1 files changed, 110 insertions, 0 deletions
diff --git a/lib/stdlib/test/random_SUITE.erl b/lib/stdlib/test/random_SUITE.erl
new file mode 100644
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+++ b/lib/stdlib/test/random_SUITE.erl
@@ -0,0 +1,110 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2000-2009. All Rights Reserved.
+%% 
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%% 
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%% 
+%% %CopyrightEnd%
+
+-module(random_SUITE).
+-export([all/1]).
+
+-export([interval_1/1, seed0/1, seed/1]).
+
+-export([init_per_testcase/2, fin_per_testcase/2]).
+
+-include("test_server.hrl").
+
+% Default timetrap timeout (set in init_per_testcase).
+-define(default_timeout, ?t:minutes(1)).
+
+init_per_testcase(_Case, Config) ->
+    ?line Dog = ?t:timetrap(?default_timeout),
+    [{watchdog, Dog} | Config].
+fin_per_testcase(_Case, Config) ->
+    Dog = ?config(watchdog, Config),
+    test_server:timetrap_cancel(Dog),
+    ok.
+
+all(doc) ->
+    ["Test cases for random."];
+all(suite) ->
+    [interval_1, seed0, seed].
+
+seed0(doc) ->
+    ["Test that seed is set implicitly, and always the same."];
+seed0(suite) ->
+    [];
+seed0(Config) when is_list(Config) ->
+    ?line Self = self(),
+    ?line _ = spawn(fun() -> Self ! random:uniform() end),
+    ?line F1 = receive
+		   Fa -> Fa
+	  end,
+    ?line _ = spawn(fun() -> random:seed(),
+			     Self ! random:uniform() end),
+    ?line F2 = receive
+		   Fb -> Fb
+	       end,
+    ?line F1 = F2,
+    ok.
+
+seed(doc) ->
+    ["Test that seed/1 and seed/3 is equivalent."];
+seed(suite) ->
+    [];
+seed(Config) when is_list(Config) ->
+    ?line Self = self(),
+    ?line Seed = {S1, S2, S3} = now(),
+    ?line _ = spawn(fun() ->
+    	random:seed(S1,S2,S3),
+    	Rands = lists:foldl(fun
+	    (_, Out) -> [random:uniform(10000)|Out]
+	end, [], lists:seq(1,100)),
+    	Self ! {seed_test, Rands}
+    end),
+    ?line Rands1 = receive {seed_test, R1s} -> R1s end,
+    ?line _ = spawn(fun() ->
+    	random:seed(Seed),
+    	Rands = lists:foldl(fun
+	    (_, Out) -> [random:uniform(10000)|Out]
+	end, [], lists:seq(1,100)),
+    	Self ! {seed_test, Rands}
+    end),
+    ?line Rands2 = receive {seed_test, R2s} -> R2s end,
+    ?line Rands1 = Rands2,
+    ok.
+
+
+interval_1(doc) ->
+    ["Check that uniform/1 returns values within the proper interval."];
+interval_1(suite) ->
+    [];
+interval_1(Config) when is_list(Config) ->
+    ?line Top = 7,
+    ?line N = 10,
+    ?line check_interval(N, Top),
+    ok.
+
+check_interval(0, _) -> ok;
+check_interval(N, Top) ->
+    X = random:uniform(Top),
+    if
+	X < 1 ->
+	    test_server:fail(too_small);
+	X > Top ->
+	    test_server:fail(too_large);
+	true ->
+	    ok
+    end,
+    check_interval(N-1, Top).