gistfile1.java

    public synchronized void cancel(Runnable task) {
        SchedulerTimerTask ticket = timerTasks.remove(task);
        if (ticket != null) {
            ticket.cancel();
            // now clear the ticket so we can remove the reference to the
            // underlying task.  This is necessary to allow GC to take effect.
            // Otherwise the Runnable will still have a reference and hog
            // memory.
            ticket.clear();
        }
    }