Merge branch 'bjorn/kernel/cuddle-with-tests'

* bjorn/kernel/cuddle-with-tests:
  Clean up rpc_SUITE:call_benchmark/1
  Eliminate use of erlang:now/0 for generating random numbers
  Eliminate use of erlang:now/0 for measuring time
  Eliminate use of erlang:now/0 for generating unique node names

7 files changed, 55 insertions, 89 deletions

diff --git a/lib/kernel/test/application_SUITE.erl b/lib/kernel/test/application_SUITE.erl
index 4901206c8e..59efe85480 100644
--- a/lib/kernel/test/application_SUITE.erl
+++ b/lib/kernel/test/application_SUITE.erl
@@ -2699,10 +2699,7 @@ node_names(Names, Config) ->
 
 node_name(Name, Config) ->
     U = "_",
-    {{Y,M,D}, {H,Min,S}} = calendar:now_to_local_time(now()),
-    Date = io_lib:format("~4w_~2..0w_~2..0w__~2..0w_~2..0w_~2..0w", 
-                         [Y,M,D, H,Min,S]),
-    L = lists:flatten(Date),
+    L = integer_to_list(erlang:unique_integer([positive])),
     lists:concat([Name,U,?testcase,U,U,L]).
 
 stop_node_nice(Node) when is_atom(Node) ->
diff --git a/lib/kernel/test/erl_distribution_SUITE.erl b/lib/kernel/test/erl_distribution_SUITE.erl
index 15c2adc957..76564d4b0e 100644
--- a/lib/kernel/test/erl_distribution_SUITE.erl
+++ b/lib/kernel/test/erl_distribution_SUITE.erl
@@ -235,11 +235,10 @@ do_test_setuptime(Setuptime) when is_list(Setuptime) ->
     Res.
 
 time_ping(Node) ->
-    T0 = erlang:now(),
+    T0 = erlang:monotonic_time(),
     pang = net_adm:ping(Node),
-    T1 = erlang:now(),
-    time_diff(T0,T1).
-    
+    T1 = erlang:monotonic_time(),
+    erlang:convert_time_unit(T1 - T0, native, milli_seconds).
 
 %% Keep the connection with the client node up.
 %% This is neccessary as the client node runs with much shorter
@@ -276,13 +275,15 @@ tick_cli_test1(Node) ->
     erlang:monitor_node(Node, true),
     sleep(2),
     rpc:call(Node, erlang, time, []), %% simulate action on the connection
-    T1 = now(),
+    T1 = erlang:monotonic_time(),
     receive
 	{nodedown, Node} ->
-	    T2 = now(),
+	    T2 = erlang:monotonic_time(),
 	    receive
 		{whats_the_result, From} ->
-		    case time_diff(T1, T2) of
+		    Diff = erlang:convert_time_unit(T2-T1, native,
+						    milli_seconds),
+		    case Diff of
 			T when T > 8000, T < 16000 ->
 			    From ! {tick_test, T};
 			T ->
@@ -1208,19 +1209,6 @@ print_my_messages() ->
     ?line ?t:format("Messages: ~p~n", [Messages]),
     ?line ok.
 
-%% Time difference in milliseconds !!
-time_diff({TimeM, TimeS, TimeU}, {CurM, CurS, CurU}) when CurM > TimeM ->
-    ((CurM - TimeM) * 1000000000) + sec_diff({TimeS, TimeU}, {CurS, CurU});
-time_diff({_, TimeS, TimeU}, {_, CurS, CurU}) ->
-    sec_diff({TimeS, TimeU}, {CurS, CurU}).
-
-sec_diff({TimeS, TimeU}, {CurS, CurU}) when CurS > TimeS ->
-    ((CurS - TimeS) * 1000) + micro_diff(TimeU, CurU);
-sec_diff({_, TimeU}, {_, CurU}) ->
-    micro_diff(TimeU, CurU).
-
-micro_diff(TimeU, CurU) ->
-    trunc(CurU/1000) - trunc(TimeU/1000).
 
 sleep(T) -> receive after T * 1000 -> ok end.	
 
