Add first phase of trace call time test suite

2 files changed, 577 insertions, 0 deletions

diff --git a/erts/emulator/test/Makefile b/erts/emulator/test/Makefile
index 97b94c466f..5ec17a5e2a 100644
--- a/erts/emulator/test/Makefile
+++ b/erts/emulator/test/Makefile
@@ -101,6 +101,7 @@ MODULES= \
 	trace_local_SUITE \
 	trace_meta_SUITE \
 	trace_call_count_SUITE \
+	trace_call_time_SUITE \
 	scheduler_SUITE \
 	old_scheduler_SUITE \
 	z_SUITE \
diff --git a/erts/emulator/test/trace_call_time_SUITE.erl b/erts/emulator/test/trace_call_time_SUITE.erl
new file mode 100644
index 0000000000..e7bccb8dac
--- /dev/null
+++ b/erts/emulator/test/trace_call_time_SUITE.erl
@@ -0,0 +1,576 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2002-2009. 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%
+%%
+
+%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%
+%%% Define to run outside of test server
+%%%
+%%% -define(STANDALONE,1).
+%%%
+%%%
+%%% Define for debug output
+%%%
+%%% -define(debug,1).
+
+-module(trace_call_time_SUITE).
+
+%% Exported end user tests
+-export([basic_test/0, on_and_off_test/0, info_test/0,
+	 pause_and_restart_test/0, called_function_test/0, scheduling_test/0, combo_test/0]).
+
+-export([seq/3, seq_r/3]).
+-export([loaded/1, a_function/1, a_called_function/1, dec/1]).
+
+-define(US_ERROR, 10000).
+-define(R_ERROR, 0.8).
+-define(SINGLE_CALL_US_TIME, 10).
+
+%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Test server related stuff
+%%
+
+
+-ifdef(STANDALONE).
+-define(config(A,B),config(A,B)).
+-export([config/2]).
+-else.
+-include("test_server.hrl").
+-endif.
+
+-ifdef(debug).
+-ifdef(STANDALONE).
+-define(line, erlang:display({?MODULE,?LINE}), ).
+-endif.
+-define(dbgformat(A,B),io:format(A,B)).
+-else.
+-ifdef(STANDALONE).
+-define(line, noop, ).
+-endif.
+-define(dbgformat(A,B),noop).
+-endif.
+
+-ifdef(STANDALONE).
+config(priv_dir,_) ->
+    ".".
+-else.
+%% When run in test server.
+-export([all/1, init_per_testcase/2, fin_per_testcase/2, not_run/1]).
+-export([basic/1, on_and_off/1, info/1,
+	 pause_and_restart/1, scheduling/1, called_function/1, combo/1]).
+
+init_per_testcase(_Case, Config) ->
+    ?line Dog=test_server:timetrap(test_server:seconds(30)),
+    erlang:trace_pattern({'_','_','_'}, false, [local,meta,call_time,call_count]),
+    erlang:trace_pattern(on_load, false, [local,meta,call_time,call_count]),
+    timer:now_diff(now(),now()),
+    [{watchdog, Dog}|Config].
+
+fin_per_testcase(_Case, Config) ->
+    erlang:trace_pattern({'_','_','_'}, false, [local,meta,call_time,call_count]),
+    erlang:trace_pattern(on_load, false, [local,meta,call_time,call_count]),
+    erlang:trace(all, false, [all]),
+    Dog=?config(watchdog, Config),
+    test_server:timetrap_cancel(Dog),
+    ok.
+
+all(doc) ->
+    ["Test call count tracing of local function calls."];
+all(suite) ->
+    case test_server:is_native(?MODULE) of
+	true -> [not_run];
+	false -> [basic, on_and_off, info,
+		  pause_and_restart, scheduling, combo, called_function]
+    end.
+
+not_run(Config) when is_list(Config) ->
+    {skipped,"Native code"}.
+
+basic(suite) ->
+    [];
+basic(doc) ->
+    ["Tests basic call count trace"];
+basic(Config) when is_list(Config) ->
+    basic_test().
