Merge in default (and make error more readable)

15 files changed, 191 insertions, 125 deletions

diff --git a/src/mirrored_supervisor.erl b/src/mirrored_supervisor.erl
index 6e8f96d9..3ba8f50d 100644
--- a/src/mirrored_supervisor.erl
+++ b/src/mirrored_supervisor.erl
@@ -144,32 +144,17 @@
 
 -type child()    :: pid() | 'undefined'.
 -type child_id() :: term().
--type mfargs()   :: {M :: module(), F :: atom(), A :: [term()] | 'undefined'}.
 -type modules()  :: [module()] | 'dynamic'.
--type restart()  :: 'permanent' | 'transient' | 'temporary'.
--type shutdown() :: 'brutal_kill' | timeout().
 -type worker()   :: 'worker' | 'supervisor'.
 -type sup_name() :: {'local', Name :: atom()} | {'global', Name :: atom()}.
 -type sup_ref()  :: (Name :: atom())
                   | {Name :: atom(), Node :: node()}
                   | {'global', Name :: atom()}
                   | pid().
--type child_spec() :: {Id :: child_id(),
-                       StartFunc :: mfargs(),
-                       Restart :: restart(),
-                       Shutdown :: shutdown(),
-                       Type :: worker(),
-                       Modules :: modules()}.
 
 -type startlink_err() :: {'already_started', pid()} | 'shutdown' | term().
 -type startlink_ret() :: {'ok', pid()} | 'ignore' | {'error', startlink_err()}.
 
--type startchild_err() :: 'already_present'
-                        | {'already_started', Child :: child()} | term().
--type startchild_ret() :: {'ok', Child :: child()}
-                        | {'ok', Child :: child(), Info :: term()}
-                        | {'error', startchild_err()}.
-
 -type group_name() :: any().
 
 -spec start_link(GroupName, Module, Args) -> startlink_ret() when
@@ -183,9 +168,9 @@
       Module :: module(),
       Args :: term().
 
--spec start_child(SupRef, ChildSpec) -> startchild_ret() when
+-spec start_child(SupRef, ChildSpec) -> supervisor:startchild_ret() when
       SupRef :: sup_ref(),
-      ChildSpec :: child_spec() | (List :: [term()]).
+      ChildSpec :: supervisor:child_spec() | (List :: [term()]).
 
 -spec restart_child(SupRef, Id) -> Result when
       SupRef :: sup_ref(),
@@ -215,12 +200,12 @@
       Modules :: modules().
 
 -spec check_childspecs(ChildSpecs) -> Result when
-      ChildSpecs :: [child_spec()],
+      ChildSpecs :: [supervisor:child_spec()],
       Result :: 'ok' | {'error', Error :: term()}.
 
 -spec start_internal(Group, ChildSpecs) -> Result when
       Group :: group_name(),
-      ChildSpecs :: [child_spec()],
+      ChildSpecs :: [supervisor:child_spec()],
       Result :: startlink_ret().
 
 -spec create_tables() -> Result when
diff --git a/src/rabbit.erl b/src/rabbit.erl
index df0847e0..2354e552 100644
--- a/src/rabbit.erl
+++ b/src/rabbit.erl
@@ -132,7 +132,7 @@
 -rabbit_boot_step({recovery,
                    [{description, "exchange, queue and binding recovery"},
                     {mfa,         {rabbit, recover, []}},
-                    {requires,    empty_db_check},
+                    {requires,    core_initialized},
                     {enables,     routing_ready}]}).
 
 -rabbit_boot_step({mirror_queue_slave_sup,
diff --git a/src/rabbit_alarm.erl b/src/rabbit_alarm.erl
index fd03ca85..517dd4ec 100644
--- a/src/rabbit_alarm.erl
+++ b/src/rabbit_alarm.erl
@@ -31,10 +31,9 @@
 
 -ifdef(use_specs).
 