@@ -1267,16 +1255,12 @@ get_nodenames(N, T) ->
 get_nodenames(0, _, Acc) ->
     Acc;
 get_nodenames(N, T, Acc) ->
-    {A, B, C} = now(),
+    U = erlang:unique_integer([positive]),
     get_nodenames(N-1, T, [list_to_atom(atom_to_list(T)
 					++ "-"
-					++ atom_to_list(?MODULE)
-					++ "-"
-					++ integer_to_list(A)
+					++ ?MODULE_STRING
 					++ "-"
-					++ integer_to_list(B)
-					++ "-"
-					++ integer_to_list(C)) | Acc]).
+					++ integer_to_list(U)) | Acc]).
 
 get_numbered_nodenames(N, T) ->
     get_numbered_nodenames(N, T, []).
@@ -1284,16 +1268,12 @@ get_numbered_nodenames(N, T) ->
 get_numbered_nodenames(0, _, Acc) ->
     Acc;
 get_numbered_nodenames(N, T, Acc) ->
-    {A, B, C} = now(),
+    U = erlang:unique_integer([positive]),
     NL = [list_to_atom(atom_to_list(T) ++ integer_to_list(N)
 		       ++ "-"
-		       ++ atom_to_list(?MODULE)
-		       ++ "-"
-		       ++ integer_to_list(A)
-		       ++ "-"
-		       ++ integer_to_list(B)
+		       ++ ?MODULE_STRING
 		       ++ "-"
-		       ++ integer_to_list(C)) | Acc],
+		       ++ integer_to_list(U)) | Acc],
     get_numbered_nodenames(N-1, T, NL).
 
 wait_until(Fun) ->
diff --git a/lib/kernel/test/erl_distribution_wb_SUITE.erl b/lib/kernel/test/erl_distribution_wb_SUITE.erl
index 3b8b2d9150..8e2bbf5b64 100644
--- a/lib/kernel/test/erl_distribution_wb_SUITE.erl
+++ b/lib/kernel/test/erl_distribution_wb_SUITE.erl
@@ -451,11 +451,8 @@ close_pair({Client, Server}) ->
 %% MD5 hashing
 %%
 
-%% This is no proper random number, but that is not really important in 
-%% this test
 gen_challenge() ->
-    {_,_,N} = erlang:now(), 
-    N.
+    rand:uniform(1000000).
     
 %% Generate a message digest from Challenge number and Cookie	
 gen_digest(Challenge, Cookie) when is_integer(Challenge), is_atom(Cookie) ->
@@ -712,13 +709,9 @@ get_nodenames(N, T) ->
 get_nodenames(0, _, Acc) ->
     Acc;
 get_nodenames(N, T, Acc) ->
-    {A, B, C} = now(),
-    get_nodenames(N-1, T, [list_to_atom(atom_to_list(?MODULE)
+    U = erlang:unique_integer([positive]),
+    get_nodenames(N-1, T, [list_to_atom(?MODULE_STRING
 					++ "-"
 					++ atom_to_list(T)
 					++ "-"
-					++ integer_to_list(A)
-					++ "-"
-					++ integer_to_list(B)
-					++ "-"
-					++ integer_to_list(C)) | Acc]).
+					++ integer_to_list(U)) | Acc]).
diff --git a/lib/kernel/test/file_SUITE.erl b/lib/kernel/test/file_SUITE.erl
index 1213d8e37e..48abc92e4c 100644
--- a/lib/kernel/test/file_SUITE.erl
+++ b/lib/kernel/test/file_SUITE.erl
@@ -3914,7 +3914,7 @@ response_analysis(Module, Function, Arguments) ->
 		  receive {Parent, start, Ts} -> ok end,
 		  Stat = 
 		      iterate(response_stat(response_stat(init, Ts),
-					    erlang:now()), 
+					    micro_ts()),
 			      done,
 			      fun (S) ->
 				      erlang:yield(),
@@ -3922,12 +3922,12 @@ response_analysis(Module, Function, Arguments) ->
 					  {Parent, stop} ->
 					      done
 				      after 0 ->
-					      response_stat(S, erlang:now())
+					      response_stat(S, micro_ts())
 				      end
 			      end),
-		  Parent ! {self(), stopped, response_stat(Stat, erlang:now())}
+		  Parent ! {self(), stopped, response_stat(Stat, micro_ts())}
 	  end),
-    ?line Child ! {Parent, start, erlang:now()},
+    Child ! {Parent, start, micro_ts()},
     ?line Result = apply(Module, Function, Arguments),
     ?line Child ! {Parent, stop},
     ?line {N, Sum, _, M, Max} = receive {Child, stopped, X} -> X end,
@@ -3941,12 +3941,13 @@ response_analysis(Module, Function, Arguments) ->
 	    [Mean_ms, Max_ms, M, (N-1)])),
     ?line {Result, Comment}.
     
