From 29b62ab563d1965c6df418c7387b7145b1648c06 Mon Sep 17 00:00:00 2001 From: Siri Hansen Date: Tue, 10 Oct 2017 10:14:59 +0200 Subject: [supervisor] Store children in map instead of list --- lib/stdlib/src/supervisor.erl | 586 ++++++++++++++++++++++++------------------ 1 file changed, 330 insertions(+), 256 deletions(-) (limited to 'lib/stdlib/src/supervisor.erl') diff --git a/lib/stdlib/src/supervisor.erl b/lib/stdlib/src/supervisor.erl index b8d98691a3..e56415650f 100644 --- a/lib/stdlib/src/supervisor.erl +++ b/lib/stdlib/src/supervisor.erl @@ -56,7 +56,7 @@ | {'global', Name :: atom()} | {'via', Module :: module(), Name :: any()} | pid(). --type child_spec() :: #{id := child_id(), % mandatory +-type child_spec() :: #{id := child_id(), % mandatory start := mfargs(), % mandatory restart => restart(), % optional shutdown => shutdown(), % optional @@ -78,6 +78,7 @@ | {RestartStrategy :: strategy(), Intensity :: non_neg_integer(), Period :: pos_integer()}. +-type children() :: {Ids :: [child_id()], Db :: #{child_id() => child_rec()}}. %%-------------------------------------------------------------------------- %% Defaults @@ -105,7 +106,7 @@ -record(state, {name, strategy :: strategy() | 'undefined', - children = [] :: [child_rec()], + children = {[],#{}} :: children(), % Ids in start order dynamics :: {'maps', #{pid() => list()}} | {'sets', sets:set(pid())} | 'undefined', @@ -320,31 +321,30 @@ init_dynamic(_State, StartSpec) -> %%----------------------------------------------------------------- %% Func: start_children/2 -%% Args: Children = [child_rec()] in start order +%% Args: Children = children() % Ids in start order %% SupName = {local, atom()} | {global, atom()} | {pid(), Mod} -%% Purpose: Start all children. The new list contains #child's +%% Purpose: Start all children. The new map contains #child's %% with pids. %% Returns: {ok, NChildren} | {error, NChildren, Reason} -%% NChildren = [child_rec()] in termination order (reversed -%% start order) +%% NChildren = children() % Ids in termination order +%% (reversed start order) %%----------------------------------------------------------------- -start_children(Children, SupName) -> start_children(Children, [], SupName). - -start_children([Child|Chs], NChildren, SupName) -> - case do_start_child(SupName, Child) of - {ok, undefined} when ?is_temporary(Child) -> - start_children(Chs, NChildren, SupName); - {ok, Pid} -> - start_children(Chs, [Child#child{pid = Pid}|NChildren], SupName); - {ok, Pid, _Extra} -> - start_children(Chs, [Child#child{pid = Pid}|NChildren], SupName); - {error, Reason} -> - report_error(start_error, Reason, Child, SupName), - {error, lists:reverse(Chs) ++ [Child | NChildren], - {failed_to_start_child,Child#child.id,Reason}} - end; -start_children([], NChildren, _SupName) -> - {ok, NChildren}. +start_children(Children, SupName) -> + Start = + fun(Id,Child) -> + case do_start_child(SupName, Child) of + {ok, undefined} when ?is_temporary(Child) -> + remove; + {ok, Pid} -> + {update,Child#child{pid = Pid}}; + {ok, Pid, _Extra} -> + {update,Child#child{pid = Pid}}; + {error, Reason} -> + report_error(start_error, Reason, Child, SupName), + {abort,{failed_to_start_child,Id,Reason}} + end + end, + children_map(Start,Children). do_start_child(SupName, Child) -> #child{mfargs = {M, F, Args}} = Child, @@ -384,7 +384,7 @@ do_start_child_i(M, F, A) -> -spec handle_call(call(), term(), state()) -> {'reply', term(), state()}. handle_call({start_child, EArgs}, _From, State) when ?is_simple(State) -> - Child = hd(State#state.children), + Child = get_dynamic_child(State), #child{mfargs = {M, F, A}} = Child, Args = A ++ EArgs, case do_start_child_i(M, F, Args) of @@ -415,15 +415,11 @@ handle_call({terminate_child, Id}, _From, State) when not is_pid(Id), {reply, {error, simple_one_for_one}, State}; handle_call({terminate_child, Id}, _From, State) -> - case get_child(Id, State, ?is_simple(State)) of - {value, Child} -> - case do_terminate(Child, State#state.name) of - NChild when ?is_temporary(NChild); ?is_simple(State) -> - {reply, ok, state_del_child(Child, State)}; - NChild -> - {reply, ok, replace_child(NChild, State)} - end; - false -> + case find_child(Id, State) of + {ok, Child} -> + do_terminate(Child, State#state.name), + {reply, ok, del_child(Child, State)}; + error -> {reply, {error, not_found}, State} end; @@ -432,21 +428,21 @@ handle_call({restart_child, _Id}, _From, State) when ?is_simple(State) -> {reply, {error, simple_one_for_one}, State}; handle_call({restart_child, Id}, _From, State) -> - case get_child(Id, State) of - {value, Child} when Child#child.pid =:= undefined -> + case find_child(Id, State) of + {ok, Child} when Child#child.pid =:= undefined -> case do_start_child(State#state.name, Child) of {ok, Pid} -> - NState = replace_child(Child#child{pid = Pid}, State), + NState = set_pid(Pid, Id, State), {reply, {ok, Pid}, NState}; {ok, Pid, Extra} -> - NState = replace_child(Child#child{pid = Pid}, State), + NState = set_pid(Pid, Id, State), {reply, {ok, Pid, Extra}, NState}; Error -> {reply, Error, State} end; - {value, #child{pid=?restarting(_)}} -> + {ok, #child{pid=?restarting(_)}} -> {reply, {error, restarting}, State}; - {value, _} -> + {ok, _} -> {reply, {error, running}, State}; _ -> {reply, {error, not_found}, State} @@ -457,29 +453,28 @@ handle_call({delete_child, _Id}, _From, State) when ?is_simple(State) -> {reply, {error, simple_one_for_one}, State}; handle_call({delete_child, Id}, _From, State) -> - case get_child(Id, State) of - {value, Child} when Child#child.pid =:= undefined -> - NState = remove_child(Child, State), + case find_child(Id, State) of + {ok, Child} when Child#child.pid =:= undefined -> + NState = remove_child(Id, State), {reply, ok, NState}; - {value, #child{pid=?restarting(_)}} -> + {ok, #child{pid=?restarting(_)}} -> {reply, {error, restarting}, State}; - {value, _} -> + {ok, _} -> {reply, {error, running}, State}; _ -> {reply, {error, not_found}, State} end; handle_call({get_childspec, Id}, _From, State) -> - case get_child(Id, State, ?is_simple(State)) of - {value, Child} -> + case find_child(Id, State) of + {ok, Child} -> {reply, {ok, child_to_spec(Child)}, State}; - false -> + error -> {reply, {error, not_found}, State} end; -handle_call(which_children, _From, #state{children = [#child{child_type = CT, - modules = Mods}]} = - State) when ?is_simple(State) -> +handle_call(which_children, _From, State) when ?is_simple(State) -> + #child{child_type = CT,modules = Mods} = get_dynamic_child(State), Reply = dyn_map(fun(?restarting(_)) -> {undefined, restarting, CT, Mods}; (Pid) -> {undefined, Pid, CT, Mods} end, State), @@ -487,20 +482,20 @@ handle_call(which_children, _From, #state{children = [#child{child_type = CT, handle_call(which_children, _From, State) -> Resp = - lists:map(fun(#child{pid = ?restarting(_), id = Id, - child_type = ChildType, modules = Mods}) -> - {Id, restarting, ChildType, Mods}; - (#child{pid = Pid, id = Id, - child_type = ChildType, modules = Mods}) -> - {Id, Pid, ChildType, Mods} - end, - State#state.children), + children_to_list( + fun(Id,#child{pid = ?restarting(_), + child_type = ChildType, modules = Mods}) -> + {Id, restarting, ChildType, Mods}; + (Id,#child{pid = Pid, + child_type = ChildType, modules = Mods}) -> + {Id, Pid, ChildType, Mods} + end, + State#state.children), {reply, Resp, State}; - -handle_call(count_children, _From, #state{dynamic_restarts = Restarts, - children = [#child{child_type = CT}]} = State) +handle_call(count_children, _From, #state{dynamic_restarts = Restarts} = State) when ?is_simple(State) -> + #child{child_type = CT} = get_dynamic_child(State), Sz = dyn_size(State), Active = Sz - Restarts, % Restarts is always 0 for temporary children Reply = case CT of @@ -514,16 +509,15 @@ handle_call(count_children, _From, #state{dynamic_restarts = Restarts, handle_call(count_children, _From, State) -> %% Specs and children are together on the children list... {Specs, Active, Supers, Workers} = - lists:foldl(fun(Child, Counts) -> - count_child(Child, Counts) - end, {0,0,0,0}, State#state.children), + children_fold(fun(_Id, Child, Counts) -> + count_child(Child, Counts) + end, {0,0,0,0}, State#state.children), %% Reformat