+
+on_and_off(suite) ->
+    [];
+on_and_off(doc) ->
+    ["Tests turning trace parameters on and off"];
+on_and_off(Config) when is_list(Config) ->
+    on_and_off_test().
+
+info(suite) ->
+    [];
+info(doc) ->
+    ["Tests the trace_info BIF"];
+info(Config) when is_list(Config) ->
+    info_test().
+
+pause_and_restart(suite) ->
+    [];
+pause_and_restart(doc) ->
+    ["Tests pausing and restarting call time counters"];
+pause_and_restart(Config) when is_list(Config) ->
+    pause_and_restart_test().
+
+scheduling(suite) ->
+    [];
+scheduling(doc) ->
+    ["Tests in/out scheduling of call time counters"];
+scheduling(Config) when is_list(Config) ->
+    scheduling_test().
+
+
+combo(suite) ->
+    [];
+combo(doc) ->
+    ["Tests combining local call trace and meta trace with call time trace"];
+combo(Config) when is_list(Config) ->
+    combo_test().
+
+called_function(suite) ->
+    [];
+called_function(doc) ->
+    ["Tests combining nested function calls and that the time accumulates to the right function"];
+called_function(Config) when is_list(Config) ->
+    called_function_test().
+
+
+-endif. %-ifdef(STANDALONE). ... -else.
+
+%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Result examination macros
+
+-define(CT(P,MFA),{trace,P,call,MFA}).
+-define(CTT(P, MFA),{trace_ts,P,call,MFA,{_,_,_}}).
+-define(RF(P,MFA,V),{trace,P,return_from,MFA,V}).
+-define(RFT(P,MFA,V),{trace_ts,P,return_from,MFA,V,{_,_,_}}).
+-define(RT(P,MFA),{trace,P,return_to,MFA}).
+-define(RTT(P,MFA),{trace_ts,P,return_to,MFA,{_,_,_}}).
+
+%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%% The Tests
+%%%
+
+basic_test() ->
+    ?line P = erlang:trace_pattern({'_','_','_'}, false, [call_time]),
+    ?line M = 1000000,
+    %%
+    ?line 1 = erlang:trace_pattern({?MODULE,seq,  '_'}, true, [call_time]),
+    ?line 2 = erlang:trace_pattern({?MODULE,seq_r,'_'}, true, [call_time]),
+    ?line Pid = setup(),
+    ?line {L,  T1} = execute(Pid, fun() -> seq(1, M+M, fun(X) -> (X+1) end) end),
+    ?line ok = check_trace_info({?MODULE, seq,   3}, [{Pid, M+M, 0, 0}], T1),
+    ?line ok = check_trace_info({?MODULE, seq_r, 3}, [], none),
+
+    ?line {Lr, T2} = execute(Pid, fun() -> seq_r(1, M, fun(X) -> (X+1) end) end),
+    ?line ok = check_trace_info({?MODULE, seq,   3}, [{Pid, M+M, 0, 0}], T1),
+    ?line ok = check_trace_info({?MODULE, seq_r, 3}, [{Pid, 1, 0, 0}], T2),
+    ?line ok = check_trace_info({?MODULE, seq_r, 4}, [{Pid, M, 0, 0}], T2),
+    ?line L = lists:reverse(Lr),
+    %%
+    ?line P = erlang:trace_pattern({'_','_','_'}, false, [call_time]),
+    ?line Pid ! quit,
+    ok.