-
+micro_ts() ->
+    erlang:monotonic_time(micro_seconds).
 
 response_stat(init, Ts) ->
     {0, 0, Ts, 0, 0};
-response_stat({N, Sum, {A1, B1, C1}, M, Max}, {A2, B2, C2} = Ts) ->
-    D = C2-C1 + 1000000*((B2-B1) + 1000000*(A2-A1)),
+response_stat({N, Sum, Ts0, M, Max}, Ts) ->
+    D = Ts - Ts0,
     if D > Max ->
 	    {N+1, Sum+D, Ts, N, D};
        true ->
diff --git a/lib/kernel/test/gen_tcp_misc_SUITE.erl b/lib/kernel/test/gen_tcp_misc_SUITE.erl
index ba4acad2e7..4f0d7a7d50 100644
--- a/lib/kernel/test/gen_tcp_misc_SUITE.erl
+++ b/lib/kernel/test/gen_tcp_misc_SUITE.erl
@@ -1641,8 +1641,7 @@ so_priority(Config) when is_list(Config) ->
 %% Accept test utilities (suites are below)
 
 millis() ->
-    {A,B,C}=erlang:now(),
-    (A*1000000*1000)+(B*1000)+(C div 1000).
+    erlang:monotonic_time(milli_seconds).
 	
 collect_accepts(0,_) -> [];
 collect_accepts(N,Tmo) ->
@@ -2103,8 +2102,8 @@ send_timeout(Config) when is_list(Config) ->
     ok.
 
 mad_sender(S) ->
-    {_, _, USec} = now(),
-    case gen_tcp:send(S, integer_to_list(USec)) of
+    U = rand:uniform(1000000),
+    case gen_tcp:send(S, integer_to_list(U)) of
         ok ->
             mad_sender(S);
         Err ->
@@ -2172,10 +2171,10 @@ get_max_diff() ->
     end.
 
 get_max_diff(Max) ->
-    T1 = millistamp(),
+    T1 = millis(),
     receive
 	ok ->
-	    Diff = millistamp() - T1,
+	    Diff = millis() - T1,
 	    if
 		Diff > Max ->
 		    get_max_diff(Diff);
@@ -2183,7 +2182,7 @@ get_max_diff(Max) ->
 		    get_max_diff(Max)
 	    end;
 	{error,timeout} ->
-	    Diff = millistamp() - T1,
+	    Diff = millis() - T1,
 	    if
 		Diff > Max ->
 		    Diff;
@@ -2324,10 +2323,6 @@ setup_active_timeout_sink(Timeout, AutoClose) ->
     {Loop,A,R,C}.
 
