Replace erlang:now() usage in emulator suite

26 files changed, 142 insertions, 190 deletions

diff --git a/erts/emulator/test/after_SUITE.erl b/erts/emulator/test/after_SUITE.erl
index 7cc329cc69..699a1436ce 100644
--- a/erts/emulator/test/after_SUITE.erl
+++ b/erts/emulator/test/after_SUITE.erl
@@ -70,30 +70,23 @@ end_per_testcase(_Func, Config) ->
 t_after(Config) when is_list(Config) ->
     ?line spawn(fun frequent_process/0),
     ?line Period = test_server:minutes(1),
-    ?line Before = erlang:now(),
+    ?line Before = erlang:monotonic_time(),
     receive
 	after Period ->
-		?line After = erlang:now(),
+		?line After = erlang:monotonic_time(),
 		?line report(Period, Before, After)
 	end.
 
-
 report(Period, Before, After) ->
-    ?line Elapsed = (element(1, After)*1000000000
-		     +element(2, After)*1000
-		     +element(3, After) div 1000) -
-	(element(1,Before)*1000000000
-	 + element(2,Before)*1000 + element(3,Before) div 1000),
-    ?line case Elapsed*100 / Period of
-	      Percent when Percent > 100.10 ->
-		  ?line test_server:fail({too_inaccurate, Percent});
-	      Percent when Percent < 100.0 ->
-		  ?line test_server:fail({too_early, Percent});
-	      Percent ->
-		  ?line Comment = io_lib:format("Elapsed/expected: ~.2f %",
-						[Percent]),
-		  {comment, lists:flatten(Comment)}
-	  end.
+    case erlang:convert_time_unit(After - Before, native, 100*1000) / Period of
+	Percent when Percent > 100.10 ->
+	    test_server:fail({too_inaccurate, Percent});
+	Percent when Percent < 100.0 ->
+	    test_server:fail({too_early, Percent});
+	Percent ->
+	    Comment = io_lib:format("Elapsed/expected: ~.2f %", [Percent]),
+	    {comment, lists:flatten(Comment)}
+    end.
 
 frequent_process() ->
     receive
diff --git a/erts/emulator/test/alloc_SUITE.erl b/erts/emulator/test/alloc_SUITE.erl
index 35c44c229a..12a48cc484 100644
--- a/erts/emulator/test/alloc_SUITE.erl
+++ b/erts/emulator/test/alloc_SUITE.erl
@@ -241,18 +241,15 @@ receive_drv_result(Port, CaseName) ->
 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, B, C} = now(),
-    ?line Name = list_to_atom(atom_to_list(?MODULE)
-			      ++ "-"
-			      ++ atom_to_list(?config(testcase, Config))
-			      ++ "-"
-			      ++ integer_to_list(A)
-			      ++ "-"
-			      ++ integer_to_list(B)
-			      ++ "-"
-			      ++ integer_to_list(C)),
-    ?line ?t:start_node(Name, slave, [{args, Opts++" -pa "++Pa}]).
+    Pa = filename:dirname(code:which(?MODULE)),
+    Name = list_to_atom(atom_to_list(?MODULE)
+			++ "-"
+			++ atom_to_list(?config(testcase, Config))
+			++ "-"
+			++ integer_to_list(erlang:system_time(seconds))
+			++ "-"
+			++ integer_to_list(erlang:unique_integer([positive]))),
+    ?t:start_node(Name, slave, [{args, Opts++" -pa "++Pa}]).
 
 stop_node(Node) ->
     ?t:stop_node(Node).
diff --git a/erts/emulator/test/binary_SUITE.erl b/erts/emulator/test/binary_SUITE.erl
index 44e9e4f243..5911652447 100644
--- a/erts/emulator/test/binary_SUITE.erl
+++ b/erts/emulator/test/binary_SUITE.erl
@@ -520,7 +520,9 @@ external_size_1(Term, Size0, Limit) when Size0 < Limit ->
 external_size_1(_, _, _) -> ok.
 
 t_iolist_size(Config) when is_list(Config) ->
-    ?line Seed = now(),
+    ?line Seed = {erlang:monotonic_time(),
+		  erlang:time_offset(),
+		  erlang:unique_integer([positive])},
     ?line io:format("Seed: ~p", [Seed]),
     ?line random:seed(Seed),
     ?line Base = <<0:(1 bsl 20)/unit:8>>,
diff --git a/erts/emulator/test/busy_port_SUITE.erl b/erts/emulator/test/busy_port_SUITE.erl
index 2ed5aaa0d0..d44a03516a 100644
--- a/erts/emulator/test/busy_port_SUITE.erl
+++ b/erts/emulator/test/busy_port_SUITE.erl
@@ -516,13 +516,13 @@ hs_busy_pcmd(Prt, Opts, StartFun, EndFun) ->
     P = spawn_link(fun () ->
 			   erlang:yield(),
 			   Tester ! {self(), doing_port_command},
-			   Start = now(),
+			   Start = erlang:monotonic_time(micro_seconds),
 			   Res = try {return,
 				      port_command(Prt, [], Opts)}
 				 catch Exception:Error -> {Exception, Error}
 				 end,
-			   End = now(),
-			   Time = round(timer:now_diff(End, Start)/1000),
+			   End = erlang:monotonic_time(micro_seconds),
+			   Time = round((End - Start)/1000),
 			   Tester ! {self(), port_command_result, Res, Time}
 		   end),
     receive
@@ -776,7 +776,7 @@ run_command(_M,spawn,{Args,Opts}) ->
 run_command(M,spawn,Args) ->
     run_command(M,spawn,{Args,[]});
 run_command(Mod,Func,Args) ->
-    erlang:display({{Mod,Func,Args},now()}),
+    erlang:display({{Mod,Func,Args}, erlang:system_time(micro_seconds)}),
     apply(Mod,Func,Args).
 