--type(mfa_tuple() :: {atom(), atom(), list()}).
 -spec(start/0 :: () -> 'ok').
 -spec(stop/0 :: () -> 'ok').
--spec(register/2 :: (pid(), mfa_tuple()) -> boolean()).
+-spec(register/2 :: (pid(), rabbit_types:mfargs()) -> boolean()).
 -spec(on_node_up/1 :: (node()) -> 'ok').
 -spec(on_node_down/1 :: (node()) -> 'ok').
 
diff --git a/src/rabbit_client_sup.erl b/src/rabbit_client_sup.erl
index dfb400e3..4ba01b4f 100644
--- a/src/rabbit_client_sup.erl
+++ b/src/rabbit_client_sup.erl
@@ -28,8 +28,9 @@
 
 -ifdef(use_specs).
 
--spec(start_link/1 :: (mfa()) -> rabbit_types:ok_pid_or_error()).
--spec(start_link/2 :: ({'local', atom()}, mfa()) ->
+-spec(start_link/1 :: (rabbit_types:mfargs()) ->
+                           rabbit_types:ok_pid_or_error()).
+-spec(start_link/2 :: ({'local', atom()}, rabbit_types:mfargs()) ->
                            rabbit_types:ok_pid_or_error()).
 
 -endif.
diff --git a/src/rabbit_exchange.erl b/src/rabbit_exchange.erl
index a15b9be4..68c0d988 100644
--- a/src/rabbit_exchange.erl
+++ b/src/rabbit_exchange.erl
@@ -355,11 +355,21 @@ peek_serial(XName) ->
         _                                  -> undefined
     end.
 
+invalid_module(T) ->
+    rabbit_log:warning(
+      "Could not find exchange type ~s.~n", [T]),
+    put({xtype_to_module, T}, rabbit_exchange_type_invalid),
+    rabbit_exchange_type_invalid.
+
 %% Used with atoms from records; e.g., the type is expected to exist.
 type_to_module(T) ->
     case get({xtype_to_module, T}) of
-        undefined -> {ok, Module} = rabbit_registry:lookup_module(exchange, T),
-                     put({xtype_to_module, T}, Module),
-                     Module;
-        Module    -> Module
+        undefined ->
+            case rabbit_registry:lookup_module(exchange, T) of
+                {ok, Module}       -> put({xtype_to_module, T}, Module),
+                                      Module;
+                {error, not_found} -> invalid_module(T)
+            end;
+        Module ->
+            Module
     end.
diff --git a/src/rabbit_exchange_type_invalid.erl b/src/rabbit_exchange_type_invalid.erl
new file mode 100644
index 00000000..8f60f7d8
--- /dev/null
+++ b/src/rabbit_exchange_type_invalid.erl
@@ -0,0 +1,47 @@
+%% The contents of this file are subject to the Mozilla Public License
+%% Version 1.1 (the "License"); you may not use this file except in
+%% compliance with the License. You may obtain a copy of the License
+%% at http://www.mozilla.org/MPL/
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and
+%% limitations under the License.
+%%
+%% The Original Code is RabbitMQ.
+%%
+%% The Initial Developer of the Original Code is VMware, Inc.
+%% Copyright (c) 2007-2012 VMware, Inc.  All rights reserved.
+%%
+
+-module(rabbit_exchange_type_invalid).
+-include("rabbit.hrl").
+
+-behaviour(rabbit_exchange_type).
+
+-export([description/0, serialise_events/0, route/2]).
+-export([validate/1, create/2, delete/3,
+         add_binding/3, remove_bindings/3, assert_args_equivalence/2]).
+-include("rabbit_exchange_type_spec.hrl").
+
+description() ->
+    [{name, <<"invalid">>},
+     {description,
+      <<"Dummy exchange type, to be used when the intended one is not found.">>
+     }].
+
+serialise_events() -> false.
+
+route(#exchange{name = Name, type = Type}, _) ->
+    rabbit_misc:protocol_error(
+      precondition_failed,
+      "Cannot route message through ~s: exchange type ~s not found",
+      [rabbit_misc:rs(Name), Type]).
+
+validate(_X) -> ok.
+create(_Tx, _X) -> ok.
+delete(_Tx, _X, _Bs) -> ok.
+add_binding(_Tx, _X, _B) -> ok.
+remove_bindings(_Tx, _X, _Bs) -> ok.
+assert_args_equivalence(X, Args) ->
+    rabbit_exchange:assert_args_equivalence(X, Args).
diff --git a/src/rabbit_networking.erl b/src/rabbit_networking.erl
index 191325f1..f78a53a1 100644
--- a/src/rabbit_networking.erl
+++ b/src/rabbit_networking.erl
@@ -24,7 +24,7 @@
          close_connection/2, force_connection_event_refresh/0]).
 
