Re: Reading class variable value always returns NULL

Hi, We have since deployed another webserver machine and observe the exact same behavior there. So it is not a hardware problem. We have also disabled various php modules, but this didn't help either. Any debug suggestions are welcome! :) Reto On Tue, Aug 14, 2012 at 10:40 AM, Reto Kaiser <reto@cargomedia.ch> wrote: > Hi, > > Thanks for your input Robert and Volmar! I have googled again with > "instance variable" instead of "class variable" - but have not found > any similar reports. > > I'm pretty sure those are the same objects. The application usually > runs alright. We only see the instance variables becoming NULL since > about a week. > > We had 3 small software upgrade coming from debian since we observe > the problem. We think they cannot be related. Still we have reverted > all of those and still see the problem. > Next step is that we setup a exact copy of the machine. Maybe it is a > hardware problem... > > Thanks, > Reto > > On Mon, Aug 13, 2012 at 5:09 PM, Robert Cummings <robert@interjinn.com> wrote: >> On 12-08-12 08:32 AM, Reto Kaiser wrote: >>> >>> Hi, >>> >>> So I have this strange situation where I assign a classvariable a >>> value, but when I read the value it is NULL. >>> >>> The class has one variable declared: >>> ========= >>> class A { >>> private $_cookies; >>> } >>> ========= >> >> >> That is a private instance variable NOT a class variable. >> >> To declare a class variable you would do the following: >> >> <?php >> >> class A >> { >> private static $_cookies; >> } >> >> ?> >> >> >>> In a method of this class I assign this classvariable plus an >>> undeclared classvariable and a local variable the value 1: >>> ========= >>> $this->_cookies = 1; >>> $this->_cookies2 = 1; >>> $cookies3 = 1; >>> ========= >>> >>> When I now read the values of those variables, the classvariables are >>> NULL while the local variable is 1: >>> ========= >>> $logEntry .= 'cookies: ' . var_export($this->_cookies, true) . PHP_EOL; >>> $logEntry .= 'cookies2: ' . var_export($this->_cookies2, true) . PHP_EOL; >>> $logEntry .= 'cookies3: ' . var_export($cookies3, true) . PHP_EOL; >>> ========= >>> cookies: NULL >>> cookies2: NULL >>> cookies3: 1 >>> ========= >>> >>> But when reading the whole object, the classvariables are 1: >>> ========= >>> $logEntry .= var_export($this, true) . PHP_EOL; >>> ========= >>> A::__set_state(array( >>> '_cookies' => 1, >>> '_cookies2' => 1, >>> )) >>> ========= >>> >>> >>> This happens periodically on a busy webserver. It seems that when it >>> happens, all classvariables cannot be read anymore (return NULL). >>> After restarting Apache it does not happen anymore, just to happen >>> again after some minutes. >>> >>> The system is current Debian Squeeze: >>> Linux: linux-image-2.6.32-5-amd64 >>> Apache: apache2-mpm-prefork 2.2.16-6+squeeze7 >>> PHP: PHP 5.3.3-7+squeeze13 with Suhosin-Patch (cli) (built: Jun 10 >>> 2012 07:31:32) >>> php -m: >>> .Z >>> Ս�Աb�dg�SZ�https://raw.github.com/gist/3331641/2f7e80bd03abfb728b659634d3f4bac0131f4d6a/gistfile1.txt >>> php -i: >>> >>> https://raw.github.com/gist/3331651/bcf6e3654bf391482627505447848de173d0bbab/gistfile1.txt >>> >>> Does anyone have an idea what could cause this, or how to further debug? >> >> >> I can't really speak to your specific problem (unless you're using two >> different instances of the class), just thought I'd clear up the difference >> between class variables and instance variables. >> >> Cheers, >> Rob. >> -- >> E-Mail Disclaimer: Information contained in this message and any >> attached documents is considered confidential and legally protected. >> This message is intended solely for the addressee(s). Disclosure, >> copying, and distribution are prohibited unless authorized.