 validate_scenario(Data,[{print,Var}|T]) ->
diff --git a/erts/emulator/test/decode_packet_SUITE.erl b/erts/emulator/test/decode_packet_SUITE.erl
index 2baf91cf29..330ad299e5 100644
--- a/erts/emulator/test/decode_packet_SUITE.erl
+++ b/erts/emulator/test/decode_packet_SUITE.erl
@@ -52,7 +52,9 @@ end_per_group(_GroupName, Config) ->
 
 
 init_per_testcase(Func, Config) when is_atom(Func), is_list(Config) ->
-    Seed = {S1,S2,S3} = now(),
+    Seed = {S1,S2,S3} = {erlang:monotonic_time(),
+			 erlang:time_offset(),
+			 erlang:unique_integer()},
     random:seed(S1,S2,S3),
     io:format("*** SEED: ~p ***\n", [Seed]),
     Dog=?t:timetrap(?t:minutes(1)),
diff --git a/erts/emulator/test/distribution_SUITE.erl b/erts/emulator/test/distribution_SUITE.erl
index aa6cf2b881..33cb56c0b9 100644
--- a/erts/emulator/test/distribution_SUITE.erl
+++ b/erts/emulator/test/distribution_SUITE.erl
@@ -1337,10 +1337,7 @@ unwanted_cixs() ->
 get_conflicting_atoms(_CIX, 0) ->
     [];
 get_conflicting_atoms(CIX, N) ->
-    {A, B, C} = now(),
-    Atom = list_to_atom("atom" ++ integer_to_list(A*1000000000000
-						  + B*1000000
-						  + C)),
+    Atom = list_to_atom("atom" ++ integer_to_list(erlang:unique_integer([positive]))),
     case erts_debug:get_internal_state({atom_out_cache_index, Atom}) of
 	CIX ->
 	    [Atom|get_conflicting_atoms(CIX, N-1)];
@@ -1351,10 +1348,7 @@ get_conflicting_atoms(CIX, N) ->
 get_conflicting_unicode_atoms(_CIX, 0) ->
     [];
 get_conflicting_unicode_atoms(CIX, N) ->
-    {A, B, C} = now(),
-    Atom = string_to_atom([16#1f608] ++ "atom" ++ integer_to_list(A*1000000000000
-								  + B*1000000
-								  + C)),
+    Atom = string_to_atom([16#1f608] ++ "atom" ++ integer_to_list(erlang:unique_integer([positive]))),
     case erts_debug:get_internal_state({atom_out_cache_index, Atom}) of
 	CIX ->
 	    [Atom|get_conflicting_unicode_atoms(CIX, N-1)];
@@ -1967,8 +1961,7 @@ dmsg_bad_atom_cache_ref() ->
 %%% Utilities
 
 timestamp() ->
-    {A,B,C} = erlang:now(),
-    (C div 1000) + (B * 1000) + (A * 1000000000).
+    erlang:monotonic_time(milli_seconds).
 
 start_node(X) ->
     start_node(X, [], []).
@@ -1992,7 +1985,9 @@ start_node(Config, Args, Rel) when is_list(Config), is_list(Rel) ->
 			 ++ "-"
 			 ++ atom_to_list(?config(testcase, Config))
 			 ++ "-"
-			 ++ integer_to_list(timestamp()))),
+			 ++ integer_to_list(erlang:system_time(seconds))
+			 ++ "-"
+			 ++ integer_to_list(erlang:unique_integer([positive])))),
     start_node(Name, Args, Rel).
 
 stop_node(Node) ->
@@ -2109,7 +2104,7 @@ node_monitor(Master) ->
 				  Master ! {nodeup, node(), Node}
 			  end,
 			  Nodes0),
-	    ?t:format("~p ~p: ~p~n", [node(), erlang:now(), Nodes0]),
+	    ?t:format("~p ~p: ~p~n", [node(), erlang:system_time(micro_seconds), Nodes0]),
 	    node_monitor_loop(Master);
 	false ->
 	    net_kernel:monitor_nodes(false, Opts),
@@ -2130,7 +2125,7 @@ node_monitor_loop(Master) ->
     receive
 	{nodeup, Node, _InfoList} = Msg ->
 	    Master ! {nodeup, node(), Node},
-	    ?t:format("~p ~p: ~p~n", [node(), erlang:now(), Msg]),
+	    ?t:format("~p ~p: ~p~n", [node(), erlang:system_time(micro_seconds), Msg]),
 	    node_monitor_loop(Master);
 	{nodedown, Node, InfoList} = Msg ->
 	    Reason = case lists:keysearch(nodedown_reason, 1, InfoList) of
@@ -2138,7 +2133,7 @@ node_monitor_loop(Master) ->
 			 _ -> undefined
 		     end,
 	    Master ! {nodedown, node(), Node, Reason},
-	    ?t:format("~p ~p: ~p~n", [node(), erlang:now(), Msg]),
+	    ?t:format("~p ~p: ~p~n", [node(), erlang:system_time(micro_seconds), Msg]),
 	    node_monitor_loop(Master)
     end.
 
