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changed out gen_server for lshift's gen_server2

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commit e064d0da471ac99a684109772ba17d2c1781bfa2 1 parent 306d6d1
zeusfaber authored
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  1. +854 −0 src/gen_server2.erl
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854 src/gen_server2.erl
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+%% This file is a copy of gen_server.erl from the R11B-5 Erlang/OTP
+%% distribution, with the following modifications:
+%%
+%% 1) the module name is gen_server2
+%%
+%% 2) more efficient handling of selective receives in callbacks
+%% gen_server2 processes drain their message queue into an internal
+%% buffer before invoking any callback module functions. Messages are
+%% dequeued from the buffer for processing. Thus the effective message
+%% queue of a gen_server2 process is the concatenation of the internal
+%% buffer and the real message queue.
+%% As a result of the draining, any selective receive invoked inside a
+%% callback is less likely to have to scan a large message queue.
+%%
+%% 3) gen_server2:cast is guaranteed to be order-preserving
+%% The original code could reorder messages when communicating with a
+%% process on a remote node that was not currently connected.
+%%
+%% All modifications are (C) 2009 LShift Ltd.
+
+%% ``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 via the world wide web at http://www.erlang.org/.
+%%
+%% 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 Initial Developer of the Original Code is Ericsson Utvecklings AB.
+%% Portions created by Ericsson are Copyright 1999, Ericsson Utvecklings
+%% AB. All Rights Reserved.''
+%%
+%% $Id$
+%%
+-module(gen_server2).
+
+%%% ---------------------------------------------------
+%%%
+%%% The idea behind THIS server is that the user module
+%%% provides (different) functions to handle different
+%%% kind of inputs.
+%%% If the Parent process terminates the Module:terminate/2
+%%% function is called.
+%%%
+%%% The user module should export:
+%%%
+%%% init(Args)
+%%% ==> {ok, State}
+%%% {ok, State, Timeout}
+%%% ignore
+%%% {stop, Reason}
+%%%
+%%% handle_call(Msg, {From, Tag}, State)
+%%%
+%%% ==> {reply, Reply, State}
+%%% {reply, Reply, State, Timeout}
+%%% {noreply, State}
+%%% {noreply, State, Timeout}
+%%% {stop, Reason, Reply, State}
+%%% Reason = normal | shutdown | Term terminate(State) is called
+%%%
+%%% handle_cast(Msg, State)
+%%%
+%%% ==> {noreply, State}
+%%% {noreply, State, Timeout}
+%%% {stop, Reason, State}
+%%% Reason = normal | shutdown | Term terminate(State) is called
+%%%
+%%% handle_info(Info, State) Info is e.g. {'EXIT', P, R}, {nodedown, N}, ...
+%%%
+%%% ==> {noreply, State}
+%%% {noreply, State, Timeout}
+%%% {stop, Reason, State}
+%%% Reason = normal | shutdown | Term, terminate(State) is called
+%%%
+%%% terminate(Reason, State) Let the user module clean up
+%%% always called when server terminates
+%%%
+%%% ==> ok
+%%%
+%%%
+%%% The work flow (of the server) can be described as follows:
+%%%
+%%% User module Generic
+%%% ----------- -------
+%%% start -----> start
+%%% init <----- .
+%%%
+%%% loop
+%%% handle_call <----- .
+%%% -----> reply
+%%%
+%%% handle_cast <----- .
+%%%
+%%% handle_info <----- .
+%%%
+%%% terminate <----- .
+%%%
+%%% -----> reply
+%%%
+%%%
+%%% ---------------------------------------------------
+
+%% API
+-export([start/3, start/4,
+ start_link/3, start_link/4,
+ call/2, call/3,
+ cast/2, reply/2,
+ abcast/2, abcast/3,
+ multi_call/2, multi_call/3, multi_call/4,
+ enter_loop/3, enter_loop/4, enter_loop/5]).
