single_session.erl

-module(single_session).

-behaviour(gen_server).

%% API
-export([start_link/0]).

%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
         terminate/2, code_change/3]).

-define(SERVER, ?MODULE). 
-define(MNESIA, 'mnesia@127.0.0.1').

-record(user, {userid, pid}).

-record(state, {}).

start_link() ->
    gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).

init([]) ->
    {ok, #state{}}.

handle_call({set, A}, _, State) ->
    {ok, Pid} = test_instance:start_link(),
    lager:debug("____~p",[rpc:call(?MNESIA, session_manager, set, [{A, Pid, node()}])]),
    {reply, ok, State};

handle_call({get, A}, _, State) ->
    P =
        case rpc:call(?MNESIA, session_manager, get, [{A}]) of
            [] ->
                undefined;
            [#user{pid = {Pid, _}}] ->
                Pid
        end,
    {reply, P, State};

handle_call(_Request, _From, State) ->
    Reply = ok,
    {reply, Reply, State}.

handle_cast(_Msg, State) ->
    {noreply, State}.

handle_info(_Info, State) ->
    {noreply, State}.

terminate(_Reason, _State) ->
    ok.

code_change(_OldVsn, State, _Extra) ->
    {ok, State}.