The WeakRef class

Introduction

(PECL weakref >= 0.1.0)

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.

Note:

The class WeakRef is not to be confused with the class WeakReference.

Class synopsis

public Weakref::acquire ( ) : bool

public Weakref::get ( ) : object

public Weakref::release ( ) : bool

public Weakref::valid ( ) : bool

Examples

<?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";
}
?>

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

Table of Contents

• Weakref::acquire — Acquires a strong reference on that object
• Weakref::__construct — Constructs a new weak reference
• Weakref::get — Returns the object pointed to by the weak reference
• Weakref::release — Releases a previously acquired reference
• Weakref::valid — Checks whether the object referenced still exists