#39254 [NEW]: Refcount error with static variables and object references

From: benoit dot heinrich at swisscom dot com Operating system: Linux PHP version: 4.4.4 PHP Bug Type: Class/Object related Bug description: Refcount error with static variables and object references Description: ------------ Hello all, I've a script that keep an object into a cache to speed up performances. To access the cached instance, I'm using a static method of the class MyFactory::getInstance(); In that method I need to have a reference on the instance itself because the attached params also need to have a reference on their owner. Case 1 --------------------------------- If I do $instance =& new MyFactory(); in the getInstance() method then I have this: $a->code: 2 $a->params[toto]->parent->code: 2 $b->code: 1657232709 $b->params[toto]->parent->code: 1657232709 So the thing here is that the static keyword does not seems to keep a refcount on the instance when it's created the first time. So each time you call the getInstance() it creates a new instance instead of keeping the first created one. Case 2 --------------------------------- If I do $instance = new MyFactory(); in the getInstance() method then I have this: $a->code: 2 $a->params[toto]->parent->code: 576672258 $b->code: 2 $b->params[toto]->parent->code: 576672258 Here we have the result we can expect accordingly to the PHP4 documentation, but this not what I need. Please, can you investigate on that one ? Cheers, /Benoit Reproduce code: --------------- <?php error_reporting(E_ALL); /** * This is an example of a param implementation class. * The constructor always need a reference on its parent * (here it's not really needed, but in the real code it is) */ class toto { var $parent; function toto(&$parent) { $this->parent =& $parent; } } /** * This the factory class used to create instances of params. * The factory instance must be unique. */ class MyFactory { var $code; var $params = array(); function MyFactory() { $this->code = rand(); $this->initParam('toto'); } /** * Initialize a parameter */ function initParam($param) { $this->params[$param] =& new $param($this); } /** * Get the unique instance of the factory */ function & getInstance() { static $instance; // Due to the bug $instance is always null if (is_null($instance)) $instance =& new MyFactory(); return $instance; } } $a =& MyFactory::getInstance(); $a->code = 2; print '$a->code: ' . $a->code . "\n"; print '$a->params[toto]->parent->code: ' . $a->params['toto']->parent->code . "\n"; $b =& MyFactory::getInstance(); print '$b->code: ' . $b->code . "\n"; print '$b->params[toto]->parent->code: ' . $b->params['toto']->parent->code . "\n"; ?> Expected result: ---------------- $a->code: 2 $a->params[toto]->parent->code: 2 $b->code: 2 $b->params[toto]->parent->code: 2 Actual result: -------------- $a->code: 2 $a->params[toto]->parent->code: 2 $b->code: 1657232709 $b->params[toto]->parent->code: 1657232709 -- Edit bug report at http://bugs.php.net/?id=39254&edit=1 -- Try a CVS snapshot (PHP 4.4): http://bugs.php.net/fix.php?id=39254&r=trysnapshot44 Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=39254&r=trysnapshot52 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=39254&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=39254&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=39254&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=39254&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=39254&r=needscript Try newer version: http://bugs.php.net/fix.php?id=39254&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=39254&r=support Expected behavior: http://bugs.php.net/fix.php?id=39254&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=39254&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=39254&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=39254&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=39254&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=39254&r=dst IIS Stability: http://bugs.php.net/fix.php?id=39254&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=39254&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=39254&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=39254&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=39254&r=mysqlcfg