+
+-export([behaviour_info/1]).
+
+%% System exports
+-export([system_continue/3,
+ system_terminate/4,
+ system_code_change/4,
+ format_status/2]).
+
+%% Internal exports
+-export([init_it/6, print_event/3]).
+
+-import(error_logger, [format/2]).
+
+%%%=========================================================================
+%%% API
+%%%=========================================================================
+
+behaviour_info(callbacks) ->
+ [{init,1},{handle_call,3},{handle_cast,2},{handle_info,2},
+ {terminate,2},{code_change,3}];
+behaviour_info(_Other) ->
+ undefined.
+
+%%% -----------------------------------------------------------------
+%%% Starts a generic server.
+%%% start(Mod, Args, Options)
+%%% start(Name, Mod, Args, Options)
+%%% start_link(Mod, Args, Options)
+%%% start_link(Name, Mod, Args, Options) where:
+%%% Name ::= {local, atom()} | {global, atom()}
+%%% Mod ::= atom(), callback module implementing the 'real' server
+%%% Args ::= term(), init arguments (to Mod:init/1)
+%%% Options ::= [{timeout, Timeout} | {debug, [Flag]}]
+%%% Flag ::= trace | log | {logfile, File} | statistics | debug
+%%% (debug == log && statistics)
+%%% Returns: {ok, Pid} |
+%%% {error, {already_started, Pid}} |
+%%% {error, Reason}
+%%% -----------------------------------------------------------------
+start(Mod, Args, Options) ->
+ gen:start(?MODULE, nolink, Mod, Args, Options).
+
+start(Name, Mod, Args, Options) ->
+ gen:start(?MODULE, nolink, Name, Mod, Args, Options).
+
+start_link(Mod, Args, Options) ->
+ gen:start(?MODULE, link, Mod, Args, Options).
+
+start_link(Name, Mod, Args, Options) ->
+ gen:start(?MODULE, link, Name, Mod, Args, Options).
+
+
+%% -----------------------------------------------------------------
+%% Make a call to a generic server.
+%% If the server is located at another node, that node will
+%% be monitored.
+%% If the client is trapping exits and is linked server termination
+%% is handled here (? Shall we do that here (or rely on timeouts) ?).
+%% -----------------------------------------------------------------
+call(Name, Request) ->
+ case catch gen:call(Name, '$gen_call', Request) of
+ {ok,Res} ->
+ Res;
+ {'EXIT',Reason} ->
+ exit({Reason, {?MODULE, call, [Name, Request]}})
+ end.
+
+call(Name, Request, Timeout) ->
+ case catch gen:call(Name, '$gen_call', Request, Timeout) of
+ {ok,Res} ->
+ Res;
+ {'EXIT',Reason} ->
+ exit({Reason, {?MODULE, call, [Name, Request, Timeout]}})
+ end.
+
+%% -----------------------------------------------------------------
+%% Make a cast to a generic server.
+%% -----------------------------------------------------------------
+cast({global,Name}, Request) ->
+ catch global:send(Name, cast_msg(Request)),
+ ok;
+cast({Name,Node}=Dest, Request) when is_atom(Name), is_atom(Node) ->
+ do_cast(Dest, Request);
+cast(Dest, Request) when is_atom(Dest) ->
+ do_cast(Dest, Request);
+cast(Dest, Request) when is_pid(Dest) ->
+ do_cast(Dest, Request).
+
+do_cast(Dest, Request) ->
+ do_send(Dest, cast_msg(Request)),
+ ok.
+
+cast_msg(Request) -> {'$gen_cast',Request}.
+
+%% -----------------------------------------------------------------
+%% Send a reply to the client.
+%% -----------------------------------------------------------------
+reply({To, Tag}, Reply) ->
+ catch To ! {Tag, Reply}.
