|
%% Copyright (c) 2013, Pedram Nimreezi <deadzen@deadzen.com>
|
|
%%
|
|
%% Permission to use, copy, modify, and/or distribute this software for any
|
|
%% purpose with or without fee is hereby granted, provided that the above
|
|
%% copyright notice and this permission notice appear in all copies.
|
|
%%
|
|
%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
|
|
|
|
%% @doc Process table manager for goldrush.
|
|
%%
|
|
%% Manager responsible for the processes, which serve as heir of the
|
|
%% {@link gr_counter:start_link/0. <em>Counter</em>} and
|
|
%% {@link gr_param:start_link/0. <em>Param</em>} ets table processes.
|
|
%% This process creates the table and initial data then assigns itself
|
|
%% to inherit the ets table if any process responsible for it is killed.
|
|
%% It then waits to give it back while that process is recreated by its
|
|
%% supervisor.
|
|
-module(gr_manager).
|
|
-behaviour(gen_server).
|
|
|
|
%% API
|
|
-export([start_link/3, wait_for_pid/1]).
|
|
|
|
%% gen_server callbacks
|
|
-export([init/1,
|
|
handle_call/3,
|
|
handle_cast/2,
|
|
handle_info/2,
|
|
terminate/2,
|
|
code_change/3]).
|
|
|
|
-define(SERVER, ?MODULE).
|
|
|
|
-record(state, {table_id :: ets:tab(), managee :: atom()}).
|
|
|
|
%%%===================================================================
|
|
%%% API
|
|
%%%===================================================================
|
|
|
|
%% Setup the initial data for the ets table
|
|
-spec setup(atom() | pid(), term()) -> ok.
|
|
setup(Name, Data) ->
|
|
gen_server:cast(Name, {setup, Data}).
|
|
|
|
%%--------------------------------------------------------------------
|
|
%% @doc
|
|
%% Starts the server
|
|
%%
|
|
%% @spec start_link(Name, Managee, Data) -> {ok, Pid} | ignore |
|
|
%% {error, Error}
|
|
%% @end
|
|
%%--------------------------------------------------------------------
|
|
start_link(Name, Managee, Data) ->
|
|
gen_server:start_link({local, Name}, ?MODULE, [Managee, Data], []).
|
|
|
|
%%%===================================================================
|
|
%%% gen_server callbacks
|
|
%%%===================================================================
|
|
|
|
%%--------------------------------------------------------------------
|
|
%% @private
|
|
%% @doc
|
|
%% Initializes the server
|
|
%%
|
|
%% @spec init(Args) -> {ok, State} |
|
|
%% {ok, State, Timeout} |
|
|
%% ignore |
|
|
%% {stop, Reason}
|
|
%% @end
|
|
%%--------------------------------------------------------------------
|
|
init([Managee, Data]) ->
|
|
process_flag(trap_exit, true),
|
|
setup(self(), Data),
|
|
{ok, #state{managee=Managee}}.
|
|
|
|
%%--------------------------------------------------------------------
|
|
%% @private
|
|
%% @doc
|
|
%% Handling call messages
|
|
%%
|
|
%% @spec handle_call(Request, From, State) ->
|
|
%% {reply, Reply, State} |
|
|
%% {reply, Reply, State, Timeout} |
|
|
%% {noreply, State} |
|
|
%% {noreply, State, Timeout} |
|
|
%% {stop, Reason, Reply, State} |
|
|
%% {stop, Reason, State}
|
|
%% @end
|
|
%%--------------------------------------------------------------------
|
|
handle_call(_Request, _From, State) ->
|
|
Reply = {error, unhandled_message},
|
|
{reply, Reply, State}.
|
|
|
|
%%--------------------------------------------------------------------
|
|
%% @private
|
|
%% @doc
|
|
%% Handling cast messages
|
|
%%
|
|
%% @spec handle_cast(Msg, State) -> {noreply, State} |
|
|
%% {noreply, State, Timeout} |
|
|
%% {stop, Reason, State}
|
|
%% @end
|
|
%%--------------------------------------------------------------------
|
|
handle_cast({setup, Data}, State = #state{managee=Managee}) ->
|
|
ManageePid = whereis(Managee),
|
|
link(ManageePid),
|
|
TableId = ets:new(?MODULE, [set, private]),
|
|
ets:insert(TableId, Data),
|
|
ets:setopts(TableId, {heir, self(), Data}),
|
|
ets:give_away(TableId, ManageePid, Data),
|
|
{noreply, State#state{table_id=TableId}};
|
|
handle_cast(_Msg, State) ->
|
|
{noreply, State}.
|
|
|
|
%%--------------------------------------------------------------------
|
|
%% @private
|
|
%% @doc
|
|
%% Handling all non call/cast messages
|
|
%%
|
|
%% @spec handle_info(Info, State) -> {noreply, State} |
|
|
%% {noreply, State, Timeout} |
|
|
%% {stop, Reason, State}
|
|
%% @end
|
|
%%--------------------------------------------------------------------
|
|
handle_info({'EXIT', _Pid, _Reason}, State) ->
|
|
{noreply, State};
|
|
handle_info({'ETS-TRANSFER', TableId, _Pid, Data}, State = #state{managee=Managee}) ->
|
|
ManageePid = wait_for_pid(Managee),
|
|
link(ManageePid),
|
|
ets:give_away(TableId, ManageePid, Data),
|
|
{noreply, State#state{table_id=TableId}}.
|
|
|
|
%% @doc Wait for a registered process to be associated to a process identifier.
|
|
%% @spec wait_for_pid(Managee) -> ManageePid
|
|
-spec wait_for_pid(atom()) -> pid().
|
|
wait_for_pid(Managee) when is_atom(Managee), Managee =/= undefined ->
|
|
case whereis(Managee) of
|
|
undefined ->
|
|
timer:sleep(1),
|
|
wait_for_pid(Managee);
|
|
ManageePid -> ManageePid
|
|
end.
|
|
|
|
|
|
|
|
%%--------------------------------------------------------------------
|
|
%% @private
|
|
%% @doc
|
|
%% This function is called by a gen_server when it is about to
|
|
%% terminate. It should be the opposite of Module:init/1 and do any
|
|
%% necessary cleaning up. When it returns, the gen_server terminates
|
|
%% with Reason. The return value is ignored.
|
|
%%
|
|
%% @spec terminate(Reason, State) -> void()
|
|
%% @end
|
|
%%--------------------------------------------------------------------
|
|
terminate(_Reason, _State) ->
|
|
ok.
|
|
|
|
%%--------------------------------------------------------------------
|
|
%% @private
|
|
%% @doc
|
|
%% Convert process state when code is changed
|
|
%%
|
|
%% @spec code_change(OldVsn, State, Extra) -> {ok, NewState}
|
|
%% @end
|
|
%%--------------------------------------------------------------------
|
|
code_change(_OldVsn, State, _Extra) ->
|
|
{ok, State}.
|
|
|
|
%%%===================================================================
|
|
%%% Internal functions
|
|
%%%===================================================================
|
|
|
|
|
|
|