1SD_BUS_CLOSE(3) sd_bus_close SD_BUS_CLOSE(3)
2
6 sd_bus_close, sd_bus_flush, sd_bus_default_flush_close - Close and
7 flush a bus connection
8
10 #include <systemd/sd-bus.h>
11 void sd_bus_close(sd_bus *bus);
13 int sd_bus_flush(sd_bus *bus);
15 void sd_bus_default_flush_close(void);
17
19 sd_bus_close() disconnects the specified bus connection. When this call
20 is invoked and the specified bus object refers to an active connection
21 it is immediately terminated. No further messages may be sent or
22 received on it. Any messages queued in the bus object (both incoming
23 and outgoing) are released. If invoked on NULL bus object or when the
24 bus connection is already closed this function executes no operation.
25 This call does not free or unreference the bus object itself. Use
26 sd_bus_unref(3) for that.
27 sd_bus_flush() synchronously writes out all outgoing queued message on
29 a bus connection if there are any. This function call may block if the
30 peer is not processing bus messages quickly.
31 Before a program exits it is usually a good idea to flush any pending
33 messages with sd_bus_flush() and then close connections with
34 sd_bus_close() to ensure that no unwritten messages are lost, no
35 further messages may be queued and all incoming but unprocessed
36 messages are released. After both operations have been done, it is a
37 good idea to also drop any remaining references to the bus object so
38 that it may be freed. Since these three operations are frequently done
39 together a helper call sd_bus_flush_close_unref(3) is provided that
40 combines them into one.
41 sd_bus_default_flush_close() is similar to sd_bus_flush_close_unref(),
43 but does not take a bus pointer argument and instead iterates over any
44 of the "default" buses opened by sd_bus_default(3),
45 sd_bus_default_user(3), sd_bus_default_system(3), and similar calls.
46 sd_bus_default_flush_close() is particularly useful to clean up any
47 buses opened using those calls before the program exits.
48
50 On success, sd_bus_flush() returns a non-negative integer. On failure,
51 it returns a negative errno-style error code.
52 Errors
54 Returned errors may indicate the following problems:
55 -ECHILD
57 The bus connection has been created in a different process, library
58 or module instance.
59
61 Functions described here are available as a shared library, which can
62 be compiled against and linked to with the libsystemd pkg-config(1)
63 file.
64 The code described here uses getenv(3), which is declared to be not
66 multi-thread-safe. This means that the code calling the functions
67 described here must not call setenv(3) from a parallel thread. It is
68 recommended to only do calls to setenv() from an early phase of the
69 program when no other threads have been started.
70
72 systemd(1), sd-bus(3), sd_bus_unref(3), sd_bus_set_close_on_exit(3)
73systemd 254 SD_BUS_CLOSE(3)