закройте и промойте автобусное соединение (Close and flush a bus connection)
Имя (Name)
sd_bus_close, sd_bus_flush, sd_bus_default_flush_close - Close
and flush a bus connection
Синопсис (Synopsis)
#include <systemd/sd-bus.h>
void sd_bus_close(sd_bus *bus);
int sd_bus_flush(sd_bus *bus);
void sd_bus_default_flush_close(void);
Описание (Description)
sd_bus_close() disconnects the specified bus connection. When
this call is invoked and the specified bus object refers to an
active connection it is immediately terminated. No further
messages may be sent or received on it. Any messages queued in
the bus object (both incoming and outgoing) are released. If
invoked on NULL bus object or when the bus connection is already
closed this function executes no operation. This call does not
free or unreference the bus object itself. Use sd_bus_unref(3)
for that.
sd_bus_flush() synchronously writes out all outgoing queued
message on a bus connection if there are any. This function call
may block if the peer is not processing bus messages quickly.
Before a program exits it is usually a good idea to flush any
pending messages with sd_bus_flush() and then close connections
with sd_bus_close() to ensure that no unwritten messages are
lost, no further messages may be queued and all incoming but
unprocessed messages are released. After both operations have
been done, it is a good idea to also drop any remaining
references to the bus object so that it may be freed. Since these
three operations are frequently done together a helper call
sd_bus_flush_close_unref(3) is provided that combines them into
one.
sd_bus_default_flush_close() is similar to
sd_bus_flush_close_unref(), but does not take a bus pointer
argument and instead iterates over any of the "default" buses
opened by sd_bus_default(3), sd_bus_default_user(3),
sd_bus_default_system(3), and similar calls.
sd_bus_default_flush_close() is particularly useful to clean up
any buses opened using those calls before the program exits.
Возвращаемое значение (Return value)
On success, sd_bus_flush() returns a non-negative integer. On
failure, it returns a negative errno-style error code.
Errors
Returned errors may indicate the following problems:
-ECHILD
The bus connection has been created in a different process.
Примечание (Note)
These APIs are implemented as a shared library, which can be
compiled and linked to with the libsystemd pkg-config(1) file.
Смотри также (See also)
systemd(1), sd-bus(3), sd_bus_unref(3),
sd_bus_set_close_on_exit(3)
