1 files changed, 103 insertions, 0 deletions
diff --git a/src/couch/src/test_engine_ref_counting.erl b/src/couch/src/test_engine_ref_counting.erl
new file mode 100644
index 000000000..18e75fb5a
--- /dev/null
+++ b/src/couch/src/test_engine_ref_counting.erl
@@ -0,0 +1,103 @@
+% 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.
+
+-module(test_engine_ref_counting).
+-compile(export_all).
+
+
+-include_lib("eunit/include/eunit.hrl").
+-include_lib("couch/include/couch_db.hrl").
+
+
+-define(NUM_CLIENTS, 1000).
+
+
+cet_empty_monitors() ->
+    {ok, Engine, St} = test_engine_util:init_engine(),
+    Pids = Engine:monitored_by(St),
+    ?assert(is_list(Pids)),
+    ?assertEqual([], Pids -- [self(), whereis(couch_stats_process_tracker)]).
+
+
+cet_incref_decref() ->
+    {ok, Engine, St} = test_engine_util:init_engine(),
+
+    {Pid, _} = Client = start_client(Engine, St),
+    wait_client(Client),
+
+    Pids1 = Engine:monitored_by(St),
+    ?assert(lists:member(Pid, Pids1)),
+
+    close_client(Client),
+
+    Pids2 = Engine:monitored_by(St),
+    ?assert(not lists:member(Pid, Pids2)).
+
+
+cet_incref_decref_many() ->
+    {ok, Engine, St} = test_engine_util:init_engine(),
+    Clients = lists:map(fun(_) ->
+        start_client(Engine, St)
+    end, lists:seq(1, ?NUM_CLIENTS)),
+
+    lists:foreach(fun(C) -> wait_client(C) end, Clients),
+
+    Pids1 = Engine:monitored_by(St),
+    % +2 for db pid and process tracker
+    ?assertEqual(?NUM_CLIENTS + 2, length(Pids1)),
+
+    lists:foreach(fun(C) -> close_client(C) end, Clients),
+
+    Pids2 = Engine:monitored_by(St),
+    ?assertEqual(2, length(Pids2)).
+
+
+start_client(Engine, St1) ->
+    spawn_monitor(fun() ->
+        {ok, St2} = Engine:incref(St1),
+
+        receive
+            {waiting, Pid} ->
+                Pid ! go
+        after 1000 ->
+            erlang:error(timeout)
+        end,
+
+        receive
+            close ->
+                ok
+        after 1000 ->
+            erlang:error(timeout)
+        end,
+
+        Engine:decref(St2)
+    end).
+
+
+wait_client({Pid, _Ref}) ->
+    Pid ! {waiting, self()},
+    receive
+        go -> ok
+    after 1000 ->
+        erlang:error(timeout)
+    end.
+
+
+close_client({Pid, Ref}) ->
+    Pid ! close,
+    receive
+        {'DOWN', Ref, _, _, _} ->
+            ok
+    after 1000 ->
+        erlang:error(timeout)
+    end.
+