diff --git a/erts/emulator/test/driver_SUITE.erl b/erts/emulator/test/driver_SUITE.erl
index 623d62f876..e6beda1ccf 100644
--- a/erts/emulator/test/driver_SUITE.erl
+++ b/erts/emulator/test/driver_SUITE.erl
@@ -390,12 +390,12 @@ timer_measure(Config) when is_list(Config) ->
 
 try_timeouts(_, 0) -> ok;
 try_timeouts(Port, Timeout) ->
-    ?line TimeBefore = now(),
+    ?line TimeBefore = erlang:monotonic_time(),
     ?line erlang:port_command(Port, <<?START_TIMER,Timeout:32>>),
     receive
 	{Port,{data,[?TIMER]}} ->
 	    ?line Elapsed = erl_millisecs() - erl_millisecs(TimeBefore),
-	    io:format("Elapsed: ~p Timeout: ~p\n", [Elapsed,Timeout]),
+	    io:format("Elapsed: ~p Timeout: ~p\n", [Elapsed, Timeout]),
 	    if
 		Elapsed < Timeout ->
 		    ?line ?t:fail(too_short);
@@ -455,7 +455,7 @@ timer_delay(Config) when is_list(Config) ->
     Name = 'timer_drv',
     ?line Port = start_driver(Config, Name, false),
 
-    ?line TimeBefore = now(),
+    ?line TimeBefore = erlang:monotonic_time(),
     Timeout0 = 350,
     ?line erlang:port_command(Port, <<?DELAY_START_TIMER,Timeout0:32>>),
     Timeout = Timeout0 +
@@ -499,7 +499,7 @@ timer_change(Config) when is_list(Config) ->
 try_change_timer(_Port, 0) -> ok;
 try_change_timer(Port, Timeout) ->
     ?line Timeout_3 = Timeout*3,
-    ?line TimeBefore = now(),
+    ?line TimeBefore = erlang:monotonic_time(),
     ?line erlang:port_command(Port, <<?START_TIMER,Timeout_3:32>>),
     ?line erlang:port_command(Port, <<?START_TIMER,Timeout:32>>),
     receive
@@ -2520,13 +2520,11 @@ uniform(N) ->
     end,
     random:uniform(N).
 
-%% return millisecs from statistics source
 erl_millisecs() ->
-    {Ms, S, Us} = erlang:now(),
-    Ms * 1000000000 + S * 1000 + Us / 1000.
+    erl_millisecs(erlang:monotonic_time()).
 
-erl_millisecs({Ms,S,Us}) ->
-    Ms * 1000000000 + S * 1000 + Us / 1000.
+erl_millisecs(MonotonicTime) ->
+    (1000*MonotonicTime)/erlang:convert_time_unit(1,seconds,native).
 
 %% Start/stop drivers.
 start_driver(Config, Name, Binary) ->
@@ -2575,18 +2573,15 @@ sleep(Ms) when is_integer(Ms), Ms >= 0 ->
 
 
 start_node(Config) when is_list(Config) ->
-    ?line Pa = filename:dirname(code:which(?MODULE)),
-    ?line {A, B, C} = now(),
-    ?line Name = list_to_atom(atom_to_list(?MODULE)
-			      ++ "-"
-			      ++ atom_to_list(?config(testcase, Config))
-			      ++ "-"
-			      ++ integer_to_list(A)
-			      ++ "-"
-			      ++ integer_to_list(B)
-			      ++ "-"
-			      ++ integer_to_list(C)),
-    ?line ?t:start_node(Name, slave, [{args, "-pa "++Pa}]).
+    Pa = filename:dirname(code:which(?MODULE)),
+    Name = list_to_atom(atom_to_list(?MODULE)
+			++ "-"
+			++ atom_to_list(?config(testcase, Config))
+			++ "-"
+			++ integer_to_list(erlang:system_time(seconds))
+			++ "-"
+			++ integer_to_list(erlang:unique_integer([positive]))),
+    ?t:start_node(Name, slave, [{args, "-pa "++Pa}]).
 
 stop_node(Node) ->
     ?t:stop_node(Node).
diff --git a/erts/emulator/test/erl_link_SUITE.erl b/erts/emulator/test/erl_link_SUITE.erl
index 435c0872e6..02c1d84d59 100644
--- a/erts/emulator/test/erl_link_SUITE.erl
+++ b/erts/emulator/test/erl_link_SUITE.erl
@@ -1035,16 +1035,13 @@ get_names(N, T) when is_atom(T) ->
 get_names(0, _, Acc) ->
     Acc;
 get_names(N, T, Acc) ->
-    {A, B, C} = now(),
     get_names(N-1, T, [list_to_atom(atom_to_list(?MODULE)
 				    ++ "-"
 				    ++ atom_to_list(T)
 				    ++ "-"
-				    ++ integer_to_list(A)
+				    ++ integer_to_list(erlang:system_time(seconds))
 				    ++ "-"
-				    ++ integer_to_list(B)
-				    ++ "-"
-				    ++ integer_to_list(C)) | Acc]).
+				    ++ integer_to_list(erlang:unique_integer([positive]))) | Acc]).
 
 start_node(Name) ->
     ?line start_node(Name, "").
diff --git a/erts/emulator/test/estone_SUITE.erl b/erts/emulator/test/estone_SUITE.erl
index 1de6d6fb56..9fe161cffc 100644
--- a/erts/emulator/test/estone_SUITE.erl
+++ b/erts/emulator/test/estone_SUITE.erl
@@ -339,7 +339,6 @@ micros() ->
     ].
 
 macro(Ms,DataDir) ->
-    erlang:now(),  %% compensate for old 4.3 firsttime clock bug :-(
     statistics(reductions),
     statistics(runtime),
     lists(500),  %% fixup cache on first round
@@ -369,10 +368,9 @@ run_micro(Top, M, DataDir) ->
 apply_micro(M) ->
     {GC0, Words0, _} = statistics(garbage_collection),
     statistics(reductions),
-    Before = erlang:now(),
-
+    Before = erlang:monotonic_time(),
     Compensate = apply_micro(M#micro.function, M#micro.loops),
-    After = erlang:now(),
+    After = erlang:monotonic_time(),
     {GC1, Words1, _} = statistics(garbage_collection),
     {_, Reds} = statistics(reductions),
     Elapsed = subtr(Before, After),
@@ -391,10 +389,7 @@ apply_micro(M) ->
 
 
 subtr(Before, After) ->
-    (element(1,After)*1000000000000
-     +element(2,After)*1000000+element(3,After)) -
-        (element(1,Before)*1000000000000
-         +element(2,Before)*1000000+element(3,Before)).
+    erlang:convert_time_unit(After-Before, native, micro_seconds).
 