+
+%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+on_and_off_test() ->
+    ?line P = erlang:trace_pattern({'_','_','_'}, false, [call_time]),
+    ?line M = 100,
+    %%
+    ?line 1 = erlang:trace_pattern({?MODULE,seq,'_'}, true, [call_time]),
+    ?line Pid = setup(),
+    ?line {L, T1} = execute(Pid, {?MODULE, seq, [1, M, fun(X) -> X+1 end]}),
+    ?line ok = check_trace_info({?MODULE, seq, 3}, [{Pid, M, 0, 0}], T1),
+
+    ?line N = erlang:trace_pattern({?MODULE,'_','_'}, true, [call_time]),
+    ?line {L, T2} = execute(Pid, fun() -> seq(1, M, fun(X) -> X+1 end) end),
+    ?line ok = check_trace_info({?MODULE, seq, 3}, [{Pid, M, 0, 0}], T2),
+
+    ?line P = erlang:trace_pattern({'_','_','_'}, true, [call_time]),
+    ?line {L, T3} = execute(Pid, fun() -> seq(1, M, fun(X) -> X+1 end) end),
+    ?line ok = check_trace_info({?MODULE, seq, 3}, [{Pid, M, 0, 0}], T3),
+
+    ?line 1 = erlang:trace_pattern({?MODULE,seq,'_'}, false, [call_time]),
+    ?line ok = check_trace_info({?MODULE, seq, 3}, false, none),
+    ?line {L, _T4} = execute(Pid, fun() -> seq(1, M, fun(X) -> X+1 end) end),
+    ?line ok = check_trace_info({?MODULE, seq, 3}, false, none),
+    ?line ok = check_trace_info({?MODULE, seq_r, 4}, [], none),
+    ?line {Lr, T5} = execute(Pid, fun() -> seq_r(1, M, fun(X) -> X+1 end) end),
+    ?line ok = check_trace_info({?MODULE, seq_r, 4}, [{Pid,M,0,0}], T5),
+
+    ?line N = erlang:trace_pattern({?MODULE,'_','_'}, false, [call_time]),
+    ?line ok = check_trace_info({?MODULE, seq_r, 4}, false, none),
+    ?line {Lr, _T6} = execute(Pid, fun() -> seq_r(1, M, fun(X) -> X+1 end) end),
+    ?line ok = check_trace_info({?MODULE, seq_r, 4}, false, none),
+    ?line L = lists:reverse(Lr),
+    %%
+    ?line Pid ! quit,
+    ?line P = erlang:trace_pattern({'_','_','_'}, false, [call_time]),
+    ok.
+
+%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+called_function_test() ->
+    ?line P = erlang:trace_pattern({'_','_','_'}, false, [call_time]),
+    ?line M = 2100,
+    ?line Pid = setup(),
+    %%
+    ?line 1 = erlang:trace_pattern({?MODULE,a_function,'_'}, true, [call_time]),
+    ?line {L, T1} = execute(Pid, {?MODULE, a_function, [M]}),
+    ?line ok = check_trace_info({?MODULE, a_function, 1}, [{Pid, M, 0, 0}], T1),
+
+    ?line 1 = erlang:trace_pattern({?MODULE,a_called_function,'_'}, true, [call_time]),
+    ?line {L, T2} = execute(Pid, {?MODULE, a_function, [M]}),
+    ?line ok = check_trace_info({?MODULE, a_function, 1}, [{Pid, M+M, 0, 0}], T1 + M*?SINGLE_CALL_US_TIME),
+    ?line ok = check_trace_info({?MODULE, a_called_function, 1}, [{Pid, M, 0, 0}], T2),
+
+
+    ?line 1 = erlang:trace_pattern({?MODULE,dec,'_'}, true, [call_time]),
+    ?line {L, T3} = execute(Pid, {?MODULE, a_function, [M]}),
+    ?line ok = check_trace_info({?MODULE, a_function, 1}, [{Pid, M+M+M, 0, 0}], T1 + (M+M)*?SINGLE_CALL_US_TIME),
+    ?line ok = check_trace_info({?MODULE, a_called_function, 1}, [{Pid, M+M, 0, 0}], T2 + M*?SINGLE_CALL_US_TIME ),
+    ?line ok = check_trace_info({?MODULE, dec, 1}, [{Pid, M, 0, 0}], T3),
+
+    ?line Pid ! quit,
+    ?line P = erlang:trace_pattern({'_','_','_'}, false, [call_time]),
+    ok.
