Introduce a new time API

The old time API is based on erlang:now/0. The major issue with
erlang:now/0 is that it was intended to be used for so many
unrelated things. This tied these unrelated operations together
and unnecessarily caused performance, scalability as well as
accuracy, and precision issues for operations that do not need
to have such issues. The new API spreads different functionality
over multiple functions in order to improve on this.

The new API consists of a number of new BIFs:
- erlang:convert_time_unit/3
- erlang:monotonic_time/0
- erlang:monotonic_time/1
- erlang:system_time/0
- erlang:system_time/1
- erlang:time_offset/0
- erlang:time_offset/1
- erlang:timestamp/0
- erlang:unique_integer/0
- erlang:unique_integer/1
- os:system_time/0
- os:system_time/1

and a number of extensions of existing BIFs:
- erlang:monitor(time_offset, clock_service)
- erlang:system_flag(time_offset, finalize)
- erlang:system_info(os_monotonic_time_source)
- erlang:system_info(time_offset)
- erlang:system_info(time_warp_mode)
- erlang:system_info(time_correction)
- erlang:system_info(start_time)

See the "Time and Time Correction in Erlang" chapter of the
ERTS User's Guide for more information.

5 files changed, 970 insertions, 37 deletions

diff --git a/erts/emulator/test/Makefile b/erts/emulator/test/Makefile
index dfbe47786a..dd2e2cb504 100644
--- a/erts/emulator/test/Makefile
+++ b/erts/emulator/test/Makefile
@@ -108,6 +108,7 @@ MODULES= \
 	trace_call_time_SUITE \
 	scheduler_SUITE \
 	old_scheduler_SUITE \
+	unique_SUITE \
 	z_SUITE \
 	old_mod \
 	long_timers_test \
diff --git a/erts/emulator/test/long_timers_test.erl b/erts/emulator/test/long_timers_test.erl
index 28a4fba9f6..f381332b51 100644
--- a/erts/emulator/test/long_timers_test.erl
+++ b/erts/emulator/test/long_timers_test.erl
@@ -28,7 +28,7 @@
 
 
 -define(MAX_TIMEOUT, 60). % Minutes
--define(MAX_LATE, 10*1000). % Milliseconds
+-define(MAX_LATE_MS, 10*1000). % Milliseconds
 -define(REG_NAME, '___LONG___TIMERS___TEST___SERVER___').
 
 -define(DRV_NAME, timer_driver).
@@ -75,7 +75,7 @@ check_result() ->
 	    erlang:demonitor(Mon),
 	    receive {'DOWN', Mon, _, _, _} -> ok after 0 -> ok end,
 	    stop_node(Node),
-	    check(TORs, (timer:now_diff(End, Start) div 1000) - ?MAX_LATE, ok)
+	    check(TORs, ms((End - Start) - max_late()), ok)
     end.
 
 check([#timeout_rec{timeout = Timeout,
@@ -83,7 +83,7 @@ check([#timeout_rec{timeout = Timeout,
 		    timeout_diff = undefined} | TORs],
       NeedRes,
       _Ok) when Timeout < NeedRes ->
-    io:format("~p timeout = ~p failed! No timeout.~n",
+    io:format("~p timeout = ~p ms failed! No timeout.~n",
 	      [Type, Timeout]),
     check(TORs, NeedRes, failed);
 check([#timeout_rec{timeout_diff = undefined} | TORs],
@@ -95,7 +95,7 @@ check([#timeout_rec{timeout = Timeout,
 		    timeout_diff = {error, Reason}} | TORs],
       NeedRes,
       _Ok) ->
-    io:format("~p timeout = ~p failed! exit reason ~p~n",
+    io:format("~p timeout = ~p ms failed! exit reason ~p~n",
 	      [Type, Timeout, Reason]),
     check(TORs, NeedRes, failed);
 check([#timeout_rec{timeout = Timeout,
@@ -103,43 +103,77 @@ check([#timeout_rec{timeout = Timeout,
 		    timeout_diff = TimeoutDiff} | TORs],
       NeedRes,
       Ok) ->
-    case (0 =< TimeoutDiff) and (TimeoutDiff =< ?MAX_LATE) of
-	true ->
-	    io:format("~p timeout = ~p succeded! timeout diff = ~p.~n",
-		      [Type, Timeout, TimeoutDiff]),
-	    check(TORs, NeedRes, Ok);
-	false ->
-	    io:format("~p timeout = ~p failed! timeout diff = ~p.~n",
-		      [Type, Timeout, TimeoutDiff]),
-	    check(TORs, NeedRes, failed)
-    end;
+    {NewOk, SuccessStr} = case ((0 =< TimeoutDiff)
+				andalso (TimeoutDiff =< max_late())) of
+			      true -> {Ok, "succeeded"};
+			      false -> {failed, "FAILED"}
+			  end,
+    io:format("~s timeout = ~s ms ~s! timeout diff = ~s.~n",
+	      [type_str(Type),
+	       time_str(Timeout),
+	       SuccessStr,
+	       time_str(TimeoutDiff, erlang:convert_time_unit(1, seconds, native))]),
+    check(TORs, NeedRes, NewOk);
 check([], _NeedRes, Ok) ->
     Ok.
 
+type_str(receive_after) -> "receive ... after";
+type_str(bif_timer) -> "BIF timer";
+type_str(driver) -> "driver".
+
+time_str(Time, Unit) ->
+    lists:flatten([time_str(Time), " ", unit_str(Unit)]).
+
+time_str(Time) ->
+    lists:reverse(conv_time_str(lists:reverse(integer_to_list(Time)))).
+
+conv_time_str([X,Y,Z,C|Cs]) when C /= $- ->
+    [X,Y,Z,$`|conv_time_str([C|Cs])];
+conv_time_str(Cs) ->
+    Cs.
+
+unit_str(1) -> "s";
+unit_str(1000) -> "ms";
+unit_str(1000000) -> "us";
+unit_str(1000000000) -> "ns";
+unit_str(Res) when is_integer(Res) -> ["/ ", integer_to_list(Res), " s"];
+unit_str(Res) -> Res.
+
+to_diff(Timeout, Start, Stop) ->
+    %% 'Timeout' in milli seconds
+    %% 'Start', 'Stop', and result in native unit
+    (Stop - Start) - erlang:convert_time_unit(Timeout, milli_seconds, native).
+
+ms(Time) ->
+    erlang:convert_time_unit(Time, native, milli_seconds).
+
+max_late() ->
+    erlang:convert_time_unit(?MAX_LATE_MS, milli_seconds, native).
+
 receive_after(Timeout) ->
-    Start = now(),
+    Start = erlang:monotonic_time(),
     receive
 	{get_result, ?REG_NAME} ->
 	    ?REG_NAME ! #timeout_rec{pid = self(),
 				     type = receive_after,
 				     timeout = Timeout}
     after Timeout ->
-	    Stop = now(),
+	    Stop = erlang:monotonic_time(),
 	    receive
 		{get_result, ?REG_NAME} ->
-	    	    TimeoutDiff = ((timer:now_diff(Stop, Start) div 1000)
-				   - Timeout),
 		    ?REG_NAME ! #timeout_rec{pid = self(),
 					     type = receive_after,
 					     timeout = Timeout,
-					     timeout_diff = TimeoutDiff}
+					     timeout_diff = to_diff(Timeout,
+								    Start,
+								    Stop)}
 	    end
     end.
 
