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-rw-r--r--lib/stdlib/test/gen_server_SUITE.erl45
1 files changed, 43 insertions, 2 deletions
diff --git a/lib/stdlib/test/gen_server_SUITE.erl b/lib/stdlib/test/gen_server_SUITE.erl
index 6efdce78a1..f753ebc534 100644
--- a/lib/stdlib/test/gen_server_SUITE.erl
+++ b/lib/stdlib/test/gen_server_SUITE.erl
@@ -30,7 +30,8 @@
call_remote_n1/1, call_remote_n2/1, call_remote_n3/1, spec_init/1,
spec_init_local_registered_parent/1,
spec_init_global_registered_parent/1,
- otp_5854/1, hibernate/1, otp_7669/1, call_format_status/1
+ otp_5854/1, hibernate/1, otp_7669/1, call_format_status/1,
+ call_with_huge_message_queue/1
]).
% spawn export
@@ -51,7 +52,8 @@ all(suite) ->
call_remote_n2, call_remote_n3, spec_init,
spec_init_local_registered_parent,
spec_init_global_registered_parent,
- otp_5854, hibernate, otp_7669, call_format_status].
+ otp_5854, hibernate, otp_7669, call_format_status,
+ call_with_huge_message_queue].
-define(default_timeout, ?t:minutes(1)).
@@ -904,6 +906,45 @@ call_format_status(Config) when is_list(Config) ->
?line [format_status_called | _] = lists:reverse(Data2),
ok.
+%% Test that the time for a huge message queue is not
+%% significantly slower than with an empty message queue.
+call_with_huge_message_queue(Config) when is_list(Config) ->
+ ?line Pid = spawn_link(fun echo_loop/0),
+
+ ?line {Time,ok} = tc(fun() -> calls(10, Pid) end),
+
+ ?line [self() ! {msg,N} || N <- lists:seq(1, 500000)],
+ erlang:garbage_collect(),
+ ?line {NewTime,ok} = tc(fun() -> calls(10, Pid) end),
+ io:format("Time for empty message queue: ~p", [Time]),
+ io:format("Time for huge message queue: ~p", [NewTime]),
+
+ case (NewTime+1) / (Time+1) of
+ Q when Q < 10 ->
+ ok;
+ Q ->
+ io:format("Q = ~p", [Q]),
+ ?line ?t:fail()
+ end,
+ ok.
+
+calls(0, _) -> ok;
+calls(N, Pid) ->
+ {ultimate_answer,42} = call(Pid, {ultimate_answer,42}),
+ calls(N-1, Pid).
+
+call(Pid, Msg) ->
+ gen_server:call(Pid, Msg, infinity).
+
+tc(Fun) ->
+ timer:tc(erlang, apply, [Fun,[]]).
+
+echo_loop() ->
+ receive
+ {'$gen_call',{Pid,Ref},Msg} ->
+ Pid ! {Ref,Msg},
+ echo_loop()
+ end.
%%--------------------------------------------------------------
%% Help functions to spec_init_*