# EvEmbed::__construct

(PECL ev >= 0.2.0)

EvEmbed::__construct — Constructs the EvEmbed object

### Description

public EvEmbed::__construct ( object `$other` [, callable `$callback` [, mixed `$data` [, int `$priority` ]]] )

This is a rather advanced watcher type that lets to embed one event loop into another(currently only IO events are supported in the embedded loop, other types of watchers might be handled in a delayed or incorrect fashion and must not be used).

See » the libev documentation for details.

This watcher is most useful on BSD systems without working `kqueue` to still be able to handle a large number of sockets. See example below.

### Parameters

`other`

  Instance of EvLoop . The loop to embed, this loop must be embeddable(see Ev::embeddableBackends() ).

`callback`

  See Watcher callbacks .

`data`

  Custom data associated with the watcher.

`priority`

  Watcher priority

### Return Values

Returns EvEmbed object on success.

### Examples

Example #1 Embedding loop created with kqueue backend into the default loop

`<?php
/*
* Check if kqueue is available but not recommended and create a kqueue backend
* for use with sockets (which usually work with any kqueue implementation).
* Store the kqueue/socket-only event loop in loop_socket. (One might optionally
* use EVFLAG_NOENV, too)
*
* Example borrowed from
* http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#Examples_CONTENT-9
*/
$loop = EvLoop::defaultLoop();
$socket_loop = NULL;
$embed = NULL;
if (Ev::supportedBackends() & ~Ev::recommendedBackends() & Ev::BACKEND_KQUEUE) {
if (($socket_loop = new EvLoop(Ev::BACKEND_KQUEUE))) {
$embed = new EvEmbed($loop);
}
}
if (!$socket_loop) {
$socket_loop = $loop;
}
// Now use $socket_loop for all sockets, and $loop for anything else
?>`

### See Also

- Ev::embeddableBackends() - Returns the set of backends that are embeddable in other event loops