Merge pull request #8221 from terry-xiaoyu/fix_delayed_module_disbled_after_emqx_stop

feat: fix the hook priorities

apps/emqx/include/emqx_hooks.hrl

@@ -0,0 +1,40 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2021-2022 EMQ Technologies Co., Ltd. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%--------------------------------------------------------------------
+
+%% Definitions for Hook Priorities
+
+%% Highest Priority = 1000, don't change this value as the plugins may depend on it.
+-define(HP_HIGHEST, 1000).
+
+%% hooks used by the emqx core app
+-define(HP_PSK, 990).
+-define(HP_REWRITE, 980).
+-define(HP_AUTHN, 970).
+-define(HP_AUTHZ, 960).
+-define(HP_SYS_MSGS, 950).
+-define(HP_TOPIC_METRICS, 940).
+-define(HP_RETAINER, 930).
+-define(HP_AUTO_SUB, 920).
+-define(HP_RULE_ENGINE, 900).
+%% apps that can work with the republish action
+-define(HP_SLOW_SUB, 880).
+-define(HP_BRIDGE, 870).
+-define(HP_DELAY_PUB, 860).
+%% apps that can stop the hooks chain from continuing
+-define(HP_EXHOOK, 100).
+
+%% == Lowest Priority = 0, don't change this value as the plugins may depend on it.
+-define(HP_LOWEST, 0).

apps/emqx/src/emqx.erl

@@ -49,10 +49,6 @@
 
 %% Hooks API
 -export([
-    hook/2,
-    hook/3,
-    hook/4,
-    unhook/2,
     run_hook/2,
     run_fold_hook/3
 ]).
@@ -160,31 +156,6 @@ subscribed(SubId, Topic) when is_atom(SubId); is_binary(SubId) ->
 %%--------------------------------------------------------------------
 %% Hooks API
 %%--------------------------------------------------------------------
-
--spec hook(emqx_hooks:hookpoint(), emqx_hooks:action()) -> ok | {error, already_exists}.
-hook(HookPoint, Action) ->
-    emqx_hooks:add(HookPoint, Action).
-
--spec hook(
-    emqx_hooks:hookpoint(),
-    emqx_hooks:action(),
-    emqx_hooks:filter() | integer() | list()
-) ->
-    ok | {error, already_exists}.
-hook(HookPoint, Action, Priority) when is_integer(Priority) ->
-    emqx_hooks:add(HookPoint, Action, Priority);
-hook(HookPoint, Action, {_M, _F, _A} = Filter) ->
-    emqx_hooks:add(HookPoint, Action, Filter).
-
--spec hook(emqx_hooks:hookpoint(), emqx_hooks:action(), emqx_hooks:filter(), integer()) ->
-    ok | {error, already_exists}.
-hook(HookPoint, Action, Filter, Priority) ->
-    emqx_hooks:add(HookPoint, Action, Filter, Priority).
-
--spec unhook(emqx_hooks:hookpoint(), emqx_hooks:action() | {module(), atom()}) -> ok.
-unhook(HookPoint, Action) ->
-    emqx_hooks:del(HookPoint, Action).
-
 -spec run_hook(emqx_hooks:hookpoint(), list(any())) -> ok | stop.
 run_hook(HookPoint, Args) ->
     emqx_hooks:run(HookPoint, Args).

apps/emqx/src/emqx_authentication.erl

@@ -25,7 +25,7 @@
 -include("emqx.hrl").
 -include("logger.hrl").
 -include("emqx_authentication.hrl").
-
+-include_lib("emqx/include/emqx_hooks.hrl").
 -include_lib("stdlib/include/ms_transform.hrl").
 
 -define(CONF_ROOT, ?EMQX_AUTHENTICATION_CONFIG_ROOT_NAME_ATOM).
@@ -698,7 +698,7 @@ maybe_hook(#{hooked := false} = State) ->
         )
     of
         true ->
-            _ = emqx:hook('client.authenticate', {?MODULE, authenticate, []}),
+            ok = emqx_hooks:put('client.authenticate', {?MODULE, authenticate, []}, ?HP_AUTHN),
             State#{hooked => true};
         false ->
             State
@@ -717,7 +717,7 @@ maybe_unhook(#{hooked := true} = State) ->
         )
     of
         true ->
-            _ = emqx:unhook('client.authenticate', {?MODULE, authenticate, []}),
+            ok = emqx_hooks:del('client.authenticate', {?MODULE, authenticate, []}),
             State#{hooked => false};
         false ->
             State

apps/emqx/src/emqx_hooks.erl

@@ -29,10 +29,8 @@
 
 %% Hooks API
 -export([
-    add/2,
     add/3,
     add/4,
-    put/2,
     put/3,
     put/4,
     del/2,
@@ -121,44 +119,34 @@ callback_priority(#callback{priority = P}) -> P.
 %% Hooks API
 %%--------------------------------------------------------------------
 
-%% @doc Register a callback
+%% @doc `add/3,4` add a new hook, returns 'already_exists' if the hook exists.
--spec add(hookpoint(), action() | callback()) -> ok_or_error(already_exists).
+-spec add(hookpoint(), action(), integer()) ->
-add(HookPoint, Callback) when is_record(Callback, callback) ->
-    gen_server:call(?SERVER, {add, HookPoint, Callback}, infinity);
-add(HookPoint, Action) when is_function(Action); is_tuple(Action) ->
-    add(HookPoint, #callback{action = Action, priority = 0}).
-
--spec add(hookpoint(), action(), filter() | integer() | list()) ->
     ok_or_error(already_exists).
-add(HookPoint, Action, {_M, _F, _A} = Filter) ->
-    add(HookPoint, #callback{action = Action, filter = Filter, priority = 0});
 add(HookPoint, Action, Priority) when is_integer(Priority) ->
-    add(HookPoint, #callback{action = Action, priority = Priority}).
+    do_add(HookPoint, #callback{action = Action, priority = Priority}).
 
