возвращает файл cookie транзакции сообщения (Returns the transaction cookie of a message)
Имя (Name)
sd_bus_message_get_cookie, sd_bus_message_get_reply_cookie -
Returns the transaction cookie of a message
Синопсис (Synopsis)
#include <systemd/sd-bus.h>
int sd_bus_message_get_cookie(sd_bus_message *message,
uint64_t *cookie);
int sd_bus_message_get_reply_cookie(sd_bus_message *message,
uint64_t *cookie);
Описание (Description)
sd_bus_message_get_cookie() returns the transaction cookie of a
message. The cookie uniquely identifies a message within each bus
peer, but is not globally unique. It is assigned when a message
is sent.
sd_bus_message_get_reply_cookie() returns the transaction cookie
of the message the specified message is a response to. When a
reply message is generated for a method call message, its cookie
is copied over into this field. Note that while every message
that is transferred is identified by a cookie, only response
messages carry a reply cookie field.
Both functions take a message object as first parameter and a
place to store the 64-bit cookie in.
Возвращаемое значение (Return value)
On success, these calls return 0 or a positive integer. On
failure, they return a negative errno-style error code.
On success, the cookie/reply cookie is returned in the specified
64-bit unsigned integer variable.
Errors
Returned errors may indicate the following problems:
-EINVAL
A specified parameter is invalid.
-ENODATA
No cookie has been assigned to this message. This either
indicates that the message has not been sent yet and hence
has no cookie assigned, or that the message is not a method
response message and hence carries a reply cookie field.
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_new(3)
