test php deferred destruction when callbacks are injected

output.txt

output:

no callback: testing...destruct...
with callback: testing...callback...destruct...
with callback 2: testing...callback...destruct...was unset...

(destruct was always called so that's ok)

test.php

<?php
	
	
	class A {
		
		protected $cb;
		
		
		public function set($cb) {
			$this->cb = $cb;
		}
		
		public function test() {
			echo 'testing...';
			$cb = $this->cb;
			$cb && $cb();
		}
		
		public function __destruct() {
			echo 'destruct...';
		}
		
	}
	
	
	function test() {
		$a = new A();
	    $a->test();	
	}
	
	function testCB() {
		$a = new A();
		$a->set(function() {
			echo 'callback...';
		});
		$a->test();	
	}
	
	function testCB2() {
		$a = new A();
		$a->set(function() {
			echo 'callback...';
		});
		$a->test();	
		unset($a);
        echo "was unset...";
	}
	
	
	
	echo 'no callback: ';
	test();
	echo PHP_EOL;
	
	echo 'with callback: ';
	testCB();
	echo PHP_EOL;
	
	echo 'with callback 2: ';
	testCB2();
	echo PHP_EOL;
	
?>