code: public void unlock() {
  
  		// do nothing when lock disabled
  
  		if (disabled.get()) {
  			return;
  		}
  
  		if (!locked.compareAndSet(true, false)) {
  			return;
  		}
  
  		LOG.debug("Unlock {}", webcam);
  
  		updater.interrupt();
  
  		write(-1);
  
  		if (!lock.delete()) {
  			lock.deleteOnExit();
  		}
  	}
docs: Unlock webcam.