From cc5a470ee25f7db55b586f4908e7e6b9057cafea Mon Sep 17 00:00:00 2001 From: Hans Bolinder Date: Wed, 30 Sep 2015 16:15:26 +0200 Subject: stdlib: Refactor the supervisor module's state The field 'dynamics' in #state{} is a union of two opaque types, which is possibly problematic. Tagging the types should make the code safe for warnings from future versions of Dialyzer. --- lib/stdlib/src/supervisor.erl | 66 +++++++++++++++++++++++-------------------- 1 file changed, 35 insertions(+), 31 deletions(-) (limited to 'lib/stdlib/src') diff --git a/lib/stdlib/src/supervisor.erl b/lib/stdlib/src/supervisor.erl index 142aaa8688..23f3aaee1f 100644 --- a/lib/stdlib/src/supervisor.erl +++ b/lib/stdlib/src/supervisor.erl @@ -109,7 +109,9 @@ -record(state, {name, strategy :: strategy() | 'undefined', children = [] :: [child_rec()], - dynamics :: ?DICT(pid(), list()) | ?SET(pid()) | 'undefined', + dynamics :: {'dict', ?DICT(pid(), list())} + | {'set', ?SET(pid())} + | 'undefined', intensity :: non_neg_integer() | 'undefined', period :: pos_integer() | 'undefined', restarts = [], @@ -577,7 +579,7 @@ handle_cast({try_again_restart,Pid}, #state{children=[Child]}=State) when ?is_simple(State) -> RT = Child#child.restart_type, RPid = restarting(Pid), - case dynamic_child_args(RPid, dynamics_db(RT, State#state.dynamics)) of + case dynamic_child_args(RPid, RT, State#state.dynamics) of {ok, Args} -> {M, F, _} = Child#child.mfargs, NChild = Child#child{pid = RPid, mfargs = {M, F, Args}}, @@ -735,7 +737,7 @@ handle_start_child(Child, State) -> restart_child(Pid, Reason, #state{children = [Child]} = State) when ?is_simple(State) -> RestartType = Child#child.restart_type, - case dynamic_child_args(Pid, dynamics_db(RestartType, State#state.dynamics)) of + case dynamic_child_args(Pid, RestartType, State#state.dynamics) of {ok, Args} -> {M, F, _} = Child#child.mfargs, NChild = Child#child{pid = Pid, mfargs = {M, F, Args}}, @@ -812,14 +814,16 @@ restart(simple_one_for_one, Child, State) -> State#state.dynamics)), case do_start_child_i(M, F, A) of {ok, Pid} -> - NState = State#state{dynamics = ?DICTS:store(Pid, A, Dynamics)}, + DynamicsDb = {dict, ?DICTS:store(Pid, A, Dynamics)}, + NState = State#state{dynamics = DynamicsDb}, {ok, NState}; {ok, Pid, _Extra} -> - NState = State#state{dynamics = ?DICTS:store(Pid, A, Dynamics)}, + DynamicsDb = {dict, ?DICTS:store(Pid, A, Dynamics)}, + NState = State#state{dynamics = DynamicsDb}, {ok, NState}; {error, Error} -> - NState = State#state{dynamics = ?DICTS:store(restarting(OldPid), A, - Dynamics)}, + DynamicsDb = {dict, ?DICTS:store(restarting(OldPid), A, Dynamics)}, + NState = State#state{dynamics = DynamicsDb}, report_error(start_error, Error, Child, State#state.name), {try_again, NState} end; @@ -1102,31 +1106,32 @@ save_child(Child, #state{children = Children} = State) -> State#state{children = [Child |Children]}. save_dynamic_child(temporary, Pid, _, #state{dynamics = Dynamics} = State) -> - State#state{dynamics = ?SETS:add_element(Pid, dynamics_db(temporary, Dynamics))}; + DynamicsDb = dynamics_db(temporary, Dynamics), + State#state{dynamics = {set, ?SETS:add_element(Pid, DynamicsDb)}}; save_dynamic_child(RestartType, Pid, Args, #state{dynamics = Dynamics} = State) -> - State#state{dynamics = ?DICTS:store(Pid, Args, dynamics_db(RestartType, Dynamics))}. + DynamicsDb = dynamics_db(RestartType, Dynamics), + State#state{dynamics = {dict, ?DICTS:store(Pid, Args, DynamicsDb)}}. dynamics_db(temporary, undefined) -> ?SETS:new(); dynamics_db(_, undefined) -> ?DICTS:new(); -dynamics_db(_,Dynamics) -> - Dynamics. - -dynamic_child_args(Pid, Dynamics) -> - case ?SETS:is_set(Dynamics) of - true -> - {ok, undefined}; - false -> - ?DICTS:find(Pid, Dynamics) - end. +dynamics_db(_, {_Tag, DynamicsDb}) -> + DynamicsDb. + +dynamic_child_args(_Pid, temporary, _DynamicsDb) -> + {ok, undefined}; +dynamic_child_args(Pid, _RT, {dict, DynamicsDb}) -> + ?DICTS:find(Pid, DynamicsDb); +dynamic_child_args(_Pid, _RT, undefined) -> + error. state_del_child(#child{pid = Pid, restart_type = temporary}, State) when ?is_simple(State) -> NDynamics = ?SETS:del_element(Pid, dynamics_db(temporary, State#state.dynamics)), - State#state{dynamics = NDynamics}; + State#state{dynamics = {set, NDynamics}}; state_del_child(#child{pid = Pid, restart_type = RType}, State) when ?is_simple(State) -> NDynamics = ?DICTS:erase(Pid, dynamics_db(RType, State#state.dynamics)), - State#state{dynamics = NDynamics}; + State#state{dynamics = {dict, NDynamics}}; state_del_child(Child, State) -> NChildren = del_child(Child#child.name, State#state.children), State#state{children = NChildren}. @@ -1160,19 +1165,19 @@ split_child(_, [], After) -> get_child(Name, State) -> get_child(Name, State, false). + get_child(Pid, State, AllowPid) when AllowPid, is_pid(Pid) -> get_dynamic_child(Pid, State); get_child(Name, State, _) -> lists:keysearch(Name, #child.name, State#state.children). get_dynamic_child(Pid, #state{children=[Child], dynamics=Dynamics}) -> - DynamicsDb = dynamics_db(Child#child.restart_type, Dynamics), - case is_dynamic_pid(Pid, DynamicsDb) of + case is_dynamic_pid(Pid, Dynamics) of true -> {value, Child#child{pid=Pid}}; false -> RPid = restarting(Pid), - case is_dynamic_pid(RPid, DynamicsDb) of + case is_dynamic_pid(RPid, Dynamics) of true -> {value, Child#child{pid=RPid}}; false -> @@ -1183,13 +1188,12 @@ get_dynamic_child(Pid, #state{children=[Child], dynamics=Dynamics}) -> end end. -is_dynamic_pid(Pid, Dynamics) -> - case ?SETS:is_set(Dynamics) of - true -> - ?SETS:is_element(Pid, Dynamics); - false -> - ?DICTS:is_key(Pid, Dynamics) - end. +is_dynamic_pid(Pid, {dict, Dynamics}) -> + ?DICTS:is_key(Pid, Dynamics); +is_dynamic_pid(Pid, {set, Dynamics}) -> + ?SETS:is_element(Pid, Dynamics); +is_dynamic_pid(_Pid, undefined) -> + false. replace_child(Child, State) -> Chs = do_replace_child(Child, State#state.children), -- cgit v1.2.3