[couchdb] branch 3.0.x-fix-mem3-sync-event-listener-test created (now 8b78441)

[da...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

davisp pushed a change to branch 3.0.x-fix-mem3-sync-event-listener-test
in repository https://gitbox.apache.org/repos/asf/couchdb.git.


      at 8b78441  Fix mem3_sync_event_listener test

This branch includes the following new commits:

     new 8b78441  Fix mem3_sync_event_listener test

The 1 revisions listed above as "new" are entirely new to this
repository and will be described in separate emails.  The revisions
listed as "add" were already present in the repository and have only
been added to this reference.

[couchdb] 01/01: Fix mem3_sync_event_listener test

[da...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

davisp pushed a commit to branch 3.0.x-fix-mem3-sync-event-listener-test
in repository https://gitbox.apache.org/repos/asf/couchdb.git

commit 8b7844172451ab03a3448436ae381325ba776600
Author: Paul J. Davis <pa...@gmail.com>
AuthorDate: Thu Feb 27 14:02:51 2020 -0600

    Fix mem3_sync_event_listener test
    
    There's a race between the meck:wait call in setup and killing the
    config_event process. Its possible that we could kill and restart the
    config_event process after meck:wait returns, but before
    gen_event:add_sup_handler is called. More likely, we could end up
    killing the config_event gen_event process before its fully handled the
    add_sup_handler message and linked the notifier pid.
    
    This avoids the race by waiting for config_event to return that it has
    processed the add_sup_handler message instead of relying on meck:wait
    for the subscription call.
---
 src/mem3/src/mem3_sync_event_listener.erl | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/mem3/src/mem3_sync_event_listener.erl b/src/mem3/src/mem3_sync_event_listener.erl
index b6fbe32..cad3422 100644
--- a/src/mem3/src/mem3_sync_event_listener.erl
+++ b/src/mem3/src/mem3_sync_event_listener.erl
@@ -236,7 +236,7 @@ teardown_all(_) ->
 setup() ->
     {ok, Pid} = ?MODULE:start_link(),
     erlang:unlink(Pid),
-    meck:wait(config_notifier, subscribe, '_', 1000),
+    wait_config_subscribed(Pid),
     Pid.
 
 teardown(Pid) ->
@@ -338,4 +338,16 @@ wait_state(Pid, Field, Val) when is_pid(Pid), is_integer(Field) ->
     end,
     test_util:wait(WaitFun).
 
+
+wait_config_subscribed(Pid) ->
+    WaitFun = fun() ->
+        Handlers = gen_event:which_handlers(config_event),
+        Pids = [Id || {config_notifier, Id} <- Handlers],
+        case lists:member(Pid, Pids) of
+            true -> true;
+            false -> wait
+        end
+    end,
+    test_util:wait(WaitFun).
+
 -endif.