Usage of cakePHP updateAll(): Possible to know where the $condition are met or not?

Question

I use cakephp updateAll() with $conditions to update database records for example:

$this->stock->updateAll(
    array('stock.qty' => 'stock.qty+'.$difference),
    array('stock.qty' => $bufferedQty)
);

My target: "array('stock.qty' => $bufferedQty)" is the condition have to be met for updating the database. I use this condition to make sure the current process is holding the latest record for updating, that to prevent double update error.

My problem Though I can prevent double update, updateAll() won't report if the "array('stock.qty' => $bufferedQty)" is met or not. I want to reply error if the condition is not met.

Is it possible know the condition met or not? Or any other better function I can choose?

Thanks!