aboutsummaryrefslogtreecommitdiffstats
path: root/erts/emulator/test/efile_SUITE.erl
blob: 6bb8487c4e3c4ac7a810c07f679cb4e882546591 (plain) (blame)
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
%%
%% %CopyrightBegin%
%% 
%% Copyright Ericsson AB 1997-2016. 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(efile_SUITE).
-export([all/0, suite/0]).
-export([iter_max_files/1, async_dist/1]).

-export([do_iter_max_files/2, do_async_dist/1]).

-include_lib("common_test/include/ct.hrl").

suite() -> [{ct_hooks,[ts_install_cth]}].

all() -> 
    [iter_max_files, async_dist].

do_async_dist(Dir) ->
    X = 100,
    AT = erlang:system_info(thread_pool_size),
    Keys = file_keys(Dir,AT*X,[],[]),
    Tab = ets:new(x,[ordered_set]),
    [ ets:insert(Tab,{N,0}) || N <- lists:seq(0,AT-1) ],
    [ ets:update_counter(Tab,(N rem AT),1) || N <- Keys ],
    Res = [ V || {_,V} <- ets:tab2list(Tab) ],
    ets:delete(Tab),
    {Res, sdev(Res)/X}.

sdev(List) ->
    Len = length(List),
    Mean = lists:sum(List)/Len,
    math:sqrt(lists:sum([ (X - Mean) * (X - Mean) || X <- List ]) / Len).

file_keys(_,0,FdList,FnList) ->
    [ file:close(FD) || FD <- FdList ],
    [ file:delete(FN) || FN <- FnList ],
    [];
file_keys(Dir,Num,FdList,FnList) ->
    Name = "dummy"++integer_to_list(Num),
    FN = filename:join([Dir,Name]),
    case file:open(FN,[write,raw]) of
        {ok,FD} ->
            {file_descriptor,prim_file,{Port,_}} = FD,
            <<X:32/integer-big>> = 
            iolist_to_binary(erlang:port_control(Port,$K,[])),
            [X | file_keys(Dir,Num-1,[FD|FdList],[FN|FnList])];
        {error,_} ->
            % Try freeing up FD's if there are any
            case FdList of 
                [] ->
                    exit({cannot_open_file,FN});
                _ ->
                    [ file:close(FD) || FD <- FdList ],
                    [ file:delete(F) || F <- FnList ],
                    file_keys(Dir,Num,[],[])
            end
    end.

%% Check that the distribution of files over async threads is fair
async_dist(Config) when is_list(Config) ->
    DataDir = proplists:get_value(data_dir,Config),
    TestFile = filename:join(DataDir, "existing_file"),
    Dir = filename:dirname(code:which(?MODULE)),
    AsyncSizes = [7,10,100,255,256,64,63,65],
    Max = 0.5,

    lists:foreach(fun(Size) ->
                          {ok,Node} = 
                          test_server:start_node
                          (test_iter_max_files,slave,
                           [{args,
                             "+A "++integer_to_list(Size)++
                             " -pa " ++ Dir}]),
                          {Distr,SD} = rpc:call(Node,?MODULE,do_async_dist,
                                                [DataDir]),
                          test_server:stop_node(Node),
                          if
                              SD > Max ->
                                  io:format("Bad async queue distribution for "
                                            "~p async threads:~n"
                                            "    Standard deviation is ~p~n"
                                            "    Key distribution:~n    ~lp~n",
                                            [Size,SD,Distr]),
                                  exit({bad_async_dist,Size,SD,Distr});
                              true ->
                                  io:format("OK async queue distribution for "
                                            "~p async threads:~n"
                                            "    Standard deviation is ~p~n"
                                            "    Key distribution:~n    ~lp~n",
                                            [Size,SD,Distr]),
                                  ok
                          end
                  end, AsyncSizes),
    ok.

%%
%% Open as many files as possible. Do this several times and check 
%% that we get the same number of files every time.
%%

iter_max_files(Config) when is_list(Config) ->
    DataDir = proplists:get_value(data_dir,Config),
    TestFile = filename:join(DataDir, "existing_file"),
    N = 10,
    %% Run on a different node in order to set the max ports
    Dir = filename:dirname(code:which(?MODULE)),
    {ok,Node} = test_server:start_node(test_iter_max_files,slave,
                                       [{args,"+Q 1524 -pa " ++ Dir}]),
    L = rpc:call(Node,?MODULE,do_iter_max_files,[N, TestFile]),
    test_server:stop_node(Node),
    io:format("Number of files opened in each test:~n~w\n", [L]),
    all_equal(L),
    Head = hd(L),
    if  Head >= 2 -> ok;
        true -> ct:fail(too_few_files)
    end,
    {comment, "Max files: " ++ integer_to_list(hd(L))}.

do_iter_max_files(N, Name) when N > 0 -> 
    [max_files(Name)| do_iter_max_files(N-1, Name)];
do_iter_max_files(_, _) ->
    [].

all_equal([E, E| T]) ->
    all_equal([E| T]);
all_equal([_]) ->
    ok;
all_equal([]) ->
    ok.

max_files(Name) ->
    Fds = open_files(Name),
    N = length(Fds),
    close_files(Fds),
    N.

close_files([Fd| Fds]) ->
    file:close(Fd),
    close_files(Fds);
close_files([]) ->
    ok.

open_files(Name) ->
    case file:open(Name, [read,raw]) of
        {ok, Fd} ->
            [Fd| open_files(Name)];
        {error, _Reason} ->
            %		  io:format("Error reason: ~p", [_Reason]),
            []
    end.