#21128 [Opn->Dup]: lost of static reference between calls

ID: 21128 Updated by: moriyoshi@php.net Reported By: alex_boyer@hotmail.com -Status: Open +Status: Duplicate Bug Type: Scripting Engine problem PHP Version: 4.2.3 New Comment: Variant of bug #20175 Previous Comments: ------------------------------------------------------------------------ [2002-12-21 04:38:52] alex_boyer@hotmail.com I want to keep a reference on a global object in a static method. But, between calls of this static method, my reference becomes NULL ! Look at this simple self-explanatory code: ------------------------------------------------ class B { var $x=100; } class A { /*Returns an instance*/ function &getInstance(){ if( !isset($GLOBALS['foo']) ){ $GLOBALS['foo'] =& new B(); } return $GLOBALS['foo']; } } /*this function gets the instance and show information*/ function staticExecution(){ static $instance=NULL; echo "ENTER staticExecution". "<BR/>\n"; //If static variable is not initialized if( $instance === NULL ){ $instance =& A::getInstance(); echo "DEBUG: getInstance is called". "<BR/>\n";; } echo 'BEFORE INCREMENT:$instance->x=='.$instance->x."<BR/>\n"; $instance->x++; echo 'AFTER INCREMENT: $instance->x == '.$instance->x . "<BR/>\n"; echo "EXIT staticExecution". "<BR/>\n";; } //ten call to staticExecution for ($i=0; $i<10; $i++){ staticExecution(); echo "<HR/>"; } RESULTS: ------------------------------------------------ ENTER staticExecution DEBUG: getInstance is called BEFORE INCREMENT: $instance->x == 100 AFTER INCREMENT: $instance->x == 101 EXIT staticExecution ------------------------------------------------------------ENTER staticExecution DEBUG: getInstance is called BEFORE INCREMENT: $instance->x == 101 AFTER INCREMENT: $instance->x == 102 EXIT staticExecution ------------------------------------------------------------ENTER staticExecution DEBUG: getInstance is called BEFORE INCREMENT: $instance->x == 102 AFTER INCREMENT: $instance->x == 103 EXIT staticExecution ------------------------------------------------------------ENTER staticExecution DEBUG: getInstance is called BEFORE INCREMENT: $instance->x == 103 AFTER INCREMENT: $instance->x == 104 EXIT staticExecution ------------------------------------------------------------ LIKE THIS TEN TIMES; WHAT DO WE NOTICE: - the reference returned is good: x is incremented - BUT the debug message appears 10 times !!! Indeed, my static variable is reinitialized between calls ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=21128&edit=1