Remove erlang:now() and random usage in tests

1 files changed, 26 insertions, 29 deletions

diff --git a/lib/mnesia/test/mnesia_dbn_meters.erl b/lib/mnesia/test/mnesia_dbn_meters.erl
index f97bd973fc..5c3ea08a1d 100644
--- a/lib/mnesia/test/mnesia_dbn_meters.erl
+++ b/lib/mnesia/test/mnesia_dbn_meters.erl
@@ -93,7 +93,7 @@ some_meters() ->
 report_meter(Meter) ->
     Times = 100,
     Micros = repeat_meter(Meter,{atomic,{0,ignore}},Times) div Times,
-    io:format("\t~-30w ~-10w micro seconds (mean of ~p repetitions)~n",[Meter,Micros,Times]).
+    io:format("\t~-30w ~-10w nano seconds (mean of ~p repetitions)~n",[Meter,Micros,Times]).
 
 repeat_meter(_Meter,{atomic,{Micros,_Result}},0) ->
     Micros;
@@ -110,9 +110,9 @@ meter(create) ->
     Key = 1,
     mnesia:transaction(fun() -> mnesia:delete({simple,Key}) end),
     Fun = fun() ->
-		  BeforeT = erlang:now(),
+		  BeforeT = erlang:monotonic_time(),
 		  R = mnesia:write(#simple{key=Key}),
-		  AfterT = erlang:now(),
+		  AfterT = erlang:monotonic_time(),
 		  elapsed_time(BeforeT,AfterT,R)
 	  end,
     mnesia:transaction(Fun);
@@ -121,9 +121,9 @@ meter(open_safe_read) ->
     Key = 2,
     mnesia:transaction(fun() -> mnesia:write(#simple{key=Key}) end),
     Fun = fun() ->
-		  BeforeT = erlang:now(),
+		  BeforeT = erlang:monotonic_time(),
 		  R = mnesia:read({simple,Key}),
-		  AfterT = erlang:now(),
+		  AfterT = erlang:monotonic_time(),
 		  elapsed_time(BeforeT,AfterT,R)
 	  end,
     mnesia:transaction(Fun);
@@ -132,9 +132,9 @@ meter(open_dirty_read) ->
     Key = 21,
     mnesia:transaction(fun() -> mnesia:write(#simple{key=Key}) end),
     Fun = fun() ->
-		  BeforeT = erlang:now(),
+		  BeforeT = erlang:monotonic_time(),
 		  R = mnesia:dirty_read({simple,Key}),
-		  AfterT = erlang:now(),
+		  AfterT = erlang:monotonic_time(),
 		  elapsed_time(BeforeT,AfterT,R)
 	  end,
     mnesia:transaction(Fun);
@@ -144,9 +144,9 @@ meter(get_int) ->
     mnesia:transaction(fun() -> mnesia:write(#simple{key=Key}) end),
     Fun = fun() ->
 		  [Simple] = mnesia:read({simple,Key}),
-		  BeforeT = erlang:now(),
+		  BeforeT = erlang:monotonic_time(),
 		  Int = Simple#simple.val,
-		  AfterT = erlang:now(),
+		  AfterT = erlang:monotonic_time(),
 		  elapsed_time(BeforeT,AfterT,Int)
 	  end,
     mnesia:transaction(Fun);
@@ -155,9 +155,9 @@ meter(open_update) ->
     Key = 3,
     mnesia:transaction(fun() -> mnesia:write(#simple{key=Key}) end),
     Fun = fun() ->
-		  BeforeT = erlang:now(),
+		  BeforeT = erlang:monotonic_time(),
 		  R = mnesia:wread({simple,Key}),
-		  AfterT = erlang:now(),
+		  AfterT = erlang:monotonic_time(),
 		  elapsed_time(BeforeT,AfterT,R)
 	  end,
     mnesia:transaction(Fun);
@@ -167,9 +167,9 @@ meter(put_int) ->
     mnesia:transaction(fun() -> mnesia:write(#simple{key=Key}) end),
     Fun = fun() ->
 		  [Simple] = mnesia:wread({simple,Key}),
-		  BeforeT = erlang:now(),
+		  BeforeT = erlang:monotonic_time(),
 		  R = Simple#simple{val=7},
-		  AfterT = erlang:now(),
+		  AfterT = erlang:monotonic_time(),
 		  elapsed_time(BeforeT,AfterT,R)
 	  end,
     mnesia:transaction(Fun);
@@ -179,10 +179,10 @@ meter(put_int_and_copy) ->
     mnesia:transaction(fun() -> mnesia:write(#simple{key=Key}) end),
     Fun = fun() ->
 		  [Simple] = mnesia:wread({simple,Key}),
-		  BeforeT = erlang:now(),
+		  BeforeT = erlang:monotonic_time(),
 		  Simple2 = Simple#simple{val=17},
 		  R = mnesia:write(Simple2),
-		  AfterT = erlang:now(),
+		  AfterT = erlang:monotonic_time(),
 		  elapsed_time(BeforeT,AfterT,R)
 	  end,
     mnesia:transaction(Fun);
@@ -191,15 +191,15 @@ meter(dirty_put_int_and_copy) ->
     Key = 55,
     mnesia:dirty_write(#simple{key=Key}),
     [Simple] = mnesia:dirty_read({simple,Key}),
-    BeforeT = erlang:now(),
+    BeforeT = erlang:monotonic_time(),
     Simple2 = Simple#simple{val=17},
     R = mnesia:dirty_write(Simple2),
-    AfterT = erlang:now(),
+    AfterT = erlang:monotonic_time(),
     {atomic,elapsed_time(BeforeT,AfterT,R)};
 
