什么时候 __destruct 不会在 PHP 中被调用？

When will __destruct not be called in PHP?

提问by user198729

class MyDestructableClass {
   function __construct() {
       print "\nIn constructor\n";
       $this->name = "MyDestructableClass";
   }

   function __destruct() {
       print "\nDestroying " . $this->name . "\n";
   }
}

$obj = new MyDestructableClass();

When the above script is in a complexenvironment,the __destructwon't get called when exit,but I can't reproduce it easily.Have someone ever noticed this ?

当上面的脚本处于复杂环境中时，__destruct不会被调用exit，但我无法轻松重现它。有人注意到了吗？

EDIT

编辑

I'll post the whole stuff here,it's the testing environment of symfony,which means you can easily reproduce it if you are familar with the framework:

我把所有的东西都贴在这里，它是symfony的测试环境，这意味着如果你熟悉框架，你可以很容易地复制它：

require_once dirname(__FILE__).'/../bootstrap/Doctrine.php';


$profiler = new Doctrine_Connection_Profiler();

$conn = Doctrine_Manager::connection();
$conn->setListener($profiler);

$t = new lime_test(0, new lime_output_color());

class MyDestructableClass {
   function __construct() {
       print "\nIn constructor\n";
       $this->name = "MyDestructableClass";
   }

   function __destruct() {
       print "\nDestroying " . $this->name . "\n";
   }
}

$obj = new MyDestructableClass();
$news = new News();

$news->setUrl('http://test');
$news->setHash('http://test');
$news->setTitle('http://test');
$news->setSummarize('http://test');
$news->setAccountId(1);
$news->setCategoryId(1);
$news->setThumbnail('http://test');
$news->setCreatedAt(date('Y-m-d H:i:s',time()));
$news->setUpdatedAt(date('Y-m-d H:i:s',time()));
$news->save();
exit();

回答by edorian

The __destructwill notbe called:

该__destruct会不会被调用：

• If exitis called in another destructor
• Depending on the PHP Version: if exitis called in a shutdown function registered with register_shutdown_function
• If there is a fatal error somewhere in the code
• If another destructor throws an exception
• If you try to handle an exception in a destructor (PHP >= 5.3.0)

• 如果exit在另一个析构函数中调用
• 取决于 PHP 版本：如果exit在注册的关闭函数中调用register_shutdown_function
• 如果代码中某处有致命错误
• 如果另一个析构函数抛出异常
• 如果您尝试在析构函数中处理异常 (PHP >= 5.3.0)

Guess that's all I can think of right now

猜猜这就是我现在能想到的

& What Pascal MARTIN said. That's the first step of debugging that.

& 帕斯卡·马丁 (Pascal MARTIN) 所说的话。这是调试它的第一步。

回答by nickel715

The __destructmethod will also not be called if script is running on CLI and receives a SIGTERM (Ctrl+C)

__destruct如果脚本在 CLI 上运行并收到 SIGTERM ( Ctrl+ C)，也不会调用该方法

回答by Pascal MARTIN

Not having an output on the screen doesn't mean the destructor is not called : the ouptut could be captured using output_buffering (maybe lime does that, to be able to work on it ? ), and not echoed when the script ends, for instance.

屏幕上没有输出并不意味着不调用析构函数：例如，可以使用 output_buffering 捕获输出（也许石灰会这样做，以便能够处理它？），并且在脚本结束时不回显，例如.

For testing purposes, you could try writing to a file, in your __destructmethod, instead of just echoing some text.
(Just make sure your application / PHP has the required privileges to write to your destination file)

出于测试目的，您可以尝试在您的__destruct方法中写入文件，而不仅仅是回显一些文本。
（只需确保您的应用程序/PHP 具有写入目标文件所需的权限）

(I've already run into situations where I would not see the output made in a destructor -- but it was actually called)

（我已经遇到过在析构函数中看不到输出的情况——但它实际上被调用了）

回答by Arek - Krakiewicz.pl

As the PHP documentationsays:

正如PHP 文档所说：

The destructor will be called even if script execution is stopped using exit(). Calling exit()in a destructor will prevent the remaining shutdown routines from executing.

即使使用 停止脚本执行，也会调用析构函数exit()。调用exit()析构函数将阻止执行剩余的关闭例程。

回答by WhiteFang

I know I'am a little late to the party but for people who are also looking to get __destructto be executed when CTRL+Cand/or Fatal errors occur, you can try this (below is a test case):

我知道我参加聚会有点晚了，但对于那些也希望__destruct在CTRL+C和/或致命错误发生时被处决的人，您可以试试这个（下面是一个测试用例）：

Index.php

索引.php

<?php

// Setup CTRL+C and System kill message handler
// The only signal that cannot be caught is the SIGKILL (very hard kill)
declare(ticks = 1); // Required else it won't work.
pcntl_signal(SIGTERM, 'close'); // System kill (Unhappy Termination)
pcntl_signal(SIGINT, 'close'); // CTRL+C (Happy Termination)

// Shutdown functions will be executed even on fatal errors
register_shutdown_function('close');

function close($signal = null) // only pcntl_signal fills $signal so null is required
{
    // Check if there was an fatal error (else code below isn't needed)
    $err = error_get_last();
    if(is_array($err))
    {
        foreach(array_keys($GLOBALS) as $key)
        {
            if(in_array($key, ['_GET', '_POST', '_COOKIE', '_FILES', '_SERVER', '_REQUEST', '_ENV', 'GLOBALS']))
                continue;

            // This will automatically call __destruct
            unset($GLOBALS[$key]);
        }
    }
}

// Example
class blah
{
    private $id = '';

    public function __construct()
    {
        $this->id = uniqid();
        // note this piece of code, doesn't work on windows!
        exec('mkdir /tmp/test_'.$this->id);
    }

    public function __destruct()
    {
        // note this piece of code, doesn't work on windows!
        exec('rm /tmp/test_'.$this->id.' -R');
    }
}

// Test
$a = new blah();
$b = new blah();
$c = new blah();
$d = new blah();
$e = new blah();
$f = new blah();
$g = new blah();
$h = new blah();
$i = new blah();
$j = new blah();
$k = new blah();
$l = new blah();
$m = new blah();
$n = new blah();
$o = new blah();
$p = new blah();
$q = new blah();
$r = new blah();
$s = new blah();
$t = new blah();
$u = new blah();
$v = new blah();
$w = new blah();
$x = new blah();
$y = new blah();
$z = new blah();

// The script that causes an fatal error
require_once(__DIR__.'/test.php');

Test.php

测试文件

<?php

// this will create a parse (E_PARSE) error.
asdsaddsaadsasd

Note:calling exit or throwing exceptions in destructors or shutdown functions will cause the script to terminate immediately.

注意：在析构函数或关闭函数中调用 exit 或抛出异常将导致脚本立即终止。

回答by Alexey Shein

Don't familiar with the Doctrine, but check one point: check for possible exceptions in __construct()/__destruct() they can produce fatal errors.

不熟悉 Doctrine，但请检查一点：检查 __construct()/__destruct() 中可能的异常，它们会产生致命错误。