 driver(Timeout) ->
     Port = open_port({spawn, ?DRV_NAME},[]),
     link(Port),
-    Start = now(),
+    Start = erlang:monotonic_time(),
     erlang:port_command(Port, <<?START_TIMER, Timeout:32>>),
     receive
 	{get_result, ?REG_NAME} ->
@@ -147,38 +181,38 @@ driver(Timeout) ->
 				     type = driver,
 				     timeout = Timeout};
 	{Port,{data,[?TIMER]}} ->
-	    Stop = now(),
+	    Stop = erlang:monotonic_time(),
 	    unlink(Port),
 	    true = erlang:port_close(Port),
 	    receive
 		{get_result, ?REG_NAME} ->
-	    	    TimeoutDiff = ((timer:now_diff(Stop, Start) div 1000)
-				   - Timeout),
 		    ?REG_NAME ! #timeout_rec{pid = self(),
 					     type = driver,
 					     timeout = Timeout,
-					     timeout_diff = TimeoutDiff}
+					     timeout_diff = to_diff(Timeout,
+								    Start,
+								    Stop)}
 	    end
     end.
 
 bif_timer(Timeout) ->
     Tmr = erlang:start_timer(Timeout, self(), ok),
-    Start = now(),
+    Start = erlang:monotonic_time(),
     receive
 	{get_result, ?REG_NAME} ->
 	    ?REG_NAME ! #timeout_rec{pid = self(),
 				     type = bif_timer,
 				     timeout = Timeout};
 	{timeout, Tmr, ok} ->
-	    Stop = now(),
+	    Stop = erlang:monotonic_time(),
 	    receive
 		{get_result, ?REG_NAME} ->
-	    	    TimeoutDiff = ((timer:now_diff(Stop, Start) div 1000)
-				   - Timeout),
 		    ?REG_NAME ! #timeout_rec{pid = self(),
 					     type = bif_timer,
 					     timeout = Timeout,
-					     timeout_diff = TimeoutDiff}
+					     timeout_diff = to_diff(Timeout,
+								    Start,
+								    Stop)}
 	    end
     end.
 
@@ -189,7 +223,7 @@ test(Starter, DrvDir, StartDone) ->
     register(?REG_NAME, self()),
     {group_leader, GL} = process_info(whereis(net_kernel),group_leader),
     group_leader(GL, self()),
-    Start = now(),
+    Start = erlang:monotonic_time(),
     TORs = lists:map(fun (Min) ->
 			     TO = Min*60*1000,
 			     [#timeout_rec{pid = spawn_opt(
@@ -222,7 +256,7 @@ test(Starter, DrvDir, StartDone) ->
 test_loop(TORs, Start) ->
     receive
 	{get_result, ?REG_NAME, Pid} ->
-	    End = now(),
+	    End = erlang:monotonic_time(),
 	    Pid ! {result, ?REG_NAME, get_test_results(TORs), Start, End},
 	    erl_ddll:unload_driver(?DRV_NAME),
 	    erl_ddll:stop(),
diff --git a/erts/emulator/test/monitor_SUITE.erl b/erts/emulator/test/monitor_SUITE.erl
index aec59867d8..07e2862b2a 100644
--- a/erts/emulator/test/monitor_SUITE.erl
+++ b/erts/emulator/test/monitor_SUITE.erl
@@ -26,7 +26,8 @@
 	 case_1/1, case_1a/1, case_2/1, case_2a/1, mon_e_1/1, demon_e_1/1, demon_1/1,
 	 demon_2/1, demon_3/1, demonitor_flush/1,
 	 local_remove_monitor/1, remote_remove_monitor/1, mon_1/1, mon_2/1,
-	 large_exit/1, list_cleanup/1, mixer/1, named_down/1, otp_5827/1]).
+	 large_exit/1, list_cleanup/1, mixer/1, named_down/1, otp_5827/1,
+	 monitor_time_offset/1]).
 
 -export([init_per_testcase/2, end_per_testcase/2]).
 
@@ -38,7 +39,8 @@ all() ->
     [case_1, case_1a, case_2, case_2a, mon_e_1, demon_e_1,
      demon_1, mon_1, mon_2, demon_2, demon_3,
      demonitor_flush, {group, remove_monitor}, large_exit,
-     list_cleanup, mixer, named_down, otp_5827].
+     list_cleanup, mixer, named_down, otp_5827,
+     monitor_time_offset].
 
 groups() -> 
     [{remove_monitor, [],
@@ -59,7 +61,7 @@ end_per_group(_GroupName, Config) ->
 
 init_per_testcase(Func, Config) when is_atom(Func), is_list(Config) ->
     Dog=?t:timetrap(?t:minutes(15)),
-    [{watchdog, Dog}|Config].
+    [{watchdog, Dog},{testcase, Func}|Config].
 
 end_per_testcase(_Func, Config) ->
     Dog=?config(watchdog, Config),
@@ -837,6 +839,89 @@ otp_5827(Config) when is_list(Config) ->
 		  ?line ?t:fail("erlang:monitor/2 hangs")
 	  end.
 