counts to a property list. Reply = [{specs, Specs}, {active, Active}, {supervisors, Supers}, {workers, Workers}], {reply, Reply, State}. - count_child(#child{pid = Pid, child_type = worker}, {Specs, Active, Supers, Workers}) -> case is_pid(Pid) andalso is_process_alive(Pid) of @@ -537,16 +531,15 @@ count_child(#child{pid = Pid, child_type = supervisor}, false -> {Specs+1, Active, Supers+1, Workers} end. - %%% If a restart attempt failed, this message is cast %%% from restart/2 in order to give gen_server the chance to %%% check it's inbox before trying again. --spec handle_cast({try_again_restart, child_id() | pid()}, state()) -> +-spec handle_cast({try_again_restart, child_id() | {'restarting',pid()}}, state()) -> {'noreply', state()} | {stop, shutdown, state()}. handle_cast({try_again_restart,TryAgainId}, State) -> - case get_child_and_args(TryAgainId, State) of - Child = #child{pid=?restarting(_)} -> + case find_child_and_args(TryAgainId, State) of + {ok, Child = #child{pid=?restarting(_)}} -> case restart(Child,State) of {ok, State1} -> {noreply, State1}; @@ -557,7 +550,6 @@ handle_cast({try_again_restart,TryAgainId}, State) -> {noreply,State} end. - %% %% Take care of terminated children. %% @@ -618,8 +610,8 @@ code_change(_, State, _) -> update_childspec(State, StartSpec) when ?is_simple(State) -> case check_startspec(StartSpec) of - {ok, [Child]} -> - {ok, State#state{children = [Child]}}; + {ok, {[_],_}=Children} -> + {ok, State#state{children = Children}}; Error -> {error, Error} end; @@ -633,37 +625,34 @@ update_childspec(State, StartSpec) -> {error, Error} end. -update_childspec1([Child|OldC], Children, KeepOld) -> - case update_chsp(Child, Children) of - {ok,NewChildren} -> - update_childspec1(OldC, NewChildren, KeepOld); +update_childspec1({[Id|OldIds], OldDb}, {Ids,Db}, KeepOld) -> + case update_chsp(maps:get(Id,OldDb), Db) of + {ok,NewDb} -> + update_childspec1({OldIds,OldDb}, {Ids,NewDb}, KeepOld); false -> - update_childspec1(OldC, Children, [Child|KeepOld]) + update_childspec1({OldIds,OldDb}, {Ids,Db}, [Id|KeepOld]) end; -update_childspec1([], Children, KeepOld) -> +update_childspec1({[],OldDb}, {Ids,Db}, KeepOld) -> + KeepOldDb = maps:with(KeepOld,OldDb), %% Return them in (kept) reverse start order. - lists:reverse(Children ++ KeepOld). - -update_chsp(OldCh, Children) -> - case lists:map(fun(Ch) when OldCh#child.id =:= Ch#child.id -> - Ch#child{pid = OldCh#child.pid}; - (Ch) -> - Ch - end, - Children) of - Children -> - false; % OldCh not found in new spec. - NewC -> - {ok, NewC} + {lists:reverse(Ids ++ KeepOld),maps:merge(KeepOldDb,Db)}. + +update_chsp(#child{id=Id}=OldChild, NewDb) -> + case maps:find(Id, NewDb) of + {ok,Child} -> + {ok,NewDb#{Id => Child#child{pid = OldChild#child.pid}}}; + error -> % Id not found in new spec. + false end. + %%% --------------------------------------------------- %%% Start a new child. %%% --------------------------------------------------- handle_start_child(Child, State) -> - case get_child(Child#child.id, State) of - false -> + case find_child(Child#child.id, State) of + error -> case do_start_child(State#state.name, Child) of {ok, undefined} when ?is_temporary(Child) -> {{ok, undefined}, State}; @@ -674,9 +663,9 @@ handle_start_child(Child, State) -> {error, What} -> {{error, {What, Child}}, State} end; - {value, OldChild} when is_pid(OldChild#child.pid) -> + {ok, OldChild} when is_pid(OldChild#child.pid) -> {{error, {already_started, OldChild#child.pid}}, State}; - {value, _OldChild} -> + {ok, _OldChild} -> {{error, already_present}, State} end. @@ -686,10 +675,10 @@ handle_start_child(Child, State) -> %%% --------------------------------------------------- restart_child(Pid, Reason, State) -> - case get_child_and_args(Pid, State) of - #child{} = Child -> + case find_child_and_args(Pid, State) of + {ok, Child} -> do_restart(Reason, Child, State); - false -> + error -> {ok, State} end. @@ -697,33 +686,33 @@ do_restart(Reason, Child, State) when ?is_permanent(Child) -> report_error(child_terminated, Reason, Child, State#state.name), restart(Child, State); do_restart(normal, Child, State) -> - NState = state_del_child(Child, State), + NState = del_child(Child, State), {ok, NState}; do_restart(shutdown, Child, State) -> - NState = state_del_child(Child, State), + NState = del_child(Child, State), {ok, NState}; do_restart({shutdown, _Term}, Child, State) -> - NState = state_del_child(Child, State), + NState = del_child(Child, State), {ok, NState}; do_restart(Reason, Child, State) when ?is_transient(Child) -> report_error(child_terminated, Reason, Child, State#state.name), restart(Child, State); do_restart(Reason, Child, State) when ?is_temporary(Child) -> report_error(child_terminated, Reason, Child, State#state.name), - NState = state_del_child(Child, State), + NState = del_child(Child, State), {ok, NState}. restart(Child, State) -> case add_restart(State) of {ok, NState} -> case restart(NState#state.strategy, Child, NState) of - {try_again, NState2, TryAgainId} -> + {{try_again, TryAgainId}, NState2} -> %% Leaving control back to gen_server before %% trying again. This way other incoming requsts %% for the supervisor can be handled - e.g. a %% shutdown request for the supervisor or the %% child. - gen_server:cast(self(), {try_again_restart, TryAgainId}), + try_again_restart(TryAgainId), {ok,NState2}; Other -> Other @@ -731,7 +720,7 @@ restart(Child, State) -> {terminate, NState} -> report_error(shutdown, reached_max_restart_intensity, Child, State#state.name), - {shutdown, state_del_child(Child, NState)} + {shutdown, del_child(Child, NState)} end. restart(simple_one_for_one, Child, State0) -> @@ -757,82 +746,72 @@ restart(simple_one_for_one, Child, State0) -> State3 = State2#state{dynamic_restarts = NRestarts}, NState = dyn_store(ROldPid, A, State3), report_error(start_error, Error, Child, NState#state.name), - {try_again, NState, ROldPid} + {{try_again, ROldPid}, NState} end; -restart(one_for_one, Child, State) -> +restart(one_for_one, #child{id=Id} = Child, State) -> OldPid = Child#child.pid, case do_start_child(State#state.name, Child) of {ok, Pid} -> - NState = replace_child(Child#child{pid = Pid}, State), + NState = set_pid(Pid, Id, State), {ok, NState}; {ok, Pid, _Extra} -> - NState = replace_child(Child#child{pid = Pid}, State), + NState = set_pid(Pid, Id, State), {ok, NState}; {error, Reason} -> - NState = replace_child(Child#child{pid = restarting(OldPid)}, State), + NState = set_pid(restarting(OldPid), Id, State), report_error(start_error, Reason, Child, State#state.name), - {try_again, NState, Child#child.id} - end; -restart(rest_for_one, Child, State) -> - {ChAfter, ChBefore} = split_child(Child#child.id, State#state.children), - ChAfter2 = terminate_children(ChAfter, State#state.name), - case start_children(ChAfter2, State#state.name) of - {ok, ChAfter3} -> - {ok, State#state{children = ChAfter3 ++ ChBefore}}; - {error, ChAfter3, {failed_to_start_child, FailedId, _Reason}} - when FailedId =:= Child#child.id -> - NChild = Child#child{pid=restarting(Child#child.pid)}, - NState = State#state{children = ChAfter3 ++ ChBefore}, - {try_again, replace_child(NChild,NState), FailedId}; - {error, ChAfter3, {failed_to_start_child, FailedId, _Reason}} -> - NChild = lists:keyfind(FailedId, #child.id, ChAfter3), - NChild2 = NChild#child{pid=?restarting(undefined)}, - NState = State#state{children = ChAfter3 ++ ChBefore}, - {try_again, replace_child(NChild2,NState), FailedId} + {{try_again,Id}, NState} end; -restart(one_for_all, Child, State) -> +restart(rest_for_one, #child{id=Id} = Child, #state{name=SupName} = State) -> + {ChAfter, ChBefore} = split_child(Id, State#state.children), + {Return, ChAfter2} = restart_multiple_children(Child, ChAfter, SupName), + {Return, State#state{children = append(ChAfter2,ChBefore)}}; +restart(one_for_all, Child, #state{name=SupName} = State) -> Children1 = del_child(Child#child.id, State#state.children), - Children2 = terminate_children(Children1, State#state.name), - case start_children(Children2, State#state.name) of - {ok, NChs} -> - {ok, State#state{children = NChs}}; - {error, NChs, {failed_to_start_child, FailedId, _Reason}} - when FailedId =:= Child#child.id -> - NChild = Child#child{pid=restarting(Child#child.pid)}, - NState = State#state{children = NChs}, - {try_again, replace_child(NChild,NState), FailedId}; - {error, NChs, {failed_to_start_child, FailedId, _Reason}} -> - NChild = lists:keyfind(FailedId, #child.id, NChs), - NChild2 = NChild#child{pid=?restarting(undefined)}, - NState = State#state{children = NChs}, - {try_again, replace_child(NChild2,NState), FailedId} + {Return, NChildren} = restart_multiple_children(Child, Children1, SupName), + {Return, State#state{children = NChildren}}. + +restart_multiple_children(Child, Children, SupName) -> + Children1 = terminate_children(Children, SupName), + case start_children(Children1, SupName) of + {ok, NChildren} -> + {ok, NChildren}; + {error, NChildren, {failed_to_start_child, FailedId, _Reason}} -> + NewPid = if FailedId =:= Child#child.id -> + restarting(Child#child.pid); + true -> + ?restarting(undefined) + end, + {{try_again, FailedId}, set_pid(NewPid,FailedId,NChildren)} end. restarting(Pid) when is_pid(Pid) -> ?restarting(Pid); restarting(RPid) -> RPid. +-spec try_again_restart(child_id() | {'restarting',pid()}) -> 'ok'. +try_again_restart(TryAgainId) -> + gen_server:cast(self(), {try_again_restart, TryAgainId}). + %%----------------------------------------------------------------- %% Func: terminate_children/2 -%% Args: Children = [child_rec()] in termination order +%% Args: Children = children() % Ids in termination order %% SupName = {local, atom()} | {global, atom()} | {pid(),Mod} -%% Returns: NChildren = [child_rec()] in -%% startup order (reversed termination order) +%% Returns: NChildren = children() % Ids in startup order +%% % (reversed termination order) %%----------------------------------------------------------------- terminate_children(Children, SupName) -> - terminate_children(Children, SupName, []). - -%% Temporary children should not be restarted and thus should -%% be skipped when building the list of terminated children, although -%% we do want them to be shut down as many functions from this module -%% use this function to just clear everything. -terminate_children([Child | Children], SupName, Res) when ?is_temporary(Child) -> - _ = do_terminate(Child, SupName), - terminate_children(Children, SupName, Res); -terminate_children([Child | Children], SupName, Res) -> - NChild = do_terminate(Child, SupName), - terminate_children(Children, SupName, [NChild | Res]); -terminate_children([], _SupName, Res) -> - Res. + Terminate = + fun(_Id,Child) when ?is_temporary(Child) -> + %% Temporary children should not be restarted and thus should + %% be skipped when building the list of terminated children. + do_terminate(Child, SupName), + remove; + (_Id,Child) -> + do_terminate(Child, SupName), + {update,Child#child{pid=undefined}} + end, + {ok,NChildren} = children_map(Terminate, Children), + NChildren. do_terminate(Child, SupName) when is_pid(Child#child.pid) -> case shutdown(Child#child.pid, Child#child.shutdown) of @@ -843,9 +822,9 @@ do_terminate(Child, SupName) when is_pid(Child#child.pid) -> {error, OtherReason} -> report_error(shutdown_error, OtherReason, Child, SupName) end, - Child#child{pid = undefined}; -do_terminate(Child, _SupName) -> - Child#child{pid = undefined}. + ok; +do_terminate(_Child, _SupName) -> + ok. %%----------------------------------------------------------------- %% Shutdowns a child. We must check the EXIT value @@ -918,7 +897,6 @@ monitor_child(Pid) -> ok end. - %%----------------------------------------------------------------- %% Func: terminate_dynamic_children/1 %% Args: State @@ -926,9 +904,10 @@ monitor_child(Pid) -> %% %% Shutdown all dynamic children. This happens when the supervisor is %% stopped. Because the supervisor can have millions of dynamic children, we -%% can have an significative overhead here. +%% can have a significative overhead