From e039c90768ea78e9deed108b72702dba49ef0302 Mon Sep 17 00:00:00 2001
From: Simon MacMullen <simon@rabbitmq.com>
Date: Wed, 20 Aug 2014 11:53:23 +0100
Subject: Fix a race.

---
 src/pg_local.erl | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/pg_local.erl b/src/pg_local.erl
index dc6401ca..4d9914d9 100644
--- a/src/pg_local.erl
+++ b/src/pg_local.erl
@@ -84,7 +84,13 @@ get_members(Name) ->
 
 in_group(Name, Pid) ->
     ensure_started(),
-    member_present(Name, Pid).
+    %% The join message is a cast and thus can race, but we want to
+    %% keep it that way to be fast in the common case.
+    case member_present(Name, Pid) of
+        true  -> true;
+        false -> sync(),
+                 member_present(Name, Pid)
+    end.
 
 sync() ->
     ensure_started(),
-- 
cgit v1.2.1