PHP析构方法 __destruct() 不触发的两个解决办法

发布时间:2024-05-05 点击:99
有时候在 php 里类循环引用时,会导致 __destruct() 不触发的问题,先上问题代码:
<?php class proxy { private $object; public function __construct($object) { $this->object = $object; } public function __destruct() { var_dump('__destruct:proxy'); } } class test { private $proxy; public function __construct() { $this->proxy = new proxy($this); } public function __destruct() { var_dump('__destruct:test'); } } $test = new test; unset($test); echo 'no __destruct, wait 3s', php_eol; sleep(3); echo '__destruct now:', php_eol;如上代码,运行unset($test)时,不会触发__destruct(),因为有了循环引用。
再看下面的解决方法1的代码:
<?php class proxy { private $object; public function __construct($object) { $this->object = $object; } public function __destruct() { var_dump('__destruct:proxy'); } } class test { private $proxy; public function __construct() { $this->proxy = new proxy($this); } public function __destruct() { var_dump('__destruct:test'); } public function close() { $this->proxy = null; } } $test = new test; $test->close(); echo '__destruct now:', php_eol; unset($test); sleep(3); echo 'no operation', php_eol;上面的代码,在unset之前,将test类中的proxy设为null,然后再unset,就可以触发__destruct()了。
当然,你也可以手动gc(解决方法2):
<?php class proxy { private $object; public function __construct($object) { $this->object = $object; } public function __destruct() { var_dump('__destruct:proxy'); } } class test { private $proxy; public function __construct() { $this->proxy = new proxy($this); } public function __destruct() { var_dump('__destruct:test'); } } $test = new test; unset($test); echo '__destruct now:', php_eol; gc_collect_cycles(); sleep(3); echo 'no operation', php_eol;

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