here. %%----------------------------------------------------------------- -terminate_dynamic_children(#state{children=[Child]} = State) -> +terminate_dynamic_children(State) -> + Child = get_dynamic_child(State), {Pids, EStack0} = monitor_dynamic_children(Child,State), Sz = sets:size(Pids), EStack = case Child#child.shutdown of @@ -963,7 +942,6 @@ monitor_dynamic_children(Child,State) -> {Pids, EStack} end, {sets:new(), dict:new()}, State). - wait_dynamic_children(_Child, _Pids, 0, undefined, EStack) -> EStack; wait_dynamic_children(_Child, _Pids, 0, TRef, EStack) -> @@ -1011,7 +989,7 @@ wait_dynamic_children(Child, Pids, Sz, TRef, EStack) -> end. %%----------------------------------------------------------------- -%% Child/State manipulating functions. +%% Access #state.children %%----------------------------------------------------------------- %% Note we do not want to save the parameter list for temporary processes as @@ -1019,90 +997,184 @@ wait_dynamic_children(Child, Pids, Sz, TRef, EStack) -> %% Especially for dynamic children to simple_one_for_one supervisors %% it could become very costly as it is not uncommon to spawn %% very many such processes. -save_child(#child{mfargs = {M, F, _}} = Child, #state{children = Children} = State) when ?is_temporary(Child) -> - State#state{children = [Child#child{mfargs = {M, F, undefined}} |Children]}; -save_child(Child, #state{children = Children} = State) -> - State#state{children = [Child |Children]}. - -state_del_child(#child{pid = Pid}, State) when ?is_simple(State) -> +-spec save_child(child_rec(), state()) -> state(). +save_child(#child{mfargs = {M, F, _}} = Child, State) when ?is_temporary(Child) -> + do_save_child(Child#child{mfargs = {M, F, undefined}}, State); +save_child(Child, State) -> + do_save_child(Child, State). + +-spec do_save_child(child_rec(), state()) -> state(). +do_save_child(#child{id = Id} = Child, #state{children = {Ids,Db}} = State) -> + State#state{children = {[Id|Ids],Db#{Id => Child}}}. + +-spec del_child(child_rec(), state()) -> state(); + (child_id(), children()) -> children(). +del_child(#child{pid = Pid}, State) when ?is_simple(State) -> dyn_erase(Pid,State); -state_del_child(Child, State) -> +del_child(Child, State) when is_record(Child,child), is_record(State,state) -> NChildren = del_child(Child#child.id, State#state.children), - State#state{children = NChildren}. - -del_child(Id, [Ch|Chs]) when Ch#child.id =:= Id, ?is_temporary(Ch) -> - Chs; -del_child(Id, [Ch|Chs]) when Ch#child.id =:= Id -> - [Ch#child{pid = undefined} | Chs]; -del_child(Id, [Ch|Chs]) -> - [Ch|del_child(Id, Chs)]; -del_child(_, []) -> - []. - -%% Chs = [S4, S3, Ch, S1, S0] -%% Ret: {[S4, S3, Ch], [S1, S0]} -split_child(Id, Chs) -> - split_child(Id, Chs, []). - -split_child(Id, [Ch|Chs], After) when Ch#child.id =:= Id -> - {lists:reverse([Ch#child{pid = undefined} | After]), Chs}; -split_child(Id, [Ch|Chs], After) -> - split_child(Id, Chs, [Ch | After]); -split_child(_, [], After) -> - {lists:reverse(After), []}. - -get_child(Id, State) -> - get_child(Id, State, false). - -get_child(Pid, State, AllowPid) when AllowPid, is_pid(Pid) -> - get_dynamic_child(Pid, State); -get_child(Id, State, _) -> - lists:keysearch(Id, #child.id, State#state.children). + State#state{children = NChildren}; +del_child(Id, {Ids,Db}) -> + case maps:get(Id, Db) of + Child when Child#child.restart_type =:= temporary -> + {lists:delete(Id, Ids), maps:remove(Id, Db)}; + Child -> + {Ids, Db#{Id=>Child#child{pid=undefined}}} + end. -get_dynamic_child(Pid, #state{children=[Child]} = State) -> - case dyn_exists(Pid, State) of - true -> - {value, Child#child{pid=Pid}}; - false -> - RPid = restarting(Pid), - case dyn_exists(RPid, State) of - true -> - {value, Child#child{pid=RPid}}; - false -> +%% In: {[S4, S3, Ch, S1, S0],Db} +%% Ret: {{[S4, S3, Ch],Db1}, {[S1, S0],Db2}} +%% Db1 and Db2 contain the keys in the lists they are associated with. +-spec split_child(child_id(), children()) -> {children(), children()}. +split_child(Id, {Ids,Db}) -> + {IdsAfter,IdsBefore} = split_ids(Id, Ids, []), + DbBefore = maps:with(IdsBefore,Db), + #{Id:=Ch} = DbAfter = maps:with(IdsAfter,Db), + {{IdsAfter,DbAfter#{Id=>Ch#child{pid=undefined}}},{IdsBefore,DbBefore}}. + +split_ids(Id, [Id|Ids], After) -> + {lists:reverse([Id|After]), Ids}; +split_ids(Id, [Other|Ids], After) -> + split_ids(Id, Ids, [Other | After]). + +%% Find the child record for a given Pid (dynamic child) or Id +%% (non-dynamic child). This is called from the API functions. +-spec find_child(pid() | child_id(), state()) -> {ok,child_rec()} | error. +find_child(Pid, State) when is_pid(Pid), ?is_simple(State) -> + case find_dynamic_child(Pid, State) of + error -> + case find_dynamic_child(restarting(Pid), State) of + error -> case erlang:is_process_alive(Pid) of - true -> false; - false -> {value, Child} - end - end + true -> error; + false -> {ok, get_dynamic_child(State)} + end; + Other -> + Other + end; + Other -> + Other + end; +find_child(Id, #state{children = {_Ids,Db}}) -> + maps:find(Id, Db). + +%% Get the child record - either by child id or by pid. If +%% simple_one_for_one, then insert the pid and args into the returned +%% child record. This is called when trying to restart the child. +-spec find_child_and_args(IdOrPid, state()) -> {ok, child_rec()} | error when + IdOrPid :: pid() | {restarting,pid()} | child_id(). +find_child_and_args(Pid, State) when ?is_simple(State) -> + case find_dynamic_child(Pid, State) of + {ok,#child{mfargs={M,F,_}} = Child} -> + {ok, Args} = dyn_args(Pid, State), + {ok, Child#child{mfargs = {M, F, Args}}}; + error -> + error + end; +find_child_and_args(Pid, State) when is_pid(Pid) -> + find_child_by_pid(Pid, State); +find_child_and_args(Id, #state{children={_Ids,Db}}) -> + maps:find(Id, Db). + +%% Given the pid, find the child record for a dynamic child, and +%% include the pid in the returned record. +-spec find_dynamic_child(IdOrPid, state()) -> {ok, child_rec()} | error when + IdOrPid :: pid() | {restarting,pid()} | child_id(). +find_dynamic_child(Pid, State) -> + case dyn_exists(Pid, State) of + true -> + Child = get_dynamic_child(State), + {ok, Child#child{pid=Pid}}; + false -> + error end. -replace_child(Child, State) -> - Chs = do_replace_child(Child, State#state.children), - State#state{children = Chs}. - -do_replace_child(Child, [Ch|Chs]) when Ch#child.id =:= Child#child.id -> - [Child | Chs]; -do_replace_child(Child, [Ch|Chs]) -> - [Ch|do_replace_child(Child, Chs)]. - -remove_child(Child, State) -> - Chs = lists:keydelete(Child#child.id, #child.id, State#state.children), - State#state{children = Chs}. +%% Given the pid, find the child record for a non-dyanamic child. +-spec find_child_by_pid(IdOrPid, state()) -> {ok,child_rec()} | error when + IdOrPid :: pid() | {restarting,pid()}. +find_child_by_pid(Pid,#state{children={_Ids,Db}}) -> + Fun = fun(_Id,#child{pid=P}=Ch,_) when P =:= Pid -> + throw(Ch); + (_,_,error) -> + error + end, + try maps:fold(Fun,error,Db) + catch throw:Child -> {ok,Child} + end. -get_child_and_args(Pid, #state{children=[Child]}=State) when ?is_simple(State) -> - case dyn_args(Pid, State) of - {ok, Args} -> - {M, F, _} = Child#child.mfargs, - Child#child{pid = Pid, mfargs = {M, F, Args}}; - error -> - false +%% Get the child record from a simple_one_for_one supervisor - no pid +%% It is assumed that the child can always be found +-spec get_dynamic_child(state()) -> child_rec(). +get_dynamic_child(#state{children={[Id],Db}}) -> + #{Id := Child} = Db, + Child. + +%% Update pid in the given child record and store it in the process state +-spec set_pid(term(), child_id(), state()) -> state(); + (term(), child_id(), children()) -> children(). +set_pid(Pid, Id, #state{children=Children} = State) -> + State#state{children = set_pid(Pid, Id, Children)}; +set_pid(Pid, Id, {Ids, Db}) -> + NewDb = maps:update_with(Id, fun(Child) -> Child#child{pid=Pid} end, Db), + {Ids,NewDb}. + +%% Remove the Id and the child record from the process state +-spec remove_child(child_id(), state()) -> state(). +remove_child(Id, #state{children={Ids,Db}} = State) -> + NewIds = lists:delete(Id,Ids), + NewDb = maps:remove(Id,Db), + State#state{children = {NewIds,NewDb}}. + +%% In the