+
+%% -----------------------------------------------------------------
+%% Asyncronous broadcast, returns nothing, it's just send'n prey
+%%-----------------------------------------------------------------
+abcast(Name, Request) when is_atom(Name) ->
+ do_abcast([node() | nodes()], Name, cast_msg(Request)).
+
+abcast(Nodes, Name, Request) when is_list(Nodes), is_atom(Name) ->
+ do_abcast(Nodes, Name, cast_msg(Request)).
+
+do_abcast([Node|Nodes], Name, Msg) when is_atom(Node) ->
+ do_send({Name,Node},Msg),
+ do_abcast(Nodes, Name, Msg);
+do_abcast([], _,_) -> abcast.
+
+%%% -----------------------------------------------------------------
+%%% Make a call to servers at several nodes.
+%%% Returns: {[Replies],[BadNodes]}
+%%% A Timeout can be given
+%%%
+%%% A middleman process is used in case late answers arrives after
+%%% the timeout. If they would be allowed to glog the callers message
+%%% queue, it would probably become confused. Late answers will
+%%% now arrive to the terminated middleman and so be discarded.
+%%% -----------------------------------------------------------------
+multi_call(Name, Req)
+ when is_atom(Name) ->
+ do_multi_call([node() | nodes()], Name, Req, infinity).
+
+multi_call(Nodes, Name, Req)
+ when is_list(Nodes), is_atom(Name) ->
+ do_multi_call(Nodes, Name, Req, infinity).
+
+multi_call(Nodes, Name, Req, infinity) ->
+ do_multi_call(Nodes, Name, Req, infinity);
+multi_call(Nodes, Name, Req, Timeout)
+ when is_list(Nodes), is_atom(Name), is_integer(Timeout), Timeout >= 0 ->
+ do_multi_call(Nodes, Name, Req, Timeout).
+
+
+%%-----------------------------------------------------------------
+%% enter_loop(Mod, Options, State, <ServerName>, <TimeOut>) ->_
+%%
+%% Description: Makes an existing process into a gen_server.
+%% The calling process will enter the gen_server receive
+%% loop and become a gen_server process.
+%% The process *must* have been started using one of the
+%% start functions in proc_lib, see proc_lib(3).
+%% The user is responsible for any initialization of the
+%% process, including registering a name for it.
+%%-----------------------------------------------------------------
+enter_loop(Mod, Options, State) ->
+ enter_loop(Mod, Options, State, self(), infinity).
+
+enter_loop(Mod, Options, State, ServerName = {_, _}) ->
+ enter_loop(Mod, Options, State, ServerName, infinity);
+
+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),
+ Queue = queue:new(),
+ loop(Parent, Name, State, Mod, Timeout, Queue, Debug).
+
+%%%========================================================================
+%%% Gen-callback functions
+%%%========================================================================
+
+%%% ---------------------------------------------------
+%%% Initiate the new process.
+%%% Register the name using the Rfunc function
+%%% Calls the Mod:init/Args function.
+%%% Finally an acknowledge is sent to Parent and the main
+%%% loop is entered.
+%%% ---------------------------------------------------
+init_it(Starter, self, Name, Mod, Args, Options) ->
+ init_it(Starter, self(), Name, Mod, Args, Options);
+init_it(Starter, Parent, Name, Mod, Args, Options) ->
+ Debug = debug_options(Name, Options),
+ Queue = queue:new(),
+ case catch Mod:init(Args) of
+ {ok, State} ->
+ proc_lib:init_ack(Starter, {ok, self()}),
+ loop(Parent, Name, State, Mod, infinity, Queue, Debug);
+ {ok, State, Timeout} ->
+ proc_lib:init_ack(Starter, {ok, self()}),
+ loop(Parent, Name, State, Mod, Timeout, Queue, Debug);
+ {stop, Reason} ->
+ proc_lib:init_ack(Starter, {error, Reason}),
+ exit(Reason);
+ ignore ->
+ proc_lib:init_ack(Starter, ignore),
+ exit(normal);
+ {'EXIT', Reason} ->
+ proc_lib:init_ack(Starter, {error, Reason}),
+ exit(Reason);
+ Else ->
+ Error = {bad_return_value, Else},
+ proc_lib:init_ack(Starter, {error, Error}),
+ exit(Error)
+ end.