+
+test_functions([Mfa|_] = Mfas, Ncalls, NP) ->
+    %% setup load processes
+    ?line lists:foreach(fun
+	    ({M,F,Args}) ->
+	    ?line erlang:trace_pattern({M,F,length(Args)}, true, [call_time])
+    end, Mfas),
+
+    ?line Pids = [setup() || _ <- lists:seq(1, NP)],
+    ?line T0   = now(),
+    ?line Res  = [execute(Pid, Mfa) || Pid <- Pids],
+    ?line T1   = now(),
+    ?line Time = timer:now_diff(T1,T0),
+    ?line [Pid ! quit || Pid <- Pids],
+
+    %% logic dictates that each process will get ~ 1/F of the schedulers time
+
+    ?line lists:foreach(fun
+	({M,F,Args}) ->
+	    io:format("~w:~w/~w~n", [M,F,length(Args)]),
+	    ?line {call_time,CT} = erlang:trace_info({M,F,length(Args)}, call_time),
+	    lists:foreach(fun
+		(Pid) ->
+		    ?line {value,{Pid, Ncalls, S, Us}} = lists:keysearch(Pid, 1, CT),
+		    io:format("- ~p ~p -> ~w (~w)~n", [Pid, Ncalls, S * 1000000 + Us, Time]),
+		    ok
+		end, Pids)
+	end, Mfas),
+
+    ?line P  = erlang:trace_pattern({'_','_','_'}, false, [call_time]),
+
+    ok.
+
+ scheduling_test() ->
+    ?line P  = erlang:trace_pattern({'_','_','_'}, false, [call_time]),
+    ?line M  = 1000000,
+    ?line Np = erlang:system_info(schedulers_online),
+    ?line F  = 12,
+
+    %% setup load processes
+    %% (single, no internal calls)
+    %test_functions([{?MODULE,Fu,[M]} || Fu <- [a_function, a_called_function, dec]], M, Np*F),
+
+    ?line erlang:trace_pattern({?MODULE,loaded,1}, true, [call_time]),
+
+    ?line Pids = [setup() || _ <- lists:seq(1, F*Np)],
+    ?line T0   = now(),
+    ?line Res  = execute(Pids, {?MODULE,loaded,[M]}),
+    ?line T1   = now(),
+    ?line Time = timer:now_diff(T1,T0),
+    ?line [Pid ! quit || Pid <- Pids],
+
+    %% logic dictates that each process will get ~ 1/F of the schedulers time
+
+    ?line {call_time,CT} = erlang:trace_info({?MODULE,loaded,1}, call_time),
+
+    ?line lists:foreach(fun (Pid) ->
+	    ?line ok = check_process_time(lists:keysearch(Pid, 1, CT), M, F, Time)
+	end, Pids),
+    ok.
+
+%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+info_test() ->
+    ?line P = erlang:trace_pattern({'_','_','_'}, false, [call_time]),
+    %%
+    ?line 1 = erlang:trace_pattern({?MODULE,seq,3}, true, [call_time]),
+    ?line {call_time,[]} = erlang:trace_info({?MODULE,seq,3}, call_time),
+    ?line 1 = erlang:trace_pattern({?MODULE,seq,'_'}, pause, [call_time]),
+    ?line {call_time,[]} = erlang:trace_info({?MODULE,seq,3}, call_time),
+    ?line {all,[_|_]=L} = erlang:trace_info({?MODULE,seq,3}, all),
+    ?line {value,{call_time,[]}} = lists:keysearch(call_time, 1, L),
+    ?line 1 = erlang:trace_pattern({?MODULE,seq,'_'}, restart, [call_time]),
+    ?line {call_time,[]} = erlang:trace_info({?MODULE,seq,3}, call_time),
+    ?line 1 = erlang:trace_pattern({?MODULE,seq,'_'}, false, [call_time]),
+    ?line {call_time,false} = erlang:trace_info({?MODULE,seq,3}, call_time),
+    ?line {all,false} = erlang:trace_info({?MODULE,seq,3}, all),
+    %%
+    ?line P = erlang:trace_pattern({'_','_','_'}, false, [call_time]),
+    ok.