order of Ids, traverse the children and update each child +%% according to the return value of the Fun. +%% On error, abort and return the merge of the old and the updated map. +%% NOTE: The returned list of Ids is reverted compared to the input. +-spec children_map(Fun, children()) -> {ok, children()} | + {error,children(),Reason} when + Fun :: fun((child_id(),child_rec()) -> {update,child_rec()} | + remove | + {abort, Reason}), + Reason :: term(). +children_map(Fun,{Ids,Db}) -> + children_map(Fun, Ids, Db, []). + +children_map(Fun,[Id|Ids],Db,Acc) -> + case Fun(Id,maps:get(Id,Db)) of + {update,Child} -> + children_map(Fun,Ids,Db#{Id => Child},[Id|Acc]); + remove -> + children_map(Fun,Ids,maps:remove(Id,Db),Acc); + {abort,Reason} -> + {error,{lists:reverse(Ids)++[Id|Acc],Db},Reason} end; -get_child_and_args(Pid, State) when is_pid(Pid) -> - lists:keyfind(Pid, #child.pid, State#state.children); -get_child_and_args(?restarting(Pid)=RPid, State) when is_pid(Pid) -> - lists:keyfind(RPid, #child.pid, State#state.children); -get_child_and_args(Id, State) -> - lists:keyfind(Id, #child.id, State#state.children). +children_map(_Fun,[],Db,Acc) -> + {ok,{Acc,Db}}. + +%% In the order of Ids, map over all children and return the list +-spec children_to_list(Fun, children()) -> List when + Fun :: fun((child_id(), child_rec()) -> Elem), + List :: list(Elem), + Elem :: term(). +children_to_list(Fun,{Ids,Db}) -> + children_to_list(Fun, Ids, Db, []). +children_to_list(Fun,[Id|Ids],Db,Acc) -> + children_to_list(Fun,Ids,Db,[Fun(Id,maps:get(Id,Db))|Acc]); +children_to_list(_Fun,[],_Db,Acc) -> + lists:reverse(Acc). + +%% The order is not important - so ignore Ids +-spec children_fold(Fun, Acc0, children()) -> Acc1 when + Fun :: fun((child_id(), child_rec(), AccIn) -> AccOut), + Acc0 :: term(), + Acc1 :: term(), + AccIn :: term(), + AccOut :: term(). +children_fold(Fun,Init,{_Ids,Db}) -> + maps:fold(Fun, Init, Db). + +-spec append(children(), children()) -> children(). +append({Ids1,Db1},{Ids2,Db2}) -> + {Ids1++Ids2,maps:merge(Db1,Db2)}. %%----------------------------------------------------------------- %% Func: init_state/4 @@ -1172,22 +1244,22 @@ supname(N, _) -> N. %%% Returns: {ok, [child_rec()]} | Error %%% ------------------------------------------------------ -check_startspec(Children) -> check_startspec(Children, []). +check_startspec(Children) -> check_startspec(Children, [], #{}). -check_startspec([ChildSpec|T], Res) -> +check_startspec([ChildSpec|T], Ids, Db) -> case check_childspec(ChildSpec) of - {ok, Child} -> - case lists:keymember(Child#child.id, #child.id, Res) of + {ok, #child{id=Id}=Child} -> + case maps:is_key(Id, Db) of %% The error message duplicate_child_name is kept for %% backwards compatibility, although %% duplicate_child_id would be more correct. - true -> {duplicate_child_name, Child#child.id}; - false -> check_startspec(T, [Child | Res]) + true -> {duplicate_child_name, Id}; + false -> check_startspec(T, [Id | Ids], Db#{Id=>Child}) end; Error -> Error end; -check_startspec([], Res) -> - {ok, lists:reverse(Res)}. +check_startspec([], Ids, Db) -> + {ok, {lists:reverse(Ids),Db}}. check_childspec(ChildSpec) when is_map(ChildSpec) -> catch do_check_childspec(maps:merge(?default_child_spec,ChildSpec)); @@ -1321,7 +1393,6 @@ report_error(Error, Reason, Child, SupName) -> {offender, extract_child(Child)}], error_logger:error_report(supervisor_report, ErrorMsg). - extract_child(Child) when is_list(Child#child.pid) -> [{nb_children, length(Child#child.pid)}, {id, Child#child.id}, @@ -1383,7 +1454,10 @@ dyn_args(_Pid, #state{dynamics={sets, _Db}}) -> dyn_args(Pid, #state{dynamics={maps, Db}}) -> maps:find(Pid, Db). -dyn_init(#state{children=[Child]}=State) when ?is_temporary(Child) -> - State#state{dynamics = {sets,sets:new()}}; dyn_init(State) -> - State#state{dynamics = {maps,#{}}}. + dyn_init(get_dynamic_child(State),State). + +dyn_init(Child,State) when ?is_temporary(Child) -> + State#state{dynamics={sets,sets:new()}}; +dyn_init(_Child,State) -> + State#state{dynamics={maps,maps:new()}}. -- cgit v1.2.3