Do the monitoring on the correct node(!) and remove all that nonsense about node-wide monitoring.

3 files changed, 18 insertions, 40 deletions

diff --git a/src/delegate.erl b/src/delegate.erl
index a205f2f1..475b087f 100644
--- a/src/delegate.erl
+++ b/src/delegate.erl
@@ -119,15 +119,19 @@ invoke_no_result(Pids, Fun) when is_list(Pids) ->
     safe_invoke(LocalPids, Fun), %% must not die
     ok.
 
+monitor(Pid) when node(Pid) =:= node() ->
+    erlang:monitor(process, Pid);
 monitor(Pid) ->
     Node = node(Pid),
     Name = delegate(Pid, [Node]),
-    gen_server2:call({Name, Node}, {monitor, self(), Pid}, infinity).
+    gen_server2:call(Name, {monitor, self(), Pid}, infinity).
 
+demonitor(Pid, Ref) when node(Pid) =:= node() ->
+    erlang:demonitor(Ref, [flush]);
 demonitor(Pid, Ref) ->
     Node = node(Pid),
     Name = delegate(Pid, [Node]),
-    gen_server2:call({Name, Node}, {demonitor, Ref}, infinity).
+    gen_server2:call(Name, {demonitor, Ref}, infinity).
 
 call(PidOrPids, Msg) ->
     invoke(PidOrPids, fun (P) -> gen_server2:call(P, Msg, infinity) end).
diff --git a/src/dmon.erl b/src/dmon.erl
index 3f89c83a..dfb420c3 100644
--- a/src/dmon.erl
+++ b/src/dmon.erl
@@ -16,8 +16,8 @@
 
 -module(dmon).
 
--export([new/0, monitor/2, monitor_all/2, demonitor/2, is_monitored/2,
-         monitored/1, monitored/2, is_empty/1]).
+-export([new/0, monitor/2, monitor_all/2, demonitor/2, is_monitored/2, erase/2,
+         monitored/1, is_empty/1]).
 
 -compile({no_auto_import, [monitor/2]}).
 
@@ -36,8 +36,8 @@
 -spec(monitor_all/2  :: ([item()], ?MODULE()) -> ?MODULE()).
 -spec(demonitor/2    :: (item(), ?MODULE()) -> ?MODULE()).
 -spec(is_monitored/2 :: (item(), ?MODULE()) -> boolean()).
+-spec(erase/2        :: (item(), ?MODULE()) -> ?MODULE()).
 -spec(monitored/1    :: (?MODULE()) -> [item()]).
--spec(monitored/2    :: (node(), ?MODULE()) -> [item()]).
 -spec(is_empty/1     :: (?MODULE()) -> boolean()).
 
 -endif.
@@ -45,14 +45,9 @@
 new() -> dict:new().
 
 monitor(Item, M) ->
-    N = case dict:find(node(Item), M) of
-            {ok, N0} -> N0;
-            error    -> dict:new()
-        end,
-    case dict:is_key(Item, N) of
+    case dict:is_key(Item, M) of
         true  -> M;
-        false -> N2 = dict:store(Item, delegate:monitor(Item), N),
-                 dict:store(node(Item), N2, M)
+        false -> dict:store(Item, delegate:monitor(Item), M)
     end.
 
 monitor_all([],     M) -> M;                %% optimisation
@@ -60,30 +55,16 @@ monitor_all([Item], M) -> monitor(Item, M); %% optimisation
 monitor_all(Items,  M) -> lists:foldl(fun monitor/2, M, Items).
 
 demonitor(Item, M) ->
-    Node = node(Item),
-    case dict:find(Node, M) of
-        {ok, N} -> case dict:find(Item, N) of
-                       {ok, MRef} -> delegate:demonitor(Item, MRef),
-                                     N2 = dict:erase(Item, N),
-                                     case dict:size(N2) of
-                                         0 -> erlang:monitor_node(Node, false),
-                                              dict:erase(Node, M);
-                                         _ -> dict:store(Node, N2, M)
-                                     end;
-                       error      -> M
-                   end;
-        error   -> M
+    case dict:find(Item, M) of
+        {ok, MRef} -> delegate:demonitor(Item, MRef),
+                      dict:erase(Item, M);
+        error      -> M
     end.
 
-is_monitored(Item, M) -> dict:is_key(node(Item), M) andalso
-                             dict:is_key(Item, dict:fetch(node(Item), M)).
+is_monitored(Item, M) -> dict:is_key(Item, M).
 
-monitored(M) -> lists:flatten([dict:fetch_keys(dict:fetch(Node, M)) ||
-                                  Node <- dict:fetch_keys(M)]).
+erase(Item, M) -> dict:erase(Item, M).
 
-monitored(Node, M) -> case dict:find(Node, M) of
-                          {ok, N} -> dict:fetch_keys(N);
-                          error   -> []
-                      end.
+monitored(M) -> dict:fetch_keys(M).
 
 is_empty(M) -> dict:size(M) == 0.
diff --git a/src/rabbit_mirror_queue_slave.erl b/src/rabbit_mirror_queue_slave.erl
index b4c01440..ac3e0df0 100644
--- a/src/rabbit_mirror_queue_slave.erl
+++ b/src/rabbit_mirror_queue_slave.erl
@@ -276,10 +276,6 @@ handle_info({'DOWN', _MonitorRef, process, ChPid, _Reason}, State) ->
     local_sender_death(ChPid, State),
     noreply(State);
 
-handle_info({node_down, Node}, State) ->
-    local_sender_node_death(Node, State),
-    noreply(State);
-
 handle_info({'EXIT', _Pid, Reason}, State) ->
     {stop, Reason, State};
 
@@ -619,9 +615,6 @@ local_sender_death(ChPid, #state { known_senders = KS }) ->
              true  -> confirm_sender_death(ChPid)
          end.
 
-local_sender_node_death(Node, State = #state { known_senders = KS }) ->
-    [local_sender_death(ChPid, State) || ChPid <- dmon:monitored(Node, KS)].
-
 confirm_sender_death(Pid) ->
     %% We have to deal with the possibility that we'll be promoted to
     %% master before this thing gets run. Consequently we set the