+monitor_time_offset(Config) when is_list(Config) ->
+    {ok, Node} = start_node(Config, "+C single_time_warp"),
+    Me = self(),
+    PMs = lists:map(fun (_) ->
+			    Pid = spawn(Node,
+					fun () ->
+						check_monitor_time_offset(Me)
+					end),
+			    {Pid, erlang:monitor(process, Pid)}
+		    end,
+		    lists:seq(1, 100)),
+    lists:foreach(fun ({P, _M}) ->
+			  P ! check_no_change_message
+		  end, PMs),
+    lists:foreach(fun ({P, M}) ->
+			  receive
+			      {no_change_message_received, P} ->
+				  ok;
+			      {'DOWN', M, process, P, Reason} ->
+				  ?t:fail(Reason)
+			  end
+		  end, PMs),
+    preliminary = rpc:call(Node, erlang, system_flag, [time_offset, finalize]),
+    lists:foreach(fun ({P, M}) ->
+			  receive
+			      {change_messages_received, P} ->
+				  erlang:demonitor(M, [flush]);
+			      {'DOWN', M, process, P, Reason} ->
+				  ?t:fail(Reason)
+			  end
+		  end, PMs),
+    stop_node(Node),
+    ok.
+
+check_monitor_time_offset(Leader) ->
+    Mon1 = erlang:monitor(time_offset, clock_service),
+    Mon2 = erlang:monitor(time_offset, clock_service),
+    Mon3 = erlang:monitor(time_offset, clock_service),
+    Mon4 = erlang:monitor(time_offset, clock_service),
+
+    erlang:demonitor(Mon2, [flush]),
+    
+    Mon5 = erlang:monitor(time_offset, clock_service),
+    Mon6 = erlang:monitor(time_offset, clock_service),
+    Mon7 = erlang:monitor(time_offset, clock_service),
+
+    receive check_no_change_message -> ok end,
+    receive
+	{'CHANGE', _, time_offset, clock_service, _} ->
+	    exit(unexpected_change_message_received)
+    after 0 ->
+	    Leader ! {no_change_message_received, self()}
+    end,
+    receive after 100 -> ok end,
+    erlang:demonitor(Mon4, [flush]),
+    receive
+	{'CHANGE', Mon3, time_offset, clock_service, _} ->
+	    ok
+    end,
+    receive
+	{'CHANGE', Mon6, time_offset, clock_service, _} ->
+	    ok
+    end,
+    erlang:demonitor(Mon5, [flush]),
+    receive
+	{'CHANGE', Mon7, time_offset, clock_service, _} ->
+	    ok
+    end,
+    receive
+	{'CHANGE', Mon1, time_offset, clock_service, _} ->
+	    ok
+    end,
+    receive
+	{'CHANGE', _, time_offset, clock_service, _} ->
+	    exit(unexpected_change_message_received)
+    after 1000 ->
+	    ok
+    end,
+    Leader ! {change_messages_received, self()}.
+
+%%
+%% ...
+%%
 
 wait_for_m(_,_,0) ->
     exit(monitor_wait_timeout);
@@ -959,3 +1044,25 @@ generate(_Fun, 0) ->
     [];
 generate(Fun, N) ->
     [Fun() | generate(Fun, N-1)].
+
+start_node(Config) ->
+    start_node(Config, "").
+
+start_node(Config, Args) ->
+    TestCase = ?config(testcase, Config),
+    PA = filename:dirname(code:which(?MODULE)),
+    ESTime = erlang:monotonic_time(1) + erlang:time_offset(1),
+    Unique = erlang:unique_integer([positive]),
+    Name = list_to_atom(atom_to_list(?MODULE)
+			++ "-"
+			++ atom_to_list(TestCase)
+			++ "-"
+			++ integer_to_list(ESTime)
+			++ "-"
+			++ integer_to_list(Unique)),
+    test_server:start_node(Name,
+			   slave,
+			   [{args, "-pa " ++ PA ++ " " ++ Args}]).
+
+stop_node(Node) ->
+    test_server:stop_node(Node).
diff --git a/erts/emulator/test/time_SUITE.erl b/erts/emulator/test/time_SUITE.erl
index a0a8a9c42c..43f7ac7f7c 100644
--- a/erts/emulator/test/time_SUITE.erl
+++ b/erts/emulator/test/time_SUITE.erl
@@ -34,7 +34,14 @@
 	 bad_univ_to_local/1, bad_local_to_univ/1,
 	 univ_to_seconds/1, seconds_to_univ/1,
 	 consistency/1,
-	 now_unique/1, now_update/1, timestamp/1]).
+	 now_unique/1, now_update/1, timestamp/1,
+	 time_warp_modes/1,
+	 monotonic_time_monotonicity/1,
+	 time_unit_conversion/1,
+	 signed_time_unit_conversion/1,
+	 erlang_timestamp/1]).
+
+-export([init_per_testcase/2, end_per_testcase/2]).
 
 -export([local_to_univ_utc/1]).
 
@@ -56,6 +63,12 @@
 
 -define(dst_timezone, 2).
 
+init_per_testcase(Func, Config) when is_atom(Func), is_list(Config) ->
+    [{testcase, Func}|Config].
+
+end_per_testcase(_Func, Config) ->
+    ok.
+
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
 all() -> 
@@ -63,7 +76,12 @@ all() ->
      bad_univ_to_local, bad_local_to_univ, 
      univ_to_seconds, seconds_to_univ,
      consistency,
-     {group, now}, timestamp].
+     {group, now}, timestamp,
+     time_warp_modes,
+     monotonic_time_monotonicity,
+     time_unit_conversion,
+     signed_time_unit_conversion,
+     erlang_timestamp].
 
 groups() -> 
     [{now, [], [now_unique, now_update]}].
@@ -420,6 +438,368 @@ now_update1(N) when N > 0 ->
 now_update1(0) ->
     ?line test_server:fail().
 
