Make erlang:phash2/1 and erlang:phash2/2 yield

The erlang:phash2 functions did not yield even if the input was very
large and a call to one of the functions did only consume a single
reduction. This commit fixes these problems.

1 files changed, 63 insertions, 0 deletions

diff --git a/erts/emulator/test/property_test/phash2_properties.erl b/erts/emulator/test/property_test/phash2_properties.erl
new file mode 100644
index 0000000000..b1f3207c56
--- /dev/null
+++ b/erts/emulator/test/property_test/phash2_properties.erl
@@ -0,0 +1,63 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2019-2019. 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(phash2_properties).
+
+-ifdef(PROPER).
+
+-include_lib("proper/include/proper.hrl").
+-export([prop_phash2_same_with_same_input/0,
+         prop_phash2_same_with_same_long_input/0,
+         prop_phash2_same_in_different_versions/1,
+         prop_phash2_same_in_different_versions_with_long_input/1]).
+-proptest([proper]).
+
+%%--------------------------------------------------------------------
+%% Properties --------------------------------------------------------
+%%--------------------------------------------------------------------
+
+prop_phash2_same_with_same_input() ->
+    ?FORALL(T, any(), erlang:phash2(T) =:= erlang:phash2(T)).
+
+prop_phash2_same_with_same_long_input() ->
+    ?FORALL(T, any(),
+            begin
+                BigTerm = lists:duplicate(10000, T),
+                erlang:phash2(BigTerm) =:= erlang:phash2(BigTerm)
+            end).
+
+prop_phash2_same_in_different_versions(DifferntVersionNode) ->
+    ?FORALL(T, any(),
+            erlang:phash2(T) =:= rpc:call(DifferntVersionNode,erlang,phash2,[T])).
+
+prop_phash2_same_in_different_versions_with_long_input(DifferntVersionNode) ->
+    ?FORALL(T, any(),
+            begin
+                BigTerm = lists:duplicate(10000, T),
+                RpcRes = rpc:call(DifferntVersionNode,erlang,phash2,[BigTerm]),
+                LocalRes = erlang:phash2(BigTerm),
+                RpcRes =:= LocalRes
+            end).
+
+%%--------------------------------------------------------------------
+%% Generators  -------------------------------------------------------
+%%--------------------------------------------------------------------
+
+-endif.