 gci(Micros, Words, Gcs) ->
     ((256 * Gcs) / Micros) + (Words / Micros).
@@ -633,10 +628,10 @@ tup_trav(T, P, End) ->
 %% Port I/O
 port_io(I) ->
     EstoneCat = get(estone_cat),
-    Before = erlang:now(),
+    Before = erlang:monotonic_time(),
     Pps = make_port_pids(5, I, EstoneCat),  %% 5 ports
     send_procs(Pps, go),
-    After = erlang:now(),
+    After = erlang:monotonic_time(),
     wait_for_pids(Pps),
     subtr(Before, After).
 
@@ -854,10 +849,10 @@ handle_call(_From, State, [abc]) ->
 
 %% Binary handling, creating, manipulating and sending binaries
 binary_h(I) ->
-    Before = erlang:now(),
+    Before = erlang:monotonic_time(),
     P = spawn(?MODULE, echo, [self()]),
     B = list_to_binary(lists:duplicate(2000, 5)),
-    After = erlang:now(),
+    After = erlang:monotonic_time(),
     Compensate = subtr(Before, After),
     binary_h_2(I, P, B),
     Compensate.
diff --git a/erts/emulator/test/float_SUITE.erl b/erts/emulator/test/float_SUITE.erl
index 4a45afa9e9..a07516b5a9 100644
--- a/erts/emulator/test/float_SUITE.erl
+++ b/erts/emulator/test/float_SUITE.erl
@@ -294,16 +294,13 @@ id(I) -> I.
     
 start_node(Config) when is_list(Config) ->
     ?line Pa = filename:dirname(code:which(?MODULE)),
-    ?line {A, B, C} = now(),
     ?line Name = list_to_atom(atom_to_list(?MODULE)
 			      ++ "-"
 			      ++ atom_to_list(?config(testcase, Config))
 			      ++ "-"
-			      ++ integer_to_list(A)
+			      ++ integer_to_list(erlang:system_time(seconds))
 			      ++ "-"
-			      ++ integer_to_list(B)
-			      ++ "-"
-			      ++ integer_to_list(C)),
+			      ++ integer_to_list(erlang:unique_integer([positive]))),
     ?line ?t:start_node(Name, slave, [{args, "-pa "++Pa}]).
 
 stop_node(Node) ->
diff --git a/erts/emulator/test/gc_SUITE.erl b/erts/emulator/test/gc_SUITE.erl
index 36889b6c36..1b92e3198e 100644
--- a/erts/emulator/test/gc_SUITE.erl
+++ b/erts/emulator/test/gc_SUITE.erl
@@ -77,7 +77,7 @@ grow_heap1(List, MaxLen, CurLen, up) ->
 grow_heap1([], _MaxLen, _, down) ->
     ok;
 grow_heap1([_|List], MaxLen, CurLen, down) ->
-    {_,_,C} = erlang:now(),
+    C=erlang:unique_integer([positive]),
     Num     = C rem (length(List))+1,
     Elem    = lists:nth(Num, List),
     NewList = lists:delete(Elem, List),
@@ -136,7 +136,7 @@ grow_stack_heap1(List, MaxLen, CurLen, up) ->
 grow_stack_heap1([], _MaxLen, _, down) -> ok;
 grow_stack_heap1([_|List], MaxLen, CurLen, down) ->
     grow_stack1(CurLen*2,0),
-    {_,_,C}=erlang:now(),
+    C=erlang:unique_integer([positive]),
     Num=C rem (length(List))+1,
     Elem=lists:nth(Num, List),
     NewList=lists:delete(Elem, List),
@@ -146,8 +146,8 @@ grow_stack_heap1([_|List], MaxLen, CurLen, down) ->
 
 %% Create an arbitrary element/term.
 make_arbit() ->
-    {AA,BB,CC}=erlang:now(),
-    A=AA+1, B=BB+1, C=CC+1,
+    {AA,BB,CC}=erlang:timestamp(),
+    A=AA+1, B=BB+1, C=(CC+erlang:unique_integer([positive])) rem 1000000 + 1,
     New =
 	case C rem 9 of
 	    0 -> make_string((B div C) +5);
@@ -171,7 +171,7 @@ make_string(Length) ->
 make_string(_, 0, Acc) ->
     Acc;
 make_string(Alph, Length, Acc) ->
-    {_,_,C}=erlang:now(),
+    C=erlang:unique_integer([positive]),
     Pos=1+(Length*C rem length(Alph)),
     make_string(Alph, Length-1, 
 		[lists:nth(Pos,Alph)|Acc]).
diff --git a/erts/emulator/test/map_SUITE.erl b/erts/emulator/test/map_SUITE.erl
index 228832ac0a..6e0a5a9668 100644
--- a/erts/emulator/test/map_SUITE.erl
+++ b/erts/emulator/test/map_SUITE.erl
@@ -521,7 +521,9 @@ t_map_equal(Config) when is_list(Config) ->
 
