%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2010-2016. 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(receive_SUITE).
%% Tests receive after.
-include_lib("common_test/include/ct.hrl").
-export([all/0, suite/0,
call_with_huge_message_queue/1,receive_in_between/1]).
suite() ->
[{ct_hooks,[ts_install_cth]},
{timetrap, {minutes, 3}}].
all() ->
[call_with_huge_message_queue, receive_in_between].
groups() ->
[].
call_with_huge_message_queue(Config) when is_list(Config) ->
Pid = spawn_link(fun echo_loop/0),
{Time,ok} = tc(fun() -> calls(10, Pid) end),
[self() ! {msg,N} || N <- lists:seq(1, 500000)],
erlang:garbage_collect(),
{NewTime1,ok} = tc(fun() -> calls(10, Pid) end),
{NewTime2,ok} = tc(fun() -> calls(10, Pid) end),
io:format("Time for empty message queue: ~p", [Time]),
io:format("Time1 for huge message queue: ~p", [NewTime1]),
io:format("Time2 for huge message queue: ~p", [NewTime2]),
case hd(lists:sort([(NewTime1+1) / (Time+1), (NewTime2+1) / (Time+1)])) of
Q when Q < 10 ->
ok;
Q ->
ct:fail("Best Q = ~p", [Q])
end,
ok.
calls(0, _) -> ok;
calls(N, Pid) ->
{ok,{ultimate_answer,42}} = call(Pid, {ultimate_answer,42}),
calls(N-1, Pid).
call(Pid, Msg) ->
Mref = erlang:monitor(process, Pid),
Pid ! {Mref,{self(),Msg}},
receive
{Mref, Reply} ->
erlang:demonitor(Mref, [flush]),
{ok, Reply};
{'DOWN', Mref, _, _, Reason} ->
exit(Reason)
end.
receive_in_between(Config) when is_list(Config) ->
Pid = spawn_link(fun echo_loop/0),
[{ok,{a,b}} = call2(Pid, {a,b}) || _ <- lists:seq(1, 100000)],
ok.
call2(Pid, Msg) ->
self() ! dummy,
Mref = erlang:monitor(process, Pid),
Pid ! {Mref,{self(),Msg}},
receive_one(),
receive
{Mref,Reply} ->
erlang:demonitor(Mref, [flush]),
{ok,Reply};
{'DOWN',Mref,_,_,Reason} ->
exit(Reason)
end.
receive_one() ->
receive
dummy -> ok
end.
%%%
%%% Common helpers.
%%%
echo_loop() ->
receive
{Ref,{Pid,Msg}} ->
Pid ! {Ref,Msg},
echo_loop()
end.
tc(Fun) ->
timer:tc(erlang, apply, [Fun,[]]).