+
+%%%========================================================================
+%%% Internal functions
+%%%========================================================================
+%%% ---------------------------------------------------
+%%% The MAIN loop.
+%%% ---------------------------------------------------
+loop(Parent, Name, State, Mod, Time, Queue, Debug) ->
+ receive
+ Input -> loop(Parent, Name, State, Mod,
+ Time, queue:in(Input, Queue), Debug)
+ after 0 ->
+ case queue:out(Queue) of
+ {{value, Msg}, Queue1} ->
+ process_msg(Parent, Name, State, Mod,
+ Time, Queue1, Debug, Msg);
+ {empty, Queue1} ->
+ receive
+ Input ->
+ loop(Parent, Name, State, Mod,
+ Time, queue:in(Input, Queue1), Debug)
+ after Time ->
+ process_msg(Parent, Name, State, Mod,
+ Time, Queue1, Debug, timeout)
+ end
+ end
+ end.
+
+process_msg(Parent, Name, State, Mod, Time, Queue, Debug, Msg) ->
+ case Msg of
+ {system, From, Req} ->
+ sys:handle_system_msg(Req, From, Parent, ?MODULE, Debug,
+ [Name, State, Mod, Time, Queue]);
+ {'EXIT', Parent, Reason} ->
+ terminate(Reason, Name, Msg, Mod, State, Debug);
+ _Msg when Debug =:= [] ->
+ handle_msg(Msg, Parent, Name, State, Mod, Time, Queue);
+ _Msg ->
+ Debug1 = sys:handle_debug(Debug, {?MODULE, print_event},
+ Name, {in, Msg}),
+ handle_msg(Msg, Parent, Name, State, Mod, Time, Queue, Debug1)
+ end.
+
+%%% ---------------------------------------------------
+%%% Send/recive functions
+%%% ---------------------------------------------------
+do_send(Dest, Msg) ->
+ catch erlang:send(Dest, Msg).
+
+do_multi_call(Nodes, Name, Req, infinity) ->
+ Tag = make_ref(),
+ Monitors = send_nodes(Nodes, Name, Tag, Req),
+ rec_nodes(Tag, Monitors, Name, undefined);
+do_multi_call(Nodes, Name, Req, Timeout) ->
+ Tag = make_ref(),
+ Caller = self(),
+ Receiver =
+ spawn(
+ fun() ->
+ %% Middleman process. Should be unsensitive to regular
+ %% exit signals. The sychronization is needed in case
+ %% the receiver would exit before the caller started
+ %% the monitor.
+ process_flag(trap_exit, true),
+ Mref = erlang:monitor(process, Caller),
+ receive
+ {Caller,Tag} ->
+ Monitors = send_nodes(Nodes, Name, Tag, Req),
+ TimerId = erlang:start_timer(Timeout, self(), ok),
+ Result = rec_nodes(Tag, Monitors, Name, TimerId),
+ exit({self(),Tag,Result});
+ {'DOWN',Mref,_,_,_} ->
+ %% Caller died before sending us the go-ahead.
+ %% Give up silently.
+ exit(normal)
+ end
+ end),
+ Mref = erlang:monitor(process, Receiver),
+ Receiver ! {self(),Tag},
+ receive
+ {'DOWN',Mref,_,_,{Receiver,Tag,Result}} ->
+ Result;
+ {'DOWN',Mref,_,_,Reason} ->
+ %% The middleman code failed. Or someone did
+ %% exit(_, kill) on the middleman process => Reason==killed
+ exit(Reason)
+ end.
