Merging default into bug 21673

26 files changed, 450 insertions, 215 deletions

diff --git a/src/delegate.erl b/src/delegate.erl
index 98353453ff..8af2812781 100644
--- a/src/delegate.erl
+++ b/src/delegate.erl
@@ -45,8 +45,8 @@
 -ifdef(use_specs).
 
 -spec(start_link/1 :: (non_neg_integer()) -> {'ok', pid()}).
--spec(invoke_no_result/2 :: (pid() | [pid()], fun((pid()) -> any())) -> 'ok').
--spec(invoke/2 :: (pid() | [pid()], fun((pid()) -> A)) -> A).
+-spec(invoke_no_result/2 :: (pid() | [pid()], fun ((pid()) -> any())) -> 'ok').
+-spec(invoke/2 :: (pid() | [pid()], fun ((pid()) -> A)) -> A).
 
 -spec(process_count/0 :: () -> non_neg_integer()).
 
@@ -73,7 +73,7 @@ invoke(Pid, Fun) when is_pid(Pid) ->
 
 invoke(Pids, Fun) when is_list(Pids) ->
     lists:foldl(
-        fun({Status, Result, Pid}, {Good, Bad}) ->
+        fun ({Status, Result, Pid}, {Good, Bad}) ->
             case Status of
                 ok    -> {[{Pid, Result}|Good], Bad};
                 error -> {Good, [{Pid, Result}|Bad]}
@@ -136,10 +136,10 @@ delegate_per_remote_node(NodePids, Fun, DelegateFun) ->
     %% block forever.
     [gen_server2:cast(
        local_server(Node),
-       {thunk, fun() ->
+       {thunk, fun () ->
                        Self ! {result,
                                DelegateFun(
-                                 Node, fun() -> safe_invoke(Pids, Fun) end)}
+                                 Node, fun () -> safe_invoke(Pids, Fun) end)}
                end}) || {Node, Pids} <- NodePids],
     [receive {result, Result} -> Result end || _ <- NodePids].
 
diff --git a/src/gen_server2.erl b/src/gen_server2.erl
index 5b899cdbc7..547f0a42e2 100644
--- a/src/gen_server2.erl
+++ b/src/gen_server2.erl
@@ -639,7 +639,7 @@ do_multi_call(Nodes, Name, Req, Timeout) ->
     Caller = self(),
     Receiver =
 	spawn(
-	  fun() ->
+	  fun () ->
 		  %% Middleman process. Should be unsensitive to regular
 		  %% exit signals. The sychronization is needed in case
 		  %% the receiver would exit before the caller started
diff --git a/src/rabbit_alarm.erl b/src/rabbit_alarm.erl
index 7e96d9a3a8..53c713e66b 100644
--- a/src/rabbit_alarm.erl
+++ b/src/rabbit_alarm.erl
@@ -47,7 +47,7 @@
 -type(mfa_tuple() :: {atom(), atom(), list()}).
 -spec(start/0 :: () -> 'ok').
 -spec(stop/0 :: () -> 'ok').
--spec(register/2 :: (pid(), mfa_tuple()) -> 'ok').
+-spec(register/2 :: (pid(), mfa_tuple()) -> boolean()).
 
 -endif.
 
@@ -67,9 +67,9 @@ stop() ->
     ok = alarm_handler:delete_alarm_handler(?MODULE).
 
 register(Pid, HighMemMFA) ->
-    ok = gen_event:call(alarm_handler, ?MODULE,
-                        {register, Pid, HighMemMFA},
-                        infinity).
+    gen_event:call(alarm_handler, ?MODULE,
+                   {register, Pid, HighMemMFA},
+                   infinity).
 
 %%----------------------------------------------------------------------------
 
@@ -84,7 +84,8 @@ handle_call({register, Pid, {M, F, A} = HighMemMFA},
              false -> ok
          end,
     NewAlertees = dict:store(Pid, HighMemMFA, Alertess),
-    {ok, ok, State#alarms{alertees = NewAlertees}};
+    {ok, State#alarms.vm_memory_high_watermark,
+     State#alarms{alertees = NewAlertees}};
 
 handle_call(_Request, State) ->
     {ok, not_understood, State}.
diff --git a/src/rabbit_amqqueue.erl b/src/rabbit_amqqueue.erl
index 483b5a93b7..3c9c41bdeb 100644
--- a/src/rabbit_amqqueue.erl
+++ b/src/rabbit_amqqueue.erl
@@ -195,7 +195,8 @@ start_queue_process(Q) ->
 add_default_binding(#amqqueue{name = QueueName}) ->
     Exchange = rabbit_misc:r(QueueName, exchange, <<>>),
     RoutingKey = QueueName#resource.name,
-    rabbit_exchange:add_binding(Exchange, QueueName, RoutingKey, []),
+    rabbit_exchange:add_binding(Exchange, QueueName, RoutingKey, [],
+                                fun (_X, _Q) -> ok end),
     ok.
 
 lookup(Name) ->
@@ -267,7 +268,7 @@ deliver(QPid, #delivery{txn = Txn, sender = ChPid, message = Message}) ->
     true.
 
 requeue(QPid, MsgIds, ChPid) ->
-    delegate_cast(QPid, {requeue, MsgIds, ChPid}).
+    delegate_call(QPid, {requeue, MsgIds, ChPid}, infinity).
 
 ack(QPid, Txn, MsgIds, ChPid) ->
     delegate_pcast(QPid, 7, {ack, Txn, MsgIds, ChPid}).
@@ -391,15 +392,13 @@ safe_delegate_call_ok(H, F, Pids) ->
     end.
 
 delegate_call(Pid, Msg, Timeout) ->
-    delegate:invoke(Pid, fun(P) -> gen_server2:call(P, Msg, Timeout) end).
+    delegate:invoke(Pid, fun (P) -> gen_server2:call(P, Msg, Timeout) end).
 
 delegate_pcall(Pid, Pri, Msg, Timeout) ->
-    delegate:invoke(Pid, fun(P) -> gen_server2:pcall(P, Pri, Msg, Timeout) end).
-
-delegate_cast(Pid, Msg) ->
-    delegate:invoke_no_result(Pid, fun(P) -> gen_server2:cast(P, Msg) end).
+    delegate:invoke(Pid, 
+                    fun (P) -> gen_server2:pcall(P, Pri, Msg, Timeout) end).
 
 delegate_pcast(Pid, Pri, Msg) ->
     delegate:invoke_no_result(Pid,
-                              fun(P) -> gen_server2:pcast(P, Pri, Msg) end).
+                              fun (P) -> gen_server2:pcast(P, Pri, Msg) end).
 
diff --git a/src/rabbit_amqqueue_process.erl b/src/rabbit_amqqueue_process.erl
index 3283cb6679..5fdf0ffa90 100644
--- a/src/rabbit_amqqueue_process.erl
+++ b/src/rabbit_amqqueue_process.erl
@@ -716,6 +716,19 @@ handle_call(purge, _From, State = #q{backing_queue = BQ,
     {Count, BQS1} = BQ:purge(BQS),
     reply({ok, Count}, State#q{backing_queue_state = BQS1});
 
+handle_call({requeue, AckTags, ChPid}, From, State) ->
+    gen_server2:reply(From, ok),
+    case lookup_ch(ChPid) of
+        not_found ->
+            rabbit_log:warning("Ignoring requeue from unknown ch: ~p~n",
+                               [ChPid]),
+            noreply(State);
+        C = #cr{acktags = ChAckTags} ->
+            ChAckTags1 = subtract_acks(ChAckTags, AckTags),
+            store_ch_record(C#cr{acktags = ChAckTags1}),
+            noreply(requeue_and_run(AckTags, State))
+    end;
+
 handle_call({maybe_run_queue_via_backing_queue, Fun}, _From, State) ->
     reply(ok, maybe_run_queue_via_backing_queue(Fun, State)).
 
@@ -743,18 +756,6 @@ handle_cast({ack, Txn, AckTags, ChPid},
 handle_cast({rollback, Txn, ChPid}, State) ->
     noreply(rollback_transaction(Txn, ChPid, State));
 
-handle_cast({requeue, AckTags, ChPid}, State) ->
-    case lookup_ch(ChPid) of
-        not_found ->
-            rabbit_log:warning("Ignoring requeue from unknown ch: ~p~n",
-                               [ChPid]),
-            noreply(State);
-        C = #cr{acktags = ChAckTags} ->
-            ChAckTags1 = subtract_acks(ChAckTags, AckTags),
-            store_ch_record(C#cr{acktags = ChAckTags1}),
-            noreply(requeue_and_run(AckTags, State))
-    end;
-
 handle_cast({unblock, ChPid}, State) ->
     noreply(
       possibly_unblock(State, ChPid,
diff --git a/src/rabbit_backing_queue.erl b/src/rabbit_backing_queue.erl
index 2dba00ad62..432d62900b 100644
--- a/src/rabbit_backing_queue.erl
+++ b/src/rabbit_backing_queue.erl
@@ -18,11 +18,11 @@
 %%   are Copyright (C) 2007-2008 LShift Ltd, Cohesive Financial
 %%   Technologies LLC, and Rabbit Technologies Ltd.
 %%
-%%   Portions created by LShift Ltd are Copyright (C) 2007-2009 LShift
+%%   Portions created by LShift Ltd are Copyright (C) 2007-2010 LShift
 %%   Ltd. Portions created by Cohesive Financial Technologies LLC are
-%%   Copyright (C) 2007-2009 Cohesive Financial Technologies
+%%   Copyright (C) 2007-2010 Cohesive Financial Technologies
 %%   LLC. Portions created by Rabbit Technologies Ltd are Copyright
-%%   (C) 2007-2009 Rabbit Technologies Ltd.
+%%   (C) 2007-2010 Rabbit Technologies Ltd.
 %%
 %%   All Rights Reserved.
 %%
diff --git a/src/rabbit_binary_generator.erl b/src/rabbit_binary_generator.erl
index 27a1275a31..81cf3ceec7 100644
--- a/src/rabbit_binary_generator.erl
+++ b/src/rabbit_binary_generator.erl
@@ -57,7 +57,7 @@
 -type(frame() :: [binary()]).
 
