Weakref
PHP Manual

The WeakRef class

(PECL weakref >= 0.1.0)

導入

The WeakRef class provides a gateway to objects without preventing the garbage collector from freeing those objects. It also provides a way to turn a weak reference into a strong one.

クラス概要

WeakRef {
/* メソッド */
public Weakref::__construct ([ object $object ] )
public bool Weakref::acquire ( void )
public object Weakref::get ( void )
public bool Weakref::release ( void )
public bool Weakref::valid ( void )
}

例

例1 WeakRef usage example

<?php
class MyClass {
    public function __destruct() {
        echo "Destroying object!\n";
    }
}

$o1 = new MyClass;

$r1 = new WeakRef($o1);

if ($r1->valid()) {
    echo "Object still exists!\n";
    var_dump($r1->get());
} else {
    echo "Object is dead!\n";
}

unset($o1);

if ($r1->valid()) {
    echo "Object still exists!\n";
    var_dump($r1->get());
} else {
    echo "Object is dead!\n";
}
?>

上の例の出力は以下となります。

Object still exists!
object(MyClass)#1 (0) {
}
Destroying object!
Object is dead!

目次

Weakref
PHP Manual