When a browser sends many requests for image conversion concurrently (e.g. an image gallery is loaded) and the destination directory does not exist, every request tries to create the directory, which ends up with CreateDestinationFolderException because of a race condition.
So instead of
if (! is_dir($dir) && ! mkdir($dir, 0777, true)) {
throw new CreateDestinationFolderException();
}
the following should be used:
if (! is_dir($dir) && ! mkdir($dir, 0777, true) && ! is_dir($dir)) {
throw new CreateDestinationFolderException();
}
When a browser sends many requests for image conversion concurrently (e.g. an image gallery is loaded) and the destination directory does not exist, every request tries to create the directory, which ends up with
CreateDestinationFolderExceptionbecause of a race condition.So instead of
the following should be used:
(code is simplified)
More info about this issue:
https://www.google.com/search?q=php+mkdir+race+condition https://bugs.php.net/bug.php?id=35326 https://stackoverflow.com/questions/44322783/is-is-dir-unreliable-or-are-there-race-conditions-that-can-be-mitigated-here/57939677#57939677 https://app.bountysource.com/issues/49427500-mkdir-race-condition-enhancement https://github.com/symfony/symfony/issues/11626