+
+send_nodes(Nodes, Name, Tag, Req) ->
+ send_nodes(Nodes, Name, Tag, Req, []).
+
+send_nodes([Node|Tail], Name, Tag, Req, Monitors)
+ when is_atom(Node) ->
+ Monitor = start_monitor(Node, Name),
+ %% Handle non-existing names in rec_nodes.
+ catch {Name, Node} ! {'$gen_call', {self(), {Tag, Node}}, Req},
+ send_nodes(Tail, Name, Tag, Req, [Monitor | Monitors]);
+send_nodes([_Node|Tail], Name, Tag, Req, Monitors) ->
+ %% Skip non-atom Node
+ send_nodes(Tail, Name, Tag, Req, Monitors);
+send_nodes([], _Name, _Tag, _Req, Monitors) ->
+ Monitors.
+
+%% Against old nodes:
+%% If no reply has been delivered within 2 secs. (per node) check that
+%% the server really exists and wait for ever for the answer.
+%%
+%% Against contemporary nodes:
+%% Wait for reply, server 'DOWN', or timeout from TimerId.
+
+rec_nodes(Tag, Nodes, Name, TimerId) ->
+ rec_nodes(Tag, Nodes, Name, [], [], 2000, TimerId).
+
+rec_nodes(Tag, [{N,R}|Tail], Name, Badnodes, Replies, Time, TimerId ) ->
+ receive
+ {'DOWN', R, _, _, _} ->
+ rec_nodes(Tag, Tail, Name, [N|Badnodes], Replies, Time, TimerId);
+ {{Tag, N}, Reply} -> %% Tag is bound !!!
+ unmonitor(R),
+ rec_nodes(Tag, Tail, Name, Badnodes,
+ [{N,Reply}|Replies], Time, TimerId);
+ {timeout, TimerId, _} ->
+ unmonitor(R),
+ %% Collect all replies that already have arrived
+ rec_nodes_rest(Tag, Tail, Name, [N|Badnodes], Replies)
+ end;
+rec_nodes(Tag, [N|Tail], Name, Badnodes, Replies, Time, TimerId) ->
+ %% R6 node
+ receive
+ {nodedown, N} ->
+ monitor_node(N, false),
+ rec_nodes(Tag, Tail, Name, [N|Badnodes], Replies, 2000, TimerId);
+ {{Tag, N}, Reply} -> %% Tag is bound !!!
+ receive {nodedown, N} -> ok after 0 -> ok end,
+ monitor_node(N, false),
+ rec_nodes(Tag, Tail, Name, Badnodes,
+ [{N,Reply}|Replies], 2000, TimerId);
+ {timeout, TimerId, _} ->
+ receive {nodedown, N} -> ok after 0 -> ok end,
+ monitor_node(N, false),
+ %% Collect all replies that already have arrived
+ rec_nodes_rest(Tag, Tail, Name, [N | Badnodes], Replies)
+ after Time ->
+ case rpc:call(N, erlang, whereis, [Name]) of
+ Pid when is_pid(Pid) -> % It exists try again.
+ rec_nodes(Tag, [N|Tail], Name, Badnodes,
+ Replies, infinity, TimerId);
+ _ -> % badnode
+ receive {nodedown, N} -> ok after 0 -> ok end,
+ monitor_node(N, false),
+ rec_nodes(Tag, Tail, Name, [N|Badnodes],
+ Replies, 2000, TimerId)
+ end
+ end;
+rec_nodes(_, [], _, Badnodes, Replies, _, TimerId) ->
+ case catch erlang:cancel_timer(TimerId) of
+ false -> % It has already sent it's message
+ receive
+ {timeout, TimerId, _} -> ok
+ after 0 ->
+ ok
+ end;
+ _ -> % Timer was cancelled, or TimerId was 'undefined'
+ ok
+ end,
+ {Replies, Badnodes}.
