flock
flock
(PHP 4, PHP 5, PHP 7)
flock — Portable advisory file locking
Description
bool flock ( resource $handle , int $operation [, int &$wouldblock ] )
flock() allows you to perform a simple reader/writer model which can be used on virtually every platform (including most Unix derivatives and even Windows).
On versions of PHP before 5.3.2, the lock is released also by fclose() (which is also called automatically when script finished).
PHP support