 
 t_map_compare(Config) when is_list(Config) ->
-    Seed = erlang:now(),
+    Seed = {erlang:monotonic_time(),
+	    erlang:time_offset(),
+	    erlang:unique_integer()},
     io:format("seed = ~p\n", [Seed]),
     random:seed(Seed),
     repeat(100, fun(_) -> float_int_compare() end, []),
diff --git a/erts/emulator/test/monitor_SUITE.erl b/erts/emulator/test/monitor_SUITE.erl
index 07e2862b2a..dc215b1529 100644
--- a/erts/emulator/test/monitor_SUITE.erl
+++ b/erts/emulator/test/monitor_SUITE.erl
@@ -763,12 +763,10 @@ named_down(doc) -> ["Test that DOWN message for a named monitor isn't"
 		    " delivered until name has been unregistered"];
 named_down(suite) -> [];
 named_down(Config) when is_list(Config) ->
-    ?line {A,B,C} = now(),
     ?line Name = list_to_atom(atom_to_list(?MODULE)
 			      ++ "-named_down-"
-			      ++ integer_to_list(A)
-			      ++ "-" ++ integer_to_list(B)
-			      ++ "-" ++ integer_to_list(C)),
+			      ++ integer_to_list(erlang:system_time(seconds))
+			      ++ "-" ++ integer_to_list(erlang:unique_integer([positive]))),
     ?line Prio = process_flag(priority,high),
     %% Spawn a bunch of high prio cpu bound processes to prevent
     %% normal prio processes from terminating during the next
diff --git a/erts/emulator/test/mtx_SUITE.erl b/erts/emulator/test/mtx_SUITE.erl
index a492501959..8dcd21f303 100644
--- a/erts/emulator/test/mtx_SUITE.erl
+++ b/erts/emulator/test/mtx_SUITE.erl
@@ -441,10 +441,10 @@ hammer_ets_rwlock_test(XOpts, UW, C, N, NP, SC) ->
 										      receive after infinity -> ok end
 									      end) | Ps0]
 							 end,
-						    Start = now(),
+						    Start = erlang:monotonic_time(),
 						    lists:foreach(fun (P) -> P ! go end, Ps),
 						    lists:foreach(fun (P) -> receive {done, P} -> ok end end, Ps),
-						    Stop = now(),
+						    Stop = erlang:monotonic_time(),
 						    lists:foreach(fun (P) ->
 									  unlink(P),
 									  exit(P, bang),
@@ -453,7 +453,7 @@ hammer_ets_rwlock_test(XOpts, UW, C, N, NP, SC) ->
 									      {'DOWN', M, process, P, _} -> ok
 									  end
 								  end, Ps),
-						    Res = timer:now_diff(Stop, Start)/1000000,
+						    Res = (Stop-Start)/erlang:convert_time_unit(1,seconds,native),
 						    Caller ! {?MODULE, self(), Res}
 					    end,
 					TP = spawn_link(T),
diff --git a/erts/emulator/test/nif_SUITE.erl b/erts/emulator/test/nif_SUITE.erl
index b0624fb8c1..78cfc595fa 100644
--- a/erts/emulator/test/nif_SUITE.erl
+++ b/erts/emulator/test/nif_SUITE.erl
@@ -1188,7 +1188,9 @@ send3(Config) when is_list(Config) ->
     %% Let a number of processes send random message blobs between each other
     %% using enif_send. Kill and spawn new ones randomly to keep a ~constant
     %% number of workers running.
-    Seed = now(),
+    Seed = {erlang:monotonic_time(),
+	    erlang:time_offset(),
+	    erlang:unique_integer()},
     io:format("seed: ~p\n",[Seed]), 
     random:seed(Seed),    
     ets:new(nif_SUITE,[named_table,public]),
diff --git a/erts/emulator/test/node_container_SUITE.erl b/erts/emulator/test/node_container_SUITE.erl
index 9c1839811a..2f505893b4 100644
--- a/erts/emulator/test/node_container_SUITE.erl
+++ b/erts/emulator/test/node_container_SUITE.erl
@@ -1120,26 +1120,18 @@ wait_until(Pred) ->
 	false -> receive after 100 -> wait_until(Pred) end
     end.
 
+get_nodefirstname_string() ->
+    atom_to_list(?MODULE)
+	++ "-"
+	++ integer_to_list(erlang:system_time(seconds))
+	++ "-"
+	++ integer_to_list(erlang:unique_integer([positive])).
 
 get_nodefirstname() ->
-    {A, B, C} = now(),
-    list_to_atom(atom_to_list(?MODULE)
-		 ++ "-"
-		 ++ integer_to_list(A)
-		 ++ "-"
-		 ++ integer_to_list(B)
-		 ++ "-"
-		 ++ integer_to_list(C)).
+    list_to_atom(get_nodefirstname_string()).
 
 get_nodename() ->
-    {A, B, C} = now(),
-    list_to_atom(atom_to_list(?MODULE)
-		 ++ "-"
-		 ++ integer_to_list(A)
-		 ++ "-"
-		 ++ integer_to_list(B)
-		 ++ "-"
-		 ++ integer_to_list(C)
+    list_to_atom(get_nodefirstname_string()
 		 ++ "@"
 		 ++ hostname()).
     
diff --git a/erts/emulator/test/old_scheduler_SUITE.erl b/erts/emulator/test/old_scheduler_SUITE.erl
index 262536a068..57f6928185 100644
--- a/erts/emulator/test/old_scheduler_SUITE.erl
+++ b/erts/emulator/test/old_scheduler_SUITE.erl
@@ -116,7 +116,7 @@ equal(Config) when is_list(Config) ->
 
     %% start controllers
     ?line Receiver = 
-	spawn(fun() -> receiver(now(), Time, Self, Normal, Low) end),
+	spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, Normal, Low) end),
     ?line Starter =
 	spawn(fun() -> starter(Normal, Low, Receiver) end),
 
