Weakref::release

(PECL weakref >= 0.1.0)

Weakref::release — Releases a previously acquired reference

说明

public Weakref::release ( void ) : bool

Releases a previously acquired reference, potentially turning a strong reference back into a weak reference.

The Weakref instance maintains an internal acquired counter to track outstanding strong references. If the call to Weakref::release() is successful, this counter will be decremented by one. Once this counter reaches zero, the strong reference is turned back into a weak reference.

参数

此函数没有参数。

返回值

Returns TRUE if the reference was previously acquired and thus could be released, FALSE otherwise.

范例

Example #1 Weakref::release() example

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

$o1 = new MyClass;

$r1 = new Weakref($o1);

$r1->acquire();

echo "Unsetting o1...\n";
unset($o1);

$o2 = $r1->get();

$r1->release();

echo "Unsetting o2...\n";
unset($o2);
?>

以上例程会输出：

Unsetting o1...
Unsetting o2...
Destroying object!

参见