+
+%% Collect all replies that already have arrived
+rec_nodes_rest(Tag, [{N,R}|Tail], Name, Badnodes, Replies) ->
+ receive
+ {'DOWN', R, _, _, _} ->
+ rec_nodes_rest(Tag, Tail, Name, [N|Badnodes], Replies);
+ {{Tag, N}, Reply} -> %% Tag is bound !!!
+ unmonitor(R),
+ rec_nodes_rest(Tag, Tail, Name, Badnodes, [{N,Reply}|Replies])
+ after 0 ->
+ unmonitor(R),
+ rec_nodes_rest(Tag, Tail, Name, [N|Badnodes], Replies)
+ end;
+rec_nodes_rest(Tag, [N|Tail], Name, Badnodes, Replies) ->
+ %% R6 node
+ receive
+ {nodedown, N} ->
+ monitor_node(N, false),
+ rec_nodes_rest(Tag, Tail, Name, [N|Badnodes], Replies);
+ {{Tag, N}, Reply} -> %% Tag is bound !!!
+ receive {nodedown, N} -> ok after 0 -> ok end,
+ monitor_node(N, false),
+ rec_nodes_rest(Tag, Tail, Name, Badnodes, [{N,Reply}|Replies])
+ after 0 ->
+ receive {nodedown, N} -> ok after 0 -> ok end,
+ monitor_node(N, false),
+ rec_nodes_rest(Tag, Tail, Name, [N|Badnodes], Replies)
+ end;
+rec_nodes_rest(_Tag, [], _Name, Badnodes, Replies) ->
+ {Replies, Badnodes}.
+
+
+%%% ---------------------------------------------------
+%%% Monitor functions
+%%% ---------------------------------------------------
+
+start_monitor(Node, Name) when is_atom(Node), is_atom(Name) ->
+ if node() =:= nonode@nohost, Node =/= nonode@nohost ->
+ Ref = make_ref(),
+ self() ! {'DOWN', Ref, process, {Name, Node}, noconnection},
+ {Node, Ref};
+ true ->
+ case catch erlang:monitor(process, {Name, Node}) of
+ {'EXIT', _} ->
+ %% Remote node is R6
+ monitor_node(Node, true),
+ Node;
+ Ref when is_reference(Ref) ->
+ {Node, Ref}
+ end
+ end.
+
+%% Cancels a monitor started with Ref=erlang:monitor(_, _).
+unmonitor(Ref) when is_reference(Ref) ->
+ erlang:demonitor(Ref),
+ receive
+ {'DOWN', Ref, _, _, _} ->
+ true
+ after 0 ->
+ true
+ 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, _Time, Queue) ->
+ case catch Mod:handle_call(Msg, From, State) of
+ {reply, Reply, NState} ->
+ reply(From, Reply),
+ loop(Parent, Name, NState, Mod, infinity, Queue, []);
+ {reply, Reply, NState, Time1} ->
+ reply(From, Reply),
+ loop(Parent, Name, NState, Mod, Time1, Queue, []);
+ {noreply, NState} ->
+ loop(Parent, Name, NState, Mod, infinity, Queue, []);
+ {noreply, NState, Time1} ->
+ loop(Parent, Name, NState, Mod, Time1, Queue, []);
+ {stop, Reason, Reply, NState} ->
+ {'EXIT', R} =
+ (catch terminate(Reason, Name, Msg, Mod, NState, [])),
+ reply(From, Reply),
+ exit(R);
+ Other -> handle_common_reply(Other,
+ Parent, Name, Msg, Mod, State, Queue)
+ end;
+handle_msg(Msg,
+ Parent, Name, State, Mod, _Time, Queue) ->
+ Reply = (catch dispatch(Msg, Mod, State)),
+ handle_common_reply(Reply, Parent, Name, Msg, Mod, State, Queue).
