void
qtimer_start (qtimer_t timer);
void
qtimer_stop (qtimer_t timer);
Before using these functions, the timer must have been initialized with qtimer_create() and must not have been destroyed with qtimer_destroy().
In general, timers should not be started multiple times in a row without an intervening stop, nor should they be stopped multiple times in a row without an intervening start, though in most cases this will not cause an error, but will just behave as a "last operation wins". Timers should also be started before they are stopped, though in most cases this will not cause an error, but will instead cause the value of qtimer_secs() to be undefined. However, the safety of mis-using qtimers is not guaranteed.