--spec add(hookpoint(), action(), filter(), integer()) ->
+-spec add(hookpoint(), action(), integer(), filter()) ->
     ok_or_error(already_exists).
-add(HookPoint, Action, Filter, Priority) when is_integer(Priority) ->
+add(HookPoint, Action, Priority, Filter) when is_integer(Priority) ->
-    add(HookPoint, #callback{action = Action, filter = Filter, priority = Priority}).
+    do_add(HookPoint, #callback{action = Action, filter = Filter, priority = Priority}).
 
-%% @doc Like add/2, it register a callback, discard 'already_exists' error.
+do_add(HookPoint, Callback) ->
--spec put(hookpoint(), action() | callback()) -> ok.
+    gen_server:call(?SERVER, {add, HookPoint, Callback}, infinity).
-put(HookPoint, Callback) when is_record(Callback, callback) ->
+
-    case add(HookPoint, Callback) of
+%% @doc `put/3,4` updates the existing hook, add it if not exists.
+-spec put(hookpoint(), action(), integer()) -> ok.
+put(HookPoint, Action, Priority) when is_integer(Priority) ->
+    do_put(HookPoint, #callback{action = Action, priority = Priority}).
+
+-spec put(hookpoint(), action(), integer(), filter()) -> ok.
+put(HookPoint, Action, Priority, Filter) when is_integer(Priority) ->
+    do_put(HookPoint, #callback{action = Action, filter = Filter, priority = Priority}).
+
+do_put(HookPoint, Callback) ->
+    case do_add(HookPoint, Callback) of
         ok -> ok;
         {error, already_exists} -> gen_server:call(?SERVER, {put, HookPoint, Callback}, infinity)
-    end;
+    end.
-put(HookPoint, Action) when is_function(Action); is_tuple(Action) ->
-    ?MODULE:put(HookPoint, #callback{action = Action, priority = 0}).
-
--spec put(hookpoint(), action(), filter() | integer() | list()) -> ok.
-put(HookPoint, Action, {_M, _F, _A} = Filter) ->
-    ?MODULE:put(HookPoint, #callback{action = Action, filter = Filter, priority = 0});
-put(HookPoint, Action, Priority) when is_integer(Priority) ->
-    ?MODULE:put(HookPoint, #callback{action = Action, priority = Priority}).
-
--spec put(hookpoint(), action(), filter(), integer()) -> ok.
-put(HookPoint, Action, Filter, Priority) when is_integer(Priority) ->
-    ?MODULE:put(HookPoint, #callback{action = Action, filter = Filter, priority = Priority}).
 
 %% @doc Unregister a callback.
 -spec del(hookpoint(), action() | {module(), atom()}) -> ok.
@@ -296,7 +284,7 @@ insert_hook(HookPoint, Callbacks) ->
     ets:insert(?TAB, #hook{name = HookPoint, callbacks = Callbacks}),
     ok.
 update_hook(HookPoint, Callbacks) ->
-    Ms = ets:fun2ms(fun({hook, K, V}) when K =:= HookPoint -> {hook, K, Callbacks} end),
+    Ms = ets:fun2ms(fun({hook, K, _V}) when K =:= HookPoint -> {hook, K, Callbacks} end),
     ets:select_replace(emqx_hooks, Ms),
     ok.
 

apps/emqx/src/emqx_sys.erl

@@ -21,6 +21,7 @@
 -include("emqx.hrl").
 -include("types.hrl").
 -include("logger.hrl").
+-include("emqx_hooks.hrl").
 
 -export([
     start_link/0,
@@ -190,7 +191,7 @@ load_event_hooks(Events) ->
                 ok;
             ({K, true}) ->
                 {HookPoint, Fun} = hook_and_fun(K),
-                emqx_hooks:put(HookPoint, {?MODULE, Fun, []})
+                emqx_hooks:put(HookPoint, {?MODULE, Fun, []}, ?HP_SYS_MSGS)
         end,
         Events
     ).

apps/emqx/test/emqx_SUITE.erl

@@ -95,52 +95,54 @@ t_emqx_pubsub_api(_) ->
     ?assertEqual([], emqx:topics()).
 
 t_hook_unhook(_) ->
-    ok = emqx:hook(test_hook, {?MODULE, hook_fun1, []}),
+    ok = emqx_hooks:add(test_hook, {?MODULE, hook_fun1, []}, 0),
-    ok = emqx:hook(test_hook, {?MODULE, hook_fun2, []}),
+    ok = emqx_hooks:add(test_hook, {?MODULE, hook_fun2, []}, 0),
     ?assertEqual(
         {error, already_exists},
-        emqx:hook(test_hook, {?MODULE, hook_fun2, []})
+        emqx_hooks:add(test_hook, {?MODULE, hook_fun2, []}, 0)
     ),
-    ok = emqx:unhook(test_hook, {?MODULE, hook_fun1}),
+    ok = emqx_hooks:del(test_hook, {?MODULE, hook_fun1}),
-    ok = emqx:unhook(test_hook, {?MODULE, hook_fun2}),
+    ok = emqx_hooks:del(test_hook, {?MODULE, hook_fun2}),
 
