diff options
Diffstat (limited to 'lib/stdlib/src/gen_server.erl')
| -rw-r--r-- | lib/stdlib/src/gen_server.erl | 358 |
1 files changed, 169 insertions, 189 deletions
diff --git a/lib/stdlib/src/gen_server.erl b/lib/stdlib/src/gen_server.erl index 202a931fae..5800aca66f 100644 --- a/lib/stdlib/src/gen_server.erl +++ b/lib/stdlib/src/gen_server.erl @@ -1,18 +1,19 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 1996-2013. All Rights Reserved. +%% Copyright Ericsson AB 1996-2016. All Rights Reserved. %% -%% The contents of this file are subject to the Erlang Public License, -%% Version 1.1, (the "License"); you may not use this file except in -%% compliance with the License. You should have received a copy of the -%% Erlang Public License along with this software. If not, it can be -%% retrieved online at http://www.erlang.org/. +%% 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 %% -%% 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. +%% 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. %% %% %CopyrightEnd% %% @@ -88,6 +89,7 @@ %% API -export([start/3, start/4, start_link/3, start_link/4, + stop/1, stop/3, call/2, call/3, cast/2, reply/2, abcast/2, abcast/3, @@ -137,6 +139,15 @@ -callback code_change(OldVsn :: (term() | {down, term()}), State :: term(), Extra :: term()) -> {ok, NewState :: term()} | {error, Reason :: term()}. +-callback format_status(Opt, StatusData) -> Status when + Opt :: 'normal' | 'terminate', + StatusData :: [PDict | State], + PDict :: [{Key :: term(), Value :: term()}], + State :: term(), + Status :: term(). + +-optional_callbacks([format_status/2]). + %%% ----------------------------------------------------------------- %%% Starts a generic server. @@ -168,6 +179,17 @@ start_link(Name, Mod, Args, Options) -> %% ----------------------------------------------------------------- +%% Stop a generic server and wait for it to terminate. +%% If the server is located at another node, that node will +%% be monitored. +%% ----------------------------------------------------------------- +stop(Name) -> + gen:stop(Name). + +stop(Name, Reason, Timeout) -> + gen:stop(Name, Reason, Timeout). + +%% ----------------------------------------------------------------- %% Make a call to a generic server. %% If the server is located at another node, that node will %% be monitored. @@ -282,9 +304,9 @@ enter_loop(Mod, Options, State, Timeout) -> enter_loop(Mod, Options, State, self(), Timeout). enter_loop(Mod, Options, State, ServerName, Timeout) -> - Name = get_proc_name(ServerName), - Parent = get_parent(), - Debug = debug_options(Name, Options), + Name = gen:get_proc_name(ServerName), + Parent = gen:get_parent(), + Debug = gen:debug_options(Name, Options), loop(Parent, Name, State, Mod, Timeout, Debug). %%%======================================================================== @@ -301,8 +323,8 @@ enter_loop(Mod, Options, State, ServerName, Timeout) -> init_it(Starter, self, Name, Mod, Args, Options) -> init_it(Starter, self(), Name, Mod, Args, Options); init_it(Starter, Parent, Name0, Mod, Args, Options) -> - Name = name(Name0), - Debug = debug_options(Name, Options), + Name = gen:name(Name0), + Debug = gen:debug_options(Name, Options), case catch Mod:init(Args) of {ok, State} -> proc_lib:init_ack(Starter, {ok, self()}), @@ -317,15 +339,15 @@ init_it(Starter, Parent, Name0, Mod, Args, Options) -> %% (Otherwise, the parent process could get %% an 'already_started' error if it immediately %% tried starting the process again.) - unregister_name(Name0), + gen:unregister_name(Name0), proc_lib:init_ack(Starter, {error, Reason}), exit(Reason); ignore -> - unregister_name(Name0), + gen:unregister_name(Name0), proc_lib:init_ack(Starter, ignore), exit(normal); {'EXIT', Reason} -> - unregister_name(Name0), + gen:unregister_name(Name0), proc_lib:init_ack(Starter, {error, Reason}), exit(Reason); Else -> @@ -334,20 +356,6 @@ init_it(Starter, Parent, Name0, Mod, Args, Options) -> exit(Error) end. -name({local,Name}) -> Name; -name({global,Name}) -> Name; -name({via,_, Name}) -> Name; -name(Pid) when is_pid(Pid) -> Pid. - -unregister_name({local,Name}) -> - _ = (catch unregister(Name)); -unregister_name({global,Name}) -> - _ = global:unregister_name(Name); -unregister_name({via, Mod, Name}) -> - _ = Mod:unregister_name(Name); -unregister_name(Pid) when is_pid(Pid) -> - Pid. - %%%======================================================================== %%% Internal functions %%%======================================================================== @@ -567,28 +575,88 @@ start_monitor(Node, Name) when is_atom(Node), is_atom(Name) -> end end. +%% --------------------------------------------------- +%% Helper functions for try-catch of callbacks. +%% Returns the return value of the callback, or +%% {'EXIT', ExitReason, ReportReason} (if an exception occurs) +%% +%% ExitReason is the reason that shall be used when the process +%% terminates. +%% +%% ReportReason is the reason that shall be printed in the error +%% report. +%% +%% These functions are introduced in order to add the stack trace in +%% the error report produced when a callback is terminated with +%% erlang:exit/1 (OTP-12263). +%% --------------------------------------------------- + +try_dispatch({'$gen_cast', Msg}, Mod, State) -> + try_dispatch(Mod, handle_cast, Msg, State); +try_dispatch(Info, Mod, State) -> + try_dispatch(Mod, handle_info, Info, State). + +try_dispatch(Mod, Func, Msg, State) -> + try + {ok, Mod:Func(Msg, State)} + catch + throw:R -> + {ok, R}; + error:R -> + Stacktrace = erlang:get_stacktrace(), + {'EXIT', {R, Stacktrace}, {R, Stacktrace}}; + exit:R -> + Stacktrace = erlang:get_stacktrace(), + {'EXIT', R, {R, Stacktrace}} + end. + +try_handle_call(Mod, Msg, From, State) -> + try + {ok, Mod:handle_call(Msg, From, State)} + catch + throw:R -> + {ok, R}; + error:R -> + Stacktrace = erlang:get_stacktrace(), + {'EXIT', {R, Stacktrace}, {R, Stacktrace}}; + exit:R -> + Stacktrace = erlang:get_stacktrace(), + {'EXIT', R, {R, Stacktrace}} + end. + +try_terminate(Mod, Reason, State) -> + try + {ok, Mod:terminate(Reason, State)} + catch + throw:R -> + {ok, R}; + error:R -> + Stacktrace = erlang:get_stacktrace(), + {'EXIT', {R, Stacktrace}, {R, Stacktrace}}; + exit:R -> + Stacktrace = erlang:get_stacktrace(), + {'EXIT', R, {R, Stacktrace}} + end. + + %%% --------------------------------------------------- %%% Message handling functions %%% --------------------------------------------------- -dispatch({'$gen_cast', Msg}, Mod, State) -> - Mod:handle_cast(Msg, State); -dispatch(Info, Mod, State) -> - Mod:handle_info(Info, State). - handle_msg({'$gen_call', From, Msg}, Parent, Name, State, Mod) -> - case catch Mod:handle_call(Msg, From, State) of - {reply, Reply, NState} -> + Result = try_handle_call(Mod, Msg, From, State), + case Result of + {ok, {reply, Reply, NState}} -> reply(From, Reply), loop(Parent, Name, NState, Mod, infinity, []); - {reply, Reply, NState, Time1} -> + {ok, {reply, Reply, NState, Time1}} -> reply(From, Reply), loop(Parent, Name, NState, Mod, Time1, []); - {noreply, NState} -> + {ok, {noreply, NState}} -> loop(Parent, Name, NState, Mod, infinity, []); - {noreply, NState, Time1} -> + {ok, {noreply, NState, Time1}} -> loop(Parent, Name, NState, Mod, Time1, []); - {stop, Reason, Reply, NState} -> + {ok, {stop, Reason, Reply, NState}} -> {'EXIT', R} = (catch terminate(Reason, Name, Msg, Mod, NState, [])), reply(From, Reply), @@ -596,26 +664,27 @@ handle_msg({'$gen_call', From, Msg}, Parent, Name, State, Mod) -> Other -> handle_common_reply(Other, Parent, Name, Msg, Mod, State) end; handle_msg(Msg, Parent, Name, State, Mod) -> - Reply = (catch dispatch(Msg, Mod, State)), + Reply = try_dispatch(Msg, Mod, State), handle_common_reply(Reply, Parent, Name, Msg, Mod, State). handle_msg({'$gen_call', From, Msg}, Parent, Name, State, Mod, Debug) -> - case