@@ -154,7 +154,7 @@ many_low(Config) when is_list(Config) ->
     Time = 30,
 
     ?line Receiver = 
-	spawn(fun() -> receiver(now(), Time, Self, Normal, Low) end),
+	spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, Normal, Low) end),
     ?line Starter =
 	spawn(fun() -> starter(Normal, Low, Receiver) end),
     ?line {NRs,NAvg,LRs,LAvg,Ratio} = 
@@ -185,7 +185,7 @@ few_low(Config) when is_list(Config) ->
     Time = 30,
 
     ?line Receiver = 
-	spawn(fun() -> receiver(now(), Time, Self, Normal, Low) end),
+	spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, Normal, Low) end),
     ?line Starter =
 	spawn(fun() -> starter(Normal, Low, Receiver) end),
     ?line {NRs,NAvg,LRs,LAvg,Ratio} = 
@@ -220,7 +220,7 @@ max(Config) when is_list(Config) ->
     Time = 30,
 
     ?line Receiver1 = 
-	spawn(fun() -> receiver(now(), Time, Self, Max, High) end),
+	spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, Max, High) end),
     ?line Starter1 =
 	spawn(fun() -> starter(Max, High, Receiver1) end),
     ?line {M1Rs,M1Avg,HRs,HAvg,Ratio1} = 
@@ -238,7 +238,7 @@ max(Config) when is_list(Config) ->
     end,
 
     ?line Receiver2 = 
-	spawn(fun() -> receiver(now(), Time, Self, Max, Normal) end),
+	spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, Max, Normal) end),
     ?line Starter2 =
 	spawn(fun() -> starter(Max, Normal, Receiver2) end),
     ?line {M2Rs,M2Avg,NRs,NAvg,Ratio2} = 
@@ -256,7 +256,7 @@ max(Config) when is_list(Config) ->
     end,
 
     ?line Receiver3 = 
-	spawn(fun() -> receiver(now(), Time, Self, Max, Low) end),
+	spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, Max, Low) end),
     ?line Starter3 =
 	spawn(fun() -> starter(Max, Low, Receiver3) end),
     ?line {M3Rs,M3Avg,LRs,LAvg,Ratio3} = 
@@ -290,7 +290,7 @@ high(Config) when is_list(Config) ->
     Time = 30,
 
     ?line Receiver1 = 
-	spawn(fun() -> receiver(now(), Time, Self, High, Normal) end),
+	spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, High, Normal) end),
     ?line Starter1 =
 	spawn(fun() -> starter(High, Normal, Receiver1) end),
     ?line {H1Rs,H1Avg,NRs,NAvg,Ratio1} = 
@@ -308,7 +308,7 @@ high(Config) when is_list(Config) ->
     end,
 
     ?line Receiver2 = 
-	spawn(fun() -> receiver(now(), Time, Self, High, Low) end),
+	spawn(fun() -> receiver(erlang:monotonic_time(), Time, Self, High, Low) end),
     ?line Starter2 =
 	spawn(fun() -> starter(High, Low, Receiver2) end),
     ?line {H2Rs,H2Avg,LRs,LAvg,Ratio2} = 
@@ -337,12 +337,13 @@ receiver(T0, TimeSec, Main, {P1,P1N}, {P2,P2N}) ->
 
 %% uncomment lines below to get life sign (debug)
 receiver(T0, Time, Main, P1,P1N,P1Rs, P2,P2N,P2Rs, 0) ->
-%    T = elapsed_ms(T0, now()),
+%    T = erlang:convert_time_unit(erlang:monotonic_time() - T0, native, milli_seconds),
 %    erlang:display({round(T/1000),P1Rs,P2Rs}),
     receiver(T0, Time, Main, P1,P1N,P1Rs, P2,P2N,P2Rs, 100000);
 
 receiver(T0, Time, Main, P1,P1N,P1Rs, P2,P2N,P2Rs, C) ->
-    Remain = Time - elapsed_ms(T0, now()),	% test time remaining
+    Remain = Time - erlang:convert_time_unit(erlang:monotonic_time() - T0,
+					     native, milli_seconds), % test time remaining
     Remain1 = if Remain < 0 ->
 		      0;
 		 true ->
@@ -409,6 +410,3 @@ flush_loop() ->
 	    ok
     end,
     flush_loop().
-
-elapsed_ms({_MS0,S0,MuS0},{_MS1,S1,MuS1}) ->
-    round(((S1-S0)*1000)+((MuS1-MuS0)/1000)). 
diff --git a/erts/emulator/test/port_SUITE.erl b/erts/emulator/test/port_SUITE.erl
index 6bbf93b7d7..e61c330861 100644
--- a/erts/emulator/test/port_SUITE.erl
+++ b/erts/emulator/test/port_SUITE.erl
@@ -1815,7 +1815,7 @@ exit_status_msb_test(Config, SleepSecs) when is_list(Config) ->
     Parent = self(),
     ?t:format("SleepSecs = ~p~n", [SleepSecs]),
     PortProg = "sleep " ++ integer_to_list(SleepSecs),
-    Start = now(),
+    Start = erlang:monotonic_time(micro_seconds),
     NoProcs = case NoSchedsOnln of
 			NProcs when NProcs < ?EXIT_STATUS_MSB_MAX_PROCS ->
 			    NProcs;
@@ -1887,12 +1887,12 @@ exit_status_msb_test(Config, SleepSecs) when is_list(Config) ->
 				   receive {P, started, SIds} -> SIds end
 			   end,
 			   Procs),
-    StartedTime = timer:now_diff(now(), Start)/1000000,
+    StartedTime = (erlang:monotonic_time(micro_seconds) - Start)/1000000,
     ?t:format("StartedTime = ~p~n", [StartedTime]),
     true = StartedTime < SleepSecs,
     erlang:system_flag(multi_scheduling, block),
     lists:foreach(fun (P) -> receive {P, done} -> ok end end, Procs),
-    DoneTime = timer:now_diff(now(), Start)/1000000,
+    DoneTime = (erlang:monotonic_time(micro_seconds) - Start)/1000000,
     ?t:format("DoneTime = ~p~n", [DoneTime]),
     true = DoneTime > SleepSecs,
     ok = verify_multi_scheduling_blocked(),
diff --git a/erts/emulator/test/process_SUITE.erl b/erts/emulator/test/process_SUITE.erl
index bf31655066..105d39f126 100644
--- a/erts/emulator/test/process_SUITE.erl
+++ b/erts/emulator/test/process_SUITE.erl
@@ -379,16 +379,15 @@ eat_high(Low) ->
     process_flag(priority, high),
     receive after 1000 -> ok end,
     exit(Low, {you, are, dead}),
-    {_, Sec, _} = now(),
-    loop(Sec, Sec).
+    loop(erlang:monotonic_time() + erlang:convert_time_unit(5,seconds,native)).
 
