Bug #72517 [Csd->Fbk]: file_exists(), is_file() and stat() report wrong result infrequently (~1%)

Edit report at https://bugs.php.net/bug.php?id=72517&edit=1 ID: 72517 Updated by: requinix@php.net Reported by: stgrein at gmail dot com Summary: file_exists(), is_file() and stat() report wrong result infrequently (~1%) -Status: Closed +Status: Feedback Type: Bug Package: Filesystem function related Operating System: Windows PHP Version: 7.0.8 Block user comment: N Private report: N New Comment: Try a similar test with Apache: /test.php: <?php var_dump(file_exists('/this/file/exists')); /loop.php: <?php $c = 0; for ($i=1; $i<=10000; $i++) { if (strpos(file_get_contents("http://localhost/test.php"), "true")) $c++; } echo $c, "/10000"; Previous Comments: ------------------------------------------------------------------------ [2016-07-12 14:01:11] stgrein at gmail dot com Sorry for the late reply. In the CLI the problem does not occur. There I get the 10000 as response for your test case. It occurs only with the php7apache2_4.dll (Apache x64 2.4.20, PHP 7.08 x64 Windows) I cannto re-open the bug: ERROR: You aren't allowed to change a bug to that state ------------------------------------------------------------------------ [2016-07-10 04:22:40] php-bugs at lists dot php dot net No feedback was provided. The bug is being suspended because we assume that you are no longer experiencing the problem. If this is not the case and you are able to provide the information that was requested earlier, please do so and change the status of the bug back to "Re-Opened". Thank you. ------------------------------------------------------------------------ [2016-06-30 07:50:05] requinix@php.net Here's a cmd command to repeat the test 10k times: (for /l %i in (1,1,10000) do php -r "var_dump(file_exists('/this/file/exists'));") | find /c "true" Naturally it needs to be run from where you have PHP installed (or give the path to php.exe) and you need to change the /this/file/exists path. If you run that, does it show 10000 or something less? What if the system and/or disk is under load? Also, if you're getting this behavior with regular PHP code, are you potentially creating that file first? Because PHP will cache stat information during execution; if you are creating the file then use clearstatcache() before re-testing for the presence of the file. http://php.net/manual/en/function.clearstatcache.php Also, testing with PHP 5.5 or 5.6 would be appreciated. ------------------------------------------------------------------------ [2016-06-29 20:10:28] stgrein at gmail dot com Additional information: I used the VC14 x64 Thread Safe build from windows.php.net ------------------------------------------------------------------------ [2016-06-29 20:08:20] stgrein at gmail dot com Description: ------------ Hi, functions which check if a file exists do report wrong results sometimes. I did not find a special pattern, but maybe higher load is triggering it more. The chance on my machine is around ~1% to hit the bug per function call. I am using PHP v7.0.8 now but also had this bug on PHP v7.0.7. I did not test with earlier Versions. Test script: --------------- <?php //check an existing file $a = file_exists("/this/file/exists"); if($a === true) { echo "File exists!"; //expected } else { echo "File does NOT exists!"; //bug hit } //expected output: //File exists! //chance to get this output is around 1% on my machine under load //File does NOT exists! ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=72517&edit=1