catch Mod:handle_call(Msg, From, State) of - {reply, Reply, NState} -> + Result = try_handle_call(Mod, Msg, From, State), + case Result of + {ok, {reply, Reply, NState}} -> Debug1 = reply(Name, From, Reply, NState, Debug), loop(Parent, Name, NState, Mod, infinity, Debug1); - {reply, Reply, NState, Time1} -> + {ok, {reply, Reply, NState, Time1}} -> Debug1 = reply(Name, From, Reply, NState, Debug), loop(Parent, Name, NState, Mod, Time1, Debug1); - {noreply, NState} -> + {ok, {noreply, NState}} -> Debug1 = sys:handle_debug(Debug, fun print_event/3, Name, {noreply, NState}), loop(Parent, Name, NState, Mod, infinity, Debug1); - {noreply, NState, Time1} -> + {ok, {noreply, NState, Time1}} -> Debug1 = sys:handle_debug(Debug, fun print_event/3, Name, {noreply, NState}), loop(Parent, Name, NState, Mod, Time1, Debug1); - {stop, Reason, Reply, NState} -> + {ok, {stop, Reason, Reply, NState}} -> {'EXIT', R} = (catch terminate(Reason, Name, Msg, Mod, NState, Debug)), _ = reply(Name, From, Reply, NState, Debug), @@ -624,39 +693,39 @@ handle_msg({'$gen_call', From, Msg}, Parent, Name, State, Mod, Debug) -> handle_common_reply(Other, Parent, Name, Msg, Mod, State, Debug) end; handle_msg(Msg, Parent, Name, State, Mod, Debug) -> - Reply = (catch dispatch(Msg, Mod, State)), + Reply = try_dispatch(Msg, Mod, State), handle_common_reply(Reply, Parent, Name, Msg, Mod, State, Debug). handle_common_reply(Reply, Parent, Name, Msg, Mod, State) -> case Reply of - {noreply, NState} -> + {ok, {noreply, NState}} -> loop(Parent, Name, NState, Mod, infinity, []); - {noreply, NState, Time1} -> + {ok, {noreply, NState, Time1}} -> loop(Parent, Name, NState, Mod, Time1, []); - {stop, Reason, NState} -> + {ok, {stop, Reason, NState}} -> terminate(Reason, Name, Msg, Mod, NState, []); - {'EXIT', What} -> - terminate(What, Name, Msg, Mod, State, []); - _ -> - terminate({bad_return_value, Reply}, Name, Msg, Mod, State, []) + {'EXIT', ExitReason, ReportReason} -> + terminate(ExitReason, ReportReason, Name, Msg, Mod, State, []); + {ok, BadReply} -> + terminate({bad_return_value, BadReply}, Name, Msg, Mod, State, []) end. handle_common_reply(Reply, Parent, Name, Msg, Mod, State, Debug) -> case Reply of - {noreply, NState} -> + {ok, {noreply, NState}} -> Debug1 = sys:handle_debug(Debug, fun print_event/3, Name, {noreply, NState}), loop(Parent, Name, NState, Mod, infinity, Debug1); - {noreply, NState, Time1} -> + {ok, {noreply, NState, Time1}} -> Debug1 = sys:handle_debug(Debug, fun print_event/3, Name, {noreply, NState}), loop(Parent, Name, NState, Mod, Time1, Debug1); - {stop, Reason, NState} -> + {ok, {stop, Reason, NState}} -> terminate(Reason, Name, Msg, Mod, NState, Debug); - {'EXIT', What} -> - terminate(What, Name, Msg, Mod, State, Debug); - _ -> - terminate({bad_return_value, Reply}, Name, Msg, Mod, State, Debug) + {'EXIT', ExitReason, ReportReason} -> + terminate(ExitReason, ReportReason, Name, Msg, Mod, State, Debug); + {ok, BadReply} -> + terminate({bad_return_value, BadReply}, Name, Msg, Mod, State, Debug) end. reply(Name, {To, Tag}, Reply, State, Debug) -> @@ -717,13 +786,20 @@ print_event(Dev, Event, Name) -> %%% Terminate the server. %%% --------------------------------------------------- +-spec terminate(_, _, _, _, _, _) -> no_return(). terminate(Reason, Name, Msg, Mod, State, Debug) -> - case catch Mod:terminate(Reason, State) of - {'EXIT', R} -> - error_info(R, Name, Msg, State, Debug), - exit(R); + terminate(Reason, Reason, Name, Msg, Mod, State, Debug). + +-spec terminate(_, _, _, _, _, _, _) -> no_return(). +terminate(ExitReason, ReportReason, Name, Msg, Mod, State, Debug) -> + Reply = try_terminate(Mod, ExitReason, State), + case Reply of + {'EXIT', ExitReason1, ReportReason1} -> + FmtState = format_status(terminate, Mod, get(), State), + error_info(ReportReason1, Name, Msg, FmtState, Debug), + exit(ExitReason1); _ -> - case Reason of + case