определить состояние ожидания источников событий (Determine pending state of event sources)
Имя (Name)
sd_event_source_get_pending - Determine pending state of event
sources
Синопсис (Synopsis)
#include <systemd/sd-event.h>
int sd_event_source_get_pending(sd_event_source *source);
Описание (Description)
sd_event_source_get_pending() may be used to determine whether
the event source object specified as source has seen events but
has not been dispatched yet (and thus is marked "pending").
Event source objects initially are not marked pending, when they
are created with calls such as sd_event_add_io(3),
sd_event_add_time(3), with the exception of those created with
sd_event_add_defer(3) which are immediately marked pending, and
sd_event_add_exit(3) for which the "pending" concept is not
defined. For details see the respective manual pages.
In each event loop iteration one event source of those marked
pending is dispatched, in the order defined by the event source
priority, as set with sd_event_source_set_priority(3).
For I/O event sources, as created with sd_event_add_io(3), the
call sd_event_source_get_io_revents(3) may be used to query the
type of event pending in more detail.
Возвращаемое значение (Return value)
On success, sd_event_source_get_pending() returns an integer
greater than zero when the event source is marked pending, and
zero when the event source is not marked pending. On failure, it
returns a negative errno-style error code.
Errors
Returned errors may indicate the following problems:
-EINVAL
source is not a valid pointer to an sd_event_source object.
-EDOM
source refers to an event source object created with
sd_event_add_exit(3).
-ENOMEM
Not enough memory.
-ESTALE
The event loop is already terminated.
-ECHILD
The event loop 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)
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_unref(3)