+
+%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+pause_and_restart_test() ->
+    ?line P = erlang:trace_pattern({'_','_','_'}, false, [call_time]),
+    ?line M = 100,
+    ?line Pid = setup(),
+    %%
+    ?line 1 = erlang:trace_pattern({?MODULE,seq,'_'}, true, [call_time]),
+    ?line ok = check_trace_info({?MODULE, seq, 3}, [], none),
+    ?line {L, T1} = execute(Pid, fun() -> seq(1, M, fun(X) -> X+1 end) end),
+    ?line ok = check_trace_info({?MODULE, seq, 3}, [{Pid,M,0,0}], T1),
+    ?line 1 = erlang:trace_pattern({?MODULE,seq,'_'}, pause, [call_time]),
+    ?line ok = check_trace_info({?MODULE, seq, 3}, [{Pid,M,0,0}], T1),
+    ?line {L, T2} = execute(Pid, fun() -> seq(1, M, fun(X) -> X+1 end) end),
+    ?line ok = check_trace_info({?MODULE, seq, 3}, [{Pid,M,0,0}], T2),
+    ?line 1 = erlang:trace_pattern({?MODULE,seq,'_'}, restart, [call_time]),
+    ?line ok = check_trace_info({?MODULE, seq, 3}, [], none),
+    ?line {L, T3} = execute(Pid, fun() -> seq(1, M, fun(X) -> X+1 end) end),
+    ?line ok = check_trace_info({?MODULE, seq, 3}, [{Pid,M,0,0}], T3),
+    %%
+    ?line Pid ! quit,
+    ?line P = erlang:trace_pattern({'_','_','_'}, false, [call_time]),
+    ok.
+
+%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+combo_test() ->
+    ?line Self = self(),
+
+    ?line MetaMatchSpec = [{'_',[],[{return_trace}]}],
+    ?line Flags = lists:sort([call, return_to]),
+    ?line LocalTracer = spawn_link(fun () -> relay_n(5, Self) end),
+    ?line MetaTracer = spawn_link(fun () -> relay_n(9, Self) end),
+    ?line 2 = erlang:trace_pattern({?MODULE,seq_r,'_'}, [], [local]),
+    ?line 2 = erlang:trace_pattern({?MODULE,seq_r,'_'}, true, [call_time]),
+    ?line 2 = erlang:trace_pattern({?MODULE,seq_r,'_'}, MetaMatchSpec, [{meta,MetaTracer}]),
+    ?line 2 = erlang:trace_pattern({?MODULE,seq_r,'_'}, true, [call_count]),
+    ?line 1 = erlang:trace(Self, true, [{tracer,LocalTracer} | Flags]),
+    %%
+    ?line {traced,local} =
+	erlang:trace_info({?MODULE,seq_r,3}, traced),
+    ?line {match_spec,[]} =
+	erlang:trace_info({?MODULE,seq_r,3}, match_spec),
+    ?line {meta,MetaTracer} =
+	erlang:trace_info({?MODULE,seq_r,3}, meta),
+    ?line {meta_match_spec,MetaMatchSpec} =
+	erlang:trace_info({?MODULE,seq_r,3}, meta_match_spec),
+    ?line ok = check_trace_info({?MODULE, seq_r, 3}, [], none),
+    %%
+    ?line {all,[_|_]=TraceInfo} =
+	erlang:trace_info({?MODULE,seq_r,3}, all),
+    ?line {value,{traced,local}} =
+	lists:keysearch(traced, 1, TraceInfo),
+    ?line {value,{match_spec,[]}} =
+	lists:keysearch(match_spec, 1, TraceInfo),
+    ?line {value,{meta,MetaTracer}} =
+	lists:keysearch(meta, 1, TraceInfo),