ExitReason of normal -> exit(normal); shutdown -> @@ -731,19 +807,9 @@ terminate(Reason, Name, Msg, Mod, State, Debug) -> {shutdown,_}=Shutdown -> exit(Shutdown); _ -> - FmtState = - case erlang:function_exported(Mod, format_status, 2) of - true -> - Args = [get(), State], - case catch Mod:format_status(terminate, Args) of - {'EXIT', _} -> State; - Else -> Else - end; - _ -> - State - end, - error_info(Reason, Name, Msg, FmtState, Debug), - exit(Reason) + FmtState = format_status(terminate, Mod, get(), State), + error_info(ReportReason, Name, Msg, FmtState, Debug), + exit(ExitReason) end end. @@ -778,120 +844,34 @@ error_info(Reason, Name, Msg, State, Debug) -> sys:print_log(Debug), ok. -%%% --------------------------------------------------- -%%% Misc. functions. -%%% --------------------------------------------------- - -opt(Op, [{Op, Value}|_]) -> - {ok, Value}; -opt(Op, [_|Options]) -> - opt(Op, Options); -opt(_, []) -> - false. - -debug_options(Name, Opts) -> - case opt(debug, Opts) of - {ok, Options} -> dbg_options(Name, Options); - _ -> dbg_options(Name, []) - end. - -dbg_options(Name, []) -> - Opts = - case init:get_argument(generic_debug) of - error -> - []; - _ -> - [log, statistics] - end, - dbg_opts(Name, Opts); -dbg_options(Name, Opts) -> - dbg_opts(Name, Opts). - -dbg_opts(Name, Opts) -> - case catch sys:debug_options(Opts) of - {'EXIT',_} -> - format("~p: ignoring erroneous debug options - ~p~n", - [Name, Opts]), - []; - Dbg -> - Dbg - end. - -get_proc_name(Pid) when is_pid(Pid) -> - Pid; -get_proc_name({local, Name}) -> - case process_info(self(), registered_name) of - {registered_name, Name} -> - Name; - {registered_name, _Name} -> - exit(process_not_registered); - [] -> - exit(process_not_registered) - end; -get_proc_name({global, Name}) -> - case global:whereis_name(Name) of - undefined -> - exit(process_not_registered_globally); - Pid when Pid =:= self() -> - Name; - _Pid -> - exit(process_not_registered_globally) - end; -get_proc_name({via, Mod, Name}) -> - case Mod:whereis_name(Name) of - undefined -> - exit({process_not_registered_via, Mod}); - Pid when Pid =:= self() -> - Name; - _Pid -> - exit({process_not_registered_via, Mod}) - end. - -get_parent() -> - case get('$ancestors') of - [Parent | _] when is_pid(Parent)-> - Parent; - [Parent | _] when is_atom(Parent)-> - name_to_pid(Parent); - _ -> - exit(process_was_not_started_by_proc_lib) - end. - -name_to_pid(Name) -> - case whereis(Name) of - undefined -> - case global:whereis_name(Name) of - undefined -> - exit(could_not_find_registered_name); - Pid -> - Pid - end; - Pid -> - Pid - end. - %%----------------------------------------------------------------- %% Status information %%----------------------------------------------------------------- format_status(Opt, StatusData) -> [PDict, SysState, Parent, Debug, [Name, State, Mod, _Time]] = StatusData, - Header = gen:format_status_header("Status for generic server", - Name), + Header = gen:format_status_header("Status for generic server", Name), Log = sys:get_debug(log, Debug, []), - DefaultStatus = [{data, [{"State", State}]}], - Specfic = - case erlang:function_exported(Mod, format_status, 2) of - true -> - case catch Mod:format_status(Opt, [PDict, State]) of - {'EXIT', _} -> DefaultStatus; - StatusList when is_list(StatusList) -> StatusList; - Else -> [Else] - end; - _ -> - DefaultStatus - end, + Specfic = case format_status(Opt, Mod, PDict, State) of + S when is_list(S) -> S; + S -> [S] + end, [{header, Header}, {data, [{"Status", SysState}, {"Parent", Parent}, {"Logged events", Log}]} | Specfic]. + +format_status(Opt, Mod, PDict, State) -> + DefStatus = case Opt of + terminate -> State; + _ -> [{data, [{"State", State}]}] + end, + case erlang:function_exported(Mod, format_status, 2) of + true -> + case catch Mod:format_status(Opt, [PDict, State]) of + {'EXIT', _} -> DefStatus; + Else -> Else + end; + _ -> + DefStatus + end. |