src/FSLock.php
public function acquire(bool $blocker = false): bool
    {
        if (!is_resource($this->lock)) {
            return false;
        }

        return flock($this->lock, ($blocker) ? LOCK_EX : LOCK_EX | LOCK_NB);
    }
public function acquire(bool $blocker = false): bool
    {
        if (!is_resource($this->lock)) {
            return false;
        }

        return flock($this->lock, ($blocker) ? LOCK_EX : LOCK_EX | LOCK_NB);
    }
public function acquire ( bool $ blocker = false ) : bool { if ( ! is_resource ( $ this -> lock ) ) { return false ; } return flock ( $ this -> lock , ( $ blocker ) ? LOCK_EX : LOCK_EX | LOCK_NB ) ; }
Acquires the lock.

@param bool $blocker if the lock is acquire by other process before,
and we call acquire as blocker, this call blocks
after previous acquire release the lock

@return bool
Acquires the lock .