 %%used by TCP-based transports, e.g. STOMP adapter
--export([check_tcp_listener_address/2,
+-export([tcp_listener_addresses/1, tcp_listener_spec/6,
          ensure_ssl/0, ssl_transform_fun/1]).
 
 -export([tcp_listener_started/3, tcp_listener_stopped/3,
@@ -47,12 +47,16 @@
 -export_type([ip_port/0, hostname/0]).
 
 -type(hostname() :: inet:hostname()).
--type(ip_port() :: inet:ip_port()).
+-type(ip_port() :: inet:port_number()).
 
 -type(family() :: atom()).
 -type(listener_config() :: ip_port() |
                            {hostname(), ip_port()} |
                            {hostname(), ip_port(), family()}).
+-type(address() :: {inet:ip_address(), ip_port(), family()}).
+-type(name_prefix() :: atom()).
+-type(protocol() :: atom()).
+-type(label() :: string()).
 
 -spec(start/0 :: () -> 'ok').
 -spec(start_tcp_listener/1 :: (listener_config()) -> 'ok').
@@ -76,8 +80,10 @@
 -spec(force_connection_event_refresh/0 :: () -> 'ok').
 
 -spec(on_node_down/1 :: (node()) -> 'ok').
--spec(check_tcp_listener_address/2 :: (atom(), listener_config())
-        -> [{inet:ip_address(), ip_port(), family(), atom()}]).
+-spec(tcp_listener_addresses/1 :: (listener_config()) -> [address()]).
+-spec(tcp_listener_spec/6 ::
+        (name_prefix(), address(), [gen_tcp:listen_option()], protocol(),
+         label(), rabbit_types:mfargs()) -> supervisor:child_spec()).
 -spec(ensure_ssl/0 :: () -> rabbit_types:infos()).
 -spec(ssl_transform_fun/1 ::
         (rabbit_types:infos())
@@ -140,39 +146,6 @@ start() ->
                 transient, infinity, supervisor, [rabbit_client_sup]}),
     ok.
 
-%% inet_parse:address takes care of ip string, like "0.0.0.0"
-%% inet:getaddr returns immediately for ip tuple {0,0,0,0},
-%%  and runs 'inet_gethost' port process for dns lookups.
-%% On Windows inet:getaddr runs dns resolver for ip string, which may fail.
-
-getaddr(Host, Family) ->
-    case inet_parse:address(Host) of
-        {ok, IPAddress} -> [{IPAddress, resolve_family(IPAddress, Family)}];
-        {error, _}      -> gethostaddr(Host, Family)
-    end.
-
-gethostaddr(Host, auto) ->
-    Lookups = [{Family, inet:getaddr(Host, Family)} || Family <- [inet, inet6]],
-    case [{IP, Family} || {Family, {ok, IP}} <- Lookups] of
-        []  -> host_lookup_error(Host, Lookups);
-        IPs -> IPs
-    end;
-
-gethostaddr(Host, Family) ->
-    case inet:getaddr(Host, Family) of
-        {ok, IPAddress} -> [{IPAddress, Family}];
-        {error, Reason} -> host_lookup_error(Host, Reason)
-    end.
-
-host_lookup_error(Host, Reason) ->
-    error_logger:error_msg("invalid host ~p - ~p~n", [Host, Reason]),
-    throw({error, {invalid_host, Host, Reason}}).
-
-resolve_family({_,_,_,_},         auto) -> inet;
-resolve_family({_,_,_,_,_,_,_,_}, auto) -> inet6;
-resolve_family(IP,                auto) -> throw({error, {strange_family, IP}});
-resolve_family(_,                 F)    -> F.
-
 ensure_ssl() ->
     ok = rabbit_misc:start_applications([crypto, public_key, ssl]),
     {ok, SslOptsConfig} = application:get_env(rabbit, ssl_options),
@@ -201,31 +174,36 @@ ssl_transform_fun(SslOpts) ->
             end
     end.
 