+    ?line {value,{meta_match_spec,MetaMatchSpec}} =
+	lists:keysearch(meta_match_spec, 1, TraceInfo),
+    ?line {value,{call_count,0}} =
+	lists:keysearch(call_count, 1, TraceInfo),
+    ?line {value,{call_time,[]}} =
+	lists:keysearch(call_time, 1, TraceInfo),
+    %%
+    ?line [3,2,1] = seq_r(1, 3, fun(X) -> X+1 end),
+    %%
+    ?line List = collect(100),
+    ?line {MetaR, LocalR} =
+	lists:foldl(
+	  fun ({P,X}, {M,L}) when P == MetaTracer ->
+		  {[X|M],L};
+	      ({P,X}, {M,L}) when P == LocalTracer ->
+		  {M,[X|L]}
+	  end,
+	  {[],[]},
+	  List),
+    ?line Meta = lists:reverse(MetaR),
+    ?line Local = lists:reverse(LocalR),
+
+    ?line [?CTT(Self,{?MODULE,seq_r,[1,3,_]}),
+	   ?CTT(Self,{?MODULE,seq_r,[1,3,_,[]]}),
+	   ?CTT(Self,{?MODULE,seq_r,[2,3,_,[1]]}),
+	   ?CTT(Self,{?MODULE,seq_r,[3,3,_,[2,1]]}),
+	   ?RFT(Self,{?MODULE,seq_r,4},[3,2,1]),
+	   ?RFT(Self,{?MODULE,seq_r,4},[3,2,1]),
+	   ?RFT(Self,{?MODULE,seq_r,4},[3,2,1]),
+	   ?RFT(Self,{?MODULE,seq_r,3},[3,2,1])] = Meta,
+
+    ?line [?CT(Self,{?MODULE,seq_r,[1,3,_]}),
+	   ?CT(Self,{?MODULE,seq_r,[1,3,_,[]]}),
+	   ?CT(Self,{?MODULE,seq_r,[2,3,_,[1]]}),
+	   ?CT(Self,{?MODULE,seq_r,[3,3,_,[2,1]]}),
+	   ?RT(Self,{?MODULE,combo_test,0})] = Local,
+
+    ?line ok = check_trace_info({?MODULE, seq_r, 3}, [{Self,1,0,0}], 1),
+    ?line ok = check_trace_info({?MODULE, seq_r, 4}, [{Self,3,0,0}], 1),
+    %%
+    ?line erlang:trace_pattern({'_','_','_'}, false, [local,meta,call_time]),
+    ?line erlang:trace_pattern(on_load, false, [local,meta,call_time]),
+    ?line erlang:trace(all, false, [all]),
+    ok.
+
+
+%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Local helpers
+
+%% Stack recursive seq
+seq(Stop, Stop, Succ) when is_function(Succ) ->
+    [Stop];
+seq(Start, Stop, Succ) when is_function(Succ) ->
+    [Start | seq(Succ(Start), Stop, Succ)].
+
+
+a_function(1) -> a_called_function(1);
+a_function(N) when N > 1 -> a_function(a_called_function(N)).
+
+a_called_function(N) -> dec(N).
+
+dec(N) ->
+    loaded(10000),
+    N - 1.
+
+loaded(N) when N > 1 -> loaded(N - 1);
+loaded(_) -> 5.
+
+
+%% Tail recursive seq, result list is reversed
+seq_r(Start, Stop, Succ) when is_function(Succ) ->
+    seq_r(Start, Stop, Succ, []).
+
+seq_r(Stop, Stop, _, R) ->
+    [Stop | R];
+seq_r(Start, Stop, Succ, R) ->
+    seq_r(Succ(Start), Stop, Succ, [Start | R]).
+
+% Check call time tracing data and print mismatches
+check_trace_info(Mfa, [{Pid, C,_,_}] = Expect, Time) ->
+    case erlang:trace_info(Mfa, call_time) of
+	% Time tests are somewhat problematic. We want to know if Time (EXPECTED_TIME) and S*1000000 + Us (ACTUAL_TIME)
+	% is the same.