 %% Busy loop for 5 seconds.
 
-loop(OrigSec, CurrentSec) when CurrentSec < OrigSec+5 ->
-    {_, NewSec, _} = now(),
-    loop(OrigSec, NewSec);
-loop(_, _) ->
-    ok.
+loop(StopTime) ->
+    case StopTime >= erlang:monotonic_time() of
+	true -> ok;
+	false -> loop(StopTime)
+    end.
 
 
 %% Tries to send two different exit messages to a process.
@@ -2450,16 +2449,13 @@ start_node(Config) ->
 
 start_node(Config, Args) when is_list(Config) ->
     Pa = filename:dirname(code:which(?MODULE)),
-    {A, B, C} = now(),
     Name = list_to_atom(atom_to_list(?MODULE)
 			      ++ "-"
 			      ++ atom_to_list(?config(testcase, Config))
 			      ++ "-"
-			      ++ integer_to_list(A)
-			      ++ "-"
-			      ++ integer_to_list(B)
+			      ++ integer_to_list(erlang:system_time(seconds))
 			      ++ "-"
-			      ++ integer_to_list(C)),
+			      ++ integer_to_list(erlang:unique_integer([positive]))),
     ?t:start_node(Name, slave, [{args, "-pa "++Pa++" "++Args}]).
 
 stop_node(Node) ->
diff --git a/erts/emulator/test/scheduler_SUITE.erl b/erts/emulator/test/scheduler_SUITE.erl
index 3906471f87..c5af12c6d1 100644
--- a/erts/emulator/test/scheduler_SUITE.erl
+++ b/erts/emulator/test/scheduler_SUITE.erl
@@ -1829,11 +1829,11 @@ do_it(Tracer, Low, Normal, High, Max) ->
 do_it(Tracer, Low, Normal, High, Max, RedsPerSchedLimit) ->
     OldPrio = process_flag(priority, max),
     go_work(Low, Normal, High, Max),
-    StartWait = now(),
+    StartWait = erlang:monotonic_time(milli_seconds),
     %% Give the emulator a chance to balance the load...
     wait_balance(5),
-    EndWait = now(),
-    BalanceWait = timer:now_diff(EndWait,StartWait) div 1000,
+    EndWait = erlang:monotonic_time(milli_seconds),
+    BalanceWait = EndWait-StartWait,
     erlang:display({balance_wait, BalanceWait}),
     Timeout = ?DEFAULT_TIMEOUT - ?t:minutes(4) - BalanceWait,
     Res = case Timeout < ?MIN_SCHEDULER_TEST_TIMEOUT of
@@ -2027,17 +2027,14 @@ start_node(Config) ->
     start_node(Config, "").
 
 start_node(Config, Args) when is_list(Config) ->
-    ?line Pa = filename:dirname(code:which(?MODULE)),
-    ?line {A, B, C} = now(),
-    ?line Name = list_to_atom(atom_to_list(?MODULE)
-			      ++ "-"
-			      ++ atom_to_list(?config(testcase, Config))
-			      ++ "-"
-			      ++ integer_to_list(A)
-			      ++ "-"
-			      ++ integer_to_list(B)
-			      ++ "-"
-			      ++ integer_to_list(C)),
+    Pa = filename:dirname(code:which(?MODULE)),
+    Name = list_to_atom(atom_to_list(?MODULE)
+			++ "-"
+			++ atom_to_list(?config(testcase, Config))
+			++ "-"
+			++ integer_to_list(erlang:system_time(seconds))
+			++ "-"
+			++ integer_to_list(erlang:unique_integer([positive]))),
     ?line ?t:start_node(Name, slave, [{args, "-pa "++Pa++" "++Args}]).
 
 stop_node(Node) ->
diff --git a/erts/emulator/test/signal_SUITE.erl b/erts/emulator/test/signal_SUITE.erl
index 736dfe5b56..dcb10c947e 100644
--- a/erts/emulator/test/signal_SUITE.erl
+++ b/erts/emulator/test/signal_SUITE.erl
@@ -515,12 +515,10 @@ repeat(Fun, N) when is_integer(N)  ->
     repeat(Fun, N-1).
 
 start_node(Config) ->
-    {A, B, C} = now(),
     Name = list_to_atom(atom_to_list(?MODULE)
 			++ "-" ++ atom_to_list(?config(testcase, Config))
-			++ "-" ++ integer_to_list(A)
-			++ "-" ++ integer_to_list(B)
-			++ "-" ++ integer_to_list(C)),
+			++ "-" ++ integer_to_list(erlang:system_time(seconds))
+			++ "-" ++ integer_to_list(erlang:unique_integer([positive]))),
     Pa = filename:dirname(code:which(?MODULE)),
     ?t:start_node(Name, slave, [{args,  "-pa " ++ Pa}]).
 
