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
|
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2011. 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(after_SUITE).
%% Tests receive after.
-include_lib("common_test/include/ct.hrl").
-export([all/0, suite/0,
t_after/1, receive_after/1, receive_after_big/1,
receive_after_errors/1, receive_var_zero/1, receive_zero/1,
multi_timeout/1, receive_after_32bit/1,
receive_after_blast/1]).
%% Internal exports.
-export([timeout_g/0]).
suite() ->
[{ct_hooks,[ts_install_cth]},
{timetrap, {minutes, 4}}].
all() ->
[t_after, receive_after, receive_after_big,
receive_after_errors, receive_var_zero, receive_zero,
multi_timeout, receive_after_32bit, receive_after_blast].
%% Tests for an old round-off error in 'receive after'."
t_after(Config) when is_list(Config) ->
spawn(fun frequent_process/0),
Period = test_server:minutes(1),
Before = erlang:monotonic_time(),
receive
after Period ->
After = erlang:monotonic_time(),
report(Period, Before, After)
end.
report(Period, Before, After) ->
case erlang:convert_time_unit(After - Before, native, 100*1000) / Period of
Percent when Percent > 100.10 ->
ct:fail({too_inaccurate, Percent});
Percent when Percent < 100.0 ->
ct:fail({too_early, Percent});
Percent ->
Comment = io_lib:format("Elapsed/expected: ~.2f %", [Percent]),
{comment, lists:flatten(Comment)}
end.
frequent_process() ->
receive
after 100 ->
frequent_process()
end.
%% Test that 'receive after' works (doesn't hang).
%% The test takes 10 seconds to complete.
receive_after(Config) when is_list(Config) ->
receive_after1(5000).
receive_after1(1) ->
io:format("Testing: receive after ~p~n", [1]),
receive after 1 -> ok end;
receive_after1(N) ->
io:format("Testing: receive after ~p~n", [N]),
receive after N -> receive_after1(N div 2) end.
receive_after_big(Config) when is_list(Config) ->
%% Test that 'receive after' with a 32 bit number works.
receive_after_big1(16#f7654321),
receive_after_big2().
receive_after_big1(Timeout) ->
Self = self(),
erlang:yield(),
spawn(fun() -> Self ! here_is_a_message end),
ok = receive
here_is_a_message ->
ok
after Timeout ->
%% We test that the timeout can be set,
%% not that an timeout occurs after the appropriate delay
%% (48 days, 56 minutes, 48 seconds)!
timeout
end.
receive_after_big2() ->
Self = self(),
erlang:yield(),
spawn(fun() -> Self ! here_is_a_message end),
ok = receive
here_is_a_message ->
ok
after 16#f7999977 ->
%% We only test that the timeout can be set.
timeout
end.
-define(TryAfter(Timeout),
{'EXIT',{timeout_value,_}} = (catch receive mission -> exit(impossible) after Timeout -> ok end),
{'EXIT',{timeout_value,_}} = (catch receive after Timeout -> ok end),
try_after(Timeout)).
%% Test error cases for 'receive after'.
receive_after_errors(Config) when is_list(Config) ->
?TryAfter(-1),
?TryAfter(0.0),
?TryAfter(3.14),
?TryAfter(16#100000000),
?TryAfter(392347129847294724972398472984729847129874),
?TryAfter(16#3fffffffffffffff),
?TryAfter(16#ffffffffffffffff),
?TryAfter(-16#100000000),
?TryAfter(-3891278094774921784123987129848),
?TryAfter(xxx),
ok.
try_after(Timeout) ->
{'EXIT',{timeout_value,_}} = (catch receive after Timeout -> ok end).
%% Test 'after Z', when Z == 0.
receive_var_zero(Config) when is_list(Config) ->
self() ! x,
self() ! y,
Z = zero(),
timeout = receive
z -> ok
after Z -> timeout
end,
timeout = receive
after Z -> timeout
end,
self() ! w,
receive
x -> ok;
Other ->
ct:fail({bad_message,Other})
end.
zero() -> 0.
%% Test 'after 0'.
receive_zero(Config) when is_list(Config) ->
self() ! x,
self() ! y,
timeout = receive
z -> ok
after 0 ->
timeout
end,
self() ! w,
timeout = receive
after 0 -> timeout
end,
receive
x -> ok;
Other ->
ct:fail({bad_message,Other})
end.
%% Test for catching invalid assertion in erl_message.c (in queue_message)
%% This failed (dumped core) with debug-compiled emulator.
multi_timeout(Config) when is_list(Config) ->
P = spawn(?MODULE, timeout_g, []),
P ! a,
P ! b,
receive
after 1000 -> ok
end,
P ! c,
receive
after 1000 -> ok
end,
P ! d,
ok.
timeout_g() ->
receive
a -> ok
end,
receive
after 100000 -> ok
end,
ok.
%% OTP-7493: Timeout for 32 bit numbers (such as 16#ffffFFFF) could
%% timeout at once.
receive_after_32bit(Config) when is_list(Config) ->
T = 16#ffffFFFF,
Pids = [spawn_link(fun() -> recv_after_32bit(I, T) end) ||
I <- lists:seq(1, 2048)],
%% Wait two seconds for any of the processes to timeout too early.
receive after 2000 -> ok end,
%% Kill the processes.
[begin unlink(Pid), exit(Pid, kill) end || Pid <- Pids],
ok.
recv_after_32bit(I, T) when I rem 2 =:= 0 ->
receive after T -> exit(timeout) end;
recv_after_32bit(_, _) ->
receive after 16#ffffFFFF -> exit(timeout) end.
blaster() ->
receive
{go, TimeoutTime} ->
Tmo = TimeoutTime - erlang:monotonic_time(milli_seconds),
receive after Tmo -> ok end
end.
spawn_blasters(0) ->
[];
spawn_blasters(N) ->
[spawn_monitor(fun () -> blaster() end)|spawn_blasters(N-1)].
receive_after_blast(Config) when is_list(Config) ->
PMs = spawn_blasters(10000),
TimeoutTime = erlang:monotonic_time(milli_seconds) + 5000,
lists:foreach(fun ({P, _}) -> P ! {go, TimeoutTime} end, PMs),
lists:foreach(fun ({P, M}) ->
receive
{'DOWN', M, process, P, normal} ->
ok
end
end, PMs).
|
