implement Alm;
include "sys.m";
	sys : Sys;

include "alarm.m";

Alarm.stop(a : self Alarm) 
{
	a.alchan <-= -1;
	fd:=sys->open("#p/"+string a.pid+"/ctl",sys->OWRITE);
	sys->fprint(fd, "killgrp");
}

Alarm.alarm(time : int) : Alarm{
	sys = load Sys Sys->PATH;
	pid:=sys->pctl(sys->NEWPGRP|sys->FORKNS,nil);
	a:=Alarm(chan of int,pid);
	spawn listener(a.alchan);
	spawn sleeper(a.alchan,time,pid);
	return a;
}
	
sleeper(ch : chan of int,time,pid:int){
	sys->sleep(time);
	alt{
		ch <-= pid =>
			;
		* =>
			exit;
	}
}

listener(ch: chan of int){
	a := <-ch;
	if (a==-1){
		exit;
	}
	fd:=sys->open("#p/"+string a+"/ctl",sys->OWRITE);
	sys->fprint(fd, "killgrp");
}