%%--------------------------------------------------------------------
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2009. All Rights Reserved.
%%
%% 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 online 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.
%%
%% %CopyrightEnd%
%%
%%
%%-----------------------------------------------------------------
%% File: orber_objectkeys.erl
%%
%% Description:
%% This file contains the object keyserver in Orber
%%
%%-----------------------------------------------------------------
-module(orber_objectkeys).
-behaviour(gen_server).
-include_lib("orber/include/corba.hrl").
%%-----------------------------------------------------------------
%% External exports
%%-----------------------------------------------------------------
-export([start/1, stop/0, stop_all/0, get_pid/1, is_persistent/1,
register/2, register/3, delete/1, create_schema/1, check/1,
remove_old_keys/0]).
%%-----------------------------------------------------------------
%% Internal exports
%%-----------------------------------------------------------------
-export([init/1, terminate/2, install/2, handle_call/3, handle_info/2, code_change/3]).
-export([handle_cast/2, dump/0, get_key_from_pid/1, gc/1]).
%%-----------------------------------------------------------------
%% Mnesia Table definition record
%%-----------------------------------------------------------------
-record(orber_objkeys, {object_key, pid, persistent=false, timestamp}).
%%-----------------------------------------------------------------
%% Macros
%%-----------------------------------------------------------------
-define(dirty_query_context, true).
%% This macro returns a read fun suitable for evaluation in a transaction
-define(read_function(Objkey),
fun() ->
mnesia:dirty_read(Objkey)
end).
%% This macro returns a write fun suitable for evaluation in a transaction
-define(write_function(R),
fun() ->
mnesia:dirty_write(R)
end).
%% This macro returns a delete fun suitable for evaluation in a transaction
-define(delete_function(R),
fun() ->
mnesia:delete(R)
end).
%% Use this fun inside a transaction to get a list of all keys.
-define(match_function(),
fun() ->
mnesia:match_object({orber_objkeys, '_', '_','_','_'})
end).
-ifdef(dirty_query_context).
-define(query_check(Q_res), Q_res).
-else.
-define(query_check(Q_res), {atomic, Q_res}).
-endif.
-define(CHECK_EXCEPTION(Res), case Res of
{'EXCEPTION', E} ->
corba:raise(E);
R ->
R
end).
-define(DEBUG_LEVEL, 6).
%%-----------------------------------------------------------------
%% Debugging function
%%-----------------------------------------------------------------
dump() ->
case catch mnesia:dirty_first('orber_objkeys') of
{'EXIT', R} ->
io:format("Exited with ~p\n",[R]);
Key ->
dump_print(Key),
dump_loop(Key)
end.
dump_loop(PreviousKey) ->
case catch mnesia:dirty_next('orber_objkeys', PreviousKey) of
{'EXIT', R} ->
io:format("Exited with ~p\n",[R]);
'$end_of_table' ->
ok;
Key ->
dump_print(Key),
dump_loop(Key)
end.
dump_print(Key) ->
case catch mnesia:dirty_read({'orber_objkeys', Key}) of
{'EXIT', R} ->
io:format("Exited with ~p\n",[R]);
[X] ->
io:format("object_key: ~p, pid: ~p, persistent: ~p, timestamp: ~p\n",
[binary_to_term(X#orber_objkeys.object_key),
X#orber_objkeys.pid,
X#orber_objkeys.persistent,
X#orber_objkeys.timestamp]);
_ ->
ok
end.
%%-----------------------------------------------------------------
%% External interface functions
%%-----------------------------------------------------------------
start(Opts) ->
gen_server:start_link({local, orber_objkeyserver}, orber_objectkeys, Opts, []).
stop() ->
gen_server:call(orber_objkeyserver, stop, infinity).
remove_old_keys() ->
%% This function may ONLY be used when restarting a crashed node.
%% We must remove all objects started with {global, "name"} otherwise
%% we cannot restart the node using the same name.
Fun = fun() ->
Node = node(),
mnesia:write_lock_table(orber_objkeys),
Objects = mnesia:match_object(orber_objkeys,
mnesia:table_info(orber_objkeys,
wild_pattern),
read),
lists:foreach(fun(Obj) ->
case node(Obj#orber_objkeys.pid) of
Node ->
mnesia:delete({orber_objkeys,
Obj#orber_objkeys.object_key});
_->
ok
end
end,
Objects),
ok
end,
write_result(mnesia:transaction(Fun)).
stop_and_remove_local(Reason) ->
%% This function may ONLY be used when this server terminates with reason
%% normal or shutdown.