+time_warp_modes(Config) when is_list(Config) ->
+    %% All time warp modes always supported in
+    %% combination with no time correction...
+    check_time_warp_mode(Config, false, no_time_warp),
+    check_time_warp_mode(Config, false, single_time_warp),
+    check_time_warp_mode(Config, false, multi_time_warp),
+
+    erts_debug:set_internal_state(available_internal_state, true),
+    try
+	case erts_debug:get_internal_state({check_time_config,
+					    true, no_time_warp}) of
+	    false -> ok;
+	    true -> check_time_warp_mode(Config, true, no_time_warp)
+	end,
+	case erts_debug:get_internal_state({check_time_config,
+					    true, single_time_warp}) of
+	    false -> ok;
+	    true -> check_time_warp_mode(Config, true, single_time_warp)
+	end,
+	case erts_debug:get_internal_state({check_time_config,
+					    true, multi_time_warp}) of
+	    false -> ok;
+	    true -> check_time_warp_mode(Config, true, multi_time_warp)
+	end
+    after
+	erts_debug:set_internal_state(available_internal_state, false)
+    end.
+
+check_time_warp_mode(Config, TimeCorrection, TimeWarpMode) ->
+    io:format("~n~n~n***** Testing TimeCorrection=~p TimeWarpMode=~p *****~n",
+	      [TimeCorrection, TimeWarpMode]),
+    Mon = erlang:monitor(time_offset, clock_service),
+    _ = erlang:time_offset(),
+    Start = erlang:monotonic_time(1000),
+    MonotonicityTimeout = 2000,
+    {ok, Node} = start_node(Config,
+			    "+c " ++ atom_to_list(TimeCorrection)
+			    ++ " +C " ++ atom_to_list(TimeWarpMode)),
+    StartTime = rpc:call(Node, erlang, system_info, [start_time]),
+    Me = self(),
+    MonotincityTestStarted = make_ref(),
+    MonotincityTestDone = make_ref(),
+    spawn_link(Node,
+	       fun () ->
+		       Me ! MonotincityTestStarted,
+		       cmp_times(erlang:start_timer(MonotonicityTimeout,
+						    self(),
+						    timeout),
+				 erlang:monotonic_time()),
+		       Me ! MonotincityTestDone
+	       end),
+    receive MonotincityTestStarted -> ok end,
+    check_time_offset(Node, TimeWarpMode),
+    TimeWarpMode = rpc:call(Node, erlang, system_info, [time_warp_mode]),
+    TimeCorrection = rpc:call(Node, erlang, system_info, [time_correction]),
+    receive MonotincityTestDone -> ok end,
+    MonotonicTime = rpc:call(Node, erlang, monotonic_time, []),
+    MonotonicTimeUnit = rpc:call(Node,
+				       erlang,
+				       convert_time_unit,
+				       [1, seconds, native]),
+    UpMilliSeconds = erlang:convert_time_unit(MonotonicTime - StartTime,
+					      MonotonicTimeUnit,
+					      milli_seconds),
+    io:format("UpMilliSeconds=~p~n", [UpMilliSeconds]),
+    End = erlang:monotonic_time(milli_seconds),
+    stop_node(Node),
+    try
+	true = (UpMilliSeconds > (98*MonotonicityTimeout) div 100),
+	true = (UpMilliSeconds < (102*(End-Start)) div 100)
+    catch
+	error:_ ->
+	    io:format("Uptime inconsistency", []),
+	    case {TimeCorrection, erlang:system_info(time_correction)} of
+		{true, true} ->
+		    ?t:fail(uptime_inconsistency);
+		{true, false} ->
+		    _ = erlang:time_offset(),
+		    receive
+			{'CHANGE', Mon, time_offset, clock_service, _} ->
+			    ignore
+		    after 1000 ->
+			    ?t:fail(uptime_inconsistency)
+		    end;
+		_ ->
+		    ignore
+	    end
+    end,
+    erlang:demonitor(Mon, [flush]),
+    ok.
+
+check_time_offset(Node, no_time_warp) ->
+    final = rpc:call(Node, erlang, system_info, [time_offset]),
+    final = rpc:call(Node, erlang, system_flag, [time_offset, finalize]),
+    final = rpc:call(Node, erlang, system_info, [time_offset]);
+check_time_offset(Node, single_time_warp) ->
+    preliminary = rpc:call(Node, erlang, system_info, [time_offset]),
+    preliminary = rpc:call(Node, erlang, system_flag, [time_offset, finalize]),
+    final = rpc:call(Node, erlang, system_info, [time_offset]),
+    final = rpc:call(Node, erlang, system_flag, [time_offset, finalize]);
+check_time_offset(Node, multi_time_warp) ->
+    volatile = rpc:call(Node, erlang, system_info, [time_offset]),
+    volatile = rpc:call(Node, erlang, system_flag, [time_offset, finalize]),
+    volatile = rpc:call(Node, erlang, system_info, [time_offset]).
+
+monotonic_time_monotonicity(Config) when is_list(Config) ->
+    Done = erlang:start_timer(10000,self(),timeout),
+    cmp_times(Done, erlang:monotonic_time()).
+
+cmp_times(Done, X0) ->
+    X1 = erlang:monotonic_time(),
+    X2 = erlang:monotonic_time(),
+    X3 = erlang:monotonic_time(),
+    X4 = erlang:monotonic_time(),
+    X5 = erlang:monotonic_time(),
+    true = (X0 =< X1),
+    true = (X1 =< X2),
+    true = (X2 =< X3),
+    true = (X3 =< X4),
+    true = (X4 =< X5),
+    receive
+	{timeout, Done, timeout} ->
+	    ok
+    after 0 ->
+	    cmp_times(Done, X5)
+    end.
+
+-define(CHK_RES_CONVS_TIMEOUT, 400).
+
+time_unit_conversion(Config) when is_list(Config) ->
+    Mon = erlang:monitor(time_offset, clock_service),
+    start_check_res_convs(Mon, 1000000000000),
+    start_check_res_convs(Mon, 2333333333333),
+    start_check_res_convs(Mon, 5732678356789),
+    erlang:demonitor(Mon, [flush]).
+    
+start_check_res_convs(Mon, Res) ->
+    io:format("Checking ~p time_unit~n", [Res]),
+    check_res_convs(Mon,
+		    erlang:start_timer(?CHK_RES_CONVS_TIMEOUT,
+				       self(),
+				       timeout),
+		    Res).
+    
+
+check_res_convs(Mon, Done, Res) ->
+    receive
+	{timeout, Done, timeout} ->
+	    case Res div 10 of
+		0 ->
+		    ok;
+		NewRes ->
+		    start_check_res_convs(Mon, NewRes)
+	    end
+    after 0 ->
+	    do_check_res_convs(Mon, Done, Res)
+    end.
+
+do_check_res_convs(Mon, Done, Res) ->
+    TStart = erlang:monotonic_time(),
+    T = erlang:monotonic_time(Res),
+    TEnd = erlang:monotonic_time(),
+    TMin = erlang:convert_time_unit(TStart, native, Res),
+    TMax = erlang:convert_time_unit(TEnd, native, Res),
+    %io:format("~p =< ~p =< ~p~n", [TMin, T, TEnd]),
+    true = (TMin =< T),
+    true = (TMax >= T),
+    check_time_offset_res_conv(Mon, Res),