-check_tcp_listener_address(NamePrefix, Port) when is_integer(Port) ->
-    check_tcp_listener_address_auto(NamePrefix, Port);
-
-check_tcp_listener_address(NamePrefix, {"auto", Port}) ->
+tcp_listener_addresses(Port) when is_integer(Port) ->
+    tcp_listener_addresses_auto(Port);
+tcp_listener_addresses({"auto", Port}) ->
     %% Variant to prevent lots of hacking around in bash and batch files
-    check_tcp_listener_address_auto(NamePrefix, Port);
-
-check_tcp_listener_address(NamePrefix, {Host, Port}) ->
+    tcp_listener_addresses_auto(Port);
+tcp_listener_addresses({Host, Port}) ->
     %% auto: determine family IPv4 / IPv6 after converting to IP address
-    check_tcp_listener_address(NamePrefix, {Host, Port, auto});
-
-check_tcp_listener_address(NamePrefix, {Host, Port, Family0}) ->
-    if is_integer(Port) andalso (Port >= 0) andalso (Port =< 65535) -> ok;
-       true -> error_logger:error_msg("invalid port ~p - not 0..65535~n",
-                                      [Port]),
-               throw({error, {invalid_port, Port}})
-    end,
-    [{IPAddress, Port, Family,
-      rabbit_misc:tcp_name(NamePrefix, IPAddress, Port)} ||
-        {IPAddress, Family} <- getaddr(Host, Family0)].
-
-check_tcp_listener_address_auto(NamePrefix, Port) ->
-    lists:append([check_tcp_listener_address(NamePrefix, Listener) ||
+    tcp_listener_addresses({Host, Port, auto});
+tcp_listener_addresses({Host, Port, Family0})
+  when is_integer(Port) andalso (Port >= 0) andalso (Port =< 65535) ->
+    [{IPAddress, Port, Family} ||
+        {IPAddress, Family} <- getaddr(Host, Family0)];
+tcp_listener_addresses({_Host, Port, _Family0}) ->
+    error_logger:error_msg("invalid port ~p - not 0..65535~n", [Port]),
+    throw({error, {invalid_port, Port}}).
+
+tcp_listener_addresses_auto(Port) ->
+    lists:append([tcp_listener_addresses(Listener) ||
                      Listener <- port_to_listeners(Port)]).
 
+tcp_listener_spec(NamePrefix, {IPAddress, Port, Family}, SocketOpts,
+                  Protocol, Label, OnConnect) ->
+    {rabbit_misc:tcp_name(NamePrefix, IPAddress, Port),
+     {tcp_listener_sup, start_link,
+      [IPAddress, Port, [Family | SocketOpts],
+       {?MODULE, tcp_listener_started, [Protocol]},
+       {?MODULE, tcp_listener_stopped, [Protocol]},
+       OnConnect, Label]},
+     transient, infinity, supervisor, [tcp_listener_sup]}.
+
 start_tcp_listener(Listener) ->
     start_listener(Listener, amqp, "TCP Listener",
                    {?MODULE, start_client, []}).
@@ -235,33 +213,27 @@ start_ssl_listener(Listener, SslOpts) ->
                    {?MODULE, start_ssl_client, [SslOpts]}).
 
 start_listener(Listener, Protocol, Label, OnConnect) ->
-    [start_listener0(Spec, Protocol, Label, OnConnect) ||
-        Spec <- check_tcp_listener_address(rabbit_tcp_listener_sup, Listener)],
+    [start_listener0(Address, Protocol, Label, OnConnect) ||
+        Address <- tcp_listener_addresses(Listener)],
     ok.
 
