aboutsummaryrefslogtreecommitdiffstats
path: root/erts/emulator/test/statistics_SUITE.erl
blob: a1f12ba93c6aeb51dad36d12516f43d160c33c74 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2016. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%%     http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%

-module(statistics_SUITE).

%% Tests the statistics/1 bif.

-export([all/0, suite/0, groups/0,
	 wall_clock_zero_diff/1, wall_clock_update/1,
	 runtime_zero_diff/1,
	 runtime_update/1, runtime_diff/1,
	 run_queue_one/1,
	 scheduler_wall_time/1,
	 reductions/1, reductions_big/1, garbage_collection/1, io/1,
	 badarg/1, run_queues_lengths_active_tasks/1, msacc/1]).

%% Internal exports.

-export([hog/1]).

-include_lib("common_test/include/ct.hrl").

suite() ->
    [{ct_hooks,[ts_install_cth]},
     {timetrap, {minutes, 4}}].

all() -> 
    [{group, wall_clock}, {group, runtime}, reductions,
     reductions_big, {group, run_queue}, scheduler_wall_time,
     garbage_collection, io, badarg,
     run_queues_lengths_active_tasks,
     msacc].

groups() -> 
    [{wall_clock, [],
      [wall_clock_zero_diff, wall_clock_update]},
     {runtime, [],
      [runtime_zero_diff, runtime_update, runtime_diff]},
     {run_queue, [], [run_queue_one]}].

%%% Testing statistics(wall_clock).

%% Tests that the 'Wall clock since last call' element of the result
%% is zero when statistics(runtime) is called twice in succession.
wall_clock_zero_diff(Config) when is_list(Config) ->
    wall_clock_zero_diff1(16).

wall_clock_zero_diff1(N) when N > 0 ->
    {Time, _} = statistics(wall_clock),
    case statistics(wall_clock) of
        {Time, 0} -> ok;
        _ -> wall_clock_zero_diff1(N-1)
    end;
wall_clock_zero_diff1(0) ->
    ct:fail("Difference never zero.").

%% Test that the time differences returned by two calls to
%% statistics(wall_clock) are compatible, and are within a small number
%% of ms of the amount of real time we waited for.
wall_clock_update(Config) when is_list(Config) ->
    wall_clock_update1(6).

wall_clock_update1(N) when N > 0 ->
    {T1_wc_time, _} = statistics(wall_clock),
    receive after 1000 -> ok end,
    {T2_wc_time, Wc_Diff} = statistics(wall_clock),

    Wc_Diff = T2_wc_time - T1_wc_time,
    io:format("Wall clock diff = ~p; should be  = 1000..1040~n", [Wc_Diff]),
    case test_server:is_debug() of
        false ->
            true = Wc_Diff =< 1040;
        true ->
            true = Wc_Diff =< 2000	%Be more tolerant in debug-compiled emulator.
    end,
    true = Wc_Diff >= 1000,
    wall_clock_update1(N-1);
wall_clock_update1(0) ->
    ok.


%%% Test statistics(runtime).


%% Tests that the difference between the times returned from two consectuitive
%% calls to statistics(runtime) is zero.
runtime_zero_diff(Config) when is_list(Config) ->
    runtime_zero_diff1(16).

runtime_zero_diff1(N) when N > 0 ->
    {T1, _} = statistics(runtime),
    case statistics(runtime) of
        {T1, 0} -> ok;
        _ -> runtime_zero_diff1(N-1)
    end;
runtime_zero_diff1(0) ->
    ct:fail("statistics(runtime) never returned zero difference").

