php析构函数疑惑

";        $this->start = microtime(true);    }        public function test() {        echo "in test()
";        throw new Exception("error", 500); // 抛出异常     }        public function __destruct() {        echo "__destruct
";    }}$test = new Test();$test->test();

方法里抛出异常后，不会调用析构函数：

try异常后能调用析构函数：

";        $this->start = microtime(true);    }        public function test() {        echo "in test()
";        try { // try 异常            throw new Exception("error", 500); // 抛出异常         } catch(Exception $e) {        }    }        public function __destruct() {        echo "__destruct
";    }}$test = new Test();$test->test();