-start_listener0({IPAddress, Port, Family, Name}, Protocol, Label, OnConnect) ->
-    case supervisor:start_child(
-           rabbit_sup,
-           {Name,
-            {tcp_listener_sup, start_link,
-             [IPAddress, Port, [Family | tcp_opts()],
-              {?MODULE, tcp_listener_started, [Protocol]},
-              {?MODULE, tcp_listener_stopped, [Protocol]},
-              OnConnect, Label]},
-            transient, infinity, supervisor, [tcp_listener_sup]}) of
+start_listener0(Address, Protocol, Label, OnConnect) ->
+    Spec = tcp_listener_spec(rabbit_tcp_listener_sup, Address, tcp_opts(),
+                             Protocol, Label, OnConnect),
+    case supervisor:start_child(rabbit_sup, Spec) of
         {ok, _} ->
             ok;
         {error, {shutdown, _}} ->
-            exit({could_not_start_tcp_listener, [{port,      Port},
-                                                 {interface, IPAddress}]})
+            {Addr, Port, _} = Address,
+            exit({could_not_start_tcp_listener, {rabbit_misc:ntoa(Addr), Port}})
     end.
 
 stop_tcp_listener(Listener) ->
-    [stop_tcp_listener0(Spec) ||
-        Spec <- check_tcp_listener_address(rabbit_tcp_listener_sup, Listener)],
+    [stop_tcp_listener0(Address) ||
+        Address <- tcp_listener_addresses(Listener)],
     ok.
 
-stop_tcp_listener0({IPAddress, Port, _Family, Name}) ->
+stop_tcp_listener0({IPAddress, Port, _Family}) ->
     Name = rabbit_misc:tcp_name(rabbit_tcp_listener_sup, IPAddress, Port),
     ok = supervisor:terminate_child(rabbit_sup, Name),
     ok = supervisor:delete_child(rabbit_sup, Name).
@@ -369,6 +341,38 @@ tcp_opts() ->
     {ok, Opts} = application:get_env(rabbit, tcp_listen_options),
     Opts.
 
+%% inet_parse:address takes care of ip string, like "0.0.0.0"
+%% inet:getaddr returns immediately for ip tuple {0,0,0,0},
+%%  and runs 'inet_gethost' port process for dns lookups.
+%% On Windows inet:getaddr runs dns resolver for ip string, which may fail.
+getaddr(Host, Family) ->
+    case inet_parse:address(Host) of
+        {ok, IPAddress} -> [{IPAddress, resolve_family(IPAddress, Family)}];
+        {error, _}      -> gethostaddr(Host, Family)
+    end.
+
+gethostaddr(Host, auto) ->
+    Lookups = [{Family, inet:getaddr(Host, Family)} || Family <- [inet, inet6]],
+    case [{IP, Family} || {Family, {ok, IP}} <- Lookups] of
+        []  -> host_lookup_error(Host, Lookups);
+        IPs -> IPs
+    end;
+
+gethostaddr(Host, Family) ->
+    case inet:getaddr(Host, Family) of
+        {ok, IPAddress} -> [{IPAddress, Family}];
+        {error, Reason} -> host_lookup_error(Host, Reason)
+    end.
+
+host_lookup_error(Host, Reason) ->
+    error_logger:error_msg("invalid host ~p - ~p~n", [Host, Reason]),
+    throw({error, {invalid_host, Host, Reason}}).
+
+resolve_family({_,_,_,_},         auto) -> inet;
+resolve_family({_,_,_,_,_,_,_,_}, auto) -> inet6;
+resolve_family(IP,                auto) -> throw({error, {strange_family, IP}});
+resolve_family(_,                 F)    -> F.
+
 %%--------------------------------------------------------------------
 
