1 files changed, 114 insertions, 0 deletions
diff --git a/apps/couch/test/etap/100-ref-counter.t b/apps/couch/test/etap/100-ref-counter.t
new file mode 100755
index 00000000..8f996d04
--- /dev/null
+++ b/apps/couch/test/etap/100-ref-counter.t
@@ -0,0 +1,114 @@
+#!/usr/bin/env escript
+%% -*- erlang -*-
+
+% 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.
+
+main(_) ->
+    test_util:init_code_path(),
+    etap:plan(8),
+    case (catch test()) of
+        ok ->
+            etap:end_tests();
+        Other ->
+            etap:diag(io_lib:format("Test died abnormally: ~p", [Other])),
+            etap:bail(Other)
+    end,
+    ok.
+
+loop() ->
+    receive
+        close -> ok
+    end.
+
+wait() ->
+    receive
+        {'DOWN', _, _, _, _} -> ok
+    after 1000 ->
+        throw(timeout_error)
+    end.
+
+test() ->
+    {ok, RefCtr} = couch_ref_counter:start([]),
+
+    etap:is(
+        couch_ref_counter:count(RefCtr),
+        1,
+        "A ref_counter is initialized with the calling process as a referer."
+    ),
+
+    ChildPid1 = spawn(fun() -> loop() end),
+
+    % This is largely implicit in that nothing else breaks
+    % as ok is just returned from gen_server:cast()
+    etap:is(
+        couch_ref_counter:drop(RefCtr, ChildPid1),
+        ok,
+        "Dropping an unknown Pid is ignored."
+    ),
+
+    couch_ref_counter:add(RefCtr, ChildPid1),
+    etap:is(
+        couch_ref_counter:count(RefCtr),
+        2,
+        "Adding a Pid to the ref_counter increases it's count."
+    ),
+
+    couch_ref_counter:add(RefCtr, ChildPid1),
+    etap:is(
+        couch_ref_counter:count(RefCtr),
+        2,
+        "Readding the same Pid maintains the count but increments it's refs."
+    ),
+
+    couch_ref_counter:drop(RefCtr, ChildPid1),
+    etap:is(
+        couch_ref_counter:count(RefCtr),
+        2,
+        "Droping the doubly added Pid only removes a ref, not a referer."
+    ),
+
+    couch_ref_counter:drop(RefCtr, ChildPid1),
+    etap:is(
+        couch_ref_counter:count(RefCtr),
+        1,
+        "Dropping the second ref drops the referer."
+    ),
+
+    couch_ref_counter:add(RefCtr, ChildPid1),
+    etap:is(
+        couch_ref_counter:count(RefCtr),
+        2,
+        "Sanity checking that the Pid was re-added."
+    ),
+
+    erlang:monitor(process, ChildPid1),
+    ChildPid1 ! close,
+    wait(),
+    
+    CheckFun = fun
+        (Iter, nil) ->
+            case couch_ref_counter:count(RefCtr) of
+                1 -> Iter;
+                _ -> nil
+            end;
+        (_, Acc) ->
+            Acc
+    end,
+    Result = lists:foldl(CheckFun, nil, lists:seq(1, 10000)),
+    etap:isnt(
+        Result,
+        nil,
+        "The referer count was decremented automatically on process exit."
+    ),
+
+    ok.