 meter(start_trans) ->
-    BeforeT = erlang:now(),
-    {atomic,AfterT} = mnesia:transaction(fun() -> erlang:now() end),
+    BeforeT = erlang:monotonic_time(),
+    {atomic,AfterT} = mnesia:transaction(fun() -> erlang:monotonic_time() end),
     {atomic,elapsed_time(BeforeT,AfterT,ok)};
 
 meter(commit_one_update) ->
@@ -209,19 +209,19 @@ meter(commit_one_update) ->
 		  [Simple] = mnesia:wread({simple,Key}),
 		  Simple2 = Simple#simple{val=27},
 		  _R = mnesia:write(Simple2),
-		  erlang:now()
+		  erlang:monotonic_time()
 	  end,
     {atomic,BeforeT} = mnesia:transaction(Fun),
-    AfterT = erlang:now(),
+    AfterT = erlang:monotonic_time(),
     {atomic,elapsed_time(BeforeT,AfterT,ok)};
 
 meter(delete) ->
     Key = 7,
     mnesia:transaction(fun() -> mnesia:write(#simple{key=Key}) end),
     Fun = fun() ->
-		  BeforeT = erlang:now(),
+		  BeforeT = erlang:monotonic_time(),
 		  R = mnesia:delete({simple,Key}),
-		  AfterT = erlang:now(),
+		  AfterT = erlang:monotonic_time(),
 		  elapsed_time(BeforeT,AfterT,R)
 	  end,
     mnesia:transaction(Fun);
@@ -229,15 +229,12 @@ meter(delete) ->
 meter(dirty_delete) ->
     Key = 75,
     mnesia:dirty_write(#simple{key=Key}),
-    BeforeT = erlang:now(),
+    BeforeT = erlang:monotonic_time(),
     R = mnesia:dirty_delete({simple,Key}),
-    AfterT = erlang:now(),
+    AfterT = erlang:monotonic_time(),
     {atomic, elapsed_time(BeforeT,AfterT,R)}.
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% Calculate the elapsed time
 elapsed_time(BeforeT,AfterT,Result) ->
-    {(element(1,AfterT)*1000000000000
-     +element(2,AfterT)*1000000+element(3,AfterT)) -
-	(element(1,BeforeT)*1000000000000
-	 +element(2,BeforeT)*1000000+element(3,BeforeT)),Result}.
+    {erlang:convert_time_unit(AfterT-BeforeT, native, nano_seconds),Result}.