 -spec(build_simple_method_frame/2 ::
-      (channel_number(), amqp_method()) -> frame()).
+      (channel_number(), amqp_method_record()) -> frame()).
 -spec(build_simple_content_frames/3 ::
       (channel_number(), content(), non_neg_integer()) -> [frame()]).
 -spec(build_heartbeat_frame/0 :: () -> frame()).
diff --git a/src/rabbit_channel.erl b/src/rabbit_channel.erl
index 31bb54c0f4..1ab34f8653 100644
--- a/src/rabbit_channel.erl
+++ b/src/rabbit_channel.erl
@@ -39,6 +39,8 @@
 -export([send_command/2, deliver/4, conserve_memory/2, flushed/2]).
 -export([list/0, info_keys/0, info/1, info/2, info_all/0, info_all/1]).
 
+-export([flow_timeout/2]).
+
 -export([init/1, terminate/2, code_change/3,
          handle_call/3, handle_cast/2, handle_info/2, handle_pre_hibernate/1]).
 
@@ -46,9 +48,12 @@
              transaction_id, tx_participants, next_tag,
              uncommitted_ack_q, unacked_message_q,
              username, virtual_host, most_recently_declared_queue,
-             consumer_mapping, blocking, queue_collector_pid}).
+             consumer_mapping, blocking, queue_collector_pid, flow}).
+
+-record(flow, {server, client, pending}).
 
 -define(MAX_PERMISSION_CACHE_SIZE, 12).
+-define(FLOW_OK_TIMEOUT, 10000). %% 10 seconds
 
 -define(INFO_KEYS,
         [pid,
@@ -66,15 +71,18 @@
 
 -ifdef(use_specs).
 
+-type(ref() :: any()).
+
 -spec(start_link/6 ::
       (channel_number(), pid(), pid(), username(), vhost(), pid()) -> pid()).
--spec(do/2 :: (pid(), amqp_method()) -> 'ok').
--spec(do/3 :: (pid(), amqp_method(), maybe(content())) -> 'ok').
+-spec(do/2 :: (pid(), amqp_method_record()) -> 'ok').
+-spec(do/3 :: (pid(), amqp_method_record(), maybe(content())) -> 'ok').
 -spec(shutdown/1 :: (pid()) -> 'ok').
 -spec(send_command/2 :: (pid(), amqp_method()) -> 'ok').
 -spec(deliver/4 :: (pid(), ctag(), boolean(), qmsg()) -> 'ok').
 -spec(conserve_memory/2 :: (pid(), boolean()) -> 'ok').
 -spec(flushed/2 :: (pid(), pid()) -> 'ok').
+-spec(flow_timeout/2 :: (pid(), ref()) -> 'ok').
 -spec(list/0 :: () -> [pid()]).
 -spec(info_keys/0 :: () -> [info_key()]).
 -spec(info/1 :: (pid()) -> [info()]).
@@ -113,6 +121,9 @@ conserve_memory(Pid, Conserve) ->
 flushed(Pid, QPid) ->
     gen_server2:cast(Pid, {flushed, QPid}).
 
+flow_timeout(Pid, Ref) ->
+    gen_server2:pcast(Pid, 7, {flow_timeout, Ref}).
+
 list() ->
     pg_local:get_members(rabbit_channels).
 
@@ -154,7 +165,9 @@ init([Channel, ReaderPid, WriterPid, Username, VHost, CollectorPid]) ->
              most_recently_declared_queue = <<>>,
              consumer_mapping        = dict:new(),
              blocking                = dict:new(),
-             queue_collector_pid     = CollectorPid},
+             queue_collector_pid     = CollectorPid,
+             flow                    = #flow{server = true, client = true,
+                                             pending = none}},
      hibernate,
      {backoff, ?HIBERNATE_AFTER_MIN, ?HIBERNATE_AFTER_MIN, ?DESIRED_HIBERNATE}}.
 
@@ -181,11 +194,9 @@ handle_cast({method, Method, Content}, State) ->
             {stop, normal, State#ch{state = terminating}}
     catch
         exit:Reason = #amqp_error{} ->
-            ok = rollback_and_notify(State),
             MethodName = rabbit_misc:method_record_type(Method),
-            State#ch.reader_pid ! {channel_exit, State#ch.channel,
-                                   Reason#amqp_error{method = MethodName}},
-            {stop, normal, State#ch{state = terminating}};
+            {stop, normal, terminating(Reason#amqp_error{method = MethodName},
+                                       State)};
         exit:normal ->
             {stop, normal, State};
         _:Reason ->
@@ -209,11 +220,25 @@ handle_cast({deliver, ConsumerTag, AckRequired, Msg},
     ok = internal_deliver(WriterPid, true, ConsumerTag, DeliveryTag, Msg),
     noreply(State1#ch{next_tag = DeliveryTag + 1});
 
-handle_cast({conserve_memory, Conserve}, State) ->
-    ok = clear_permission_cache(),
-    ok = rabbit_writer:send_command(
-           State#ch.writer_pid, #'channel.flow'{active = not(Conserve)}),
-    noreply(State).
+handle_cast({conserve_memory, true}, State = #ch{state = starting}) ->
+    noreply(State);
+handle_cast({conserve_memory, false}, State = #ch{state = starting}) ->
+    ok = rabbit_writer:send_command(State#ch.writer_pid, #'channel.open_ok'{}),
+    noreply(State#ch{state = running});
+handle_cast({conserve_memory, Conserve}, State = #ch{state = running}) ->
+    flow_control(not Conserve, State);
+handle_cast({conserve_memory, _Conserve}, State) ->
+    noreply(State);
+
+handle_cast({flow_timeout, Ref},
+            State = #ch{flow = #flow{client = Flow, pending = {Ref, _TRef}}}) ->
+    {stop, normal, terminating(
+                     rabbit_misc:amqp_error(
+                       precondition_failed,
+                       "timeout waiting for channel.flow_ok{active=~w}",
+                       [not Flow], none), State)};
+handle_cast({flow_timeout, _Ref}, State) ->
+    {noreply, State}.
 
 handle_info({'EXIT', WriterPid, Reason = {writer, send_failed, _Error}},
             State = #ch{writer_pid = WriterPid}) ->
@@ -254,6 +279,11 @@ return_ok(State, false, Msg)  -> {reply, Msg, State}.
 ok_msg(true, _Msg) -> undefined;
 ok_msg(false, Msg) -> Msg.
 
+terminating(Reason, State = #ch{channel = Channel, reader_pid = Reader}) ->
+    ok = rollback_and_notify(State),
+    Reader ! {channel_exit, Channel, Reason},
+    State#ch{state = terminating}.
+
 return_queue_declare_ok(State, NoWait, Q) ->
     NewState = State#ch{most_recently_declared_queue =
                         (Q#amqqueue.name)#resource.name},
@@ -299,25 +329,22 @@ check_write_permitted(Resource, #ch{ username = Username}) ->
 check_read_permitted(Resource, #ch{ username = Username}) ->
     check_resource_access(Username, Resource, read).
 
+check_exclusive_access(#amqqueue{exclusive_owner = Owner}, Owner, _MatchType) ->
+    ok;
+check_exclusive_access(#amqqueue{exclusive_owner = none}, _ReaderPid, lax) ->
+    ok;
+check_exclusive_access(#amqqueue{name = QName}, _ReaderPid, _MatchType) ->
+    rabbit_misc:protocol_error(
+      resource_locked,
+      "cannot obtain exclusive access to locked ~s", [rabbit_misc:rs(QName)]).
+
 with_exclusive_access_or_die(QName, ReaderPid, F) ->
-    case rabbit_amqqueue:with_or_die(
-           QName, fun (Q = #amqqueue{exclusive_owner = Owner})
-                      when Owner =:= none orelse Owner =:= ReaderPid ->
-                          F(Q);
-                      (_) ->
-                          {error, wrong_exclusive_owner}
-                  end) of
-        {error, wrong_exclusive_owner} ->
-            rabbit_misc:protocol_error(
-              resource_locked, "cannot obtain exclusive access to locked ~s",
-              [rabbit_misc:rs(QName)]);
-        Other ->
-            Other
-    end.
+    rabbit_amqqueue:with_or_die(
+      QName, fun (Q) -> check_exclusive_access(Q, ReaderPid, lax), F(Q) end).
 
