55       -ECHILD
56           The bus connection has been created in a different process.
57

NOTES

59       These APIs are implemented as a shared library, which can be compiled
60       and linked to with the libsystemd pkg-config(1) file.
61

SEE ALSO

63       systemd(1), sd-bus(3), inotify(7), sd_bus_call(3), sd_bus_add_match(3),
64       sd_bus_request_name(3), sd_bus_is_ready(3),
65       sd_bus_set_connected_signal(3)
66
67
68
69systemd 251                                           SD_BUS_SET_WATCH_BIND(3)
Impressum