Fun = fun() ->
Node = node(),
mnesia:write_lock_table(orber_objkeys),
Objects = mnesia:match_object(orber_objkeys,
mnesia:table_info(orber_objkeys,
wild_pattern),
read),
lists:foreach(fun(Obj) ->
case node(Obj#orber_objkeys.pid) of
Node ->
exit(Obj#orber_objkeys.pid, Reason),
mnesia:delete({orber_objkeys,
Obj#orber_objkeys.object_key});
_->
ok
end
end,
Objects),
ok
end,
write_result(mnesia:transaction(Fun)).
stop_all() ->
Fun = ?match_function(),
case mnesia:transaction(Fun) of
{atomic, Objects} ->
lists:foreach(fun(Obj) ->
gen_server:call(Obj#orber_objkeys.pid,
stop, infinity)
end,
Objects);
R ->
R
end.
get_pid(Objkey) ->
case catch ets:lookup_element(orber_objkeys, Objkey, 3) of
Pid when is_pid(Pid) ->
Pid;
dead ->
{error, "unable to contact object"};
_ ->
%% This call is necessary if a persistent object have died
%% and the objectkey server is currently updating the Pid
%% to equal 'dead'. Without this case 'OBJECT_NOT_EXIST'
%% would be raised which is uncorrect if the object is
%% persistent.
?CHECK_EXCEPTION(gen_server:call(orber_objkeyserver,
{get_pid, Objkey},
infinity))
end.
is_persistent(Pid) when is_pid(Pid) ->
case catch get_key_from_pid(Pid) of
{'EXCEPTION', _} ->
corba:raise(#'OBJECT_NOT_EXIST'{completion_status=?COMPLETED_NO});
Key ->
is_persistent(Key)
end;
is_persistent(Objkey) ->
case catch ets:lookup_element(orber_objkeys, Objkey, 4) of
{'EXIT', _R} ->
corba:raise(#'OBJECT_NOT_EXIST'{completion_status=?COMPLETED_NO});
Boolean ->
Boolean
end.
gc(Sec) when is_integer(Sec) ->
Fun = fun() ->
mnesia:write_lock_table(orber_objkeys),
Objects = mnesia:match_object({orber_objkeys, '_', dead, true,'_'}),
lists:foreach(fun(Obj) ->
case timetest(Sec, Obj#orber_objkeys.timestamp) of
true ->
mnesia:delete({orber_objkeys,
Obj#orber_objkeys.object_key});
_->
ok
end
end,
Objects),
ok
end,
write_result(mnesia:transaction(Fun)).
register(Objkey, Pid) ->
'register'(Objkey, Pid, false).
register(Objkey, Pid, Type) when is_pid(Pid) ->
?CHECK_EXCEPTION(gen_server:call(orber_objkeyserver,
{register, Objkey, Pid, Type},
infinity));
register(Objkey, Pid, Type) ->
orber:dbg("[~p] orber_objectkeys:register(~p, ~p); Not a Pid ~p",
[?LINE, Objkey, Type, Pid], ?DEBUG_LEVEL),
corba:raise(#'INTERNAL'{completion_status=?COMPLETED_NO}).
delete(Objkey) ->
?CHECK_EXCEPTION(gen_server:call(orber_objkeyserver,
{delete, Objkey}, infinity)).
check(Objkey) ->
?CHECK_EXCEPTION(gen_server:call(orber_objkeyserver,
{check, Objkey}, infinity)).
%%-----------------------------------------------------------------
%% Server functions
%%-----------------------------------------------------------------
init(_Env) ->
case mnesia:wait_for_tables(['orber_objkeys'], infinity) of
ok ->
process_flag(trap_exit, true),
start_gc_timer(orber:objectkeys_gc_time());
StopReason ->
{stop, StopReason}
end.
terminate(shutdown, _State) ->
stop_and_remove_local(shutdown),
ok;
terminate(normal, _State) ->
stop_and_remove_local(normal),
ok;
terminate(_Reason, _State) ->
ok.
start_gc_timer(infinity) ->
{ok, []};
start_gc_timer(Time) ->
timer:start(),
case timer:send_after(timer:seconds(Time),
orber_objkeyserver, {oe_gc, Time}) of
{ok, _} ->
{ok, []};
StopReason ->
{stop, StopReason}
end.
install(Timeout, Options) ->
%% check if there already exists a database. If not, create one.
