%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2017. 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) ->
Frequent = spawn_link(fun frequent_process/0),
Period = test_server:minutes(1),
Before = erlang:monotonic_time(),
receive
after Period ->
After = erlang:monotonic_time(),
unlink(Frequent),
exit(Frequent, die),
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(millisecond),
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(millisecond) + 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).