+	% If the ratio EXPECTED_TIME/ACTUAL_TIME is ~ 1 or if EXPECTED_TIME - ACTUAL_TIME is near zero, the test is ok.
+	{call_time,[{Pid,C,S,Us}]} when S >= 0, Us >= 0,  abs(1 - Time/(S*1000000 + Us)) < ?R_ERROR; abs(Time - S*1000000 - Us) < ?US_ERROR ->
+	    ok;
+	{call_time,[{Pid,C,S,Us}]} ->
+	    Sum = S*1000000 + Us,
+	    io:format("Expected ~p -> {call_time, ~p (Time ~p us)}~n - got ~w s. ~w us. = ~w us. - ~w -> delta ~w (ratio ~.2f, should be 1.0)~n",
+		[Mfa, Expect, Time, S, Us, Sum, Time, Sum - Time, Time/Sum]),
+	    time_error;
+	Other ->
+	    io:format("Expected ~p -> {call_time, ~p (Time ~p us)}~n - got ~p~n", [ Mfa, Expect, Time, Other]),
+	    time_count_error
+    end;
+check_trace_info(Mfa, Expect, _) ->
+    case erlang:trace_info(Mfa, call_time) of
+	{call_time, Expect} ->
+	    ok;
+	Other ->
+	    io:format("Expected ~p -> {call_time, ~p}~n - got ~p~n", [Mfa, Expect, Other]),
+	    result_not_expected_error
+    end.
+
+
+%check process time
+check_process_time({value,{Pid, M, S, Us}}, M, F, Time) ->
+    ?line Sum = S*1000000 + Us,
+    if
+	abs(1 - (F/(Time/Sum))) < ?R_ERROR ->
+	    ok;
+	true ->
+	    io:format("- Pid ~p, Got ratio ~.2f, expected ratio ~w~n", [Pid, Time/Sum,F]),
+	    schedule_time_error
+    end;
+check_process_time(Other, M, _, _) ->
+    io:format(" - Got ~p, expected count ~w~n", [Other, M]),
+    error.
+
+
+
+%% Message relay process
+relay_n(0, _) ->
+    ok;
+relay_n(N, Dest) ->
+    receive Msg ->
+	    Dest ! {self(), Msg},
+	    relay_n(N-1, Dest)
+    end.
+
+
+
+%% Collect received messages
+collect(Time) ->
+    Ref = erlang:start_timer(Time, self(), done),
+    L = lists:reverse(collect([], Ref)),
+    ?dbgformat("Got: ~p~n",[L]),
+    L.
+
+collect(A, 0) ->
+    receive
+	Mess ->
+	    collect([Mess | A], 0)
+    after 0 ->
+	    A
+    end;
+collect(A, Ref) ->
+    receive
+	{timeout, Ref, done} ->
+	    collect(A, 0);
+	Mess ->
+	    collect([Mess | A], Ref)
+    end.
+
+setup() ->
+    Pid = spawn_link(fun() -> loop() end),
+    ?line 1 = erlang:trace(Pid, true, [call]),
+    Pid.
+
+execute(Pids, Mfa) when is_list(Pids) ->
+    T0 = now(),
+    [P  ! {self(), execute, Mfa} || P <- Pids],
+    As = [receive {P, answer, Answer} -> Answer end || P <- Pids],
+    T1 = now(),
+    {As, timer:now_diff(T1,T0)};
+execute(P, Mfa) ->
+    T0 = now(),
+    P  ! {self(), execute, Mfa},
+    A  = receive {P, answer, Answer} -> Answer end,
+    T1 = now(),
+    {A, timer:now_diff(T1,T0)}.
+
+
+
+loop() ->
+    receive
+	quit ->
+	    ok;
+	{Pid, execute, Fun } when is_function(Fun) ->
+	    Pid ! {self(), answer, erlang:apply(Fun, [])},
+	    loop();
+	{Pid, execute, {M, F, A}} ->
+	    Pid ! {self(), answer, erlang:apply(M, F, A)},
+	    loop()
+    end.