      
-millistamp() ->
-    {Mega, Secs, Micros} = erlang:now(),
-    (Micros div 1000) + Secs * 1000 + Mega * 1000000000.
-
 has_superfluous_schedulers() ->
     case {erlang:system_info(schedulers),
 	  erlang:system_info(logical_processors)} of
diff --git a/lib/kernel/test/interactive_shell_SUITE.erl b/lib/kernel/test/interactive_shell_SUITE.erl
index 3fb7c68886..89c574b025 100644
--- a/lib/kernel/test/interactive_shell_SUITE.erl
+++ b/lib/kernel/test/interactive_shell_SUITE.erl
@@ -718,8 +718,7 @@ toerl_loop(Port,Acc) ->
     end.
 	
 millistamp() ->
-    {Mega, Secs, Micros} = erlang:now(),
-    (Micros div 1000) + Secs * 1000 + Mega * 1000000000.
+    erlang:monotonic_time(milli_seconds).
     
 get_data_within(Port, X, Acc) when X =< 0 ->
     ?dbg({get_data_within, X, Acc, ?LINE}),
diff --git a/lib/kernel/test/rpc_SUITE.erl b/lib/kernel/test/rpc_SUITE.erl
index 7adef49014..867b448b36 100644
--- a/lib/kernel/test/rpc_SUITE.erl
+++ b/lib/kernel/test/rpc_SUITE.erl
@@ -456,32 +456,33 @@ called_throws(Config) when is_list(Config) ->
 
 call_benchmark(Config) when is_list(Config) ->
     Timetrap = ?t:timetrap(?t:seconds(120)),
-    ?line PA = filename:dirname(code:which(?MODULE)),
-    ?line {ok, Node} = ?t:start_node(rpc_SUITE_call_benchmark, slave, 
-				     [{args, "-pa " ++ PA}]),
+    PA = filename:dirname(code:which(?MODULE)),
+    {ok, Node} = ?t:start_node(rpc_SUITE_call_benchmark, slave,
+			       [{args, "-pa " ++ PA}]),
     Iter = case erlang:system_info(modified_timing_level) of
 	       undefined -> 10000;
-	       _ -> 500				%Moified timing - spawn is slower
+	       _ -> 500		     %Modified timing - spawn is slower
 	   end,
-    ?line do_call_benchmark(Node, Iter),
+    Res = do_call_benchmark(Node, Iter),
+    ?t:stop_node(Node),
     ?t:timetrap_cancel(Timetrap),
-    ok.
+    Res.
 
 do_call_benchmark(Node, M) when is_integer(M), M > 0 ->
-    do_call_benchmark(Node, erlang:now(), 0, M).
-
-do_call_benchmark(Node, {A,B,C}, M, M) ->
-    ?line {D,E,F} = erlang:now(),
-    ?line T = float(D-A)*1000000.0 + float(E-B) + float(F-C)*0.000001,
-    ?line Q = 3.0 * float(M) / T,
-    ?line ?t:stop_node(Node),
-    {comment, 
-     lists:flatten([float_to_list(Q)," RPC calls per second"])};
-do_call_benchmark(Node, Then, I, M) ->
-    ?line Node = rpc:call(Node, erlang, node, []),
-    ?line _ = rpc:call(Node, erlang, whereis, [rex]),
-    ?line 3 = rpc:call(Node, erlang, '+', [1,2]),
-    ?line do_call_benchmark(Node, Then, I+1, M).
+    {Micros,ok} = timer:tc(fun() ->
+				   do_call_benchmark(Node, 0, M)
+			   end),
+    Calls = 3*M,
+    S = io_lib:format("~p RPC calls/second", [Calls*1000000 div Micros]),
+    {comment,lists:flatten(S)}.
+
+do_call_benchmark(_Node, M, M) ->
+    ok;
+do_call_benchmark(Node, I, M) ->
+    Node = rpc:call(Node, erlang, node, []),
+    _ = rpc:call(Node, erlang, whereis, [rex]),
+    3 = rpc:call(Node, erlang, '+', [1,2]),
+    do_call_benchmark(Node, I+1, M).
 
 async_call(Config) when is_list(Config) ->
     Dog = ?t:timetrap(?t:seconds(120)),