%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2013. 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%
%%
%% Test the garbage collector (or Memory Recycler)
-module(gc_SUITE).
-include_lib("common_test/include/ct.hrl").
-export([all/0, suite/0]).
-export([grow_heap/1, grow_stack/1, grow_stack_heap/1]).
suite() ->
[{ct_hooks,[ts_install_cth]}].
all() ->
[grow_heap, grow_stack, grow_stack_heap].
grow_heap(doc) -> ["Produce a growing list of elements, ",
"for X calls, then drop one item per call",
"until the list is empty."];
grow_heap(Config) when is_list(Config) ->
ct:timetrap({minutes, 40}),
ok = grow_heap1(256),
ok = grow_heap1(512),
ok = grow_heap1(1024),
ok = grow_heap1(2048),
ok.
grow_heap1(Len) ->
io:format("~ngrow_heap with ~p items.",[Len]),
show_heap("before:"),
grow_heap1([], Len, 0, up),
show_heap("after:").
grow_heap1(List, MaxLen, MaxLen, up) ->
show_heap("top:"),
grow_heap1(List, MaxLen, MaxLen-1, down);
grow_heap1(List, MaxLen, CurLen, up) ->
NewList=[make_arbit()|List],
grow_heap1(NewList, MaxLen, CurLen+1, up);
grow_heap1([], _MaxLen, _, down) ->
ok;
grow_heap1([_|List], MaxLen, CurLen, down) ->
C=erlang:unique_integer([positive]),
Num = C rem (length(List))+1,
Elem = lists:nth(Num, List),
NewList = lists:delete(Elem, List),
grow_heap1(NewList, MaxLen, CurLen-1, down).
grow_stack(doc) -> ["Increase and decrease stack size, and ",
"drop off some garbage from time to time."];
grow_stack(Config) when is_list(Config) ->
ct:timetrap({minutes, 80}),
show_heap("before:"),
grow_stack1(200, 0),
show_heap("after:"),
ok.
grow_stack1(0, _) ->
ok;
grow_stack1(Recs, 0) ->
% show_heap("running:"),
grow_stack1(Recs-1, Recs),
grow_stack1(0,0);
grow_stack1(Recs, CurRecs) ->
grow_stack1(Recs, CurRecs-1),
make_arbit(),
grow_stack1(1,0),
ok.
%% Let's see how BEAM handles this one...
grow_stack_heap(doc) -> ["While growing the heap, bounces the size ",
"of the stack, and while reducing the heap",
"bounces the stack usage."];
grow_stack_heap(Config) when is_list(Config) ->
ct:timetrap({minutes, 40}),
grow_stack_heap1(16),
grow_stack_heap1(32),
ok.
grow_stack_heap1(MaxLen) ->
io:format("~ngrow_stack_heap with ~p items.",[MaxLen]),
show_heap("before:"),
grow_stack_heap1([], MaxLen, 0, up),
show_heap("after:").
grow_stack_heap1(List, MaxLen, MaxLen, up) ->
show_heap("top:"),
grow_stack_heap1(List, MaxLen, MaxLen-1, down);
grow_stack_heap1(List, MaxLen, CurLen, up) ->
grow_stack1(CurLen*2,0),
grow_stack_heap1([make_arbit()|List], MaxLen, CurLen+1, up),
ok;
grow_stack_heap1([], _MaxLen, _, down) -> ok;
grow_stack_heap1([_|List], MaxLen, CurLen, down) ->
grow_stack1(CurLen*2,0),
C=erlang:unique_integer([positive]),
Num=C rem (length(List))+1,
Elem=lists:nth(Num, List),
NewList=lists:delete(Elem, List),
grow_stack_heap1(NewList, MaxLen, CurLen-1, down),
ok.
%% Create an arbitrary element/term.
make_arbit() ->
{AA,BB,CC}=erlang:timestamp(),
A=AA+1, B=BB+1, C=(CC+erlang:unique_integer([positive])) rem 1000000 + 1,
New =
case C rem 9 of
0 -> make_string((B div C) +5);
1 -> C;
2 -> make_ref();
3 -> self();
4 -> list_to_binary(make_string((C div B) + 12));
5 -> (C*B)/(A+1);
6 -> list_to_tuple(make_string((B div C) +5));
7 -> list_to_atom(make_string(((C div B) rem 254) + 2));
8 -> fun(X) -> {X,AA,make_string((B div C)+10)} end
end,
New.
%% Create an arbitrary string of a certain length.
make_string(Length) ->
Alph="abcdefghjiklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"++
"0123456789",
make_string(Alph, Length, []).
make_string(_, 0, Acc) ->
Acc;
make_string(Alph, Length, Acc) ->
C=erlang:unique_integer([positive]),
Pos=1+(Length*C rem length(Alph)),
make_string(Alph, Length-1,
[lists:nth(Pos,Alph)|Acc]).
show_heap(String) ->
garbage_collect(self()),
receive after 1 -> ok end,
{heap_size, HSize}=process_info(self(), heap_size),
{stack_size, SSize}=process_info(self(), stack_size),
io:format("Heap/Stack "++String++"~p/~p", [HSize, SSize]).
