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+%%%-------------------------------------------------------------------
+%%% @author Joe Zhao
+%%% @copyright (C) 2014, <COMPANY>
+%%% @doc
+%%% This module serves the purpose of registering and monitoring different events
+%%% Whether they are periodic or oneshot.
+%%% Events are happening in a sense that none should be depending on those that happend before.
+%%% Spawning one with mutable state is thus not recommended and not supported in such modules.
+%%% Thus, the events are defined so that none of them would have states change during different invocations.
+%%% @end
+%%% Created : 27. 四月 2014 19:11
+%%%-------------------------------------------------------------------
+-module(eventserv).
+-author("Joe Zhao").
+
+-include("eventserv.hrl").
+-compile([debug_info,export_all]).
+
+%% API
+%%-export([]).
+
+event(Pid,S) ->
+  receive
+    {_PPid,shutdown} ->
+      io:format("I, ~p, am killed.\n",[S#event.name])
+  after S#event.period ->
+    Pid ! {self(),run,S},
+    if
+      S#event.spawn -> spawn(S#event.call,[self()]);
+      true -> (S#event.call)(self())
+    end,
+    case S#event.type of
+      oneshot -> ok;
+      periodic -> event(Pid,S);
+      _Else -> ok
+    end
+  end.
+
+recloop(Events) ->
+  receive
+    {Pid,shutdown} -> [ Proc ! {self(),shutdown} || Proc<- orddict:fetch_keys(Events)];
+    {PPid,reg,S} ->
+      Pid = spawn(?MODULE,event,[self(),S]),
+      link(Pid),
+      recloop(orddict:store(Pid,S,Events));
+    {Pid,run,S} ->
+      io:format("Event run, type ~p: ~p\n",[S#event.type,S#event.name]),
+      recloop(Events);
+    {'EXIT',Pid,Cond} when Cond==normal;Cond==shutdown ->
+      io:format("Event died naturally, pid: ~p\n.",[Pid]),
+      recloop(orddict:erase(Pid,Events));
+    {'EXIT',Pid,Cause} ->
+      S=orddict:fetch(Pid,Events),
+      io:format("Event died abruptly(~p), pid: ~p ; name: ~p\n.",[Cause,Pid,S#event.name]),
+      if
+        S#event.type == periodic ->
+          io:format("Event(periodic) will restart, name: ~p\n.",[S#event.name]),
+          self() !  {self(),reg,S}
+      end,
+      recloop(orddict:erase(Pid,Events))
+  end.
+
+evemon(Events) ->
+  process_flag(trap_exit,true),
+  register(?MODULE,self()),
+  recloop(Events).
+
+start() ->
+  spawn(?MODULE,evemon,[orddict:new()]).
+
+reg_future(Name,Call,T) ->
+  eventserv ! {self(),reg,#event{name=Name,server=eventserv,
+    call=Call,period=T,type=oneshot}}.
+
+reg_future(Call,T) ->
+  eventserv ! {self(),reg,#event{name="Unamed",server=eventserv,
+    call=Call,period=T,type=oneshot}}.
+
+reg_periodic(Name,Call,T) ->
+  eventserv ! {self(),reg,#event{name=Name,server=eventserv,
+    call=Call,period=T}}.
+
+reg_periodic(Call,T) ->
+  eventserv ! {self(),reg,#event{name="Unamed",server=eventserv,
+    call=Call,period=T}}.
+
+regevent(Pid,S) ->
+  Pid ! {self(),reg,S}.
+
+test() ->
+  Pid=start(),
+  Pid ! {self(),reg,#event{name="test1",server=Pid,
+    call=fun (PPid) -> io:format("HAHA im here!!!!\n") end,period=1000}},
+  timer:sleep(500),
+  Pid ! {self(),reg,#event{name="test2",server=Pid,
+  call=fun (PPid) -> io:format("HAHA im away and buggy!!!!\n"),exit("I just love to die") end,period=1000}},
+  timer:sleep(10000),
+  Pid ! {self(),shutdown}.
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