 %% There are three kinds of machine (for our purposes).
diff --git a/src/rabbit_plugins.erl b/src/rabbit_plugins.erl
index 6a5f4d1b..de2ba8ad 100644
--- a/src/rabbit_plugins.erl
+++ b/src/rabbit_plugins.erl
@@ -332,6 +332,9 @@ lookup_plugins(Names, AllPlugins) ->
 read_enabled_plugins(PluginsFile) ->
     case rabbit_file:read_term_file(PluginsFile) of
         {ok, [Plugins]} -> Plugins;
+        {ok, []}        -> [];
+        {ok, [_|_]}      -> throw({error, {malformed_enabled_plugins_file,
+                                           PluginsFile}});
         {error, enoent} -> [];
         {error, Reason} -> throw({error, {cannot_read_enabled_plugins_file,
                                           PluginsFile, Reason}})
diff --git a/src/rabbit_restartable_sup.erl b/src/rabbit_restartable_sup.erl
index cda3ccbe..1a08efed 100644
--- a/src/rabbit_restartable_sup.erl
+++ b/src/rabbit_restartable_sup.erl
@@ -28,7 +28,8 @@
 
 -ifdef(use_specs).
 
--spec(start_link/2 :: (atom(), mfa()) -> rabbit_types:ok_pid_or_error()).
+-spec(start_link/2 :: (atom(), rabbit_types:mfargs()) ->
+                           rabbit_types:ok_pid_or_error()).
 
 -endif.
 
diff --git a/src/rabbit_types.erl b/src/rabbit_types.erl
index 2db960ac..ae2b5d3f 100644
--- a/src/rabbit_types.erl
+++ b/src/rabbit_types.erl
@@ -28,12 +28,9 @@
               binding/0, binding_source/0, binding_destination/0,
               amqqueue/0, exchange/0,
               connection/0, protocol/0, user/0, internal_user/0,
-              username/0, password/0, password_hash/0, ok/1, error/1,
-              ok_or_error/1, ok_or_error2/2, ok_pid_or_error/0, channel_exit/0,
-              connection_exit/0]).
-
--type(channel_exit() :: no_return()).
--type(connection_exit() :: no_return()).
+              username/0, password/0, password_hash/0,
+              ok/1, error/1, ok_or_error/1, ok_or_error2/2, ok_pid_or_error/0,
+              channel_exit/0, connection_exit/0, mfargs/0]).
 
 -type(maybe(T) :: T | 'none').
 -type(vhost() :: binary()).
@@ -156,4 +153,9 @@
 -type(ok_or_error2(A, B) :: ok(A) | error(B)).
 -type(ok_pid_or_error() :: ok_or_error2(pid(), any())).
 
+-type(channel_exit() :: no_return()).
+-type(connection_exit() :: no_return()).
+
+-type(mfargs() :: {atom(), atom(), [any()]}).
+
 -endif. % use_specs
diff --git a/src/tcp_acceptor_sup.erl b/src/tcp_acceptor_sup.erl
index 4c835598..cb3dd02c 100644
--- a/src/tcp_acceptor_sup.erl
+++ b/src/tcp_acceptor_sup.erl
@@ -25,7 +25,11 @@
 %%----------------------------------------------------------------------------
 
 -ifdef(use_specs).
--spec(start_link/2 :: (atom(), mfa()) -> rabbit_types:ok_pid_or_error()).
+
+-type(mfargs() :: {atom(), atom(), [any()]}).
+
+-spec(start_link/2 :: (atom(), mfargs()) -> rabbit_types:ok_pid_or_error()).
+
 -endif.
 