%% Test that the statistics(runtime) returns a substanstially
%% updated difference after running a process that takes all CPU
%% power of the Erlang process for a second.
runtime_update(Config) when is_list(Config) ->
    case test_server:is_cover() of
        false ->
            process_flag(priority, high),
            do_runtime_update(10);
        true ->
            {skip,"Cover-compiled"}
    end.

do_runtime_update(0) ->
    {comment,"Never close enough"};
do_runtime_update(N) ->
    {T1,Diff0} = statistics(runtime),
    {CPUHog, CPUHogMon} = spawn_opt(fun cpu_heavy/0,[link,monitor]),
    receive after 1000 -> ok end,
    {T2,Diff} = statistics(runtime),
    unlink(CPUHog),
    exit(CPUHog, kill),
    
    true = is_integer(T1+T2+Diff0+Diff),
    io:format("T1 = ~p, T2 = ~p, Diff = ~p, T2-T1 = ~p", [T1,T2,Diff,T2-T1]),
    receive {'DOWN',CPUHogMon,process,CPUHog,_} -> ok end,
    if
        T2 - T1 =:= Diff, 900 =< Diff, Diff =< 1500 -> ok;
        true -> do_runtime_update(N-1)
    end.

cpu_heavy() ->
    cpu_heavy().

%% Test that the difference between two consecutive absolute runtimes is
%% equal to the last relative runtime. The loop runs a lot of times since
%% the bug which this test case tests for showed up only rarely.
runtime_diff(Config) when is_list(Config) ->
    runtime_diff1(1000).

runtime_diff1(N) when N > 0 ->
    {T1_wc_time, _} = statistics(runtime),
    do_much(),
    {T2_wc_time, Wc_Diff} = statistics(runtime),
    Wc_Diff = T2_wc_time - T1_wc_time,
    runtime_diff1(N-1);
runtime_diff1(0) ->
    ok.

%%% do_much(100000) takes about 760 ms on boromir.
%%% do_much(1000) takes about 8 ms on boromir.

do_much() ->
    do_much(1000).

do_much(0) ->
    ok;
do_much(N) ->
    _ = 4784728478274827 * 72874284728472,
    do_much(N-1).


%% Test that statistics(reductions) is callable, and that
%% Total_Reductions and Reductions_Since_Last_Call make sense.
%% This to fail on pre-R3A version of JAM.
reductions(Config) when is_list(Config) ->
    {Reductions, _} = statistics(reductions),

    %% Each loop of reductions/2 takes 4 reductions + that the garbage built
    %% outside the heap in the BIF calls will bump the reductions.
    %% 300 * 4 is more than CONTEXT_REDS (1000).  Thus, there will be one or
    %% more context switches.

    Mask = (1 bsl erlang:system_info(wordsize)*8) - 1,
    reductions(300, Reductions, Mask).

reductions(N, Previous, Mask) when N > 0 ->
    {Reductions, Diff} = statistics(reductions),
    build_some_garbage(),
    if Reductions > 0 -> ok end,
    if Diff >= 0 -> ok end,
    io:format("Previous = ~p, Reductions = ~p, Diff = ~p, DiffShouldBe = ~p",
              [Previous, Reductions, Diff, (Reductions-Previous) band Mask]),
    if Reductions == ((Previous+Diff) band Mask) -> reductions(N-1, Reductions, Mask) end;
reductions(0, _, _) ->
    ok.

build_some_garbage() ->
    %% This will build garbage outside the process heap, which will cause
    %% a garbage collection in the scheduler.
    processes().

%% Test that the number of reductions can be returned as a big number.
reductions_big(Config) when is_list(Config) ->
    reductions_big_loop(),
    ok.

reductions_big_loop() ->
    erlang:yield(),
    case statistics(reductions) of
        {Red, Diff} when Red >= 16#7ffFFFF ->
            ok = io:format("Reductions = ~w, Diff = ~w", [Red, Diff]);
        _ ->
            reductions_big_loop()
    end.


%%% Tests of statistics(run_queue).