-    ok = emqx:hook(emqx_hook, {?MODULE, hook_fun8, []}, 8),
+    ok = emqx_hooks:add(emqx_hook, {?MODULE, hook_fun8, []}, 8),
-    ok = emqx:hook(emqx_hook, {?MODULE, hook_fun2, []}, 2),
+    ok = emqx_hooks:add(emqx_hook, {?MODULE, hook_fun2, []}, 2),
-    ok = emqx:hook(emqx_hook, {?MODULE, hook_fun10, []}, 10),
+    ok = emqx_hooks:add(emqx_hook, {?MODULE, hook_fun10, []}, 10),
-    ok = emqx:hook(emqx_hook, {?MODULE, hook_fun9, []}, 9),
+    ok = emqx_hooks:add(emqx_hook, {?MODULE, hook_fun9, []}, 9),
-    ok = emqx:unhook(emqx_hook, {?MODULE, hook_fun2, []}),
+    ok = emqx_hooks:del(emqx_hook, {?MODULE, hook_fun2, []}),
-    ok = emqx:unhook(emqx_hook, {?MODULE, hook_fun8, []}),
+    ok = emqx_hooks:del(emqx_hook, {?MODULE, hook_fun8, []}),
-    ok = emqx:unhook(emqx_hook, {?MODULE, hook_fun9, []}),
+    ok = emqx_hooks:del(emqx_hook, {?MODULE, hook_fun9, []}),
-    ok = emqx:unhook(emqx_hook, {?MODULE, hook_fun10, []}).
+    ok = emqx_hooks:del(emqx_hook, {?MODULE, hook_fun10, []}).
 
 t_run_hook(_) ->
-    ok = emqx:hook(foldl_hook, {?MODULE, hook_fun3, [init]}),
+    ok = emqx_hooks:add(foldl_hook, {?MODULE, hook_fun3, [init]}, 0),
-    ok = emqx:hook(foldl_hook, {?MODULE, hook_fun4, [init]}),
+    ok = emqx_hooks:add(foldl_hook, {?MODULE, hook_fun4, [init]}, 0),
-    ok = emqx:hook(foldl_hook, {?MODULE, hook_fun5, [init]}),
+    ok = emqx_hooks:add(foldl_hook, {?MODULE, hook_fun5, [init]}, 0),
     [r5, r4] = emqx:run_fold_hook(foldl_hook, [arg1, arg2], []),
     [] = emqx:run_fold_hook(unknown_hook, [], []),
 
-    ok = emqx:hook(foldl_hook2, {?MODULE, hook_fun9, []}),
+    ok = emqx_hooks:add(foldl_hook2, {?MODULE, hook_fun9, []}, 0),
-    ok = emqx:hook(foldl_hook2, {?MODULE, hook_fun10, []}),
+    ok = emqx_hooks:add(foldl_hook2, {?MODULE, hook_fun10, []}, 0),
     [r10] = emqx:run_fold_hook(foldl_hook2, [arg], []),
 
-    ok = emqx:hook(foreach_hook, {?MODULE, hook_fun6, [initArg]}),
+    ok = emqx_hooks:add(foreach_hook, {?MODULE, hook_fun6, [initArg]}, 0),
-    {error, already_exists} = emqx:hook(foreach_hook, {?MODULE, hook_fun6, [initArg]}),
+    {error, already_exists} = emqx_hooks:add(foreach_hook, {?MODULE, hook_fun6, [initArg]}, 0),
-    ok = emqx:hook(foreach_hook, {?MODULE, hook_fun7, [initArg]}),
+    ok = emqx_hooks:add(foreach_hook, {?MODULE, hook_fun7, [initArg]}, 0),
-    ok = emqx:hook(foreach_hook, {?MODULE, hook_fun8, [initArg]}),
+    ok = emqx_hooks:add(foreach_hook, {?MODULE, hook_fun8, [initArg]}, 0),
     ok = emqx:run_hook(foreach_hook, [arg]),
 
-    ok = emqx:hook(foreach_filter1_hook, {?MODULE, hook_fun1, []}, {?MODULE, hook_filter1, []}, 0),
+    ok = emqx_hooks:add(
+        foreach_filter1_hook, {?MODULE, hook_fun1, []}, 0, {?MODULE, hook_filter1, []}
+    ),
     %% filter passed
     ?assertEqual(ok, emqx:run_hook(foreach_filter1_hook, [arg])),
     %% filter failed
     ?assertEqual(ok, emqx:run_hook(foreach_filter1_hook, [arg1])),
 
-    ok = emqx:hook(
+    ok = emqx_hooks:add(
-        foldl_filter2_hook, {?MODULE, hook_fun2, []}, {?MODULE, hook_filter2, [init_arg]}
+        foldl_filter2_hook, {?MODULE, hook_fun2, []}, 0, {?MODULE, hook_filter2, [init_arg]}
     ),
-    ok = emqx:hook(
+    ok = emqx_hooks:add(
-        foldl_filter2_hook, {?MODULE, hook_fun2_1, []}, {?MODULE, hook_filter2_1, [init_arg]}
+        foldl_filter2_hook, {?MODULE, hook_fun2_1, []}, 0, {?MODULE, hook_filter2_1, [init_arg]}
     ),
     ?assertEqual(3, emqx:run_fold_hook(foldl_filter2_hook, [arg], 1)),
     ?assertEqual(2, emqx:run_fold_hook(foldl_filter2_hook, [arg1], 1)).

apps/emqx/test/emqx_hooks_SUITE.erl

@@ -66,7 +66,7 @@ add_hook_order_prop() ->
         hooks(),
         try
             {ok, _} = emqx_hooks:start_link(),
-            [ok = emqx:hook(prop_hook, {M, F, []}, Prio) || {Prio, M, F} <- Hooks],
+            [ok = emqx_hooks:add(prop_hook, {M, F, []}, Prio) || {Prio, M, F} <- Hooks],
             Callbacks = emqx_hooks:lookup(prop_hook),
             Order = [{Prio, M, F} || {callback, {M, F, _}, _Filter, Prio} <- Callbacks],
             ?assertEqual(
@@ -93,11 +93,11 @@ hooks() ->
 
 t_add_put_del_hook(_) ->
     {ok, _} = emqx_hooks:start_link(),
-    ok = emqx:hook(test_hook, {?MODULE, hook_fun1, []}),
+    ok = emqx_hooks:add(test_hook, {?MODULE, hook_fun1, []}, 0),
-    ok = emqx:hook(test_hook, {?MODULE, hook_fun2, []}),
+    ok = emqx_hooks:add(test_hook, {?MODULE, hook_fun2, []}, 0),
     ?assertEqual(
         {error, already_exists},
-        emqx:hook(test_hook, {?MODULE, hook_fun2, []})
+        emqx_hooks:add(test_hook, {?MODULE, hook_fun2, []}, 0)
     ),
     Callbacks0 = [
         {callback, {?MODULE, hook_fun1, []}, undefined, 0},
@@ -105,23 +105,23 @@ t_add_put_del_hook(_) ->
     ],
     ?assertEqual(Callbacks0, emqx_hooks:lookup(test_hook)),
 