+    check_res_convs(Mon, Done, Res).
+
+
+check_time_offset_res_conv(Mon, Res) ->
+    TORes = erlang:time_offset(Res),
+    TO = erlang:time_offset(),
+    case erlang:convert_time_unit(TO, native, Res) of
+	TORes ->
+	    ok;
+	TORes2 ->
+	    case check_time_offset_change(Mon, TO, 1000) of
+		{TO, false} ->
+		    ?t:fail({time_unit_conversion_inconsistency,
+			     TO, TORes, TORes2});
+		{_NewTO, true} ->
+		    ?t:format("time_offset changed", []),
+		    check_time_offset_res_conv(Mon, Res)
+	    end
+    end.
+
+signed_time_unit_conversion(Config) when is_list(Config) ->
+    chk_strc(1000000000, 1000000),
+    chk_strc(1000000000, 1000),
+    chk_strc(1000000000, 1),
+    chk_strc(1000000, 1000),
+    chk_strc(1000000, 1),
+    chk_strc(1000, 1),
+    chk_strc(4711, 17),
+    chk_strc(1 bsl 10, 1),
+    chk_strc(1 bsl 16, 10),
+    chk_strc(1 bsl 17, 1 bsl 8),
+    chk_strc((1 bsl 17) + 1, (1 bsl 8) - 1),
+    chk_strc(1 bsl 17, 11),
+    ok.
+
+chk_strc(Res0, Res1) ->
+    case (Res0 /= Res1) andalso (Res0 =< 1000000) andalso (Res1 =< 1000000) of
+	true ->
+	    {FromRes, ToRes} = case Res0 > Res1 of
+				   true -> {Res0, Res1};
+				   false -> {Res1, Res0}
+			       end,
+	    MinFromValuesPerToValue = FromRes div ToRes,
+	    MaxFromValuesPerToValue = ((FromRes-1) div ToRes)+1,
+	    io:format("~p -> ~p [~p, ~p]~n",
+		      [FromRes, ToRes,
+		       MinFromValuesPerToValue, MaxFromValuesPerToValue]),
+	    chk_values_per_value(FromRes, ToRes,
+				 -10*FromRes, 10*FromRes,
+				 MinFromValuesPerToValue,
+				 MaxFromValuesPerToValue,
+				 undefined, MinFromValuesPerToValue);
+	_ ->
+	    ok
+    end,
+    chk_random_values(Res0, Res1),
+    chk_random_values(Res1, Res0),
+    ok.
+
+chk_random_values(FR, TR) ->
+%    case (FR rem TR == 0) orelse (TR rem FR == 0) of
+%	true ->
+	    io:format("rand values ~p -> ~p~n", [FR, TR]),
+	    random:seed(268438039, 268440479, 268439161),
+	    Values = lists:map(fun (_) -> random:uniform(1 bsl 65) - (1 bsl 64) end,
+			       lists:seq(1, 100000)),
+	    CheckFun = fun (V) ->
+			       CV = erlang:convert_time_unit(V, FR, TR),
+			       case {(FR*CV) div TR =< V,
+				     (FR*(CV+1)) div TR >= V} of
+				   {true, true} ->
+				       ok;
+				   Failure ->
+				       ?t:fail({Failure, CV, V, FR, TR})
+			       end
+		       end,
+	    lists:foreach(CheckFun, Values).%;
+%	false -> ok
+%    end.
+		       
+
+chk_values_per_value(_FromRes, _ToRes,
+	 EndValue, EndValue,
+	 MinFromValuesPerToValue, MaxFromValuesPerToValue,
+	 _ToValue, FromValueCount) ->
+%    io:format("~p [~p]~n", [EndValue, FromValueCount]),
+    case ((MinFromValuesPerToValue =< FromValueCount)
+	  andalso (FromValueCount =< MaxFromValuesPerToValue)) of
+	false ->
+	    ?t:fail({MinFromValuesPerToValue,
+		     FromValueCount,
+		     MaxFromValuesPerToValue});
+	true ->
+	    ok
+    end;
+chk_values_per_value(FromRes, ToRes, Value, EndValue,
+		     MinFromValuesPerToValue, MaxFromValuesPerToValue,
+		     ToValue, FromValueCount) ->
+    case erlang:convert_time_unit(Value, FromRes, ToRes) of
+	ToValue ->
+	    chk_values_per_value(FromRes, ToRes,
+				 Value+1, EndValue,
+				 MinFromValuesPerToValue,
+				 MaxFromValuesPerToValue,
+				 ToValue, FromValueCount+1);
+	NewToValue ->
+	    case ((MinFromValuesPerToValue =< FromValueCount)
+		  andalso (FromValueCount =< MaxFromValuesPerToValue)) of
+		false ->
+		    ?t:fail({MinFromValuesPerToValue,
+			     FromValueCount,
+			     MaxFromValuesPerToValue});
+		true ->
+%		    io:format("~p -> ~p [~p]~n",
+%			      [Value, NewToValue, FromValueCount]),
+		    chk_values_per_value(FromRes, ToRes,
+					 Value+1, EndValue,
+					 MinFromValuesPerToValue,
+					 MaxFromValuesPerToValue,
+					 NewToValue, 1)
+	    end
+    end.
+
+erlang_timestamp(Config) when is_list(Config) ->
+    Mon = erlang:monitor(time_offset, clock_service),
+    {TO, _} = check_time_offset_change(Mon,
+				       erlang:time_offset(),
+				       0),
+    Done = erlang:start_timer(10000,self(),timeout),
+    ok = check_erlang_timestamp(Done, Mon, TO).
+
+check_erlang_timestamp(Done, Mon, TO) ->
+    receive
+	{timeout, Done, timeout} ->
+	    erlang:demonitor(Mon, [flush]),
+	    ok
+    after 0 ->
+	    do_check_erlang_timestamp(Done, Mon, TO)
+    end.
+
+do_check_erlang_timestamp(Done, Mon, TO) ->
+    MinMon = erlang:monotonic_time(),
+    {MegaSec, Sec, MicroSec} = erlang:timestamp(),
+    MaxMon = erlang:monotonic_time(),
+    TsMin = erlang:convert_time_unit(MinMon+TO,
+				     native,
+				     micro_seconds),
+    TsMax = erlang:convert_time_unit(MaxMon+TO,
+				     native,
+				     micro_seconds),
+    TsTime = (MegaSec*1000000+Sec)*1000000+MicroSec,
+    case (TsMin =< TsTime) andalso (TsTime =< TsMax) of
+	true ->
+	    NewTO = case erlang:time_offset() of
+			TO ->
+			    TO;
+			_ ->
+			    check_time_offset_change(Mon, TO, 0)
+		    end,
+	    check_erlang_timestamp(Done, Mon, NewTO);
+	false ->
+	    io:format("TsMin=~p TsTime=~p TsMax=~p~n", [TsMin, TsTime, TsMax]),
+	    ?t:format("Detected inconsistency; "
+		      "checking for time_offset change...", []),
+	    case check_time_offset_change(Mon, TO, 1000) of
+		{TO, false} ->
+		    ?t:fail(timestamp_inconsistency);
+		{NewTO, true} ->
+		    ?t:format("time_offset changed", []),
+		    check_erlang_timestamp(Done, Mon, NewTO)
+	    end
+    end.
+
+check_time_offset_change(Mon, TO, Wait) ->
+    process_changed_time_offset(Mon, TO, false, Wait).
+
+process_changed_time_offset(Mon, TO, Changed, Wait) ->
+    receive
+	{'CHANGE', Mon, time_offset, clock_service, NewTO} ->
+	    process_changed_time_offset(Mon, NewTO, true, Wait)
+    after Wait ->
+	    case erlang:time_offset() of
+		TO ->
+		    {TO, Changed};
+		_OtherTO ->
+		    receive
+			{'CHANGE', Mon, time_offset, clock_service, NewTO} ->
+			    process_changed_time_offset(Mon, NewTO, true, Wait)
+		    end
+	    end
+    end.
+    
+
+
 %% Returns the test data: a list of {Utc, Local} tuples.
 