%% Tests that statistics(run_queue) returns 1 if we start a
%% CPU-bound process.
run_queue_one(Config) when is_list(Config) ->
    MS = erlang:system_flag(multi_scheduling, block),
    run_queue_one_test(Config),
    erlang:system_flag(multi_scheduling, unblock),
    case MS of
        blocked ->
            {comment,
             "Multi-scheduling blocked during test. This test-case "
             "was not written to work with multiple schedulers."};
        _ -> ok
    end.


run_queue_one_test(Config) when is_list(Config) ->
    _Hog = spawn_link(?MODULE, hog, [self()]),
    receive
        hog_started -> ok
    end,
    receive after 100 -> ok end,		% Give hog a head start.
    case statistics(run_queue) of
        N when N >= 1 -> ok;
        Other -> ct:fail({unexpected,Other})
    end,
    ok.

%% CPU-bound process, going at low priority.  It will always be ready
%% to run.

hog(Pid) ->
    process_flag(priority, low),
    Pid ! hog_started,
    Mon = erlang:monitor(process, Pid),
    hog_iter(0, Mon).

hog_iter(N, Mon) when N > 0 ->
    receive
        {'DOWN', Mon, _, _, _} ->  ok
    after 0 ->
              hog_iter(N-1, Mon)
    end;
hog_iter(0, Mon) ->
    hog_iter(10000, Mon).

%%% Tests of statistics(scheduler_wall_time).

%% Tests that statistics(scheduler_wall_time) works as intended
scheduler_wall_time(Config) when is_list(Config) ->
    %% Should return undefined if system_flag is not turned on yet
    undefined = statistics(scheduler_wall_time),
    %% Turn on statistics
    false = erlang:system_flag(scheduler_wall_time, true),
    try
        Schedulers = erlang:system_info(schedulers_online),
        %% Let testserver and everyone else finish their work
        timer:sleep(1500),
        %% Empty load
        EmptyLoad = get_load(),
        {false, _} = {lists:any(fun(Load) -> Load > 50 end, EmptyLoad),EmptyLoad},
        MeMySelfAndI = self(),
        StartHog = fun() ->
                           Pid = spawn(?MODULE, hog, [self()]),
                           receive hog_started -> MeMySelfAndI ! go end,
                           Pid
                   end,
        P1 = StartHog(),
        %% Max on one, the other schedulers empty (hopefully)
        %% Be generous the process can jump between schedulers
        %% which is ok and we don't want the test to fail for wrong reasons
        _L1 = [S1Load|EmptyScheds1] = get_load(),
        {true,_}  = {S1Load > 50,S1Load},
        {false,_} = {lists:any(fun(Load) -> Load > 50 end, EmptyScheds1),EmptyScheds1},
        {true,_}  = {lists:sum(EmptyScheds1) < 60,EmptyScheds1},

        %% 50% load
        HalfHogs = [StartHog() || _ <- lists:seq(1, (Schedulers-1) div 2)],
        HalfLoad = lists:sum(get_load()) div Schedulers,
        if Schedulers < 2, HalfLoad > 80 -> ok; %% Ok only one scheduler online and one hog
           %% We want roughly 50% load
           HalfLoad > 40, HalfLoad < 60 -> ok;
           true -> exit({halfload, HalfLoad})
        end,

        %% 100% load
        LastHogs = [StartHog() || _ <- lists:seq(1, Schedulers div 2)],
        FullScheds = get_load(),
        {false,_} = {lists:any(fun(Load) -> Load < 80 end, FullScheds),FullScheds},
        FullLoad = lists:sum(FullScheds) div Schedulers,
        if FullLoad > 90 -> ok;
           true -> exit({fullload, FullLoad})
        end,

	KillHog = fun (HP) ->
			  HPM = erlang:monitor(process, HP),
			  exit(HP, kill),
			  receive
			      {'DOWN', HPM, process, HP, killed} ->
				  ok
			  end
		  end,
        [KillHog(Pid) || Pid <- [P1|HalfHogs++LastHogs]],
        AfterLoad = get_load(),
	io:format("AfterLoad=~p~n", [AfterLoad]),
        {false,_} = {lists:any(fun(Load) -> Load > 25 end, AfterLoad),AfterLoad},
        true = erlang:system_flag(scheduler_wall_time, false)
    after
        erlang:system_flag(scheduler_wall_time, false)
    end.

get_load() ->
    Start = erlang:statistics(scheduler_wall_time),
    timer:sleep(1500),
    End = erlang:statistics(scheduler_wall_time),
    lists:reverse(lists:sort(load_percentage(lists:sort(Start),lists:sort(End)))).

load_percentage([{Id, WN, TN}|Ss], [{Id, WP, TP}|Ps]) ->
    [100*(WN-WP) div (TN-TP)|load_percentage(Ss, Ps)];
load_percentage([], []) -> [].