%% DB_initialized = perhaps_create_schema(Nodelist),
%% check if mnesia is running. If not, start mnesia.
perhaps_start_mnesia(),
%% Do we have a complete set of IFR tables? If not, create them.
AllTabs = mnesia:system_info(tables),
DB_Result = case lists:member(orber_objkeys, AllTabs) of
true ->
case lists:member({local_content, true},
Options) of
true->
mnesia:add_table_copy(orber_objkeys,
node(),
ram_copies);
_ ->
mnesia:create_table(orber_objkeys,
[{attributes,
record_info(fields,
orber_objkeys)}
|Options])
end;
_ ->
mnesia:create_table(orber_objkeys,
[{attributes,
record_info(fields,
orber_objkeys)}
|Options])
end,
Wait = mnesia:wait_for_tables([orber_objkeys], Timeout),
%% Check if any error has occured yet. If there are errors, return them.
if
DB_Result == {atomic, ok},
Wait == ok ->
ok;
true ->
{error, {DB_Result, Wait}}
end.
%%-----------------------------------------------------------------
%% Func: handle_call/3
%%
%% Comment:
%% In objectkey gen_server all exceptions are tupples and corba:raise
%% may not be used. It is too time consuming to add catches in every
%% function before returning. On the client side there is a case which
%% maps every tupple on the format {'exception', E} to corba:raise(E).
%%-----------------------------------------------------------------
handle_call(stop, _From, State) ->
{stop, normal, [], State};
handle_call({get, Objkey}, _From, State) ->
R = query_result(mnesia:dirty_read({orber_objkeys, Objkey})),
{reply, R, State};
handle_call({register, Objkey, Pid, Type}, _From, State) ->
_WF = fun() ->
case mnesia:wread({orber_objkeys, Objkey}) of
[] ->
%% No key exists. Ok to register.
mnesia:write(#orber_objkeys{object_key=Objkey, pid=Pid,
persistent=Type,
timestamp=now()});
[X] when X#orber_objkeys.persistent==true,
X#orber_objkeys.pid == dead ->
%% A persistent object is being restarted. Update Pid & time.
mnesia:write(X#orber_objkeys{pid=Pid, timestamp=now()});
[X] when is_pid(X#orber_objkeys.pid) ->
%% Object exists, i.e., trying to create an object with
%% the same name.
orber:dbg("[~p] orber_objectkeys:register(~p, ~p); Object already exists.",
[?LINE, Objkey, Type], ?DEBUG_LEVEL),
{'EXCEPTION', #'BAD_PARAM'{completion_status=?COMPLETED_NO}};
Why ->
%% Something else occured.
orber:dbg("[~p] orber_objectkeys:register(~p, ~p); error reading from DB(~p)",
[?LINE, Objkey, Type, Why], ?DEBUG_LEVEL),
{'EXCEPTION', #'INTERNAL'{completion_status=?COMPLETED_NO}}
end
end,
R = write_result(mnesia:transaction(_WF)),
if
R == ok andalso is_pid(Pid) ->
link(Pid);
true ->
true
end,
{reply, R, State};
handle_call({delete, Objkey}, _From, State) ->
?query_check(Qres) = mnesia:dirty_read({orber_objkeys, Objkey}),
case Qres of
[] ->
true;
[X] when is_pid(X#orber_objkeys.pid) ->
unlink(X#orber_objkeys.pid);
_ ->
true
end,
_F = ?delete_function({orber_objkeys, Objkey}),
R = write_result(mnesia:transaction(_F)),
{reply, R, State};
handle_call({get_pid, Objkey}, _From, State) ->
_F = fun() ->
mnesia:read({orber_objkeys, Objkey})
end,
case mnesia:transaction(_F) of
{atomic, [X]} when is_pid(X#orber_objkeys.pid) ->
{reply, X#orber_objkeys.pid, State};
{atomic, [X]} when X#orber_objkeys.pid == dead ->
{reply,
{'EXCEPTION', #'TRANSIENT'{completion_status=?COMPLETED_NO}},
State};
_Res ->
{reply,
{'EXCEPTION', #'OBJECT_NOT_EXIST'{completion_status=?COMPLETED_NO}},
State}
end;
handle_call({check, {_, 'key', Objkey, _, _, _}}, _From, State) ->
?query_check(Qres) = mnesia:dirty_read({orber_objkeys, Objkey}),
case Qres of
[_X] ->
{reply, 'object_here', State};
_ ->
{reply, 'unknown_object', State}
end;
handle_call({check, {_, 'registered', Objkey, _, _, _}}, _From, State) ->
case whereis(Objkey) of
undefined ->
case catch ets:lookup_element(orber_objkeys, Objkey, 4) of
true ->
{reply, 'object_here', State};
_->
{reply, 'unknown_object', State}
end;
_ ->
{reply, 'object_here', State}
end;
handle_call({check, {_, 'pseudo', Module, _, _, _}}, _From, State) ->
case code:is_loaded(Module) of
false ->
{reply, 'unknown_object', State};
_ ->
{reply, 'object_here', State}
end;
handle_call({check, "INIT"}, _From, State) ->
{reply, 'object_here', State};
handle_call({check, _}, _From, State) ->
{reply, 'unknown_object', State}.
