baberl_loader.erl

%% Copyright (c) 2009 Electronic Arts, Inc.

%% Permission is hereby granted, free of charge, to any person obtaining a copy
%% of this software and associated documentation files (the "Software"), to deal
%% in the Software without restriction, including without limitation the rights
%% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
%% copies of the Software, and to permit persons to whom the Software is
%% furnished to do so, subject to the following conditions:
%%
%% The above copyright notice and this permission notice shall be included in
%% all copies or substantial portions of the Software.
%%
%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
%% THE SOFTWARE.

-module(baberl_loader).

-behaviour(gen_server).

-export([start_link/0]).

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

start_link() ->
  gen_server:start_link(?MODULE, [], []).

init([]) ->
  case load_driver() of
    ok ->
      {ok, undefined};
    Error ->
      {stop, Error}
  end.

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) ->
  erl_ddll:unload(baberl_drv).

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

%% Internal functions
load_driver() ->
  Dir = filename:join([filename:dirname(code:which(baberl)), "..", "priv"]),
  case erl_ddll:load(Dir, baberl_drv) of
    ok ->
      ok;
    {error, Error} ->
      erl_ddll:format_error(Error)
  end.