-    ok = emqx_hooks:put(test_hook, {?MODULE, hook_fun1, [test]}),
+    ok = emqx_hooks:put(test_hook, {?MODULE, hook_fun1, [test]}, 0),
-    ok = emqx_hooks:put(test_hook, {?MODULE, hook_fun2, [test]}),
+    ok = emqx_hooks:put(test_hook, {?MODULE, hook_fun2, [test]}, 0),
     Callbacks1 = [
         {callback, {?MODULE, hook_fun1, [test]}, undefined, 0},
         {callback, {?MODULE, hook_fun2, [test]}, undefined, 0}
     ],
     ?assertEqual(Callbacks1, emqx_hooks:lookup(test_hook)),
 
-    ok = emqx:unhook(test_hook, {?MODULE, hook_fun1}),
+    ok = emqx_hooks:del(test_hook, {?MODULE, hook_fun1}),
-    ok = emqx:unhook(test_hook, {?MODULE, hook_fun2}),
+    ok = emqx_hooks:del(test_hook, {?MODULE, hook_fun2}),
     timer:sleep(200),
     ?assertEqual([], emqx_hooks:lookup(test_hook)),
 
-    ok = emqx:hook(emqx_hook, {?MODULE, hook_fun8, []}, 8),
+    ok = emqx_hooks:add(emqx_hook, {?MODULE, hook_fun8, []}, 8),
-    ok = emqx:hook(emqx_hook, {?MODULE, hook_fun2, []}, 2),
+    ok = emqx_hooks:add(emqx_hook, {?MODULE, hook_fun2, []}, 2),
-    ok = emqx:hook(emqx_hook, {?MODULE, hook_fun10, []}, 10),
+    ok = emqx_hooks:add(emqx_hook, {?MODULE, hook_fun10, []}, 10),
-    ok = emqx:hook(emqx_hook, {?MODULE, hook_fun9, []}, 9),
+    ok = emqx_hooks:add(emqx_hook, {?MODULE, hook_fun9, []}, 9),
     Callbacks2 = [
         {callback, {?MODULE, hook_fun10, []}, undefined, 10},
         {callback, {?MODULE, hook_fun9, []}, undefined, 9},
@@ -142,43 +142,45 @@ t_add_put_del_hook(_) ->
     ],
     ?assertEqual(Callbacks3, emqx_hooks:lookup(emqx_hook)),
 
-    ok = emqx:unhook(emqx_hook, {?MODULE, hook_fun2, [test]}),
+    ok = emqx_hooks:del(emqx_hook, {?MODULE, hook_fun2, [test]}),
-    ok = emqx:unhook(emqx_hook, {?MODULE, hook_fun8, [test]}),
+    ok = emqx_hooks:del(emqx_hook, {?MODULE, hook_fun8, [test]}),
-    ok = emqx:unhook(emqx_hook, {?MODULE, hook_fun9, [test]}),
+    ok = emqx_hooks:del(emqx_hook, {?MODULE, hook_fun9, [test]}),
-    ok = emqx:unhook(emqx_hook, {?MODULE, hook_fun10, [test]}),
+    ok = emqx_hooks:del(emqx_hook, {?MODULE, hook_fun10, [test]}),
     timer:sleep(200),
     ?assertEqual([], emqx_hooks:lookup(emqx_hook)).
 
 t_run_hooks(_) ->
     {ok, _} = emqx_hooks:start_link(),
-    ok = emqx:hook(foldl_hook, {?MODULE, hook_fun3, [init]}),
+    ok = emqx_hooks:add(foldl_hook, {?MODULE, hook_fun3, [init]}, 0),
-    ok = emqx:hook(foldl_hook, {?MODULE, hook_fun4, [init]}),
+    ok = emqx_hooks:add(foldl_hook, {?MODULE, hook_fun4, [init]}, 0),
-    ok = emqx:hook(foldl_hook, {?MODULE, hook_fun5, [init]}),
+    ok = emqx_hooks:add(foldl_hook, {?MODULE, hook_fun5, [init]}, 0),
     [r5, r4] = emqx:run_fold_hook(foldl_hook, [arg1, arg2], []),
     [] = emqx:run_fold_hook(unknown_hook, [], []),
 
-    ok = emqx:hook(foldl_hook2, {?MODULE, hook_fun9, []}),
+    ok = emqx_hooks:add(foldl_hook2, {?MODULE, hook_fun9, []}, 0),
-    ok = emqx:hook(foldl_hook2, {?MODULE, hook_fun10, []}),
+    ok = emqx_hooks:add(foldl_hook2, {?MODULE, hook_fun10, []}, 0),
     %% Note: 10 is _less_ than 9 per lexicographic order
     [r10] = emqx:run_fold_hook(foldl_hook2, [arg], []),
 
