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Date: Sun, 03 Feb 2013 17:28:33 +0100
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To: Hans-Juergen Petrich <petrich@tronic-media.com>
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Subject: Re: [PHP-DEV] (non)growing memory while creating anoymous functions
 via eval()
From: keisial@gmail.com (=?UTF-8?B?w4FuZ2VsIEdvbnrDoWxleg==?=)

On 03/02/13 16:27, Hans-Juergen Petrich wrote:
> The only different in the second example is the fixed body length of
> the eval()-created anoymous function.
> I wondering why the memory in the second code-example will be freed at
> some point while in the first example not.
>
> I don't think it's a PHP-Bug but i also not understand this behavior.
>
> Is there one who can explain this?
> Thank you very much.
>
> Greetings
> Hans-Juergen Petrich

It can be simplified to:
> <?php
> while (true) {
>     $value = mt_rand(1, 10000);
>     $a = '$ano_fnc = function() {' . str_repeat(" ", $value) . '};';
>     eval ($a);
>     echo "Mem usage: ".memory_get_usage()."\n";
> }
The function *is* being removed, $ano_fnc alternates between
object(Closure)#1 and object(Closure)#2, it's not leaking function objects.
I suspect eval is checking a hashtable which is being forced to resize
continuously, but it shouldn't grow unbounded either.