 expand_queue_name_shortcut(<<>>, #ch{ most_recently_declared_queue = <<>> }) ->
     rabbit_misc:protocol_error(
-      not_allowed, "no previously declared queue", []);
+      not_found, "no previously declared queue", []);
 expand_queue_name_shortcut(<<>>, #ch{ virtual_host = VHostPath,
                                       most_recently_declared_queue = MRDQ }) ->
     rabbit_misc:r(VHostPath, queue, MRDQ);
@@ -327,7 +354,7 @@ expand_queue_name_shortcut(QueueNameBin, #ch{ virtual_host = VHostPath }) ->
 expand_routing_key_shortcut(<<>>, <<>>,
                             #ch{ most_recently_declared_queue = <<>> }) ->
     rabbit_misc:protocol_error(
-      not_allowed, "no previously declared queue", []);
+      not_found, "no previously declared queue", []);
 expand_routing_key_shortcut(<<>>, <<>>,
                             #ch{ most_recently_declared_queue = MRDQ }) ->
     MRDQ;
@@ -369,8 +396,10 @@ queue_blocked(QPid, State = #ch{blocking = Blocking}) ->
     end.
 
 handle_method(#'channel.open'{}, _, State = #ch{state = starting}) ->
-    rabbit_alarm:register(self(), {?MODULE, conserve_memory, []}),
-    {reply, #'channel.open_ok'{}, State#ch{state = running}};
+    case rabbit_alarm:register(self(), {?MODULE, conserve_memory, []}) of
+        true  -> {noreply, State};
+        false -> {reply, #'channel.open_ok'{}, State#ch{state = running}}
+    end;
 
 handle_method(#'channel.open'{}, _, _State) ->
     rabbit_misc:protocol_error(
@@ -387,13 +416,17 @@ handle_method(#'channel.close'{}, _, State = #ch{writer_pid = WriterPid}) ->
 handle_method(#'access.request'{},_, State) ->
     {reply, #'access.request_ok'{ticket = 1}, State};
 
-handle_method(#'basic.publish'{exchange = ExchangeNameBin,
+handle_method(#'basic.publish'{}, _, #ch{flow = #flow{client = false}}) ->
+    rabbit_misc:protocol_error(
+      command_invalid,
+      "basic.publish received after channel.flow_ok{active=false}", []);
+handle_method(#'basic.publish'{exchange    = ExchangeNameBin,
                                routing_key = RoutingKey,
-                               mandatory = Mandatory,
-                               immediate = Immediate},
-              Content, State = #ch{ virtual_host = VHostPath,
-                                    transaction_id = TxnKey,
-                                    writer_pid = WriterPid}) ->
+                               mandatory   = Mandatory,
+                               immediate   = Immediate},
+              Content, State = #ch{virtual_host   = VHostPath,
+                                   transaction_id = TxnKey,
+                                   writer_pid     = WriterPid}) ->
     ExchangeName = rabbit_misc:r(VHostPath, exchange, ExchangeNameBin),
     check_write_permitted(ExchangeName, State),
     Exchange = rabbit_exchange:lookup_or_die(ExchangeName),
@@ -430,13 +463,7 @@ handle_method(#'basic.publish'{exchange = ExchangeNameBin,
 handle_method(#'basic.ack'{delivery_tag = DeliveryTag,
                            multiple = Multiple},
               _, State = #ch{transaction_id = TxnKey,
-                             next_tag = NextDeliveryTag,
                              unacked_message_q = UAMQ}) ->
-    if DeliveryTag >= NextDeliveryTag ->
-            rabbit_misc:protocol_error(
-              command_invalid, "unknown delivery tag ~w", [DeliveryTag]);
-       true -> ok
-    end,
     {Acked, Remaining} = collect_acks(UAMQ, DeliveryTag, Multiple),
     Participants = ack(TxnKey, Acked),
     {noreply, case TxnKey of
@@ -453,11 +480,12 @@ handle_method(#'basic.ack'{delivery_tag = DeliveryTag,
 handle_method(#'basic.get'{queue = QueueNameBin,
                            no_ack = NoAck},
               _, State = #ch{ writer_pid = WriterPid,
+                              reader_pid = ReaderPid,
                               next_tag = DeliveryTag }) ->
     QueueName = expand_queue_name_shortcut(QueueNameBin, State),
     check_read_permitted(QueueName, State),
-    case rabbit_amqqueue:with_or_die(
-           QueueName,
+    case with_exclusive_access_or_die(
+           QueueName, ReaderPid,
            fun (Q) -> rabbit_amqqueue:basic_get(Q, self(), NoAck) end) of
         {ok, MessageCount,
          Msg = {_QName, _QPid, _MsgId, Redelivered,
@@ -497,9 +525,9 @@ handle_method(#'basic.consume'{queue = QueueNameBin,
                     Other -> Other
                 end,
 
-            %% In order to ensure that the consume_ok gets sent before
-            %% any messages are sent to the consumer, we get the queue
-            %% process to send the consume_ok on our behalf.
+            %% We get the queue process to send the consume_ok on our
+            %% behalf. This is for symmetry with basic.cancel - see
+            %% the comment in that method for why.
             case with_exclusive_access_or_die(
                    QueueName, ReaderPid,
                    fun (Q) ->
@@ -653,18 +681,17 @@ handle_method(#'exchange.declare'{exchange = ExchangeNameBin,
                                         AutoDelete,
                                         Args)
         end,
-    ok = rabbit_exchange:assert_type(X, CheckedType),
+    ok = rabbit_exchange:assert_equivalence(X, CheckedType, Durable,
+                                            AutoDelete, Args),
     return_ok(State, NoWait, #'exchange.declare_ok'{});
 
 handle_method(#'exchange.declare'{exchange = ExchangeNameBin,
-                                  type = TypeNameBin,
                                   passive = true,
                                   nowait = NoWait},
               _, State = #ch{ virtual_host = VHostPath }) ->
     ExchangeName = rabbit_misc:r(VHostPath, exchange, ExchangeNameBin),
     check_configure_permitted(ExchangeName, State),
-    X = rabbit_exchange:lookup_or_die(ExchangeName),
-    ok = rabbit_exchange:assert_type(X, rabbit_exchange:check_type(TypeNameBin)),
+    _ = rabbit_exchange:lookup_or_die(ExchangeName),
     return_ok(State, NoWait, #'exchange.declare_ok'{});
 
 handle_method(#'exchange.delete'{exchange = ExchangeNameBin,
@@ -699,25 +726,28 @@ handle_method(#'queue.declare'{queue       = QueueNameBin,
             end,
     %% We use this in both branches, because queue_declare may yet return an
     %% existing queue.
-    Finish =
-        fun (#amqqueue{name = QueueName, exclusive_owner = Owner1} = Q)
-            when Owner =:= Owner1 ->
-                check_configure_permitted(QueueName, State),
-                %% We need to notify the reader within the channel
-                %% process so that we can be sure there are no
-                %% outstanding exclusive queues being declared as the
-                %% connection shuts down.
-                case Owner of
-                    none -> ok;
-                    _    -> ok = rabbit_reader_queue_collector:register_exclusive_queue(CollectorPid, Q)
-                end,
-                Q;
-            (#amqqueue{name = QueueName}) ->
-                rabbit_misc:protocol_error(
-                  resource_locked,
-                  "cannot obtain exclusive access to locked ~s",
-                  [rabbit_misc:rs(QueueName)])
-        end,
+    Finish = fun (#amqqueue{name = QueueName,
+                            durable = Durable1,
+                            auto_delete = AutoDelete1} = Q)
+                   when Durable =:= Durable1, AutoDelete =:= AutoDelete1 ->
+                     check_exclusive_access(Q, Owner, strict),
+                     check_configure_permitted(QueueName, State),
+                     %% We need to notify the reader within the channel
+                     %% process so that we can be sure there are no
+                     %% outstanding exclusive queues being declared as the
+                     %% connection shuts down.
+                     case Owner of
+                         none -> ok;
+                         _    -> ok = rabbit_reader_queue_collector:register_exclusive_queue(CollectorPid, Q)
+                     end,
+                     Q;
+                 %% non-equivalence trumps exclusivity arbitrarily
+                 (#amqqueue{name = QueueName}) ->
+                     rabbit_misc:protocol_error(
+                       precondition_failed,
+                       "parameters for ~s not equivalent",
+                       [rabbit_misc:rs(QueueName)])
+             end,
     Q = case rabbit_amqqueue:with(
                rabbit_misc:r(VHostPath, queue, QueueNameBin),
                Finish) of
@@ -771,7 +801,7 @@ handle_method(#'queue.bind'{queue = QueueNameBin,
                             routing_key = RoutingKey,
                             nowait = NoWait,
                             arguments = Arguments}, _, State) ->
-    binding_action(fun rabbit_exchange:add_binding/4, ExchangeNameBin,
+    binding_action(fun rabbit_exchange:add_binding/5, ExchangeNameBin,
                    QueueNameBin, RoutingKey, Arguments, #'queue.bind_ok'{},
                    NoWait, State);
 
@@ -779,7 +809,7 @@ handle_method(#'queue.unbind'{queue = QueueNameBin,
                               exchange = ExchangeNameBin,
                               routing_key = RoutingKey,
                               arguments = Arguments}, _, State) ->
-    binding_action(fun rabbit_exchange:delete_binding/4, ExchangeNameBin,
+    binding_action(fun rabbit_exchange:delete_binding/5, ExchangeNameBin,
                    QueueNameBin, RoutingKey, Arguments, #'queue.unbind_ok'{},
                    false, State);
 