-    ok = emqx:hook(foreach_hook, {?MODULE, hook_fun6, [initArg]}),
+    ok = emqx_hooks:add(foreach_hook, {?MODULE, hook_fun6, [initArg]}, 0),
-    {error, already_exists} = emqx:hook(foreach_hook, {?MODULE, hook_fun6, [initArg]}),
+    {error, already_exists} = emqx_hooks:add(foreach_hook, {?MODULE, hook_fun6, [initArg]}, 0),
-    ok = emqx:hook(foreach_hook, {?MODULE, hook_fun7, [initArg]}),
+    ok = emqx_hooks:add(foreach_hook, {?MODULE, hook_fun7, [initArg]}, 0),
-    ok = emqx:hook(foreach_hook, {?MODULE, hook_fun8, [initArg]}),
+    ok = emqx_hooks:add(foreach_hook, {?MODULE, hook_fun8, [initArg]}, 0),
     ok = emqx:run_hook(foreach_hook, [arg]),
 
-    ok = emqx:hook(foreach_filter1_hook, {?MODULE, hook_fun1, []}, {?MODULE, hook_filter1, []}, 0),
+    ok = emqx_hooks:add(
+        foreach_filter1_hook, {?MODULE, hook_fun1, []}, 0, {?MODULE, hook_filter1, []}
+    ),
     %% filter passed
     ?assertEqual(ok, emqx:run_hook(foreach_filter1_hook, [arg])),
     %% filter failed
     ?assertEqual(ok, emqx:run_hook(foreach_filter1_hook, [arg1])),
 
-    ok = emqx:hook(
+    ok = emqx_hooks:add(
-        foldl_filter2_hook, {?MODULE, hook_fun2, []}, {?MODULE, hook_filter2, [init_arg]}
+        foldl_filter2_hook, {?MODULE, hook_fun2, []}, 0, {?MODULE, hook_filter2, [init_arg]}
     ),
-    ok = emqx:hook(
+    ok = emqx_hooks:add(
-        foldl_filter2_hook, {?MODULE, hook_fun2_1, []}, {?MODULE, hook_filter2_1, [init_arg]}
+        foldl_filter2_hook, {?MODULE, hook_fun2_1, []}, 0, {?MODULE, hook_filter2_1, [init_arg]}
     ),
     ?assertEqual(3, emqx:run_fold_hook(foldl_filter2_hook, [arg], 1)),
     ?assertEqual(2, emqx:run_fold_hook(foldl_filter2_hook, [arg1], 1)).

apps/emqx/test/props/prop_emqx_sys.erl

@@ -114,7 +114,7 @@ do_mock(mria_mnesia) ->
 do_mock(emqx_metrics) ->
     meck:expect(emqx_metrics, all, fun() -> [{hello, 3}] end);
 do_mock(emqx_hooks) ->
-    meck:expect(emqx_hooks, put, fun(_HookPoint, _MFA) -> ok end),
+    meck:expect(emqx_hooks, put, fun(_HookPoint, _MFA, _) -> ok end),
     meck:expect(emqx_hooks, del, fun(_HookPoint, _MF) -> ok end);
 do_mock(emqx_config_handler) ->
     meck:expect(emqx_config_handler, add_handler, fun(_, _) -> ok end).

apps/emqx_authz/src/emqx_authz.erl

@@ -19,6 +19,7 @@
 
 -include("emqx_authz.hrl").
 -include_lib("emqx/include/logger.hrl").
+-include_lib("emqx/include/emqx_hooks.hrl").
 
 -ifdef(TEST).
 -compile(export_all).
@@ -100,7 +101,7 @@ init() ->
     Sources = emqx_conf:get(?CONF_KEY_PATH, []),
     ok = check_dup_types(Sources),
     NSources = create_sources(Sources),
-    ok = emqx_hooks:add('client.authorize', {?MODULE, authorize, [NSources]}, -1).
+    ok = emqx_hooks:put('client.authorize', {?MODULE, authorize, [NSources]}, ?HP_AUTHZ).
 
 deinit() ->
     ok = emqx_hooks:del('client.authorize', {?MODULE, authorize}),
@@ -501,7 +502,7 @@ get_source_by_type(Type, Sources) ->
 
 %% @doc put hook with (maybe) initialized new source and old sources
 update_authz_chain(Actions) ->
-    emqx_hooks:put('client.authorize', {?MODULE, authorize, [Actions]}, -1).
+    emqx_hooks:put('client.authorize', {?MODULE, authorize, [Actions]}, ?HP_AUTHZ).
 
 check_acl_file_rules(RawRules) ->
     %% TODO: make sure the bin rules checked

apps/emqx_auto_subscribe/src/emqx_auto_subscribe.erl

@@ -16,6 +16,8 @@
 
 -module(emqx_auto_subscribe).
 
+-include_lib("emqx/include/emqx_hooks.hrl").
+
 -define(HOOK_POINT, 'client.connected').
 
 -define(MAX_AUTO_SUBSCRIBE, 20).
@@ -114,5 +116,7 @@ update_hook() ->
 
 update_hook(Config) ->
     {TopicHandler, Options} = emqx_auto_subscribe_handler:init(Config),
-    emqx_hooks:put(?HOOK_POINT, {?MODULE, on_client_connected, [{TopicHandler, Options}]}),
+    emqx_hooks:put(
+        ?HOOK_POINT, {?MODULE, on_client_connected, [{TopicHandler, Options}]}, ?HP_AUTO_SUB
+    ),
     ok.

apps/emqx_bridge/src/emqx_bridge.erl

@@ -17,6 +17,7 @@
 -behaviour(emqx_config_handler).
 -include_lib("emqx/include/emqx.hrl").
 -include_lib("emqx/include/logger.hrl").
+-include_lib("emqx/include/emqx_hooks.hrl").
 -include_lib("snabbkaffe/include/snabbkaffe.hrl").
 
