The WeakRef class

(PECL weakref >= 0.1.0)

简介

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.

类摘要

WeakRef {

/* 方法 */

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 )

}

范例

Example #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";
}
?>

以上例程会输出：

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

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

The WeakRef class

简介

类摘要

范例

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