mnesia locs

loop(State) ->
    receive
	{From, {write, Tid, Oid}} ->
	    try_sticky_lock(Tid, write, From, Oid),
	    loop(State);

	%% If Key == ?ALL it's a request to lock the entire table
	%%

	{From, {read, Tid, Oid}} ->
	    try_sticky_lock(Tid, read, From, Oid),
	    loop(State);

	%% Really do a  read, but get hold of a write lock
	%% used by mnesia:wread(Oid).

	{From, {read_write, Tid, Oid}} ->
	    try_sticky_lock(Tid, read_write, From, Oid),
	    loop(State);

	%% Tid has somehow terminated, clear up everything
	%% and pass locks on to queued processes.
	%% This is the purpose of the mnesia_tid_locks table

	{release_tid, Tid} ->
	    do_release_tid(Tid),
	    loop(State);

	%% stick lock, first tries this to the where_to_read Node
	{From, {test_set_sticky, Tid, {Tab, _} = Oid, Lock}} ->
	    case ?ets_lookup(mnesia_sticky_locks, Tab) of
		[] ->
		    reply(From, not_stuck),
		    loop(State);
		[{_,Node}] when Node == node() ->
		    %% Lock is stuck here, see now if we can just set
		    %% a regular write lock
		    try_lock(Tid, Lock, From, Oid),
		    loop(State);
		[{_,Node}] ->
		    reply(From, {stuck_elsewhere, Node}),
		    loop(State)
	    end;

	%% If test_set_sticky fails, we send this to all nodes
	%% after aquiring a real write lock on Oid

	{stick, {Tab, _}, N} ->
	    ?ets_insert(mnesia_sticky_locks, {Tab, N}),
	    loop(State);

	%% The caller which sends this message, must have first
	%% aquired a write lock on the entire table
	{unstick, Tab} ->
	    ?ets_delete(mnesia_sticky_locks, Tab),
	    loop(State);

	{From, {ix_read, Tid, Tab, IxKey, Pos}} ->
	    case ?ets_lookup(mnesia_sticky_locks, Tab) of
		[] ->
		    set_read_lock_on_all_keys(Tid,From,Tab,IxKey,Pos),
		    loop(State);
		[{_,N}] when N == node() ->
		    set_read_lock_on_all_keys(Tid,From,Tab,IxKey,Pos),
		    loop(State);
		[{_,N}] ->
		    Req = {From, {ix_read, Tid, Tab, IxKey, Pos}},
		    From ! {?MODULE, node(), {switch, N, Req}},
		    loop(State)
	    end;

	{From, {sync_release_tid, Tid}} ->
	    do_release_tid(Tid),
	    reply(From, {tid_released, Tid}),
	    loop(State);

	{{From, Ref},{release_remote_non_pending, Node, Pending}} ->
	    release_remote_non_pending(Node, Pending),
	    From ! {Ref, ok},
	    loop(State);

	{From, {is_locked, Oid}} ->
	    Held = ?ets_lookup(mnesia_held_locks, Oid),
	    reply(From, Held),
	    loop(State);

	{'EXIT', Pid, _} when Pid == State#state.supervisor ->
	    do_stop();

	{system, From, Msg} ->
	    verbose("~p got {system, ~p, ~p}~n", [?MODULE, From, Msg]),
	    Parent = State#state.supervisor,
	    sys:handle_system_msg(Msg, From, Parent, ?MODULE, [], State);

	{get_table, From, LockTable} ->
	    From ! {LockTable, ?ets_match_object(LockTable, '_')},
	    loop(State);

	Msg ->
	    error("~p got unexpected message: ~p~n", [?MODULE, Msg]),
	    loop(State)
    end.