 test_data() ->
@@ -554,4 +934,25 @@ bad_dates() ->
 
      {{1996, 4, 30}, {12, 0, -1}},		% Sec
      {{1996, 4, 30}, {12, 0, 60}}].
-     
+
+start_node(Config) ->
+    start_node(Config, "").
+
+start_node(Config, Args) ->
+    TestCase = ?config(testcase, Config),
+    PA = filename:dirname(code:which(?MODULE)),
+    ESTime = erlang:monotonic_time(1) + erlang:time_offset(1),
+    Unique = erlang:unique_integer([positive]),
+    Name = list_to_atom(atom_to_list(?MODULE)
+			++ "-"
+			++ atom_to_list(TestCase)
+			++ "-"
+			++ integer_to_list(ESTime)
+			++ "-"
+			++ integer_to_list(Unique)),
+    test_server:start_node(Name,
+			   slave,
+			   [{args, "-pa " ++ PA ++ " " ++ Args}]).
+
+stop_node(Node) ->
+    test_server:stop_node(Node).
diff --git a/erts/emulator/test/unique_SUITE.erl b/erts/emulator/test/unique_SUITE.erl
new file mode 100644
index 0000000000..5ad6e59272
--- /dev/null
+++ b/erts/emulator/test/unique_SUITE.erl
@@ -0,0 +1,390 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2014. All Rights Reserved.
+%% 
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%% 
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-module(unique_SUITE).
+
+-export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, 
+	 init_per_group/2,end_per_group/2,
+	 init_per_testcase/2,end_per_testcase/2]).
+-export([unique_monotonic_integer_white_box/1,
+	 unique_integer_white_box/1]).
+
+-include_lib("test_server/include/test_server.hrl").
+
+%-define(P(V), V).
+-define(P(V), print_ret_val(?FILE, ?LINE, V)).
+
+-define(PRINT(V), print_ret_val(?FILE, ?LINE, V)).
+
+
+init_per_testcase(Case, Config) ->
+    ?line Dog=test_server:timetrap(test_server:minutes(2)),
+    [{watchdog, Dog}, {testcase, Case}|Config].
+
+end_per_testcase(_, Config) ->
+    Dog=?config(watchdog, Config),
+    test_server:timetrap_cancel(Dog),
+    ok.
+
+suite() -> [{ct_hooks,[ts_install_cth]}].
+
+all() -> 
+    [unique_monotonic_integer_white_box,
+     unique_integer_white_box].
+
+groups() -> 
+    [].
+
+init_per_suite(Config) ->
+    erts_debug:set_internal_state(available_internal_state, true),
+    Config.
+
+end_per_suite(_Config) ->
+    erts_debug:set_internal_state(available_internal_state, false),
+    ok.
+
+init_per_group(_GroupName, Config) ->
+    Config.
+
+end_per_group(_GroupName, Config) ->
+    Config.
+
+%%
+%%
+%% Unique counter white box test case
+%%
+%%
+
+unique_monotonic_integer_white_box(Config) when is_list(Config) ->
+    {ok, Node} = start_node(Config),
+    TestServer = self(),
+    Success = make_ref(),
+    %% Run this in a separate node, so we don't mess up
+    %% the system when moving the strict monotonic counter
+    %% around in a non-strict monotonic way...
+    Test = spawn(Node,
+		 fun () ->
+			 unique_monotonic_integer_white_box_test(TestServer, Success)
+		 end),
+    Mon = erlang:monitor(process, Test),
+    receive
+	{'DOWN', Mon, process, Test, Error} ->
+	    ?t:fail(Error);
+	Success ->
+	    ok
+    end,
+    erlang:demonitor(Mon, [flush]),
+    stop_node(Node),
+    ok.
+
+set_unique_monotonic_integer_state(MinCounter, NextValue) ->
+    true = erts_debug:set_internal_state(unique_monotonic_integer_state,
+					 NextValue-MinCounter-1).
+    
+    
+
+unique_monotonic_integer_white_box_test(TestServer, Success) ->
+    erts_debug:set_internal_state(available_internal_state, true),
+
+    WordSize = erlang:system_info({wordsize, internal}),
+    SmallBits = WordSize*8 - 4,
+
+    MinSmall = -1*(1 bsl (SmallBits-1)),
+    MaxSmall = (1 bsl (SmallBits-1))-1,
+    %% Make sure we got small sizes correct...
+    0 = erts_debug:size(MinSmall),
+    false = 0 =:= erts_debug:size(MinSmall-1),
+    0 = erts_debug:size(MaxSmall),
+    false = 0 =:= erts_debug:size(MaxSmall+1),
+
+    ?PRINT({min_small, MinSmall}),
+    ?PRINT({max_small, MaxSmall}),
+
+    MinSint64 = -1*(1 bsl 63),
+    MaxSint64 = (1 bsl 63)-1,
+
+    ?PRINT({min_Sint64, MinSint64}),
+    ?PRINT({max_Sint64, MaxSint64}),
+
+    MinCounter = erts_debug:get_internal_state(min_unique_monotonic_integer),
+    MaxCounter = MinCounter + (1 bsl 64) - 1,
+
+    ?PRINT({min_counter, MinCounter}),
+    ?PRINT({max_counter, MaxCounter}),
+
+    case WordSize of
+	4 ->
+	    MinCounter = MinSint64;
+	8 ->
+	    MinCounter = MinSmall
+    end,
+
+    StartState = erts_debug:get_internal_state(unique_monotonic_integer_state),
+
+    %% Verify that we get expected results over all internal limits...
+
+    case MinCounter < MinSmall of
+	false ->
+	    8 = WordSize,
+	    ok;
+	true ->
+	    4 = WordSize,
+	    ?PRINT(over_min_small),
+	    set_unique_monotonic_integer_state(MinCounter, MinSmall-2),
