#46790 [NEW]: Memory leak with classes

From: o_O_Tync at mail dot ru Operating system: Win, FreeBSD PHP version: 5.2.7 PHP Bug Type: Class/Object related Bug description: Memory leak with classes Description: ------------ I've come across a memory leak: garbage collector failes to free memory occupied by linked objects, such as: $obj1->pair = $obj2; $obj2->pair = $obj1; Below goes the problematic piece of code: over many iterations - it occupies a lot of memory. If we comment 'line1' or 'line2' or both - memory is okay (48 Kb), but cross-linking reveals a bug (839 Kb) despite of explicit unsetting. The commented 'this helps' line solves the problem. Tested under WinXP, and FreeBSD 6.1 using the latest PHP 5.2.7 Reproduce code: --------------- <?php class Paired { /** Paired object * @var Paired */ public $pair; } for ($i=0;$i<2000;$i++) { $obj1 = new Paired; $obj2 = new Paired; $obj1->pair = $obj2; // 'line1' $obj2->pair = $obj1; // 'line2' // $obj1->pair = null; $obj2->pair = null; // this helps unset($obj1); unset($obj2); // Explicitly } print 'Mem: '.floor(memory_get_usage()/1024).' Kb'; ?> Expected result: ---------------- Mem: 48 Kb Actual result: -------------- Mem: 839 Kb -- Edit bug report at http://bugs.php.net/?id=46790&edit=1 -- Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=46790&r=trysnapshot52 Try a CVS snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=46790&r=trysnapshot53 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=46790&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=46790&r=fixedcvs Fixed in CVS and need be documented: http://bugs.php.net/fix.php?id=46790&r=needdocs Fixed in release: http://bugs.php.net/fix.php?id=46790&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=46790&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=46790&r=needscript Try newer version: http://bugs.php.net/fix.php?id=46790&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=46790&r=support Expected behavior: http://bugs.php.net/fix.php?id=46790&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=46790&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=46790&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=46790&r=globals PHP 4 support discontinued: http://bugs.php.net/fix.php?id=46790&r=php4 Daylight Savings: http://bugs.php.net/fix.php?id=46790&r=dst IIS Stability: http://bugs.php.net/fix.php?id=46790&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=46790&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=46790&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=46790&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=46790&r=mysqlcfg