@@ -802,14 +832,14 @@ handle_method(#'tx.select'{}, _, State) ->
 
 handle_method(#'tx.commit'{}, _, #ch{transaction_id = none}) ->
     rabbit_misc:protocol_error(
-      not_allowed, "channel is not transactional", []);
+      precondition_failed, "channel is not transactional", []);
 
 handle_method(#'tx.commit'{}, _, State) ->
     {reply, #'tx.commit_ok'{}, internal_commit(State)};
 
 handle_method(#'tx.rollback'{}, _, #ch{transaction_id = none}) ->
     rabbit_misc:protocol_error(
-      not_allowed, "channel is not transactional", []);
+      precondition_failed, "channel is not transactional", []);
 
 handle_method(#'tx.rollback'{}, _, State) ->
     {reply, #'tx.rollback_ok'{}, internal_rollback(State)};
@@ -822,7 +852,6 @@ handle_method(#'channel.flow'{active = true}, _,
                   end,
     {reply, #'channel.flow_ok'{active = true},
      State#ch{limiter_pid = LimiterPid1}};
-
 handle_method(#'channel.flow'{active = false}, _,
               State = #ch{limiter_pid = LimiterPid,
                           consumer_mapping = Consumers}) ->
@@ -840,11 +869,25 @@ handle_method(#'channel.flow'{active = false}, _,
                                  blocking = dict:from_list(Queues)}}
     end;
 
-handle_method(#'channel.flow_ok'{active = _}, _, State) ->
-    %% TODO: We may want to correlate this to channel.flow messages we
-    %% have sent, and complain if we get an unsolicited
-    %% channel.flow_ok, or the client refuses our flow request.
-    {noreply, State};
+handle_method(#'channel.flow_ok'{active = Active}, _,
+              State = #ch{flow = #flow{server = Active, client = Flow,
+                                       pending = {_Ref, TRef}} = F})
+  when Flow =:= not Active ->
+    {ok, cancel} = timer:cancel(TRef),
+    {noreply, State#ch{flow = F#flow{client = Active, pending = none}}};
+handle_method(#'channel.flow_ok'{active = Active}, _,
+              State = #ch{flow = #flow{server = Flow, client = Flow,
+                                       pending = {_Ref, TRef}}})
+  when Flow =:= not Active ->
+    {ok, cancel} = timer:cancel(TRef),
+    {noreply, issue_flow(Flow, State)};
+handle_method(#'channel.flow_ok'{}, _, #ch{flow = #flow{pending = none}}) ->
+    rabbit_misc:protocol_error(
+      command_invalid, "unsolicited channel.flow_ok", []);
+handle_method(#'channel.flow_ok'{active = Active}, _, _State) ->
+    rabbit_misc:protocol_error(
+      command_invalid,
+      "received channel.flow_ok{active=~w} has incorrect polarity", [Active]);
 
 handle_method(_MethodRecord, _Content, _State) ->
     rabbit_misc:protocol_error(
@@ -852,8 +895,26 @@ handle_method(_MethodRecord, _Content, _State) ->
 
 %%----------------------------------------------------------------------------
 
+flow_control(Active, State = #ch{flow = #flow{server = Flow, pending = none}})
+  when Flow =:= not Active ->
+    ok = clear_permission_cache(),
+    noreply(issue_flow(Active, State));
+flow_control(Active, State = #ch{flow = F}) ->
+    noreply(State#ch{flow = F#flow{server = Active}}).
+
+issue_flow(Active, State) ->
+    ok = rabbit_writer:send_command(
+           State#ch.writer_pid, #'channel.flow'{active = Active}),
+    Ref = make_ref(),
+    {ok, TRef} = timer:apply_after(?FLOW_OK_TIMEOUT, ?MODULE, flow_timeout,
+                                   [self(), Ref]),
+    State#ch{flow = #flow{server = Active, client = not Active,
+                          pending = {Ref, TRef}}}.
+
 binding_action(Fun, ExchangeNameBin, QueueNameBin, RoutingKey, Arguments,
-               ReturnMethod, NoWait, State = #ch{virtual_host = VHostPath}) ->
+               ReturnMethod, NoWait,
+               State = #ch{virtual_host = VHostPath,
+                           reader_pid   = ReaderPid}) ->
     %% FIXME: connection exception (!) on failure??
     %% (see rule named "failure" in spec-XML)
     %% FIXME: don't allow binding to internal exchanges -
@@ -864,7 +925,8 @@ binding_action(Fun, ExchangeNameBin, QueueNameBin, RoutingKey, Arguments,
                                                    State),
     ExchangeName = rabbit_misc:r(VHostPath, exchange, ExchangeNameBin),
     check_read_permitted(ExchangeName, State),
-    case Fun(ExchangeName, QueueName, ActualRoutingKey, Arguments) of
+    case Fun(ExchangeName, QueueName, ActualRoutingKey, Arguments,
+             fun (_X, Q) -> check_exclusive_access(Q, ReaderPid, lax) end) of
         {error, exchange_not_found} ->
             rabbit_misc:not_found(ExchangeName);
         {error, queue_not_found} ->
@@ -878,10 +940,6 @@ binding_action(Fun, ExchangeNameBin, QueueNameBin, RoutingKey, Arguments,
               not_found, "no binding ~s between ~s and ~s",
               [RoutingKey, rabbit_misc:rs(ExchangeName),
                rabbit_misc:rs(QueueName)]);
-        {error, durability_settings_incompatible} ->
-            rabbit_misc:protocol_error(
-              not_allowed, "durability settings of ~s incompatible with ~s",
-              [rabbit_misc:rs(QueueName), rabbit_misc:rs(ExchangeName)]);
         ok -> return_ok(State, NoWait, ReturnMethod)
     end.
 
@@ -916,7 +974,8 @@ collect_acks(ToAcc, PrefixAcc, Q, DeliveryTag, Multiple) ->
                                  QTail, DeliveryTag, Multiple)
             end;
         {empty, _} ->
-            {ToAcc, PrefixAcc}
+            rabbit_misc:protocol_error(
+              not_found, "unknown delivery tag ~w", [DeliveryTag])
     end.
 
 add_tx_participants(MoreP, State = #ch{tx_participants = Participants}) ->
diff --git a/src/rabbit_control.erl b/src/rabbit_control.erl
index d1834b3b73..323d4d2fd1 100644
--- a/src/rabbit_control.erl
+++ b/src/rabbit_control.erl
@@ -59,8 +59,8 @@ start() ->
         parse_args(FullCommand, #params{quiet = false,
                                         node = rabbit_misc:makenode(NodeStr)}),
     Inform = case Quiet of
-                 true  -> fun(_Format, _Args1) -> ok end;
-                 false -> fun(Format, Args1) ->
+                 true  -> fun (_Format, _Args1) -> ok end;
+                 false -> fun (Format, Args1) ->
                                   io:format(Format ++ " ...~n", Args1)
                          end
              end,
diff --git a/src/rabbit_exchange.erl b/src/rabbit_exchange.erl
index 8f41392f83..c5149b08b9 100644
--- a/src/rabbit_exchange.erl
+++ b/src/rabbit_exchange.erl
@@ -36,10 +36,12 @@
 -export([recover/0, declare/5, lookup/1, lookup_or_die/1,
          list/1, info_keys/0, info/1, info/2, info_all/1, info_all/2,
          publish/2]).
--export([add_binding/4, delete_binding/4, list_bindings/1]).
+-export([add_binding/5, delete_binding/5, list_bindings/1]).
 -export([delete/2]).
 -export([delete_queue_bindings/1, delete_transient_queue_bindings/1]).
--export([check_type/1, assert_type/2]).
+-export([assert_equivalence/5]).
+-export([assert_args_equivalence/2]).
+-export([check_type/1]).
 
 %% EXTENDED API
 -export([list_exchange_bindings/1]).
@@ -58,11 +60,15 @@
                             'queue_not_found' |
                             'exchange_not_found' |
                             'exchange_and_queue_not_found'}).
+-type(inner_fun() :: fun((exchange(), queue()) -> any())).
+
 -spec(recover/0 :: () -> 'ok').
 -spec(declare/5 :: (exchange_name(), exchange_type(), boolean(), boolean(),
                     amqp_table()) -> exchange()).
 -spec(check_type/1 :: (binary()) -> atom()).
--spec(assert_type/2 :: (exchange(), atom()) -> 'ok').
+-spec(assert_equivalence/5 :: (exchange(), atom(), boolean(), boolean(),
+                               amqp_table()) -> 'ok').
+-spec(assert_args_equivalence/2 :: (exchange(), amqp_table()) -> 'ok').
 -spec(lookup/1 :: (exchange_name()) -> {'ok', exchange()} | not_found()).
 -spec(lookup_or_die/1 :: (exchange_name()) -> exchange()).
 -spec(list/1 :: (vhost()) -> [exchange()]).
@@ -72,16 +78,17 @@
 -spec(info_all/1 :: (vhost()) -> [[info()]]).
 -spec(info_all/2 :: (vhost(), [info_key()]) -> [[info()]]).
 -spec(publish/2 :: (exchange(), delivery()) -> {routing_result(), [pid()]}).
--spec(add_binding/4 ::
-      (exchange_name(), queue_name(), routing_key(), amqp_table()) ->
-             bind_res() | {'error', 'durability_settings_incompatible'}).
--spec(delete_binding/4 ::
-      (exchange_name(), queue_name(), routing_key(), amqp_table()) ->
+-spec(add_binding/5 ::
+      (exchange_name(), queue_name(), routing_key(), amqp_table(), inner_fun()) ->
+             bind_res()).
+-spec(delete_binding/5 ::
+      (exchange_name(), queue_name(), routing_key(), amqp_table(), inner_fun()) ->
              bind_res() | {'error', 'binding_not_found'}).
 -spec(list_bindings/1 :: (vhost()) ->
              [{exchange_name(), queue_name(), routing_key(), amqp_table()}]).
--spec(delete_queue_bindings/1 :: (queue_name()) -> fun(() -> none())).
--spec(delete_transient_queue_bindings/1 :: (queue_name()) -> fun(() -> none())).
+-spec(delete_queue_bindings/1 :: (queue_name()) -> fun (() -> none())).
+-spec(delete_transient_queue_bindings/1 :: (queue_name()) -> 
+             fun (() -> none())).
 -spec(delete/2 :: (exchange_name(), boolean()) ->
              'ok' | not_found() | {'error', 'in_use'}).
 -spec(list_queue_bindings/1 :: (queue_name()) ->
@@ -97,12 +104,12 @@
 