 %%----------------------------------------------------------------------------
diff --git a/src/tcp_listener.erl b/src/tcp_listener.erl
index 9665a494..e5db4c9f 100644
--- a/src/tcp_listener.erl
+++ b/src/tcp_listener.erl
@@ -28,9 +28,14 @@
 %%----------------------------------------------------------------------------
 
 -ifdef(use_specs).
+
+-type(mfargs() :: {atom(), atom(), [any()]}).
+
 -spec(start_link/8 ::
-        (gen_tcp:ip_address(), integer(), rabbit_types:infos(), integer(),
-         atom(), mfa(), mfa(), string()) -> rabbit_types:ok_pid_or_error()).
+        (inet:ip_address(), inet:port_number(), [gen_tcp:listen_option()],
+         integer(), atom(), mfargs(), mfargs(), string()) ->
+                           rabbit_types:ok_pid_or_error()).
+
 -endif.
 
 %%--------------------------------------------------------------------
diff --git a/src/tcp_listener_sup.erl b/src/tcp_listener_sup.erl
index 5bff5c27..74297b6d 100644
--- a/src/tcp_listener_sup.erl
+++ b/src/tcp_listener_sup.erl
@@ -26,12 +26,16 @@
 
 -ifdef(use_specs).
 
+-type(mfargs() :: {atom(), atom(), [any()]}).
+
 -spec(start_link/7 ::
-        (gen_tcp:ip_address(), integer(), rabbit_types:infos(), mfa(), mfa(),
-         mfa(), string()) -> rabbit_types:ok_pid_or_error()).
+        (inet:ip_address(), inet:port_number(), [gen_tcp:listen_option()],
+         mfargs(), mfargs(), mfargs(), string()) ->
+                           rabbit_types:ok_pid_or_error()).
 -spec(start_link/8 ::
-        (gen_tcp:ip_address(), integer(), rabbit_types:infos(), mfa(), mfa(),
-         mfa(), integer(), string()) -> rabbit_types:ok_pid_or_error()).
+        (inet:ip_address(), inet:port_number(), [gen_tcp:listen_option()],
+         mfargs(), mfargs(), mfargs(), integer(), string()) ->
+                           rabbit_types:ok_pid_or_error()).
 
 -endif.
 
diff --git a/src/worker_pool.erl b/src/worker_pool.erl
index 456ff39f..fcb07a16 100644
--- a/src/worker_pool.erl
+++ b/src/worker_pool.erl
@@ -37,10 +37,11 @@
 
 -ifdef(use_specs).
 
+-type(mfargs() :: {atom(), atom(), [any()]}).
+
 -spec(start_link/0 :: () -> {'ok', pid()} | {'error', any()}).
--spec(submit/1 :: (fun (() -> A) | {atom(), atom(), [any()]}) -> A).
--spec(submit_async/1 ::
-      (fun (() -> any()) | {atom(), atom(), [any()]}) -> 'ok').
+-spec(submit/1 :: (fun (() -> A) | mfargs()) -> A).
+-spec(submit_async/1 :: (fun (() -> any()) | mfargs()) -> 'ok').
 -spec(idle/1 :: (any()) -> 'ok').
 
 -endif.
diff --git a/src/worker_pool_worker.erl b/src/worker_pool_worker.erl
index 78ab4df3..b42530e2 100644
--- a/src/worker_pool_worker.erl
+++ b/src/worker_pool_worker.erl
@@ -29,12 +29,12 @@
 
 -ifdef(use_specs).
 
+-type(mfargs() :: {atom(), atom(), [any()]}).
+
 -spec(start_link/1 :: (any()) -> {'ok', pid()} | {'error', any()}).
--spec(submit/2 :: (pid(), fun (() -> A) | {atom(), atom(), [any()]}) -> A).
--spec(submit_async/2 ::
-      (pid(), fun (() -> any()) | {atom(), atom(), [any()]}) -> 'ok').
--spec(run/1 :: (fun (() -> A)) -> A;
-               ({atom(), atom(), [any()]}) -> any()).
+-spec(submit/2 :: (pid(), fun (() -> A) | mfargs()) -> A).
+-spec(submit_async/2 :: (pid(), fun (() -> any()) | mfargs()) -> 'ok').
+-spec(run/1 :: (fun (() -> A)) -> A; (mfargs()) -> any()).
 -spec(set_maximum_since_use/2 :: (pid(), non_neg_integer()) -> 'ok').
 
 -endif.