 -export([post_config_update/5]).
@@ -105,7 +106,7 @@ load_hook(Bridges) ->
 
 do_load_hook(#{local_topic := _} = Conf) ->
     case maps:get(direction, Conf, egress) of
-        egress -> emqx_hooks:put('message.publish', {?MODULE, on_message_publish, []});
+        egress -> emqx_hooks:put('message.publish', {?MODULE, on_message_publish, []}, ?HP_BRIDGE);
         ingress -> ok
     end;
 do_load_hook(_Conf) ->

apps/emqx_exhook/src/emqx_exhook_mgr.erl

@@ -317,7 +317,7 @@ code_change(_OldVsn, State, _Extra) ->
 
 unload_exhooks() ->
     [
-        emqx:unhook(Name, {M, F})
+        emqx_hooks:del(Name, {M, F})
      || {Name, {M, F, _A}} <- ?ENABLED_HOOKS
     ].
 

apps/emqx_exhook/src/emqx_exhook_server.erl

@@ -18,6 +18,7 @@
 
 -include("emqx_exhook.hrl").
 -include_lib("emqx/include/logger.hrl").
+-include_lib("emqx/include/emqx_hooks.hrl").
 
 %% The exhook proto version should be fixed as `v2` in EMQX v5.x
 %% to make sure the exhook proto version is compatible
@@ -255,7 +256,7 @@ ensure_hooks(HookSpecs) ->
                 false ->
                     ?SLOG(error, #{msg => "skipped_unknown_hookpoint", hookpoint => Hookpoint});
                 {Hookpoint, {M, F, A}} ->
-                    emqx_hooks:put(Hookpoint, {M, F, A}),
+                    emqx_hooks:put(Hookpoint, {M, F, A}, ?HP_EXHOOK),
                     ets:update_counter(?HOOKS_REF_COUNTER, Hookpoint, {2, 1}, {Hookpoint, 0})
             end
         end,

apps/emqx_gateway/test/emqx_coap_SUITE.erl

@@ -330,8 +330,8 @@ t_clients_get_subscription_api(_) ->
 
 t_on_offline_event(_) ->
     Fun = fun(Channel) ->
-        emqx_hooks:add('client.connected', {emqx_sys, on_client_connected, []}),
+        emqx_hooks:add('client.connected', {emqx_sys, on_client_connected, []}, 1000),
-        emqx_hooks:add('client.disconnected', {emqx_sys, on_client_disconnected, []}),
+        emqx_hooks:add('client.disconnected', {emqx_sys, on_client_disconnected, []}, 1000),
 
         ConnectedSub = <<"$SYS/brokers/+/gateway/coap/clients/+/connected">>,
         emqx_broker:subscribe(ConnectedSub),

apps/emqx_gateway/test/emqx_exproto_SUITE.erl

@@ -19,6 +19,8 @@
 -compile(export_all).
 -compile(nowarn_export_all).
 
+-include_lib("emqx/include/emqx_hooks.hrl").
+
 -import(
     emqx_exproto_echo_svr,
     [
@@ -262,8 +264,8 @@ t_hook_connected_disconnected(Cfg) ->
     ConnAckBin = frame_connack(0),
 
     Parent = self(),
-    emqx:hook('client.connected', {?MODULE, hook_fun1, [Parent]}),
+    emqx_hooks:add('client.connected', {?MODULE, hook_fun1, [Parent]}, 1000),
-    emqx:hook('client.disconnected', {?MODULE, hook_fun2, [Parent]}),
+    emqx_hooks:add('client.disconnected', {?MODULE, hook_fun2, [Parent]}, 1000),
 
     send(Sock, ConnBin),
     {ok, ConnAckBin} = recv(Sock, 5000),
@@ -287,8 +289,8 @@ t_hook_connected_disconnected(Cfg) ->
         begin
             {error, closed} = recv(Sock, 5000)
         end,
-    emqx:unhook('client.connected', {?MODULE, hook_fun1}),
+    emqx_hooks:del('client.connected', {?MODULE, hook_fun1}),
-    emqx:unhook('client.disconnected', {?MODULE, hook_fun2}).
+    emqx_hooks:del('client.disconnected', {?MODULE, hook_fun2}).
 
 t_hook_session_subscribed_unsubscribed(Cfg) ->
     SockType = proplists:get_value(listener_type, Cfg),
@@ -308,8 +310,8 @@ t_hook_session_subscribed_unsubscribed(Cfg) ->
     {ok, ConnAckBin} = recv(Sock, 5000),
 
     Parent = self(),
-    emqx:hook('session.subscribed', {?MODULE, hook_fun3, [Parent]}),
+    emqx_hooks:add('session.subscribed', {?MODULE, hook_fun3, [Parent]}, 1000),
-    emqx:hook('session.unsubscribed', {?MODULE, hook_fun4, [Parent]}),
+    emqx_hooks:add('session.unsubscribed', {?MODULE, hook_fun4, [Parent]}, 1000),
 
     SubBin = frame_subscribe(<<"t/#">>, 1),
     SubAckBin = frame_suback(0),
@@ -336,8 +338,8 @@ t_hook_session_subscribed_unsubscribed(Cfg) ->
     end,
 
     close(Sock),
-    emqx:unhook('session.subscribed', {?MODULE, hook_fun3}),
+    emqx_hooks:del('session.subscribed', {?MODULE, hook_fun3}),
-    emqx:unhook('session.unsubscribed', {?MODULE, hook_fun4}).
+    emqx_hooks:del('session.unsubscribed', {?MODULE, hook_fun4}).
 
 t_hook_message_delivered(Cfg) ->
     SockType = proplists:get_value(listener_type, Cfg),
@@ -362,14 +364,14 @@ t_hook_message_delivered(Cfg) ->
     send(Sock, SubBin),
     {ok, SubAckBin} = recv(Sock, 5000),
 
-    emqx:hook('message.delivered', {?MODULE, hook_fun5, []}),
+    emqx_hooks:add('message.delivered', {?MODULE, hook_fun5, []}, 1000),
 
     emqx:publish(emqx_message:make(<<"t/dn">>, <<"1">>)),
     PubBin1 = frame_publish(<<"t/dn">>, 0, <<"2">>),
     {ok, PubBin1} = recv(Sock, 5000),
 
     close(Sock),
-    emqx:unhook('message.delivered', {?MODULE, hook_fun5}).
+    emqx_hooks:del('message.delivered', {?MODULE, hook_fun5}).
 