 recover() ->
     Exs = rabbit_misc:table_fold(
-            fun(Exchange, Acc) ->
+            fun (Exchange, Acc) ->
                     ok = mnesia:write(rabbit_exchange, Exchange, write),
                     [Exchange | Acc]
             end, [], rabbit_durable_exchange),
     Bs = rabbit_misc:table_fold(
-           fun(Route = #route{binding = B}, Acc) ->
+           fun (Route = #route{binding = B}, Acc) ->
                    {_, ReverseRoute} = route_with_reverse(Route),
                    ok = mnesia:write(rabbit_route,
                                      Route, write),
@@ -182,13 +189,36 @@ check_type(TypeBin) ->
             T
     end.
 
-assert_type(#exchange{ type = ActualType }, RequiredType)
-  when ActualType == RequiredType ->
-    ok;
-assert_type(#exchange{ name = Name, type = ActualType }, RequiredType) ->
+assert_equivalence(X = #exchange{ durable = Durable,
+                                  auto_delete = AutoDelete,
+                                  type = Type},
+                   Type, Durable, AutoDelete,
+                   RequiredArgs) ->
+    ok = (type_to_module(Type)):assert_args_equivalence(X, RequiredArgs);
+assert_equivalence(#exchange{ name = Name }, _Type, _Durable, _AutoDelete,
+                   _Args) ->
     rabbit_misc:protocol_error(
-      not_allowed, "cannot redeclare ~s of type '~s' with type '~s'",
-      [rabbit_misc:rs(Name), ActualType, RequiredType]).
+      precondition_failed,
+      "cannot redeclare ~s with different type, durable or autodelete value",
+      [rabbit_misc:rs(Name)]).
+
+alternate_exchange_value(Args) ->
+    lists:keysearch(<<"alternate-exchange">>, 1, Args).
+
+assert_args_equivalence(#exchange{ name = Name,
+                                   arguments = Args },
+                        RequiredArgs) ->
+    %% The spec says "Arguments are compared for semantic
+    %% equivalence".  The only arg we care about is
+    %% "alternate-exchange".
+    Ae1 = alternate_exchange_value(RequiredArgs),
+    Ae2 = alternate_exchange_value(Args),
+    if Ae1==Ae2 -> ok;
+       true     -> rabbit_misc:protocol_error(
+                     precondition_failed,
+                     "cannot redeclare ~s with inequivalent args",
+                     [rabbit_misc:rs(Name)])
+    end.
 
 lookup(Name) ->
     rabbit_misc:dirty_read({rabbit_exchange, Name}).
@@ -349,7 +379,7 @@ continue({[], Continuation}) -> continue(mnesia:select(Continuation)).
 
 call_with_exchange(Exchange, Fun) ->
     rabbit_misc:execute_mnesia_transaction(
-      fun() -> case mnesia:read({rabbit_exchange, Exchange}) of
+      fun () -> case mnesia:read({rabbit_exchange, Exchange}) of
                    []  -> {error, not_found};
                    [X] -> Fun(X)
                end
@@ -357,7 +387,7 @@ call_with_exchange(Exchange, Fun) ->
 
 call_with_exchange_and_queue(Exchange, Queue, Fun) ->
     rabbit_misc:execute_mnesia_transaction(
-      fun() -> case {mnesia:read({rabbit_exchange, Exchange}),
+      fun () -> case {mnesia:read({rabbit_exchange, Exchange}),
                      mnesia:read({rabbit_queue, Queue})} of
                    {[X], [Q]} -> Fun(X, Q);
                    {[ ], [_]} -> {error, exchange_not_found};
@@ -366,21 +396,23 @@ call_with_exchange_and_queue(Exchange, Queue, Fun) ->
                end
       end).
 
-add_binding(ExchangeName, QueueName, RoutingKey, Arguments) ->
+add_binding(ExchangeName, QueueName, RoutingKey, Arguments, InnerFun) ->
     case binding_action(
            ExchangeName, QueueName, RoutingKey, Arguments,
            fun (X, Q, B) ->
-                   if Q#amqqueue.durable and not(X#exchange.durable) ->
-                           {error, durability_settings_incompatible};
-                      true ->
-                           case mnesia:read({rabbit_route, B}) of
-                               [] ->
-                                   sync_binding(B, Q#amqqueue.durable,
-                                                fun mnesia:write/3),
-                                   {new, X, B};
-                               [_R] ->
-                                   {existing, X, B}
-                           end
+                   %% this argument is used to check queue exclusivity;
+                   %% in general, we want to fail on that in preference to
+                   %% anything else
+                   InnerFun(X, Q),
+                   case mnesia:read({rabbit_route, B}) of
+                       [] ->
+                           sync_binding(B,
+                                        X#exchange.durable andalso
+                                        Q#amqqueue.durable,
+                                        fun mnesia:write/3),
+                           {new, X, B};
+                       [_R] ->
+                           {existing, X, B}
                    end
            end) of
         {new, Exchange = #exchange{ type = Type }, Binding} ->
@@ -391,14 +423,15 @@ add_binding(ExchangeName, QueueName, RoutingKey, Arguments) ->
             Err
     end.
 
-delete_binding(ExchangeName, QueueName, RoutingKey, Arguments) ->
+delete_binding(ExchangeName, QueueName, RoutingKey, Arguments, InnerFun) ->
     case binding_action(
            ExchangeName, QueueName, RoutingKey, Arguments,
            fun (X, Q, B) ->
                    case mnesia:match_object(rabbit_route, #route{binding = B},
                                             write) of
                        [] -> {error, binding_not_found};
-                       _  -> ok = sync_binding(B, Q#amqqueue.durable,
+                       _  -> InnerFun(X, Q),
+                             ok = sync_binding(B, Q#amqqueue.durable,
                                                fun mnesia:delete_object/3),
                              {maybe_auto_delete(X), B}
                    end
diff --git a/src/rabbit_exchange_type.erl b/src/rabbit_exchange_type.erl
index a8c071e681..85760edce4 100644
--- a/src/rabbit_exchange_type.erl
+++ b/src/rabbit_exchange_type.erl
@@ -18,11 +18,11 @@
 %%   are Copyright (C) 2007-2008 LShift Ltd, Cohesive Financial
 %%   Technologies LLC, and Rabbit Technologies Ltd.
 %%
-%%   Portions created by LShift Ltd are Copyright (C) 2007-2009 LShift
+%%   Portions created by LShift Ltd are Copyright (C) 2007-2010 LShift
 %%   Ltd. Portions created by Cohesive Financial Technologies LLC are
-%%   Copyright (C) 2007-2009 Cohesive Financial Technologies
+%%   Copyright (C) 2007-2010 Cohesive Financial Technologies
 %%   LLC. Portions created by Rabbit Technologies Ltd are Copyright
-%%   (C) 2007-2009 Rabbit Technologies Ltd.
+%%   (C) 2007-2010 Rabbit Technologies Ltd.
 %%
 %%   All Rights Reserved.
 %%
@@ -54,7 +54,11 @@ behaviour_info(callbacks) ->
      {add_binding, 2},
 
      %% called after bindings have been deleted.
-     {remove_bindings, 2}
+     {remove_bindings, 2},
+
+     %% called when comparing exchanges for equivalence - should return ok or
+     %% exit with #amqp_error{}
+     {assert_args_equivalence, 2}
 
     ];
 behaviour_info(_Other) ->
diff --git a/src/rabbit_exchange_type_direct.erl b/src/rabbit_exchange_type_direct.erl
index 9b71e0e1d1..4f6eb85199 100644
--- a/src/rabbit_exchange_type_direct.erl
+++ b/src/rabbit_exchange_type_direct.erl
@@ -18,11 +18,11 @@
 %%   are Copyright (C) 2007-2008 LShift Ltd, Cohesive Financial
 %%   Technologies LLC, and Rabbit Technologies Ltd.
 %%
-%%   Portions created by LShift Ltd are Copyright (C) 2007-2009 LShift
+%%   Portions created by LShift Ltd are Copyright (C) 2007-2010 LShift
 %%   Ltd. Portions created by Cohesive Financial Technologies LLC are
-%%   Copyright (C) 2007-2009 Cohesive Financial Technologies
+%%   Copyright (C) 2007-2010 Cohesive Financial Technologies
 %%   LLC. Portions created by Rabbit Technologies Ltd are Copyright
-%%   (C) 2007-2009 Rabbit Technologies Ltd.
+%%   (C) 2007-2010 Rabbit Technologies Ltd.
 %%
 %%   All Rights Reserved.
 %%
@@ -36,7 +36,7 @@
 
 -export([description/0, publish/2]).
 -export([validate/1, create/1, recover/2, delete/2,
-         add_binding/2, remove_bindings/2]).
+         add_binding/2, remove_bindings/2, assert_args_equivalence/2]).
 -include("rabbit_exchange_type_spec.hrl").
 
