установить или получить указатель пользовательских данных источников событий (Set or retrieve user data pointer of event sources)
Имя (Name)
sd_event_source_set_userdata, sd_event_source_get_userdata - Set
or retrieve user data pointer of event sources
Синопсис (Synopsis)
#include <systemd/sd-event.h>
void* sd_event_source_set_userdata(sd_event_source *source,
void *userdata);
void* sd_event_source_get_userdata(sd_event_source *source);
Описание (Description)
sd_event_source_set_userdata() may be used to set an arbitrary
user data pointer for the event source object specified as
source. The user data pointer is usually specified when creating
an event source object with calls such as sd_event_add_io(3) or
sd_event_add_time(3), and may be updated with this call. The user
data pointer is also passed to all handler callback functions
associated with the event source. The userdata parameter
specifies the new user data pointer to set, the function returns
the previous user data pointer. Note that NULL is a valid user
data pointer.
sd_event_source_get_userdata() may be used to query the current
user data pointer assigned to the event source object source.
Возвращаемое значение (Return value)
On success, sd_event_source_set_userdata() and
sd_event_source_get_userdata() return the previously set user
data pointer. On failure, they return NULL.
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)
sd-event(3), sd_event_add_io(3), sd_event_add_time(3),
sd_event_add_signal(3), sd_event_add_child(3),
sd_event_add_inotify(3), sd_event_add_defer(3),
sd_event_source_set_description(3)
