includes/class-fs-user-lock.php
function try_lock( $expiration = 0 ) {
            if ( $this->is_locked() ) {
                // Already locked.
                return false;
            }

            set_site_transient( "locked_{$this->_wp_user_id}", $this->_thread_id, $expiration );

            if ( $this->has_lock() ) {
                set_site_transient( "locked_{$this->_wp_user_id}", true, $expiration );

                return true;
            }

            return false;
        }
function try_lock( $expiration = 0 ) {
            if ( $this->is_locked() ) {
                // Already locked.
                return false;
            }

            set_site_transient( "locked_{$this->_wp_user_id}", $this->_thread_id, $expiration );

            if ( $this->has_lock() ) {
                set_site_transient( "locked_{$this->_wp_user_id}", true, $expiration );

                return true;
            }

            return false;
        }
function try_lock ( $ expiration = 0 ) { if ( $ this -> is_locked ( ) ) { // Already locked. return false ; } set_site_transient ( "locked_{$this->_wp_user_id}" , $ this -> _thread_id , $ expiration ) ; if ( $ this -> has_lock ( ) ) { set_site_transient ( "locked_{$this->_wp_user_id}" , true , $ expiration ) ; return true ; } return false ; }
Try to acquire lock. If the lock is already set or is being acquired by another locker, don't do anything.

@author Vova Feldman (@svovaf)
@since  2.1.0

@param int $expiration

@return bool TRUE if successfully acquired lock.
Try to acquire lock . If the lock is already set or is being acquired by another locker don t do anything .