Путеводитель по Руководству Linux

  User  |  Syst  |  Libr  |  Device  |  Files  |  Other  |  Admin  |  Head  |



   sd_event_source_get_pending    ( 3 )

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)