%% Tests that statistics(garbage_collection) is callable.
%% It is not clear how to test anything more.
garbage_collection(Config) when is_list(Config) ->
    Bin = list_to_binary(lists:duplicate(19999, 42)),
    case statistics(garbage_collection) of
        {Gcs0,R,0} when is_integer(Gcs0), is_integer(R) ->
            io:format("Reclaimed: ~p", [R]),
            Gcs = garbage_collection_1(Gcs0, Bin),
            io:format("Reclaimed: ~p",
                      [element(2, statistics(garbage_collection))]),
            {comment,integer_to_list(Gcs-Gcs0)++" GCs"}
    end.

garbage_collection_1(Gcs0, Bin) ->
    case statistics(garbage_collection) of
        {Gcs,Reclaimed,0} when Gcs >= Gcs0 ->
            if
                Reclaimed > 16#7ffffff ->
                    Gcs;
                true ->
                    _ = binary_to_list(Bin),
                    erlang:garbage_collect(),
                    garbage_collection_1(Gcs, Bin)
            end
    end.

%% Tests that statistics(io) is callable.
%% This could be improved to test something more.
io(Config) when is_list(Config) ->
    case statistics(io) of
        {{input,In},{output,Out}} when is_integer(In), is_integer(Out) -> ok
    end.

%% Tests that some illegal arguments to statistics fails.
badarg(Config) when is_list(Config) ->
    case catch statistics(1) of
        {'EXIT', {badarg, _}} -> ok
    end,
    case catch statistics(bad_atom) of
        {'EXIT', {badarg, _}} -> ok
    end.

tok_loop() ->
    tok_loop().

run_queues_lengths_active_tasks(Config) ->
    TokLoops = lists:map(fun (_) ->
                                 spawn_opt(fun () ->
                                                   tok_loop()
                                           end,
                                           [link, {priority, low}])
                         end,
                         lists:seq(1,10)),

    TRQLs0 = statistics(total_run_queue_lengths),
    TATs0 = statistics(total_active_tasks),
    true = is_integer(TRQLs0),
    true = is_integer(TATs0),
    true = TRQLs0 >= 0,
    true = TATs0 >= 11,

    NoScheds = erlang:system_info(schedulers),
    RQLs0 = statistics(run_queue_lengths),
    ATs0 = statistics(active_tasks),
    NoScheds = length(RQLs0),
    NoScheds = length(ATs0),
    true = lists:sum(RQLs0) >= 0,
    true = lists:sum(ATs0) >= 11,

    SO = erlang:system_flag(schedulers_online, 1),

    %% Give newly suspended schedulers some time to
    %% migrate away work from their run queues...
    receive after 1000 -> ok end,

    TRQLs1 = statistics(total_run_queue_lengths),
    TATs1 = statistics(total_active_tasks),
    true = TRQLs1 >= 10,
    true = TATs1 >= 11,
    NoScheds = erlang:system_info(schedulers),

    RQLs1 = statistics(run_queue_lengths),
    ATs1 = statistics(active_tasks),
    NoScheds = length(RQLs1),
    NoScheds = length(ATs1),
    TRQLs2 = lists:sum(RQLs1),
    TATs2 = lists:sum(ATs1),
    true = TRQLs2 >= 10,
    true = TATs2 >= 11,
    [TRQLs2|_] = RQLs1,
    [TATs2|_] = ATs1,

    erlang:system_flag(schedulers_online, SO),

    lists:foreach(fun (P) ->
                          unlink(P),
                          exit(P, bang)
                  end,
                  TokLoops),

    ok.

