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
|
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2009. 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%
%%
-module(statistics_SUITE).
%% Tests the statistics/1 bif.
-export([all/1,
init_per_testcase/2,
fin_per_testcase/2,
wall_clock/1, wall_clock_zero_diff/1, wall_clock_update/1,
runtime/1, runtime_zero_diff/1, runtime_zero_update/1,
runtime_update/1, runtime_diff/1,
run_queue/1, run_queue_one/1,
reductions/1, reductions_big/1, garbage_collection/1, io/1,
badarg/1]).
%% Internal exports.
-export([hog/1]).
-include("test_server.hrl").
init_per_testcase(_, Config) ->
?line Dog = test_server:timetrap(test_server:seconds(300)),
[{watchdog, Dog}|Config].
fin_per_testcase(_, Config) ->
Dog = ?config(watchdog, Config),
test_server:timetrap_cancel(Dog),
ok.
all(suite) -> [wall_clock, runtime, reductions, reductions_big, run_queue,
garbage_collection, io, badarg].
%%% Testing statistics(wall_clock).
wall_clock(suite) -> [wall_clock_zero_diff, wall_clock_update].
wall_clock_zero_diff(doc) ->
"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 ->
?line {Time, _} = statistics(wall_clock),
?line case statistics(wall_clock) of
{Time, 0} -> ok;
_ -> wall_clock_zero_diff1(N-1)
end;
wall_clock_zero_diff1(0) ->
?line test_server:fail("Difference never zero.").
wall_clock_update(doc) ->
"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 ->
?line {T1_wc_time, _} = statistics(wall_clock),
?line receive after 1000 -> ok end,
?line {T2_wc_time, Wc_Diff} = statistics(wall_clock),
?line Wc_Diff = T2_wc_time - T1_wc_time,
?line test_server:format("Wall clock diff = ~p; should be = 1000..1040~n",
[Wc_Diff]),
case ?t:is_debug() of
false ->
?line true = Wc_Diff =< 1040;
true ->
?line true = Wc_Diff =< 2000 %Be more tolerant in debug-compiled emulator.
end,
?line true = Wc_Diff >= 1000,
wall_clock_update1(N-1);
wall_clock_update1(0) ->
ok.
%%% Test statistics(runtime).
runtime(suite) -> [runtime_zero_diff, runtime_zero_update, runtime_update,
runtime_diff].
runtime_zero_diff(doc) ->
"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) ->
?line runtime_zero_diff1(16).
runtime_zero_diff1(N) when N > 0 ->
?line {T1, _} = statistics(runtime),
?line case statistics(runtime) of
{T1, 0} -> ok;
_ -> runtime_zero_diff1(N-1)
end;
runtime_zero_diff1(0) ->
?line test_server:fail("statistics(runtime) never returned zero difference").
runtime_zero_update(doc) ->
"Test that the time differences returned by two calls to "
"statistics(runtime) several seconds apart is zero.";
runtime_zero_update(Config) when is_list(Config) ->
case ?t:is_debug() of
false -> ?line runtime_zero_update1(6);
true -> {skip,"Unreliable in DEBUG build"}
end.
runtime_zero_update1(N) when N > 0 ->
?line {T1, _} = statistics(runtime),
?line receive after 7000 -> ok end,
?line case statistics(runtime) of
{T, Td} when Td =< 80 ->
test_server:format("ok, Runtime before: {~p, _} after: {~p, ~p}",
[T1, T, Td]),
ok;
{T, R} ->
test_server:format("nok, Runtime before: {~p, _} after: {~p, ~p}",
[T1, T, R]),
runtime_zero_update1(N-1)
end;
runtime_zero_update1(0) ->
?line test_server:fail("statistics(runtime) never returned zero difference").
runtime_update(doc) ->
"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 ?t:is_cover() of
false ->
?line process_flag(priority, high),
?line test_server:m_out_of_n(1, 10, fun runtime_update/0);
true ->
{skip,"Cover-compiled"}
end.
runtime_update() ->
?line {T1,_} = statistics(runtime),
?line spawn_link(fun cpu_heavy/0),
receive after 1000 -> ok end,
?line {T2,Diff} = statistics(runtime),
?line Delta = abs(Diff-1000),
?line test_server:format("T1 = ~p, T2 = ~p, Diff = ~p, abs(Diff-1000) = ~p",
[T1,T2,Diff,Delta]),
?line if
abs(Diff-1000) =:= Delta, Delta =< 100 ->
ok
end.
cpu_heavy() ->
cpu_heavy().
runtime_diff(doc) ->
"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 ->
?line {T1_wc_time, _} = statistics(runtime),
?line do_much(),
?line {T2_wc_time, Wc_Diff} = statistics(runtime),
?line 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).
reductions(doc) ->
"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.
reductions(300, Reductions).
reductions(N, Previous) when N > 0 ->
?line {Reductions, Diff} = statistics(reductions),
?line build_some_garbage(),
?line if Reductions > 0 -> ok end,
?line if Diff >= 0 -> ok end,
io:format("Previous = ~p, Reductions = ~p, Diff = ~p, DiffShouldBe = ~p",
[Previous, Reductions, Diff, Reductions-Previous]),
?line if Reductions == Previous+Diff -> reductions(N-1, Reductions) 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().
reductions_big(doc) ->
"Test that the number of reductions can be returned as a big number.";
reductions_big(Config) when is_list(Config) ->
?line 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).
run_queue(suite) -> [run_queue_one].
run_queue_one(doc) ->
"Tests that statistics(run_queue) returns 1 if we start a "
"CPU-bound process.";
run_queue_one(Config) when is_list(Config) ->
?line MS = erlang:system_flag(multi_scheduling, block),
?line run_queue_one_test(Config),
?line 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) ->
?line Hog = spawn_link(?MODULE, hog, [self()]),
?line receive
hog_started ->
Hog ! go
end,
?line receive after 100 -> ok end, % Give hog a head start.
?line case statistics(run_queue) of
N when N >= 1 -> ok;
Other -> ?line ?t:fail({unexpected,Other})
end,
ok.
%% CPU-bound process, going at low priority. It will always be ready
%% to run.
hog(Pid) ->
?line process_flag(priority, low),
?line Pid ! hog_started,
?line receive
go -> hog_iter(0)
end.
hog_iter(N) when N > 0 ->
?line hog_iter(N-1);
hog_iter(0) ->
?line hog_iter(10000).
garbage_collection(doc) ->
"Tests that statistics(garbage_collection) is callable. "
"It is not clear how to test anything more.";
garbage_collection(Config) when is_list(Config) ->
?line Bin = list_to_binary(lists:duplicate(19999, 42)),
?line case statistics(garbage_collection) of
{Gcs0,R,0} when is_integer(Gcs0), is_integer(R) ->
?line io:format("Reclaimed: ~p", [R]),
?line Gcs = garbage_collection_1(Gcs0, Bin),
?line 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.
io(doc) ->
"Tests that statistics(io) is callable. "
"This could be improved to test something more.";
io(Config) when is_list(Config) ->
?line case statistics(io) of
{{input,In},{output,Out}} when is_integer(In), is_integer(Out) -> ok
end.
badarg(doc) ->
"Tests that some illegal arguments to statistics fails.";
badarg(Config) when is_list(Config) ->
?line case catch statistics(1) of
{'EXIT', {badarg, _}} -> ok
end,
?line case catch statistics(bad_atom) of
{'EXIT', {badarg, _}} -> ok
end.
|