+	    true = (?P(erlang:unique_integer([monotonic])) == MinSmall - 2),
+	    true = (?P(erlang:unique_integer([monotonic])) == MinSmall - 1),
+	    true = (?P(erlang:unique_integer([monotonic])) == MinSmall),
+	    true = (?P(erlang:unique_integer([monotonic]))  == MinSmall + 1),
+	    true = (?P(erlang:unique_integer([monotonic]))  == MinSmall + 2),
+	    garbage_collect(),
+	    ok
+    end,
+
+    ?PRINT(over_zero), %% Not really an interesting limit, but...
+    set_unique_monotonic_integer_state(MinCounter, -2),
+    true = (?P(erlang:unique_integer([monotonic])) == -2),
+    true = (?P(erlang:unique_integer([monotonic])) == -1),
+    true = (?P(erlang:unique_integer([monotonic])) == 0),
+    true = (?P(erlang:unique_integer([monotonic]))  == 1),
+    true = (?P(erlang:unique_integer([monotonic]))  == 2),
+    garbage_collect(),
+
+    ?PRINT(over_max_small),
+    set_unique_monotonic_integer_state(MinCounter, MaxSmall-2),
+    true = (?P(erlang:unique_integer([monotonic])) == MaxSmall - 2),
+    true = (?P(erlang:unique_integer([monotonic])) == MaxSmall - 1),
+    true = (?P(erlang:unique_integer([monotonic])) == MaxSmall),
+    true = (?P(erlang:unique_integer([monotonic]))  == MaxSmall + 1),
+    true = (?P(erlang:unique_integer([monotonic]))  == MaxSmall + 2),
+    garbage_collect(),
+
+    case MaxCounter > MaxSint64 of
+	false ->
+	    4 = WordSize,
+	    ok;
+	true ->
+	    8 = WordSize,
+	    ?PRINT(over_max_sint64),
+	    set_unique_monotonic_integer_state(MinCounter, MaxSint64-2),
+	    true = (?P(erlang:unique_integer([monotonic])) == MaxSint64 - 2),
+	    true = (?P(erlang:unique_integer([monotonic])) == MaxSint64 - 1),
+	    true = (?P(erlang:unique_integer([monotonic])) == MaxSint64),
+	    true = (?P(erlang:unique_integer([monotonic])) == MaxSint64 + 1),
+	    true = (?P(erlang:unique_integer([monotonic])) == MaxSint64 + 2),
+	    garbage_collect()
+    end,
+
+    ?PRINT(over_max_min_counter),
+    set_unique_monotonic_integer_state(MinCounter, if MaxCounter == MaxSint64 ->
+							   MaxCounter-2;
+						      true ->
+							   MinCounter-3
+						   end),
+    true = (?P(erlang:unique_integer([monotonic])) == MaxCounter - 2),
+    true = (?P(erlang:unique_integer([monotonic])) == MaxCounter - 1),
+    true = (?P(erlang:unique_integer([monotonic])) == MaxCounter),
+    true = (?P(erlang:unique_integer([monotonic])) == MinCounter),
+    true = (?P(erlang:unique_integer([monotonic])) == MinCounter + 1),
+    true = (?P(erlang:unique_integer([monotonic])) == MinCounter + 2),
+    garbage_collect(),
+
+    %% Restore initial state and hope we didn't mess it up for the
+    %% system...
+    true = erts_debug:set_internal_state(unique_monotonic_integer_state,
+					 StartState),
+
+    TestServer ! Success.
+
+%%
+%%
+%% Unique integer white box test case
+%%
+%%
+
+-record(uniqint_info, {min_int,
+		       max_int,
+		       max_small,
+		       schedulers,
+		       sched_bits}).
+
+unique_integer_white_box(Config) when is_list(Config) ->
+    UinqintInfo = init_uniqint_info(),
+    #uniqint_info{min_int = MinInt,
+		  max_int = MaxInt,
+		  max_small = MaxSmall} = UinqintInfo,
+    io:format("****************************************************~n", []),
+    io:format("*** Around MIN_UNIQ_INT ~p ***~n", [MinInt]),
+    io:format("****************************************************~n", []),
+    check_unique_integer_around(MinInt, UinqintInfo),
+    io:format("****************************************************~n", []),
+    io:format("*** Around 0 ***~n", []),
+    io:format("****************************************************~n", []),
+    check_unique_integer_around(0, UinqintInfo),
+    io:format("****************************************************~n", []),
+    io:format("*** Around MAX_SMALL ~p ***~n", [MaxSmall]),
+    io:format("****************************************************~n", []),
+    check_unique_integer_around(MaxSmall, UinqintInfo),
+    io:format("****************************************************~n", []),
+    io:format("*** Around 2^64+MIN_UNIQ_INT ~p ***~n", [(1 bsl 64)+MinInt]),
+    io:format("****************************************************~n", []),
+    check_unique_integer_around((1 bsl 64)+MinInt, UinqintInfo),
+    io:format("****************************************************~n", []),
+    io:format("*** Around 2^64 ~p~n", [(1 bsl 64)]),
+    io:format("****************************************************~n", []),
+    check_unique_integer_around((1 bsl 64), UinqintInfo),
+    io:format("****************************************************~n", []),
