Two click at the same time
<p>How to prevent the calling of two function if the user press two UIButton at the same time?</p>

<p>Suppose to connect two IBAction to two UIButton.
If the user press simultaneously both print are called.
Is that a code not thread safe?</p>

<pre><code>@IBAction func firstAction(sender: AnyObject) {
print("first")
}
@IBAction func secondAction(sender: AnyObject) {
print("second")
}
</code></pre>