handle_info({'EXIT', Pid, Reason}, State) when is_pid(Pid) ->
_WF = fun() ->
case mnesia:match_object({orber_objkeys, '_', Pid,'_','_'}) of
[] ->
ok;
[X] when X#orber_objkeys.persistent==false ->
mnesia:delete({orber_objkeys, X#orber_objkeys.object_key});
[X] when is_pid(X#orber_objkeys.pid) andalso
X#orber_objkeys.persistent==true andalso
Reason /= normal andalso
Reason /= shutdown ->
mnesia:write(X#orber_objkeys{pid=dead,
timestamp=now()});
[X] when X#orber_objkeys.persistent==true ->
mnesia:delete({orber_objkeys, X#orber_objkeys.object_key});
_->
ok
end
end,
case write_result(mnesia:transaction(_WF)) of
ok ->
unlink(Pid);
_->
true
end,
{noreply, State};
handle_info({oe_gc, Secs}, State) ->
catch gc(Secs),
{noreply, State}.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%-----------------------------------------------------------------
%% Internal Functions
%%-----------------------------------------------------------------
timetest(S, {MeSec, Sec, USec}) ->
{MeSec, Sec+S, USec} < now().
get_key_from_pid(Pid) ->
case mnesia:dirty_match_object({orber_objkeys, '_', Pid,'_','_'}) of
[Keys] ->
Keys#orber_objkeys.object_key;
_ ->
corba:raise(#'OBJECT_NOT_EXIST'{completion_status=?COMPLETED_NO})
end.
%remove_keys([], _) ->
% ok;
%remove_keys([H|T], R) when H#orber_objkeys.persistent==false ->
% _F = ?delete_function({orber_objkeys, H#orber_objkeys.object_key}),
% write_result(mnesia:transaction(_F)),
% remove_keys(T, R).
%%-----------------------------------------------------------------
%% Check a read transaction
query_result(?query_check(Qres)) ->
case Qres of
[Hres] ->
Hres#orber_objkeys.pid;
[] ->
{'EXCEPTION', #'OBJECT_NOT_EXIST'{completion_status=?COMPLETED_NO}};
Other ->
orber:dbg("[~p] orber_objectkeys:query_result(); DB lookup failed(~p)",
[?LINE, Other], ?DEBUG_LEVEL),
{'EXCEPTION', #'INTERNAL'{completion_status=?COMPLETED_NO}}
end.
%%-----------------------------------------------------------------
%% Check a write transaction
write_result({atomic,ok}) -> ok;
write_result(Foo) ->
orber:dbg("[~p] orber_objectkeys:query_result(); DB write failed(~p)",
[?LINE, Foo], ?DEBUG_LEVEL),
{'EXCEPTION', #'INTERNAL'{completion_status=?COMPLETED_NO}}.
create_schema(Nodes) ->
case mnesia:system_info(use_dir) of
false ->
mnesia:create_schema(Nodes);
_ ->
ok
end.
perhaps_start_mnesia() ->
case mnesia:system_info(is_running) of
no ->
mnesia:start();
_ ->
ok
end.
%%------------------------------------------------------------
%% Standard gen_server cast handle
%%
handle_cast(_, State) ->
{noreply, State}.
