-module(timer1).

-export([tc/4, tc/5]).


tc(N, M, F, A) when N > 0 ->
    tc(N, M, F, A, false).

tc(N, M, F, A, Do_acc) when N > 0, is_boolean(Do_acc) ->
    Pid = spawn_opt(fun() ->
			    if Do_acc ->
				    exit(call_acc(N, M, F, A,
						  erlang:now(), []));
			       true ->
				    exit(call(N, M, F, A, erlang:now()))
			    end
		    end, [{min_heap_size, 10000}]),
    MRef = erlang:monitor(process, Pid),
    receive
	{'DOWN', MRef, process, _, Result} ->
	    Result
    end.

call(1, M, F, A, Start) ->
    Res = (catch apply(M, F, A)),
    Stop = erlang:now(),
    {timer:now_diff(Stop, Start), Res};
call(N, M, F, A, St) when N > 0 ->
    catch apply(M, F, A),
    call(N-1, M, F, A, St).

call_acc(N, M, F, A, St, Acc) when N > 0 ->
    call_acc(N-1, M, F, A, St, [catch apply(M, F, A)|Acc]);
call_acc(0, _, _, _, Start, Acc) ->
    Stop = erlang:now(),
    {timer:now_diff(Stop, Start), lists:reverse(Acc)}.