A simple timer class is defined in ~ns/tcl/mcast/timer.tcl. Subclasses of Timer can be defined as needed. Unlike the C++ timer API, where a []sched aborts if the timer is already set, []sched and []resched are the same; i.e., no state is kept for the OTcl timers. The following methods are defined in the Timer base class:
$self sched $delay # causes "$self timeout" to be called $delay seconds in the future;
$self resched $delay # same as "$self sched $delay" ;
$self cancel # cancels any pending scheduled callback;
$self destroy # same as "$self cancel";
$self expire # calls "$self timeout" immediately;