 %%--------------------------------------------------------------------
 %% Utils

apps/emqx_modules/src/emqx_delayed.erl

@@ -22,6 +22,7 @@
 -include_lib("emqx/include/types.hrl").
 -include_lib("emqx/include/logger.hrl").
 -include_lib("snabbkaffe/include/snabbkaffe.hrl").
+-include_lib("emqx/include/emqx_hooks.hrl").
 
 %% Mnesia bootstrap
 -export([mnesia/1]).
@@ -379,7 +380,7 @@ do_publish(Key = {Ts, _Id}, Now, Acc) when Ts =< Now ->
 delayed_count() -> mnesia:table_info(?TAB, size).
 
 do_load_or_unload(true, State) ->
-    emqx_hooks:put('message.publish', {?MODULE, on_message_publish, []}),
+    emqx_hooks:put('message.publish', {?MODULE, on_message_publish, []}, ?HP_DELAY_PUB),
     State;
 do_load_or_unload(false, #{publish_timer := PubTimer} = State) ->
     emqx_hooks:del('message.publish', {?MODULE, on_message_publish}),

apps/emqx_modules/src/emqx_rewrite.erl

@@ -19,6 +19,7 @@
 -include_lib("emqx/include/emqx.hrl").
 -include_lib("emqx/include/logger.hrl").
 -include_lib("emqx/include/emqx_mqtt.hrl").
+-include_lib("emqx/include/emqx_hooks.hrl").
 
 -ifdef(TEST).
 -export([
@@ -76,9 +77,9 @@ register_hook([]) ->
     unregister_hook();
 register_hook(Rules) ->
     {PubRules, SubRules, ErrRules} = compile(Rules),
-    emqx_hooks:put('client.subscribe', {?MODULE, rewrite_subscribe, [SubRules]}),
+    emqx_hooks:put('client.subscribe', {?MODULE, rewrite_subscribe, [SubRules]}, ?HP_REWRITE),
-    emqx_hooks:put('client.unsubscribe', {?MODULE, rewrite_unsubscribe, [SubRules]}),
+    emqx_hooks:put('client.unsubscribe', {?MODULE, rewrite_unsubscribe, [SubRules]}, ?HP_REWRITE),
-    emqx_hooks:put('message.publish', {?MODULE, rewrite_publish, [PubRules]}),
+    emqx_hooks:put('message.publish', {?MODULE, rewrite_publish, [PubRules]}, ?HP_REWRITE),
     case ErrRules of
         [] ->
             ok;

apps/emqx_modules/src/emqx_topic_metrics.erl

@@ -22,6 +22,7 @@
 -include_lib("emqx/include/logger.hrl").
 -include_lib("emqx/include/emqx_mqtt.hrl").
 -include_lib("snabbkaffe/include/snabbkaffe.hrl").
+-include_lib("emqx/include/emqx_hooks.hrl").
 
 -export([
     on_message_publish/1,
@@ -106,9 +107,9 @@ max_limit() ->
     ?MAX_TOPICS.
 
 enable() ->
-    emqx_hooks:put('message.publish', {?MODULE, on_message_publish, []}),
+    emqx_hooks:put('message.publish', {?MODULE, on_message_publish, []}, ?HP_TOPIC_METRICS),
-    emqx_hooks:put('message.dropped', {?MODULE, on_message_dropped, []}),
+    emqx_hooks:put('message.dropped', {?MODULE, on_message_dropped, []}, ?HP_TOPIC_METRICS),
-    emqx_hooks:put('message.delivered', {?MODULE, on_message_delivered, []}).
+    emqx_hooks:put('message.delivered', {?MODULE, on_message_delivered, []}, ?HP_TOPIC_METRICS).
 
 disable() ->
     emqx_hooks:del('message.publish', {?MODULE, on_message_publish}),

apps/emqx_modules/test/emqx_delayed_SUITE.erl

@@ -65,6 +65,7 @@ end_per_testcase(_Case, _Config) ->
 
 t_enable_disable_case(_) ->
     emqx_delayed:unload(),
+    timer:sleep(100),
     Hooks = emqx_hooks:lookup('message.publish'),
     MFA = {emqx_delayed, on_message_publish, []},
     ?assertEqual(false, lists:keyfind(MFA, 2, Hooks)),
@@ -81,6 +82,7 @@ t_enable_disable_case(_) ->
     ?assertMatch(#{data := Datas} when Datas =/= [], emqx_delayed:list(#{})),
 
     emqx_delayed:unload(),
+    timer:sleep(100),
     ?assertEqual(false, lists:keyfind(MFA, 2, Hooks)),
     ?assertMatch(#{data := []}, emqx_delayed:list(#{})),
     ok.
@@ -188,6 +190,7 @@ t_unknown_messages(_) ->
     ).
 
 t_get_basic_usage_info(_Config) ->
+    emqx:update_config([delayed, max_delayed_messages], 10000),
     ?assertEqual(#{delayed_message_count => 0}, emqx_delayed:get_basic_usage_info()),
     lists:foreach(
         fun(N) ->

apps/emqx_plugins/test/emqx_plugins_SUITE.erl

@@ -22,7 +22,7 @@
 -include_lib("emqx/include/emqx.hrl").
 -include_lib("eunit/include/eunit.hrl").
 
--define(EMQX_PLUGIN_TEMPLATE_VSN, "5.0-rc.1").
+-define(EMQX_PLUGIN_TEMPLATE_VSN, "5.0.0-rc.3").
 -define(EMQX_ELIXIR_PLUGIN_TEMPLATE_VSN, "0.1.0").
 -define(PACKAGE_SUFFIX, ".tar.gz").
 

apps/emqx_psk/src/emqx_psk.erl

@@ -19,6 +19,7 @@
 -behaviour(gen_server).
 
