# The EvChild class

(PECL ev >= 0.2.0)

## Introduction

EvChild watchers trigger when the process receives a `SIGCHLD` in response to some child status changes (most typically when a child dies or exits). It is permissible to install an `EvChild` watcher after the child has been forked(which implies it might have already exited), as long as the event loop isn't entered(or is continued from a watcher), i.e. forking and then immediately registering a watcher for the child is fine, but forking and registering a watcher a few event loop iterations later or in the next callback invocation is not.

It is allowed to register EvChild watchers in the default loop only.

## Class synopsis

EvChild extends EvWatcher {
/* Properties */
public $pid ;
public $rpid ;
public $rstatus ;
/* Inherited properties */
public $is_active ;
public $data ;
public $is_pending ;
public $priority ;
/* Methods */
public __construct ( int `$pid` , bool `$trace` , callable `$callback` [, mixed `$data` = `NULL` [, int `$priority` = 0 ]] )
final public static createStopped ( int `$pid` , bool `$trace` , callable `$callback` [, mixed `$data` [, int `$priority` ]] ) : object
public set ( int `$pid` , bool `$trace` ) : void
/* Inherited methods */
public EvWatcher::clear ( ) : int
abstract public EvWatcher::__construct ( )
public EvWatcher::feed ( int `$revents` ) : void
public EvWatcher::getLoop ( ) : EvLoop
public EvWatcher::invoke ( int `$revents` ) : void
public EvWatcher::keepalive ([ bool `$value` ] ) : bool
public EvWatcher::setCallback ( callable `$callback` ) : void
public EvWatcher::start ( ) : void
public EvWatcher::stop ( ) : void
}

## Properties

pid

  Readonly . The process ID this watcher watches out for, or `0` , meaning any process ID.

rpid

  Readonly .The process ID that detected a status change.

rstatus

  Readonly . The process exit status caused by rpid .

## Table of Contents

- EvChild::__construct — Constructs the EvChild watcher object
- EvChild::createStopped — Create instance of a stopped EvCheck watcher
- EvChild::set — Configures the watcher