diff --git a/erts/emulator/test/smoke_test_SUITE.erl b/erts/emulator/test/smoke_test_SUITE.erl
index 10b7e16a74..4c50b8ba8c 100644
--- a/erts/emulator/test/smoke_test_SUITE.erl
+++ b/erts/emulator/test/smoke_test_SUITE.erl
@@ -167,16 +167,13 @@ start_node(Config) ->
 
 start_node(Config, Args) when is_list(Config) ->
     Pa = filename:dirname(code:which(?MODULE)),
-    {A, B, C} = now(),
     Name = list_to_atom(atom_to_list(?MODULE)
 	      ++ "-"
 	      ++ atom_to_list(?config(testcase, Config))
 	      ++ "-"
-	      ++ integer_to_list(A)
+	      ++ integer_to_list(erlang:system_time(seconds))
 	      ++ "-"
-	      ++ integer_to_list(B)
-	      ++ "-"
-	      ++ integer_to_list(C)),
+	      ++ integer_to_list(erlang:unique_integer([positive]))),
     Opts = [{args, "-pa "++Pa++" "++Args}],
     ?t:start_node(Name, slave, Opts).
 
diff --git a/erts/emulator/test/system_info_SUITE.erl b/erts/emulator/test/system_info_SUITE.erl
index f959714be7..0fd6696536 100644
--- a/erts/emulator/test/system_info_SUITE.erl
+++ b/erts/emulator/test/system_info_SUITE.erl
@@ -533,16 +533,13 @@ get_ets_limit(Config, EtsMax) ->
 
 start_node(Config, Envs) when is_list(Config) ->
     Pa = filename:dirname(code:which(?MODULE)),
-    {A, B, C} = now(),
     Name = list_to_atom(atom_to_list(?MODULE)
                         ++ "-"
                         ++ atom_to_list(?config(testcase, Config))
                         ++ "-"
-                        ++ integer_to_list(A)
+                        ++ integer_to_list(erlang:system_time(seconds))
                         ++ "-"
-                        ++ integer_to_list(B)
-                        ++ "-"
-                        ++ integer_to_list(C)),
+                        ++ integer_to_list(erlang:unique_integer([positive]))),
     ?t:start_node(Name, peer, [{args, "-pa "++Pa}, {env, Envs}]).
 
 stop_node(Node) ->
diff --git a/erts/emulator/test/time_SUITE.erl b/erts/emulator/test/time_SUITE.erl
index 43f7ac7f7c..55e1b7858c 100644
--- a/erts/emulator/test/time_SUITE.erl
+++ b/erts/emulator/test/time_SUITE.erl
@@ -18,6 +18,7 @@
 %%
 
 -module(time_SUITE).
+-compile({nowarn_deprecated_function, {erlang,now,0}}).
 
 %% "Time is on my side." -- The Rolling Stones
 
diff --git a/erts/emulator/test/timer_bif_SUITE.erl b/erts/emulator/test/timer_bif_SUITE.erl
index 56a1cef761..3701dd8437 100644
--- a/erts/emulator/test/timer_bif_SUITE.erl
+++ b/erts/emulator/test/timer_bif_SUITE.erl
@@ -502,9 +502,10 @@ get_msg() ->
     end.
 
 start_slave() ->
-    ?line {A, B, C} = now(),
     ?line Pa = filename:dirname(code:which(?MODULE)),
-    ?line Name = atom_to_list(?MODULE) ++ "-" ++ integer_to_list(A+B+C),
+    ?line Name = atom_to_list(?MODULE)
+	++ "-" ++ integer_to_list(erlang:system_time(seconds))
+	++ "-" ++ integer_to_list(erlang:unique_integer([positive])),
     {ok, Node} = ?t:start_node(Name, slave, [{args, "-pa " ++ Pa}]),
     Node.
 
diff --git a/erts/emulator/test/trace_call_time_SUITE.erl b/erts/emulator/test/trace_call_time_SUITE.erl
index 3036d2957b..9c444ed682 100644
--- a/erts/emulator/test/trace_call_time_SUITE.erl
+++ b/erts/emulator/test/trace_call_time_SUITE.erl
@@ -326,10 +326,10 @@ combo(Config) when is_list(Config) ->
 
     %%
     ?line [3,2,1] = seq_r(1, 3, fun(X) -> X+1 end),
-    ?line T0 = now(),
+    ?line T0 = erlang:monotonic_time(),
     ?line with_bif(Nbc),
-    ?line T1 = now(),
-    ?line TimeB = timer:now_diff(T1,T0),
+    ?line T1 = erlang:monotonic_time(),
+    ?line TimeB = erlang:convert_time_unit(T1-T0, native, micro_seconds),
     %%
 
     ?line List = collect(100),
@@ -695,17 +695,17 @@ setup(Opts) ->
     Pid.
 
 execute(Pids, Mfa) when is_list(Pids) ->
-    T0 = now(),
+    T0 = erlang:monotonic_time(),
     [P  ! {self(), execute, Mfa} || P <- Pids],
     As = [receive {P, answer, Answer} -> Answer end || P <- Pids],
-    T1 = now(),
-    {As, timer:now_diff(T1,T0)};
+    T1 = erlang:monotonic_time(),
+    {As, erlang:convert_time_unit(T1-T0, native, micro_seconds)};
 execute(P, Mfa) ->
-    T0 = now(),
+    T0 = erlang:monotonic_time(),
     P  ! {self(), execute, Mfa},
     A  = receive {P, answer, Answer} -> Answer end,
-    T1 = now(),
-    {A, timer:now_diff(T1,T0)}.
+    T1 = erlang:monotonic_time(),
+    {A, erlang:convert_time_unit(T1-T0, native, micro_seconds)}.