There are three different methods for attaching a timer to an event-handling method or function: TimerAt, TimerAfter, and TimerEvery. They use the Gamma functions at, after, and every respectively. For example:

method Application.TimerEvery (seconds, fn)
{
    local    tid = every (seconds, fn);
    ._TimerIDs = cons (tid, ._TimerIDs);
    tid;
}

This is a wrapper on the Gamma every function. It creates a timer ID and adds it to the class's list of timer IDs (_TimerIDs). This way the timer can be identified and removed when necessary.

method Application.RemoveTimer(tid)
{
    if (find_equal (tid, ._TimerIDs))
    {
        cancel (tid);
        .droptimer (tid);
    }
}

This method uses the Gamma find_equal function to locate a timer according to its ID number (tid), and then uses the Gamma cancel function to cancel it.

	Timers created using TimerAt, TimerAfter, and TimerEvery are automatically cancelled when the Application instance is destroyed.