get gpio time push button

I need to make sure that one of the buttons on the cc3200 launchpad is pressed for a certain time interval, for accuracy 1 millisecond, in order to be sure that the button has been pressed. How would it be possible to realize such a check? To capture the interruption given by pressing buttons SW2 and SW3 on the launchpad I used the example email that comes the falling edge of the button is released.
you can then check that the button is pressed for a time?
I thought that you might set in this way

MAP_GPIOIntTypeSet (GPIOA2_BASE, GPIO_PIN_6, GPIO_BOTH_EDGES);

and in the handler management interruption check the status of GPIO corresponding to the button, if high, it means that the button is pressed and then start a timer after a millisecond raises a control variable to 1, and then later on the falling edge the button you go to check the status of this variable and make the desired operation.

How would you suggest to do such a thing?