+    io:format("*** Around 2^64-MIN_UNIQ_INT ~p ***~n", [(1 bsl 64)-MinInt]),
+    io:format("****************************************************~n", []),
+    check_unique_integer_around((1 bsl 64)-MinInt, UinqintInfo),
+    io:format("****************************************************~n", []),
+    io:format("*** Around MAX_UNIQ_INT ~p ***~n", [MaxInt]),
+    io:format("****************************************************~n", []),
+    check_unique_integer_around(MaxInt, UinqintInfo),
+    ok.
+	
+
+%%% Internal unique_integer_white_box/1 test case
+
+calc_sched_bits(NoScheds, Shift) when NoScheds < 1 bsl Shift ->
+    Shift;
+calc_sched_bits(NoScheds, Shift) ->
+    calc_sched_bits(NoScheds, Shift+1).
+
+init_uniqint_info() ->
+    SmallBits = erlang:system_info({wordsize, internal})*8-4,
+    io:format("SmallBits=~p~n", [SmallBits]),
+    Schedulers = erlang:system_info(schedulers),
+    io:format("Schedulers=~p~n", [Schedulers]),
+    MinSmall = -1*(1 bsl (SmallBits-1)),
+    io:format("MinSmall=~p~n", [MinSmall]),
+    MaxSmall = (1 bsl (SmallBits-1))-1,
+    io:format("MaxSmall=~p~n", [MaxSmall]),
+    SchedBits = calc_sched_bits(Schedulers, 0),
+    io:format("SchedBits=~p~n", [SchedBits]),
+    MaxInt = ((((1 bsl 64) - 1) bsl SchedBits) bor Schedulers) + MinSmall,
+    io:format("MaxInt=~p~n", [MaxInt]),
+    #uniqint_info{min_int = MinSmall,
+		  max_int = MaxInt,
+		  max_small = MaxSmall,
+		  schedulers = Schedulers,
+		  sched_bits = SchedBits}.
+
+valid_uniqint(Int, #uniqint_info{min_int = MinInt} = UinqintInfo) when Int < MinInt ->
+    valid_uniqint(MinInt, UinqintInfo);
+valid_uniqint(Int, #uniqint_info{min_int = MinInt,
+				 sched_bits = SchedBits,
+				 schedulers = Scheds}) ->
+    Int1 = Int - MinInt,
+    {Inc, ThreadNo} = case Int1 band ((1 bsl SchedBits) - 1) of
+			  TN when TN > Scheds ->
+			      {1, Scheds};
+			  TN ->
+			      {0, TN}
+		      end,
+    Counter = ((Int1 bsr SchedBits) + Inc) rem (1 bsl 64),
+    ((Counter bsl SchedBits) bor ThreadNo) + MinInt.
+
+smaller_valid_uniqint(Int, UinqintInfo) ->
+    Cand = Int-1,
+    case valid_uniqint(Cand, UinqintInfo) of
+	RI when RI < Int ->
+	    RI;
+	_ ->
+	    smaller_valid_uniqint(Cand, UinqintInfo)
+    end.
+
+int32_to_bigendian_list(Int) ->
+    0 = Int bsr 32,
+    [(Int bsr 24) band 16#ff,
+     (Int bsr 16) band 16#ff,
+     (Int bsr 8) band 16#ff,
+     Int band 16#ff].
+
+mk_uniqint(Int, #uniqint_info {min_int = MinInt,
+			       sched_bits = SchedBits} = _UinqintInfo) ->
+    Int1 = Int - MinInt,
+    ThrId = Int1 band ((1 bsl SchedBits) - 1),
+    Value = (Int1 bsr SchedBits) band ((1 bsl 64) - 1),
+    0 = Int1 bsr (SchedBits + 64),
+    NodeName = atom_to_list(node()),
+    Make = {make_unique_integer, ThrId, Value},
+    %% erlang:display(Make),
+    Res = erts_debug:get_internal_state(Make),
+    %% erlang:display({uniq_int, Res}),
+    Res.
+
+check_uniqint(Int, UinqintInfo) ->
+    UniqInt = mk_uniqint(Int, UinqintInfo),
+    io:format("UniqInt=~p ", [UniqInt]),
+    case UniqInt =:= Int of
+	true ->
+	    io:format("OK~n~n", []);
+	false ->
+	    io:format("result UniqInt=~p FAILED~n", [UniqInt]),
+	    exit(badres)
+    end.
+
+check_unique_integer_around(Int, #uniqint_info{min_int = MinInt,
+					       max_int = MaxInt} = UinqintInfo) ->
+    {Start, End} = case {Int =< MinInt+100, Int >= MaxInt-100} of
+		       {true, false} ->
+			   {MinInt, MinInt+100};
+		       {false, false} ->
+			   {smaller_valid_uniqint(Int-100, UinqintInfo),
+			    valid_uniqint(Int+100, UinqintInfo)};
+		       {false, true} ->
+			   {MaxInt-100, MaxInt}
+		   end,
+    lists:foldl(fun (I, OldRefInt) ->
+			RefInt = valid_uniqint(I, UinqintInfo),
+			case OldRefInt =:= RefInt of
+			    true ->
+				ok;
+			    false ->
+				check_uniqint(RefInt, UinqintInfo)
+			end,
+			RefInt
+		end,
+		none,
+		lists:seq(Start, End)).
+
+
+%% helpers
+
+print_ret_val(File, Line, Value) ->    
+    io:format("~s:~p: ~p~n", [File, Line, Value]),
+    Value.
+
+start_node(Config) ->
+    start_node(Config, []).
+start_node(Config, Opts) when is_list(Config), is_list(Opts) ->
+    ?line Pa = filename:dirname(code:which(?MODULE)),
+    ?line A = erlang:monotonic_time(1) + erlang:time_offset(1),
+    ?line B = erlang:unique_integer([positive]),
+    ?line Name = list_to_atom(atom_to_list(?MODULE)
+			      ++ "-"
+			      ++ atom_to_list(?config(testcase, Config))
+			      ++ "-"
+			      ++ integer_to_list(A)
+			      ++ "-"
+			      ++ integer_to_list(B)),
+    ?line ?t:start_node(Name, slave, [{args, Opts++" -pa "++Pa}]).
+
+stop_node(Node) ->
+    ?t:stop_node(Node).