+
+handle_msg({'$gen_call', From, Msg},
+ Parent, Name, State, Mod, _Time, Queue, Debug) ->
+ case catch Mod:handle_call(Msg, From, State) of
+ {reply, Reply, NState} ->
+ Debug1 = reply(Name, From, Reply, NState, Debug),
+ loop(Parent, Name, NState, Mod, infinity, Queue, Debug1);
+ {reply, Reply, NState, Time1} ->
+ Debug1 = reply(Name, From, Reply, NState, Debug),
+ loop(Parent, Name, NState, Mod, Time1, Queue, Debug1);
+ {noreply, NState} ->
+ Debug1 = sys:handle_debug(Debug, {?MODULE, print_event}, Name,
+ {noreply, NState}),
+ loop(Parent, Name, NState, Mod, infinity, Queue, Debug1);
+ {noreply, NState, Time1} ->
+ Debug1 = sys:handle_debug(Debug, {?MODULE, print_event}, Name,
+ {noreply, NState}),
+ loop(Parent, Name, NState, Mod, Time1, Queue, Debug1);
+ {stop, Reason, Reply, NState} ->
+ {'EXIT', R} =
+ (catch terminate(Reason, Name, Msg, Mod, NState, Debug)),
+ reply(Name, From, Reply, NState, Debug),
+ exit(R);
+ Other ->
+ handle_common_reply(Other,
+ Parent, Name, Msg, Mod, State, Queue, Debug)
+ end;
+handle_msg(Msg,
+ Parent, Name, State, Mod, _Time, Queue, Debug) ->
+ Reply = (catch dispatch(Msg, Mod, State)),
+ handle_common_reply(Reply,
+ Parent, Name, Msg, Mod, State, Queue, Debug).
+
+handle_common_reply(Reply, Parent, Name, Msg, Mod, State, Queue) ->
+ case Reply of
+ {noreply, NState} ->
+ loop(Parent, Name, NState, Mod, infinity, Queue, []);
+ {noreply, NState, Time1} ->
+ loop(Parent, Name, NState, Mod, Time1, Queue, []);
+ {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, [])
+ end.
+
+handle_common_reply(Reply, Parent, Name, Msg, Mod, State, Queue, Debug) ->
+ case Reply of
+ {noreply, NState} ->
+ Debug1 = sys:handle_debug(Debug, {?MODULE, print_event}, Name,
+ {noreply, NState}),
+ loop(Parent, Name, NState, Mod, infinity, Queue, Debug1);
+ {noreply, NState, Time1} ->
+ Debug1 = sys:handle_debug(Debug, {?MODULE, print_event}, Name,
+ {noreply, NState}),
+ loop(Parent, Name, NState, Mod, Time1, Queue, Debug1);
+ {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)
+ end.
+
+reply(Name, {To, Tag}, Reply, State, Debug) ->
+ reply({To, Tag}, Reply),
+ sys:handle_debug(Debug, {?MODULE, print_event}, Name,
+ {out, Reply, To, State} ).
+
+
+%%-----------------------------------------------------------------
+%% Callback functions for system messages handling.
+%%-----------------------------------------------------------------
+system_continue(Parent, Debug, [Name, State, Mod, Time, Queue]) ->
+ loop(Parent, Name, State, Mod, Time, Queue, Debug).
+
+system_terminate(Reason, _Parent, Debug, [Name, State, Mod, _Time, _Queue]) ->
+ terminate(Reason, Name, [], Mod, State, Debug).
+
+system_code_change([Name, State, Mod, Time, Queue], _Module, OldVsn, Extra) ->
+ case catch Mod:code_change(OldVsn, State, Extra) of
+ {ok, NewState} -> {ok, [Name, NewState, Mod, Time, Queue]};
+ Else -> Else
+ end.
+
+%%-----------------------------------------------------------------
+%% Format debug messages. Print them as the call-back module sees
+%% them, not as the real erlang messages. Use trace for that.
