struct timeval {
    ULONG tv_secs;
    ULONG tv_micro;
};

struct timerequest {
    struct IORequest tr_node;
    struct timeval tr_time;
};

struct timerequest *create_timer(ULONG unit)
{
	LONG error;
	struct MsgPort *timerport;
	struct timerequest *TimerIO;

	timerport = CreatePort(0, 0);
	if (timerport == NULL)
	{
		return(NULL);
	}

	TimerIO = (struct timerequest *) CreateExtIO(timerport, sizeof(struct timerequest));
	if (TimerIO == NULL)
	{
		DeletePort(timerport);
		return(NULL);
	}

	error = OpenDevice(TIMERNAME, unit, (struct IORequest *) TimerIO, 0L);
	if (error != 0)
	{
		delete_timer(TimerIO);
		return(NULL);
	}
	return( TimerIO );
}

void wait_for_timer(struct timerequest *tr, struct timeval *tv)
{
	tr->tr_node.io_Command = TR_ADDREQUEST;
	tr->tr_time = *tv;
	DoIO((struct IORequest *) tr);
}

void delete_timer(struct timerequest *tr )
{
	struct MsgPort *tp;

	if (tr != 0 )
	{
		tp = tr->tr_node.io_Message.mn_ReplyPort;

		if (tp != 0)
		{
			DeletePort(tp);
		}

		CloseDevice( (struct IORequest *) tr);
		DeleteExtIO( (struct IORequest *) tr);
	}
}

LONG time_delay(struct timeval *tv, LONG unit)
{
	struct timerequest *tr;

	tr = create_timer(unit);
	if (tr == NULL)
	{
		return(-1L);
	}
	wait_for_timer(tr, tv);

	delete_timer(tr);
	return (0L);
}

type

	ttimeval = packed record
		tv_secs: longword;
		tv_micro: longword;
	end;
	ptimeval = ^ttimeval;

	ttimerequest = packed record
		tr_node: tiorequest;
		tr_time: ttimeval;
	end;
	ptimerequest = ^ttimerequest;

function create_timer(_unit: longword): pttimerequest;
var
	error: longint;
	timerport: pmessageport;
	timerio: ptimerequest;
begin
	timerport := createport(0, 0);
	if (timerport = nil) then
	begin
		create_timer := nil;
		exit
	end;
	
	timerio := ptimerequest(createextio(timerport, sizeof(ttimerequest)));
	if (timerio = nil) then
	begin
		deleteport(timerport);
		create_timer := nil;
		exit;
	end;

	error := opendevice('timer.device', _unit, piorequest(timerio), 0);
	if (error <> 0) then
	begin
		delete_timer(timerio);
		create_timer := nil;
		exit;
	end;
	create_timer := timerio;
end;

procedure wait_for_timer(tr: ptimerequest; tv: ptimeval);
begin
	tr.tr_node.io := 9;
	tr.tr_time := tv^;
	doio(piorequest(tr));
end;

procedure delete_timer(tr: ptimerequest);
var tp: pmsgport;
begin
	if (tr <> nil) then
	begin
		tp := tr.tr_node.io_message.mn_replyport;
		if (tp <> nil) then
		begin
			deleteport(tp);
		end;
		closedevice(piorequest(tr));
		deleteextio(piorequest(tr));
	end;
end;


function time_delay(tv: ptimeval, _unit: longword): longint;
var tr: ptimerequest;
begin
	tr := create_timer(_unit);
	if (tr = nil) then
	begin
		time_delay := -1;
		exit;
	end;
	wait_for_timer(tr, tv);

	delete_timer(tr);
	time_delay := 0;
end;