 -rabbit_boot_step({?MODULE,
@@ -61,3 +61,5 @@ recover(_X, _Bs) -> ok.
 delete(_X, _Bs) -> ok.
 add_binding(_X, _B) -> ok.
 remove_bindings(_X, _Bs) -> ok.
+assert_args_equivalence(X, Args) ->
+    rabbit_exchange:assert_args_equivalence(X, Args).
diff --git a/src/rabbit_exchange_type_fanout.erl b/src/rabbit_exchange_type_fanout.erl
index 311654ab21..4f9712b14e 100644
--- a/src/rabbit_exchange_type_fanout.erl
+++ b/src/rabbit_exchange_type_fanout.erl
@@ -18,11 +18,11 @@
 %%   are Copyright (C) 2007-2008 LShift Ltd, Cohesive Financial
 %%   Technologies LLC, and Rabbit Technologies Ltd.
 %%
-%%   Portions created by LShift Ltd are Copyright (C) 2007-2009 LShift
+%%   Portions created by LShift Ltd are Copyright (C) 2007-2010 LShift
 %%   Ltd. Portions created by Cohesive Financial Technologies LLC are
-%%   Copyright (C) 2007-2009 Cohesive Financial Technologies
+%%   Copyright (C) 2007-2010 Cohesive Financial Technologies
 %%   LLC. Portions created by Rabbit Technologies Ltd are Copyright
-%%   (C) 2007-2009 Rabbit Technologies Ltd.
+%%   (C) 2007-2010 Rabbit Technologies Ltd.
 %%
 %%   All Rights Reserved.
 %%
@@ -36,7 +36,7 @@
 
 -export([description/0, publish/2]).
 -export([validate/1, create/1, recover/2, delete/2,
-         add_binding/2, remove_bindings/2]).
+         add_binding/2, remove_bindings/2, assert_args_equivalence/2]).
 -include("rabbit_exchange_type_spec.hrl").
 
 -rabbit_boot_step({?MODULE,
@@ -59,3 +59,5 @@ recover(_X, _Bs) -> ok.
 delete(_X, _Bs) -> ok.
 add_binding(_X, _B) -> ok.
 remove_bindings(_X, _Bs) -> ok.
+assert_args_equivalence(X, Args) ->
+    rabbit_exchange:assert_args_equivalence(X, Args).
diff --git a/src/rabbit_exchange_type_headers.erl b/src/rabbit_exchange_type_headers.erl
index 285dab1a03..315e800021 100644
--- a/src/rabbit_exchange_type_headers.erl
+++ b/src/rabbit_exchange_type_headers.erl
@@ -18,11 +18,11 @@
 %%   are Copyright (C) 2007-2008 LShift Ltd, Cohesive Financial
 %%   Technologies LLC, and Rabbit Technologies Ltd.
 %%
-%%   Portions created by LShift Ltd are Copyright (C) 2007-2009 LShift
+%%   Portions created by LShift Ltd are Copyright (C) 2007-2010 LShift
 %%   Ltd. Portions created by Cohesive Financial Technologies LLC are
-%%   Copyright (C) 2007-2009 Cohesive Financial Technologies
+%%   Copyright (C) 2007-2010 Cohesive Financial Technologies
 %%   LLC. Portions created by Rabbit Technologies Ltd are Copyright
-%%   (C) 2007-2009 Rabbit Technologies Ltd.
+%%   (C) 2007-2010 Rabbit Technologies Ltd.
 %%
 %%   All Rights Reserved.
 %%
@@ -37,7 +37,7 @@
 
 -export([description/0, publish/2]).
 -export([validate/1, create/1, recover/2, delete/2,
-         add_binding/2, remove_bindings/2]).
+         add_binding/2, remove_bindings/2, assert_args_equivalence/2]).
 -include("rabbit_exchange_type_spec.hrl").
 
 -rabbit_boot_step({?MODULE,
@@ -135,3 +135,5 @@ recover(_X, _Bs) -> ok.
 delete(_X, _Bs) -> ok.
 add_binding(_X, _B) -> ok.
 remove_bindings(_X, _Bs) -> ok.
+assert_args_equivalence(X, Args) ->
+    rabbit_exchange:assert_args_equivalence(X, Args).
diff --git a/src/rabbit_exchange_type_registry.erl b/src/rabbit_exchange_type_registry.erl
index 175d15ad83..33ea0e926b 100644
--- a/src/rabbit_exchange_type_registry.erl
+++ b/src/rabbit_exchange_type_registry.erl
@@ -18,11 +18,11 @@
 %%   are Copyright (C) 2007-2008 LShift Ltd, Cohesive Financial
 %%   Technologies LLC, and Rabbit Technologies Ltd.
 %%
-%%   Portions created by LShift Ltd are Copyright (C) 2007-2009 LShift
+%%   Portions created by LShift Ltd are Copyright (C) 2007-2010 LShift
 %%   Ltd. Portions created by Cohesive Financial Technologies LLC are
-%%   Copyright (C) 2007-2009 Cohesive Financial Technologies
+%%   Copyright (C) 2007-2010 Cohesive Financial Technologies
 %%   LLC. Portions created by Rabbit Technologies Ltd are Copyright
-%%   (C) 2007-2009 Rabbit Technologies Ltd.
+%%   (C) 2007-2010 Rabbit Technologies Ltd.
 %%
 %%   All Rights Reserved.
 %%
diff --git a/src/rabbit_exchange_type_topic.erl b/src/rabbit_exchange_type_topic.erl
index 8a3dceeaeb..0e22d5458e 100644
--- a/src/rabbit_exchange_type_topic.erl
+++ b/src/rabbit_exchange_type_topic.erl
@@ -18,11 +18,11 @@
 %%   are Copyright (C) 2007-2008 LShift Ltd, Cohesive Financial
 %%   Technologies LLC, and Rabbit Technologies Ltd.
 %%
-%%   Portions created by LShift Ltd are Copyright (C) 2007-2009 LShift
+%%   Portions created by LShift Ltd are Copyright (C) 2007-2010 LShift
 %%   Ltd. Portions created by Cohesive Financial Technologies LLC are
-%%   Copyright (C) 2007-2009 Cohesive Financial Technologies
+%%   Copyright (C) 2007-2010 Cohesive Financial Technologies
 %%   LLC. Portions created by Rabbit Technologies Ltd are Copyright
-%%   (C) 2007-2009 Rabbit Technologies Ltd.
+%%   (C) 2007-2010 Rabbit Technologies Ltd.
 %%
 %%   All Rights Reserved.
 %%
@@ -36,7 +36,7 @@
 
 -export([description/0, publish/2]).
 -export([validate/1, create/1, recover/2, delete/2,
-         add_binding/2, remove_bindings/2]).
+         add_binding/2, remove_bindings/2, assert_args_equivalence/2]).
 -include("rabbit_exchange_type_spec.hrl").
 
 -rabbit_boot_step({?MODULE,
@@ -99,3 +99,5 @@ recover(_X, _Bs) -> ok.
 delete(_X, _Bs) -> ok.
 add_binding(_X, _B) -> ok.
 remove_bindings(_X, _Bs) -> ok.
+assert_args_equivalence(X, Args) ->
+    rabbit_exchange:assert_args_equivalence(X, Args).
diff --git a/src/rabbit_misc.erl b/src/rabbit_misc.erl
index 9a911ab15d..35739dcbdf 100644
--- a/src/rabbit_misc.erl
+++ b/src/rabbit_misc.erl
@@ -242,12 +242,12 @@ report_cover([Root]) when is_atom(Root) ->
 report_cover(Root) ->
     Dir = filename:join(Root, "cover"),
     ok = filelib:ensure_dir(filename:join(Dir,"junk")),
-    lists:foreach(fun(F) -> file:delete(F) end,
+    lists:foreach(fun (F) -> file:delete(F) end,
                   filelib:wildcard(filename:join(Dir, "*.html"))),
     {ok, SummaryFile} = file:open(filename:join(Dir, "summary.txt"), [write]),
     {CT, NCT} =
         lists:foldl(
-          fun(M,{CovTot, NotCovTot}) ->
+          fun (M,{CovTot, NotCovTot}) ->
                   {ok, {M, {Cov, NotCov}}} = cover:analyze(M, module),
                   ok = report_coverage_percentage(SummaryFile,
                                                   Cov, NotCov, M),
@@ -367,7 +367,7 @@ upmap(F, L) ->
     Parent = self(),
     Ref = make_ref(),
     [receive {Ref, Result} -> Result end
-     || _ <- [spawn(fun() -> Parent ! {Ref, F(X)} end) || X <- L]].
+     || _ <- [spawn(fun () -> Parent ! {Ref, F(X)} end) || X <- L]].
 
