(non)growing memory while creating anoymous functions via eval()

From: Date: Sun, 03 Feb 2013 15:27:16 +0000
Subject: (non)growing memory while creating anoymous functions via eval()
Groups: php.internals php.internals 
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Hi all

In this example (using php-5.4.11 on Linux) the memory will grow non-stop:

for ( $fp = fopen('/dev/urandom', 'rb'); true;) {

    eval ('$ano_fnc = function() {$x = "'.bin2hex(fread($fp, mt_rand(1, 10000))).'";};');
    echo "Mem usage: ".memory_get_usage()."\n";

}


But in this example not:

for ( $fp = fopen('/dev/urandom', 'rb'); true;) {

    eval ('$ano_fnc = function() {$x = "'.bin2hex(fread($fp, 10000)).'";};');
    echo "Mem usage: ".memory_get_usage()."\n";

}

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

Thread (1 message)

  • Hans-Juergen Petrich
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