Description:
------------
I did found on the internet some code to have test and measure memory usage. After tweaking it a bit, I discovered that when finishes (and unsetting all vars), PHP does not go back to initial memory usage which seems a memory leak.

This is the output the test script produces:

Note that memory usave in Stage 1, should be equal to memory usage in Stage 8 theoretically.

Test script:
---------------
<?php

echo "Stage 1: Mem usage is: ", memory_get_usage(), "\n";

$arr = array();

for ($i = 0; $i < 100000; ++$i) {
	$arr[] = rand();
}

echo "Stage 2: Mem usage is: ", memory_get_usage(), "\n";

$foo = 1;
$bar = 2;

echo "Stage 3: Mem usage is: ", memory_get_usage(), "\n";

$foo = $arr;
$bar = $arr;

echo "Stage 4: Mem usage is: ", memory_get_usage(), "\n";

$arr = array();

echo "Stage 5: Mem usage is: ", memory_get_usage(), "\n";

$bar[] = "hello, world";

echo "Stage 6: Mem usage is: ", memory_get_usage(), "\n";

$foo = array();

echo "Stage 7: Mem usage is: ", memory_get_usage(), "\n";

unset($arr);
unset($foo);
unset($bar);
flush();
echo "Stage 8: Mem usage is: ", memory_get_usage(), "\n";
?>

Expected result:
----------------
Expected output:
PHP 5.4.0:
Stage 1: Mem usage is: 234104
Stage 2: Mem usage is: 14883160
Stage 3: Mem usage is: 14883432
Stage 4: Mem usage is: 14883336
Stage 5: Mem usage is: 14883472
Stage 6: Mem usage is: 24732360
Stage 7: Mem usage is: 14883736
Stage 8: Mem usage is: 234104

Actual result:
--------------
PHP 5.4.0:
Stage 1: Mem usage is: 234104
Stage 2: Mem usage is: 14883160
Stage 3: Mem usage is: 14883432
Stage 4: Mem usage is: 14883336
Stage 5: Mem usage is: 14883472
Stage 6: Mem usage is: 24732360
Stage 7: Mem usage is: 14883736
Stage 8: Mem usage is: 234240

PHP 5.2.7:
Stage 1: Mem usage is: 95520
Stage 2: Mem usage is: 13945080
Stage 3: Mem usage is: 13945352
Stage 4: Mem usage is: 13945272
Stage 5: Mem usage is: 13945480
Stage 6: Mem usage is: 23794376
Stage 7: Mem usage is: 13945680
Stage 8: Mem usage is: 95656

(Much more memory used in 5.4.0?)