This method returns TRUE on custom wrappers by default if you don't implement the stream_lock() method inside the wrapper : http://php.net/manual/en/streamwrapper.stream-lock.php
(PHP 5 >= 5.3.0, PHP 7)
stream_supports_lock — Tells whether the stream supports locking.
$stream
)Tells whether the stream supports locking through flock().
streamThe stream to check.
Returns TRUE on success or FALSE on failure.
This method returns TRUE on custom wrappers by default if you don't implement the stream_lock() method inside the wrapper : http://php.net/manual/en/streamwrapper.stream-lock.php
stream_supports_lock() always returns TRUE on custom wrappers.