%% Tests that statistics(microstate_statistics) works.
msacc(Config) ->

    %% Test if crypto nif is available
    Niff = try crypto:strong_rand_bytes(1), ok catch _:_ -> nok end,
    TmpFile = filename:join(proplists:get_value(priv_dir,Config),"file.tmp"),

    false = erlang:system_flag(microstate_accounting, true),

    msacc_test(TmpFile),

    true = erlang:system_flag(microstate_accounting, false),

    MsaccStats = erlang:statistics(microstate_accounting),

    case os:type() of
        {win32, _} ->
            %% Some windows have a very poor accuracy on their
            %% timing primitives, so we just make sure that
            %% some state besides sleep has been triggered.
            Sum = lists:sum(
                    lists:map(fun({sleep, _V}) -> 0;
                                 ({_, V}) -> V
                              end, maps:to_list(msacc_sum_states()))
                   ),
            if Sum > 0 ->
                   ok;
               true ->
                   ct:fail({no_states_triggered, MsaccStats})
            end;
        _ ->

            %% Make sure that all states were triggered at least once
            maps:map(fun(nif, 0) ->
                             case Niff of
                                 ok ->
                                     ct:fail({zero_state,nif});
                                 nok ->
                                     ok
                             end;
                        (aux, 0) ->
                             %% aux will be zero if we do not have smp support
                             %% or no async threads
                             case erlang:system_info(smp_support) orelse
                                  erlang:system_info(thread_pool_size) > 0
                             of
                                 false ->
                                     ok;
                                 true ->
                                     ct:log("msacc: ~p",[MsaccStats]),
                                     ct:fail({zero_state,aux})
                             end;
                        (Key, 0) ->
                             ct:log("msacc: ~p",[MsaccStats]),
                             ct:fail({zero_state,Key});
                        (_,_) -> ok
                     end, msacc_sum_states())
    end,

    erlang:system_flag(microstate_accounting, reset),

    msacc_test(TmpFile),

    %% Make sure all counters are zero after stopping and resetting
    maps:map(fun(_Key, 0) -> ok;
                (Key,_) ->
                     ct:log("msacc: ~p",[erlang:statistics(microstate_accounting)]),
                     ct:fail({non_zero_state,Key})
             end,msacc_sum_states()).

%% This test tries to make sure to trigger all of the different available states
msacc_test(TmpFile) ->

    %% We write some data
    [file:write_file(TmpFile,<<0:(1024*1024*8)>>,[raw]) || _ <- lists:seq(1,100)],

    %% Do some ETS operations
    Tid = ets:new(table, []),
    ets:insert(Tid, {1, hello}),
    ets:delete(Tid),

    %% Collect some garbage
    [erlang:garbage_collect() || _ <- lists:seq(1,100)],

    %% Send some messages
    [begin self() ! {hello},receive _ -> ok end end ||  _ <- lists:seq(1,100)],

    %% Setup some timers
    Refs = [erlang:send_after(10000,self(),ok) ||  _ <- lists:seq(1,100)],

    %% Do some nif work
    catch [crypto:strong_rand_bytes(128) || _ <- lists:seq(1,100)],

    %% Cancel some timers
    [erlang:cancel_timer(R) ||  R <- Refs],

    %% Wait for a while
    timer:sleep(100).

msacc_sum_states() ->
    Stats = erlang:statistics(microstate_accounting),
    [#{ counters := C }|_] = Stats,
    InitialCounters = maps:map(fun(_,_) -> 0 end,C),
    lists:foldl(fun(#{ counters := Counters }, Cnt) ->
                        maps:fold(fun(Key, Value, Acc) ->
                                          NewValue = Value+maps:get(Key,Acc),
                                          maps:update(Key, NewValue, Acc)
                                  end, Cnt, Counters)
                end,InitialCounters,Stats).