 -include_lib("emqx/include/logger.hrl").
+-include_lib("emqx/include/emqx_hooks.hrl").
 
 -export([
     load/0,
@@ -85,10 +86,10 @@ mnesia(boot) ->
 %%------------------------------------------------------------------------------
 
 load() ->
-    emqx:hook('tls_handshake.psk_lookup', {?MODULE, on_psk_lookup, []}).
+    ok = emqx_hooks:put('tls_handshake.psk_lookup', {?MODULE, on_psk_lookup, []}, ?HP_PSK).
 
 unload() ->
-    emqx:unhook('tls_handshake.psk_lookup', {?MODULE, on_psk_lookup}).
+    ok = emqx_hooks:del('tls_handshake.psk_lookup', {?MODULE, on_psk_lookup}).
 
 on_psk_lookup(PSKIdentity, _UserState) ->
     case mnesia:dirty_read(?TAB, PSKIdentity) of

apps/emqx_retainer/src/emqx_retainer.erl

@@ -20,6 +20,7 @@
 
 -include("emqx_retainer.hrl").
 -include_lib("emqx/include/logger.hrl").
+-include_lib("emqx/include/emqx_hooks.hrl").
 
 -export([start_link/0]).
 
@@ -428,13 +429,15 @@ close_resource(_) ->
 
 -spec load(context()) -> ok.
 load(Context) ->
-    _ = emqx:hook('session.subscribed', {?MODULE, on_session_subscribed, [Context]}),
+    ok = emqx_hooks:put(
-    _ = emqx:hook('message.publish', {?MODULE, on_message_publish, [Context]}),
+        'session.subscribed', {?MODULE, on_session_subscribed, [Context]}, ?HP_RETAINER
+    ),
+    ok = emqx_hooks:put('message.publish', {?MODULE, on_message_publish, [Context]}, ?HP_RETAINER),
     emqx_stats:update_interval(emqx_retainer_stats, fun ?MODULE:stats_fun/0),
     ok.
 
 unload() ->
-    emqx:unhook('message.publish', {?MODULE, on_message_publish}),
+    ok = emqx_hooks:del('message.publish', {?MODULE, on_message_publish}),
-    emqx:unhook('session.subscribed', {?MODULE, on_session_subscribed}),
+    ok = emqx_hooks:del('session.subscribed', {?MODULE, on_session_subscribed}),
     emqx_stats:cancel_update(emqx_retainer_stats),
     ok.

apps/emqx_rule_engine/src/emqx_rule_events.erl

@@ -19,6 +19,7 @@
 -include("rule_engine.hrl").
 -include_lib("emqx/include/emqx.hrl").
 -include_lib("emqx/include/logger.hrl").
+-include_lib("emqx/include/emqx_hooks.hrl").
 
 -export([
     reload/0,
@@ -87,7 +88,9 @@ reload() ->
 
 load(Topic) ->
     HookPoint = event_name(Topic),
-    emqx_hooks:put(HookPoint, {?MODULE, hook_fun(HookPoint), [#{event_topic => Topic}]}).
+    emqx_hooks:put(
+        HookPoint, {?MODULE, hook_fun(HookPoint), [#{event_topic => Topic}]}, ?HP_RULE_ENGINE
+    ).
 
 unload() ->
     lists:foreach(

apps/emqx_slow_subs/src/emqx_slow_subs.erl

@@ -21,6 +21,7 @@
 -include_lib("emqx/include/emqx.hrl").
 -include_lib("emqx/include/logger.hrl").
 -include_lib("emqx_slow_subs/include/emqx_slow_subs.hrl").
+-include_lib("emqx/include/emqx_hooks.hrl").
 
 -export([
     start_link/0,
@@ -212,7 +213,7 @@ load(State) ->
         threshold := Threshold
     } = emqx:get_config([slow_subs]),
     MaxSize = erlang:min(MaxSizeT, ?MAX_SIZE),
-    _ = emqx:hook(
+    ok = emqx_hooks:put(
         'delivery.completed',
         {?MODULE, on_delivery_completed, [
             #{
@@ -220,14 +221,15 @@ load(State) ->
                 stats_type => StatsType,
                 threshold => Threshold
             }
-        ]}
+        ]},
+        ?HP_SLOW_SUB
     ),
 
     State1 = start_timer(expire_timer, fun expire_tick/0, State),
     State1#{enable := true, last_tick_at => ?NOW}.
 
 unload(#{expire_timer := ExpireTimer} = State) ->
-    emqx:unhook('delivery.completed', {?MODULE, on_delivery_completed}),
+    emqx_hooks:del('delivery.completed', {?MODULE, on_delivery_completed}),
     State#{
         enable := false,
         expire_timer := cancel_timer(ExpireTimer)

lib-ee/emqx_license/src/emqx_license.erl

@@ -27,6 +27,11 @@
 
 -define(CONF_KEY_PATH, [license]).
 
+%% Give the license app the highest priority.
+%% We don't define it in the emqx_hooks.hrl becasue that is an opensource code
+%% and can be changed by the communitiy.
+-define(HP_LICENSE, 2000).
+
 %%------------------------------------------------------------------------------
 %% API
 %%------------------------------------------------------------------------------
@@ -114,7 +119,7 @@ post_config_update(_Path, _Cmd, NewConf, _Old, _AppEnvs) ->
 %%------------------------------------------------------------------------------
 
 add_license_hook() ->
-    ok = emqx_hooks:put('client.connect', {?MODULE, check, []}).
+    ok = emqx_hooks:put('client.connect', {?MODULE, check, []}, ?HP_LICENSE).
 
 del_license_hook() ->
     _ = emqx_hooks:del('client.connect', {?MODULE, check, []}),