 map_in_order(F, L) ->
     lists:reverse(
diff --git a/src/rabbit_mnesia.erl b/src/rabbit_mnesia.erl
index 55a6761d2d..a0b7aa4e7f 100644
--- a/src/rabbit_mnesia.erl
+++ b/src/rabbit_mnesia.erl
@@ -346,7 +346,7 @@ table_has_copy_type(TabDef, DiscType) ->
 
 create_local_table_copies(Type) ->
     lists:foreach(
-      fun({Tab, TabDef}) ->
+      fun ({Tab, TabDef}) ->
               HasDiscCopies     = table_has_copy_type(TabDef, disc_copies),
               HasDiscOnlyCopies = table_has_copy_type(TabDef, disc_only_copies),
               LocalTab          = proplists:get_bool(local_content, TabDef),
diff --git a/src/rabbit_multi.erl b/src/rabbit_multi.erl
index 336f74bf9a..5db1d77a32 100644
--- a/src/rabbit_multi.erl
+++ b/src/rabbit_multi.erl
@@ -111,7 +111,7 @@ action(start_all, [NodeCount], RpcTimeout) ->
 action(status, [], RpcTimeout) ->
     io:format("Status of all running nodes...~n", []),
     call_all_nodes(
-      fun({Node, Pid}) ->
+      fun ({Node, Pid}) ->
               RabbitRunning =
                   case is_rabbit_running(Node, RpcTimeout) of
                       false -> not_running;
@@ -123,7 +123,7 @@ action(status, [], RpcTimeout) ->
 
 action(stop_all, [], RpcTimeout) ->
     io:format("Stopping all nodes...~n", []),
-    call_all_nodes(fun({Node, Pid}) ->
+    call_all_nodes(fun ({Node, Pid}) ->
                            io:format("Stopping node ~p~n", [Node]),
                            rpc:call(Node, rabbit, stop_and_halt, []),
                            case kill_wait(Pid, RpcTimeout, false) of
diff --git a/src/rabbit_net.erl b/src/rabbit_net.erl
index 406977b42a..975954fcd2 100644
--- a/src/rabbit_net.erl
+++ b/src/rabbit_net.erl
@@ -66,7 +66,7 @@ async_recv(Sock, Length, Timeout) when is_record(Sock, ssl_socket) ->
     Pid = self(),
     Ref = make_ref(),
 
-    spawn(fun() -> Pid ! {inet_async, Sock, Ref,
+    spawn(fun () -> Pid ! {inet_async, Sock, Ref,
                     ssl:recv(Sock#ssl_socket.ssl, Length, Timeout)}
         end),
 
diff --git a/src/rabbit_persister.erl b/src/rabbit_persister.erl
index 3cd42e4753..8d3c2dc082 100644
--- a/src/rabbit_persister.erl
+++ b/src/rabbit_persister.erl
@@ -236,7 +236,7 @@ log_work(CreateWorkUnit, MessageList,
            snapshot = Snapshot = #psnapshot{messages = Messages}}) ->
     Unit = CreateWorkUnit(
              rabbit_misc:map_in_order(
-               fun(M = {publish, Message, QK = {_QName, PKey}}) ->
+               fun (M = {publish, Message, QK = {_QName, PKey}}) ->
                        case ets:lookup(Messages, PKey) of
                            [_] -> {tied, QK};
                            []  -> ets:insert(Messages, {PKey, Message}),
diff --git a/src/rabbit_reader_queue_collector.erl b/src/rabbit_reader_queue_collector.erl
index 841549e98f..8d4e8fdb42 100644
--- a/src/rabbit_reader_queue_collector.erl
+++ b/src/rabbit_reader_queue_collector.erl
@@ -82,8 +82,8 @@ handle_call({register_exclusive_queue, Q}, _From,
 handle_call(delete_all, _From,
             State = #state{exclusive_queues = ExclusiveQueues}) ->
     [rabbit_misc:with_exit_handler(
-       fun() -> ok end,
-       fun() ->
+       fun () -> ok end,
+       fun () ->
                erlang:demonitor(MonitorRef),
                rabbit_amqqueue:delete(Q, false, false)
        end)
diff --git a/src/rabbit_router.erl b/src/rabbit_router.erl
index 03979d6c60..5cd15a9462 100644
--- a/src/rabbit_router.erl
+++ b/src/rabbit_router.erl
@@ -57,14 +57,17 @@ deliver(QPids, Delivery = #delivery{mandatory = false,
     %% is preserved. This scales much better than the non-immediate
     %% case below.
     delegate:invoke_no_result(
-      QPids, fun(Pid) -> rabbit_amqqueue:deliver(Pid, Delivery) end),
+      QPids, fun (Pid) -> rabbit_amqqueue:deliver(Pid, Delivery) end),
     {routed, QPids};
 
 deliver(QPids, Delivery) ->
     {Success, _} =
         delegate:invoke(QPids,
-                        fun(Pid) -> rabbit_amqqueue:deliver(Pid, Delivery) end),
-    {Routed, Handled} = lists:foldl(fun fold_deliveries/2, {false, []}, Success),
+                        fun (Pid) -> 
+                                rabbit_amqqueue:deliver(Pid, Delivery) 
+                        end),
+    {Routed, Handled} =
+        lists:foldl(fun fold_deliveries/2, {false, []}, Success),
     check_delivery(Delivery#delivery.mandatory, Delivery#delivery.immediate,
                    {Routed, Handled}).
 
@@ -88,7 +91,7 @@ match_routing_key(Name, RoutingKey) ->
 
 lookup_qpids(Queues) ->
     sets:fold(
-      fun(Key, Acc) ->
+      fun (Key, Acc) ->
               case mnesia:dirty_read({rabbit_queue, Key}) of
                   [#amqqueue{pid = QPid}] -> [QPid | Acc];
                   []                      -> Acc
diff --git a/src/rabbit_tests.erl b/src/rabbit_tests.erl
index 04ee96d8a1..7ce03e5d6d 100644
--- a/src/rabbit_tests.erl
+++ b/src/rabbit_tests.erl
@@ -65,6 +65,7 @@ all_tests() ->
     passed = test_log_management(),
     passed = test_app_management(),
     passed = test_log_management_during_startup(),
+    passed = test_memory_pressure(),
     passed = test_cluster_management(),
     passed = test_user_management(),
     passed = test_server_status(),
@@ -985,7 +986,7 @@ test_hooks() ->
     {[arg1, arg2], 1, 3} = get(arg_hook_test_fired),
 
     %% Invoking Pids
-    Remote = fun() ->
+    Remote = fun () ->
         receive
             {rabbitmq_hook,[remote_test,test,[],Target]} ->
                 Target ! invoked
@@ -1002,11 +1003,137 @@ test_hooks() ->
     end,
     passed.
 
