Fix timeout in couchdb_views_test for couchdb_1283

[davisp]

Fix for #655

[nickva]

Confirmed this fixes the issue.

Couldn't replicate this easily on my artificially slowed down VM even. Got it to where the test itself would timeout but it wouldn't fail like on Travis. I think the idea is to slow down the storage subsystem not the CPU.

There is a way to do it, but I am lazy so did resorted to just adding a sleep to the update runner before the:

exit({updated, self(), FinalIdxState}) line.

And a few log statements:

(655-fix-couchdb-views-tests)$ git diff
diff --git a/src/couch_index/src/couch_index_updater.erl b/src/couch_index/src/couch_index_updater.erl
index ad48f40..aedd2d1 100644
--- a/src/couch_index/src/couch_index_updater.erl
+++ b/src/couch_index/src/couch_index_updater.erl
@@ -69,6 +69,7 @@ handle_call({update, IdxState}, _From, #st{idx=Idx, mod=Mod}=State) ->
     Args = [Mod:get(db_name, IdxState), Mod:get(idx_name, IdxState)],
     couch_log:info("Starting index update for db: ~s idx: ~s", Args),
     Pid = spawn_link(?MODULE, update, [Idx, Mod, IdxState]),
+    io:format(standard_error, "~n XXXXXX handle_call update spawned ~p~n", [Pid]),
     {reply, ok, State#st{pid=Pid}};
 handle_call({restart, IdxState}, _From, #st{idx=Idx, mod=Mod}=State) ->
     Args = [Mod:get(db_name, IdxState), Mod:get(idx_name, IdxState)],
@@ -100,6 +101,7 @@ handle_info({'EXIT', _, {reset, Pid}}, #st{idx=Idx, pid=Pid}=State) ->
     Pid2 = spawn_link(?MODULE, update, [Idx, State#st.mod, NewIdxState]),
     {noreply, State#st{pid=Pid2}};
 handle_info({'EXIT', Pid, normal}, #st{pid=Pid}=State) ->
+    io:format(standard_error, "~n XXXXXX handle_info Pid normal set to undefined ~p~n", [Pid]),
     {noreply, State#st{pid=undefined}};
 handle_info({'EXIT', Pid, {{nocatch, Error}, _Trace}}, State) ->
     handle_info({'EXIT', Pid, Error}, State);
@@ -193,6 +195,8 @@ update(Idx, Mod, IdxState) ->
         end,

         {ok, FinalIdxState} = Mod:finish_update(LastIdxSt),
+        timer:sleep(1000),
+        io:format(standard_error, "~n XXXXXX  update exiting self() = ~p~n", [self()]),
         exit({updated, self(), FinalIdxState})
     end).

Now could see the failure:

*failed*
in function couchdb_views_tests:wait_for_process_shutdown/3 (test/couchdb_views_tests.erl, line 413)
in call from couchdb_views_tests:'-couchdb_1283/0-fun-21-'/0 (test/couchdb_views_tests.erl, line 358)
**error:{assertion_failed,[{module,couchdb_views_tests},
                   {line,415},
                   {reason,"Failure waiting for db shutdown"}]}

Then the PR fixes the failure:

==> couch (eunit)
    Running test function(s):
      couchdb_views_tests:view_group_shutdown_test_/0
======================== EUnit ========================
View group shutdown
Application crypto was left running!
  couchdb_views_tests:315: couchdb_1283...
 XXXXXX handle_call update spawned <0.318.0>

 XXXXXX  update exiting self() = <0.318.0>
[1.286 s] ok

+1

Very nice!