Handle rejected queues on confirm.

When one queue confirms a message and another queue failed
without confirming it, the message should be rejected.

Fixes some races between confirms and rejects.

Author: hairyhum

src/rabbit_amqqueue_process.erl

@@ -603,13 +603,22 @@ confirm_messages(MsgIds, MTC) ->
                       none ->
                           {CMs, MTC0};
                       {SenderPid, MsgSeqNo} ->
-                          {rabbit_misc:gb_trees_cons(SenderPid,
-                                                     MsgSeqNo, CMs),
+                          {maps:update_with(SenderPid,
+                                            fun(MsgSeqNos) ->
+                                                [MsgSeqNo | MsgSeqNos]
+                                            end,
+                                            [MsgSeqNo],
+                                            CMs),
                            maps:remove(MsgId, MTC0)}
 
                   end
-          end, {gb_trees:empty(), MTC}, MsgIds),
-    rabbit_misc:gb_trees_foreach(fun rabbit_misc:confirm_to_sender/2, CMs),
+          end, {#{}, MTC}, MsgIds),
+    maps:fold(
+        fun(Pid, MsgSeqNos, _) ->
+            rabbit_misc:confirm_to_sender(Pid, MsgSeqNos)
+        end,
+        ok,
+        CMs),
     MTC1.
 
 send_or_record_confirm(#delivery{confirm    = false}, State) ->

src/rabbit_channel.erl

@@ -2233,10 +2233,11 @@ confirm(MsgSeqNos, QRef, State = #ch{queue_names = QNames, unconfirmed = UC}) ->
     %% does not exist in unconfirmed messages.
     %% Neither does the 'ignore' atom, so it's a reasonable fallback.
     QName = maps:get(QRef, QNames, ignore),
-    {MXs, UC1} =
+    {ConfirmMXs, RejectMXs, UC1} =
         unconfirmed_messages:confirm_multiple_msg_ref(MsgSeqNos, QName, QRef, UC),
     %% NB: don't call noreply/1 since we don't want to send confirms.
-    record_confirms(MXs, State#ch{unconfirmed = UC1}).
+    State1 = record_confirms(ConfirmMXs, State#ch{unconfirmed = UC1}),
+    record_rejects(RejectMXs, State1).
 
 send_confirms_and_nacks(State = #ch{tx = none, confirmed = [], rejected = []}) ->
     State;

src/unconfirmed_messages.erl

@@ -33,7 +33,6 @@
 
 -export([new/0,
          insert/5,
-         confirm_msg_ref/4,
          confirm_multiple_msg_ref/4,
          forget_ref/2,
 
@@ -112,27 +111,22 @@ insert(MsgId, QueueNames, QueueRefs, XName,
             error({message_already_exists, MsgId, QueueNames, QueueRefs, XName, UC})
     end.
 
-%% Confirms a message on behalf of the given queue. If it was the last queue (ref)
-%% on the waiting list, returns 'confirmed' and performs the necessary cleanup.
--spec confirm_msg_ref(msg_id(), queue_name(), queue_ref(), ?MODULE()) ->
-    {{confirmed | rejected, {msg_id(), exchange_name()}} | not_confirmed, ?MODULE()}.
-confirm_msg_ref(MsgId, QueueName, QueueRef,
-                #unconfirmed{reverse = Reverse} = UC) ->
-    remove_msg_ref(confirm, MsgId, QueueName, QueueRef,
-                   UC#unconfirmed{reverse = remove_from_reverse(QueueRef, [MsgId], Reverse)}).
-
+%% Confirms messages on behalf of the given queue. If it was the last queue (ref)
+%% on the waiting list, returns message id and excahnge name
+%% and performs the necessary cleanup.
 -spec confirm_multiple_msg_ref(msg_id(), queue_name(), queue_ref(), ?MODULE()) ->
-    {{confirmed | rejected, {msg_id(), exchange_name()}} | not_confirmed, ?MODULE()}.
+    {[{msg_id(), exchange_name()}], [{msg_id(), exchange_name()}], ?MODULE()}.
 confirm_multiple_msg_ref(MsgIds, QueueName, QueueRef,
                          #unconfirmed{reverse = Reverse} = UC0) ->
     lists:foldl(
-        fun(MsgId, {C, UC}) ->
+        fun(MsgId, {C, R, UC}) ->
             case remove_msg_ref(confirm, MsgId, QueueName, QueueRef, UC) of
-                {{confirmed, V}, UC1} -> {[V | C], UC1};
-                {not_confirmed, UC1}  -> {C, UC1}
+                {{confirmed, V}, UC1} -> {[V | C], R,       UC1};
+                {{rejected, V}, UC1}  -> {C,       [V | R], UC1};
+                {not_confirmed, UC1}  -> {C,       R,       UC1}
             end
         end,
-        {[], UC0#unconfirmed{reverse = remove_from_reverse(QueueRef, MsgIds, Reverse)}},
+        {[], [], UC0#unconfirmed{reverse = remove_from_reverse(QueueRef, MsgIds, Reverse)}},
         MsgIds).
 
 %% Removes all messages for a queue.
@@ -179,14 +173,15 @@ reject_msg(MsgId, #unconfirmed{ordered = Ordered, index = Index, reverse = Rever
     {Rejected :: [{msg_id(), exchange_name()}], ?MODULE()}.
 reject_all_for_queue(QueueRef, #unconfirmed{reverse = Reverse0} = UC0) ->
     MsgIds = maps:keys(maps:get(QueueRef, Reverse0, #{})),
-    lists:foldl(fun(MsgId, {R, UC}) ->
-        case reject_msg(MsgId, UC) of
-            {not_confirmed, UC1} -> {R, UC1};
-            {{rejected, V}, UC1} -> {[V | R], UC1}
-        end
-    end,
-    {[], UC0#unconfirmed{reverse = maps:remove(QueueRef, Reverse0)}},
-    MsgIds).
+    lists:foldl(
+        fun(MsgId, {R, UC}) ->
+            case reject_msg(MsgId, UC) of
+                {not_confirmed, UC1} -> {R, UC1};
+                {{rejected, V}, UC1} -> {[V | R], UC1}
+            end
+        end,
+        {[], UC0#unconfirmed{reverse = maps:remove(QueueRef, Reverse0)}},
+        MsgIds).
 
 %% Returns a smallest message id.
 -spec smallest(?MODULE()) -> msg_id().