Err TimerCancel (TimerHandle thandle)
If an event had occurred for this timer and a notification message was sent, this function withdraws the notification message from your port. If you had already received the message but not yet replied to it, the timers resources are released after you reply to the message, in other words, you can respond to a timer event message by cancelling the timer that sent the message, and you can safely do so before replying to the message.
If the timer notification was signal-based and a notification signal was sent, you will still receive it since there is no way to withdraw a signal once it has been sent.
TimerSuspend