Do the queue deletion synchronously. Instead of replying immediately

using gen_server2:call, then doing the work, we include the reply in
the return value for gen_server2 to pass on.  It happens that
gen_server2 will terminate the process, on getting stop, before it
sends the reply on -- just what we want here.

NB: here we translate between the return value of handle_ch_down/2,
which was intended to be the return value for handle_call, and an
actual return value.  Slightly nicer would be for handle_ch_down to
return the state and (say) 'ok' or 'stop', to make its contract more
explicit.

1 files changed, 11 insertions, 3 deletions

diff --git a/src/rabbit_amqqueue_process.erl b/src/rabbit_amqqueue_process.erl
index fe2e8509..477484c1 100644
--- a/src/rabbit_amqqueue_process.erl
+++ b/src/rabbit_amqqueue_process.erl
@@ -577,9 +577,17 @@ handle_call({commit, Txn}, From, State) ->
     noreply(NewState);
 
 handle_call({notify_down, ChPid}, From, State) ->
-    %% optimisation: we reply straight away so the sender can continue
-    gen_server2:reply(From, ok),
-    handle_ch_down(ChPid, State);
+    %% we want to do this synchronously, so that auto_deleted queues
+    %% are no longer visible by the time we send a response to the
+    %% client.  The queue is ultimately deleted in terminate/2; if we
+    %% return stop with a reply, terminate/2 will be called by
+    %% gen_server/2 *before* the reply is sent.
+    case handle_ch_down(ChPid, State) of
+        {noreply, NewState, Timeout} ->
+            {reply, ok, NewState, Timeout};
+        {stop, normal, NewState2} ->
+            {stop, normal, ok, NewState2}
+    end;
 
 handle_call({basic_get, ChPid, NoAck}, _From,
             State = #q{q = #amqqueue{name = QName},