+test_memory_pressure_receiver(Pid) ->
+    receive
+        shutdown ->
+            ok;
+        {send_command, Method} ->
+            ok = case Method of
+                     #'channel.flow'{}    -> ok;
+                     #'basic.qos_ok'{}    -> ok;
+                     #'channel.open_ok'{} -> ok
+                 end,
+            Pid ! Method,
+            test_memory_pressure_receiver(Pid);
+        sync ->
+            Pid ! sync,
+            test_memory_pressure_receiver(Pid)
+    end.
+
+test_memory_pressure_receive_flow(Active) ->
+    receive #'channel.flow'{active = Active} -> ok
+    after 1000 -> throw(failed_to_receive_channel_flow)
+    end,
+    receive #'channel.flow'{} ->
+            throw(pipelining_sync_commands_detected)
+    after 0 ->
+            ok
+    end.
+
+test_memory_pressure_sync(Ch, Writer) ->
+    ok = rabbit_channel:do(Ch, #'basic.qos'{}),
+    Writer ! sync,
+    receive sync -> ok after 1000 -> throw(failed_to_receive_writer_sync) end,
+    receive #'basic.qos_ok'{} -> ok
+    after 1000 -> throw(failed_to_receive_basic_qos_ok)
+    end.
+
+test_memory_pressure_spawn() ->
+    Me = self(),
+    Writer = spawn(fun () -> test_memory_pressure_receiver(Me) end),
+    Ch = rabbit_channel:start_link(1, self(), Writer, <<"user">>, <<"/">>,
+                                   self()),
+    ok = rabbit_channel:do(Ch, #'channel.open'{}),
+    MRef = erlang:monitor(process, Ch),
+    receive #'channel.open_ok'{} -> ok
+    after 1000 -> throw(failed_to_receive_channel_open_ok)
+    end,
+    {Writer, Ch, MRef}.
+
+expect_normal_channel_termination(MRef, Ch) ->
+    receive {'DOWN', MRef, process, Ch, normal} -> ok
+    after 1000 -> throw(channel_failed_to_exit)
+    end.
+
+test_memory_pressure() ->
+    {Writer0, Ch0, MRef0} = test_memory_pressure_spawn(),
+    [ok = rabbit_channel:conserve_memory(Ch0, Conserve) ||
+        Conserve <- [false, false, true, false, true, true, false]],
+    ok = test_memory_pressure_sync(Ch0, Writer0),
+    receive {'DOWN', MRef0, process, Ch0, Info0} ->
+            throw({channel_died_early, Info0})
+    after 0 -> ok
+    end,
+
+    %% we should have just 1 active=false waiting for us
+    ok = test_memory_pressure_receive_flow(false),
+
+    %% if we reply with flow_ok, we should immediately get an
+    %% active=true back
+    ok = rabbit_channel:do(Ch0, #'channel.flow_ok'{active = false}),
+    ok = test_memory_pressure_receive_flow(true),
+
+    %% if we publish at this point, the channel should die
+    Content = #content{class_id = element(1, rabbit_framing:method_id(
+                                               'basic.publish')),
+                       properties = none,
+                       properties_bin = <<>>,
+                       payload_fragments_rev = []},
+    ok = rabbit_channel:do(Ch0, #'basic.publish'{}, Content),
+    expect_normal_channel_termination(MRef0, Ch0),
+
+    {Writer1, Ch1, MRef1} = test_memory_pressure_spawn(),
+    ok = rabbit_channel:conserve_memory(Ch1, true),
+    ok = test_memory_pressure_receive_flow(false),
+    ok = rabbit_channel:do(Ch1, #'channel.flow_ok'{active = false}),
+    ok = test_memory_pressure_sync(Ch1, Writer1),
+    ok = rabbit_channel:conserve_memory(Ch1, false),
+    ok = test_memory_pressure_receive_flow(true),
+    %% send back the wrong flow_ok. Channel should die.
+    ok = rabbit_channel:do(Ch1, #'channel.flow_ok'{active = false}),
+    expect_normal_channel_termination(MRef1, Ch1),
+
+    {_Writer2, Ch2, MRef2} = test_memory_pressure_spawn(),
+    %% just out of the blue, send a flow_ok. Life should end.
+    ok = rabbit_channel:do(Ch2, #'channel.flow_ok'{active = true}),
+    expect_normal_channel_termination(MRef2, Ch2),
+
+    {_Writer3, Ch3, MRef3} = test_memory_pressure_spawn(),
+    ok = rabbit_channel:conserve_memory(Ch3, true),
+    receive {'DOWN', MRef3, process, Ch3, _} ->
+            ok
+    after 12000 ->
+            throw(channel_failed_to_exit)
+    end,
+
+    alarm_handler:set_alarm({vm_memory_high_watermark, []}),
+    Me = self(),
+    Writer4 = spawn(fun () -> test_memory_pressure_receiver(Me) end),
+    Ch4 = rabbit_channel:start_link(1, self(), Writer4, <<"user">>, <<"/">>,
+                                    self()),
+    ok = rabbit_channel:do(Ch4, #'channel.open'{}),
+    MRef4 = erlang:monitor(process, Ch4),
+    Writer4 ! sync,
+    receive sync -> ok after 1000 -> throw(failed_to_receive_writer_sync) end,
+    receive #'channel.open_ok'{} -> throw(unexpected_channel_open_ok)
+    after 0 -> ok
+    end,
+    alarm_handler:clear_alarm(vm_memory_high_watermark),
+    Writer4 ! sync,
+    receive sync -> ok after 1000 -> throw(failed_to_receive_writer_sync) end,
+    receive #'channel.open_ok'{} -> ok
+    after 1000 -> throw(failed_to_receive_channel_open_ok)
+    end,
+    rabbit_channel:shutdown(Ch4),
+    expect_normal_channel_termination(MRef4, Ch4),
+
+    passed.
+
 test_delegates_async(SecondaryNode) ->
     Self = self(),
-    Sender = fun(Pid) -> Pid ! {invoked, Self} end,
+    Sender = fun (Pid) -> Pid ! {invoked, Self} end,
 
-    Responder = make_responder(fun({invoked, Pid}) -> Pid ! response end),
+    Responder = make_responder(fun ({invoked, Pid}) -> Pid ! response end),
 
     ok = delegate:invoke_no_result(spawn(Responder), Sender),
     ok = delegate:invoke_no_result(spawn(SecondaryNode, Responder), Sender),
@@ -1021,7 +1148,7 @@ test_delegates_async(SecondaryNode) ->
 
 make_responder(FMsg) -> make_responder(FMsg, timeout).
 make_responder(FMsg, Throw) ->
-    fun() ->
+    fun () ->
         receive Msg -> FMsg(Msg)
         after 1000 -> throw(Throw)
         end
@@ -1050,22 +1177,22 @@ must_exit(Fun) ->
     end.
 
 test_delegates_sync(SecondaryNode) ->
-    Sender = fun(Pid) -> gen_server:call(Pid, invoked) end,
-    BadSender = fun(_Pid) -> exit(exception) end,
+    Sender = fun (Pid) -> gen_server:call(Pid, invoked) end,
+    BadSender = fun (_Pid) -> exit(exception) end,
 
-    Responder = make_responder(fun({'$gen_call', From, invoked}) ->
+    Responder = make_responder(fun ({'$gen_call', From, invoked}) ->
                                    gen_server:reply(From, response)
                                end),
 
-    BadResponder = make_responder(fun({'$gen_call', From, invoked}) ->
+    BadResponder = make_responder(fun ({'$gen_call', From, invoked}) ->
                                           gen_server:reply(From, response)
                                   end, bad_responder_died),
 
     response = delegate:invoke(spawn(Responder), Sender),
     response = delegate:invoke(spawn(SecondaryNode, Responder), Sender),
 
-    must_exit(fun() -> delegate:invoke(spawn(BadResponder), BadSender) end),
-    must_exit(fun() ->
+    must_exit(fun () -> delegate:invoke(spawn(BadResponder), BadSender) end),
+    must_exit(fun () ->
         delegate:invoke(spawn(SecondaryNode, BadResponder), BadSender) end),
 
     LocalGoodPids = spawn_responders(node(), Responder, 2),
diff --git a/src/rabbit_writer.erl b/src/rabbit_writer.erl
index 54c60f5be0..3d10dc121e 100644
--- a/src/rabbit_writer.erl
+++ b/src/rabbit_writer.erl
@@ -50,17 +50,17 @@
 
 -spec(start/3 :: (socket(), channel_number(), non_neg_integer()) -> pid()).
 -spec(start_link/3 :: (socket(), channel_number(), non_neg_integer()) -> pid()).
--spec(send_command/2 :: (pid(), amqp_method()) -> 'ok').
--spec(send_command/3 :: (pid(), amqp_method(), content()) -> 'ok').
+-spec(send_command/2 :: (pid(), amqp_method_record()) -> 'ok').
+-spec(send_command/3 :: (pid(), amqp_method_record(), content()) -> 'ok').
 -spec(send_command_and_signal_back/3 :: (pid(), amqp_method(), pid()) -> 'ok').
 -spec(send_command_and_signal_back/4 ::
       (pid(), amqp_method(), content(), pid()) -> 'ok').
 -spec(send_command_and_notify/5 ::
-      (pid(), pid(), pid(), amqp_method(), content()) -> 'ok').
+      (pid(), pid(), pid(), amqp_method_record(), content()) -> 'ok').
 -spec(internal_send_command/3 ::
-      (socket(), channel_number(), amqp_method()) -> 'ok').
+      (socket(), channel_number(), amqp_method_record()) -> 'ok').
 -spec(internal_send_command/5 ::
-      (socket(), channel_number(), amqp_method(),
+      (socket(), channel_number(), amqp_method_record(),
        content(), non_neg_integer()) -> 'ok').
 
 -endif.
diff --git a/src/supervisor2.erl b/src/supervisor2.erl
index 5575351269..0b1d726562 100644
--- a/src/supervisor2.erl
+++ b/src/supervisor2.erl
@@ -301,13 +301,13 @@ handle_call({terminate_child, Name}, _From, State) ->
 
 handle_call(which_children, _From, State) when ?is_simple(State) ->
     [#child{child_type = CT, modules = Mods}] = State#state.children,
-    Reply = lists:map(fun({Pid, _}) -> {undefined, Pid, CT, Mods} end,
+    Reply = lists:map(fun ({Pid, _}) -> {undefined, Pid, CT, Mods} end,
 		      ?DICT:to_list(State#state.dynamics)),
     {reply, Reply, State};
 
 handle_call(which_children, _From, State) ->
     Resp =
-	lists:map(fun(#child{pid = Pid, name = Name,
+	lists:map(fun (#child{pid = Pid, name = Name,
 			     child_type = ChildType, modules = Mods}) ->
 		    {Name, Pid, ChildType, Mods}
 		  end,
@@ -415,7 +415,7 @@ update_childspec1([], Children, KeepOld) ->
     lists:reverse(Children ++ KeepOld).  
 
 update_chsp(OldCh, Children) ->
-    case lists:map(fun(Ch) when OldCh#child.name =:= Ch#child.name ->
+    case lists:map(fun (Ch) when OldCh#child.name =:= Ch#child.name ->
 			   Ch#child{pid = OldCh#child.pid};
 		      (Ch) ->
 			   Ch
@@ -828,7 +828,7 @@ validShutdown(Shutdown, _)             -> throw({invalid_shutdown, Shutdown}).
 
 validMods(dynamic) -> true;
 validMods(Mods) when is_list(Mods) ->
-    lists:foreach(fun(Mod) ->
+    lists:foreach(fun (Mod) ->
 		    if
 			is_atom(Mod) -> ok;
 			true -> throw({invalid_module, Mod})