# The Event class

(PECL event >= 1.2.6-beta)

## はじめに

Event class represents and event firing on a file descriptor being ready to read from or write to; a file descriptor becoming ready to read from or write to(edge-triggered I/O only); a timeout expiring; a signal occuring; a user-triggered event.

Every event is associated with EventBase . However, event will never fire until it is added (via Event::add() ). An added event remains in pending state until the registered event occurs, thus turning it to active state. To handle events user may register a callback which is called when event becomes active. If event is configured persistent , it remains pending. If it is not persistent, it stops being pending when it's callback runs. Event::del() method deletes event, thus making it non-pending. By means of Event::add() method it could be added again.

## クラス概要

final Event {
/* Constants */
const integer ET = 32 ;
const integer PERSIST = 16 ;
const integer READ = 2 ;
const integer WRITE = 4 ;
const integer SIGNAL = 8 ;
const integer TIMEOUT = 1 ;
/* プロパティ */
public readonly bool $pending ;
/* メソッド */
public add ([ float `$timeout` ] ) : bool
public addSignal ([ float `$timeout` ] ) : bool
public addTimer ([ float `$timeout` ] ) : bool
public __construct ( EventBase `$base` , mixed `$fd` , int `$what` , callable `$cb` [, mixed `$arg` = NULL ] )
public del ( void ) : bool
public delSignal ( void ) : bool
public delTimer ( void ) : bool
public free ( void ) : void
public static getSupportedMethods ( void ) : array
public pending ( int `$flags` ) : bool
public set ( EventBase `$base` , mixed `$fd` [, int `$what` [, callable `$cb` [, mixed `$arg` ]]] ) : bool
public setPriority ( int `$priority` ) : bool
public setTimer ( EventBase `$base` , callable `$cb` [, mixed `$arg` ] ) : bool
public static signal ( EventBase `$base` , int `$signum` , callable `$cb` [, mixed `$arg` ] ) : Event
public static timer ( EventBase `$base` , callable `$cb` [, mixed `$arg` ] ) : Event
}

## プロパティ

pending

  Whether event is pending. See About event persistence .

## 定義済み定数

`Event::ET`

  Indicates that the event should be edge-triggered, if the underlying event base backend supports edge-triggered events. This affects the semantics of `Event::READ` and `Event::WRITE` .

`Event::PERSIST`

  Indicates that the event is persistent. See About event persistence .

`Event::READ`

  This flag indicates an event that becomes active when the provided file descriptor(usually a stream resource, or socket) is ready for reading.

`Event::WRITE`

  This flag indicates an event that becomes active when the provided file descriptor(usually a stream resource, or socket) is ready for reading.

`Event::SIGNAL`

  Used to implement signal detection. See "Constructing signal events" below.

`Event::TIMEOUT`

  This flag indicates an event that becomes active after a timeout elapses.

  The `Event::TIMEOUT` flag is ignored when constructing an event: one can either set a timeout when event is added , or not. It is set in the $what argument to the callback function when a timeout has occurred.

## 目次

- Event::add — Makes event pending
- Event::addSignal — Makes signal event pending
- Event::addTimer — Makes timer event pending
- Event::__construct — Constructs Event object
- Event::del — Makes event non-pending
- Event::delSignal — Makes signal event non-pending
- Event::delTimer — Makes timer event non-pending
- Event::free — Make event non-pending and free resources allocated for this event
- Event::getSupportedMethods — Returns array with of the names of the methods supported in this version of Libevent
- Event::pending — Detects whether event is pending or scheduled
- Event::set — Re-configures event
- Event::setPriority — Set event priority
- Event::setTimer — Re-configures timer event
- Event::signal — Constructs signal event object
- Event::timer — Constructs timer event object