+%%-----------------------------------------------------------------
+print_event(Dev, {in, Msg}, Name) ->
+ case Msg of
+ {'$gen_call', {From, _Tag}, Call} ->
+ io:format(Dev, "*DBG* ~p got call ~p from ~w~n",
+ [Name, Call, From]);
+ {'$gen_cast', Cast} ->
+ io:format(Dev, "*DBG* ~p got cast ~p~n",
+ [Name, Cast]);
+ _ ->
+ io:format(Dev, "*DBG* ~p got ~p~n", [Name, Msg])
+ end;
+print_event(Dev, {out, Msg, To, State}, Name) ->
+ io:format(Dev, "*DBG* ~p sent ~p to ~w, new state ~w~n",
+ [Name, Msg, To, State]);
+print_event(Dev, {noreply, State}, Name) ->
+ io:format(Dev, "*DBG* ~p new state ~w~n", [Name, State]);
+print_event(Dev, Event, Name) ->
+ io:format(Dev, "*DBG* ~p dbg ~p~n", [Name, Event]).
+
+
+%%% ---------------------------------------------------
+%%% Terminate the server.
+%%% ---------------------------------------------------
+
+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);
+ _ ->
+ case Reason of
+ normal ->
+ exit(normal);
+ shutdown ->
+ exit(shutdown);
+ _ ->
+ error_info(Reason, Name, Msg, State, Debug),
+ exit(Reason)
+ end
+ end.
+
+error_info(_Reason, application_controller, _Msg, _State, _Debug) ->
+ %% OTP-5811 Don't send an error report if it's the system process
+ %% application_controller which is terminating - let init take care
+ %% of it instead
+ ok;
+error_info(Reason, Name, Msg, State, Debug) ->
+ Reason1 =
+ case Reason of
+ {undef,[{M,F,A}|MFAs]} ->
+ case code:is_loaded(M) of
+ false ->
+ {'module could not be loaded',[{M,F,A}|MFAs]};
+ _ ->
+ case erlang:function_exported(M, F, length(A)) of
+ true ->
+ Reason;
+ false ->
+ {'function not exported',[{M,F,A}|MFAs]}
+ end
+ end;
+ _ ->
+ Reason
+ end,
+ format("** Generic server ~p terminating \n"
+ "** Last message in was ~p~n"
+ "** When Server state == ~p~n"
+ "** Reason for termination == ~n** ~p~n",
+ [Name, Msg, State, Reason1]),
+ 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:safe_whereis_name(Name) of
+ undefined ->
+ exit(process_not_registered_globally);
+ Pid when Pid =:= self() ->
+ Name;
+ _Pid ->
+ exit(process_not_registered_globally)
+ 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:safe_whereis_name(Name) of
+ undefined ->
+ exit(could_not_find_registerd_name);
+ Pid ->
+ Pid
+ end;
+ Pid ->
+ Pid
+ end.
+
+%%-----------------------------------------------------------------
+%% Status information
+%%-----------------------------------------------------------------
+format_status(Opt, StatusData) ->
+ [PDict, SysState, Parent, Debug, [Name, State, Mod, _Time, Queue]] =
+ StatusData,
+ NameTag = if is_pid(Name) ->
+ pid_to_list(Name);
+ is_atom(Name) ->
+ Name
+ end,
+ Header = lists:concat(["Status for generic server ", NameTag]),
+ Log = sys:get_debug(log, Debug, []),
+ Specfic =
+ case erlang:function_exported(Mod, format_status, 2) of
+ true ->
+ case catch Mod:format_status(Opt, [PDict, State]) of
+ {'EXIT', _} -> [{data, [{"State", State}]}];
+ Else -> Else
+ end;
+ _ ->
+ [{data, [{"State", State}]}]
+ end,
+ [{header, Header},
+ {data, [{"Status", SysState},
+ {"Parent", Parent},
+ {"Logged events", Log},
+ {"Queued messages", queue:to_list(Queue)}]} |
+ Specfic].
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