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-rw-r--r--lib/mnesia/src/mnesia_locker.erl100
1 files changed, 53 insertions, 47 deletions
diff --git a/lib/mnesia/src/mnesia_locker.erl b/lib/mnesia/src/mnesia_locker.erl
index 55df074c29..a9eb27dea2 100644
--- a/lib/mnesia/src/mnesia_locker.erl
+++ b/lib/mnesia/src/mnesia_locker.erl
@@ -235,17 +235,17 @@ loop(State) ->
loop(State)
end.
-set_lock(Tid, Oid, Op) ->
- ?dbg("Granted ~p ~p ~p~n", [Tid,Oid,Op]),
- case ?ets_lookup(mnesia_held_locks, Oid) of
- [] ->
- ?ets_insert(mnesia_held_locks, {Oid, Op, [{Op, Tid}]});
- [{Oid, Prev, Items}] when Op == read ->
- ?ets_insert(mnesia_held_locks, {Oid, Prev, [{Op, Tid}|Items]});
- [{Oid, _, Items}] when Op == write ->
- ?ets_insert(mnesia_held_locks, {Oid, Op, [{Op, Tid}|Items]})
- end,
- ?ets_insert(mnesia_tid_locks, {Tid, Oid, Op}).
+set_lock(Tid, Oid, Op, []) ->
+ ?ets_insert(mnesia_tid_locks, {Tid, Oid, Op}),
+ ?ets_insert(mnesia_held_locks, {Oid, Op, [{Op, Tid}]});
+set_lock(Tid, Oid, read, [{Oid, Prev, Items}]) ->
+ ?ets_insert(mnesia_tid_locks, {Tid, Oid, read}),
+ ?ets_insert(mnesia_held_locks, {Oid, Prev, [{read, Tid}|Items]});
+set_lock(Tid, Oid, write, [{Oid, _Prev, Items}]) ->
+ ?ets_insert(mnesia_tid_locks, {Tid, Oid, write}),
+ ?ets_insert(mnesia_held_locks, {Oid, write, [{write, Tid}|Items]});
+set_lock(Tid, Oid, Op, undefined) ->
+ set_lock(Tid, Oid, Op, ?ets_lookup(mnesia_held_locks, Oid)).
%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Acquire locks
@@ -268,14 +268,14 @@ try_lock(Tid, Op, Pid, Oid) ->
try_lock(Tid, Op, SimpleOp, Lock, Pid, Oid) ->
case can_lock(Tid, Lock, Oid, {no, bad_luck}) of
- yes ->
- Reply = grant_lock(Tid, SimpleOp, Lock, Oid),
+ {yes, Default} ->
+ Reply = grant_lock(Tid, SimpleOp, Lock, Oid, Default),
reply(Pid, Reply);
- {no, Lucky} ->
+ {{no, Lucky},_} ->
C = #cyclic{op = SimpleOp, lock = Lock, oid = Oid, lucky = Lucky},
?dbg("Rejected ~p ~p ~p ~p ~n", [Tid, Oid, Lock, Lucky]),
reply(Pid, {not_granted, C});
- {queue, Lucky} ->
+ {{queue, Lucky},_} ->
?dbg("Queued ~p ~p ~p ~p ~n", [Tid, Oid, Lock, Lucky]),
%% Append to queue: Nice place for trace output
?ets_insert(mnesia_lock_queue,
@@ -284,16 +284,16 @@ try_lock(Tid, Op, SimpleOp, Lock, Pid, Oid) ->
?ets_insert(mnesia_tid_locks, {Tid, Oid, {queued, Op}})
end.
-grant_lock(Tid, read, Lock, Oid = {Tab, Key})
+grant_lock(Tid, read, Lock, Oid = {Tab, Key}, Default)
when Key /= ?ALL, Tab /= ?GLOBAL ->
case node(Tid#tid.pid) == node() of
true ->
- set_lock(Tid, Oid, Lock),
+ set_lock(Tid, Oid, Lock, Default),
{granted, lookup_in_client};
false ->
try
Val = mnesia_lib:db_get(Tab, Key), %% lookup as well
- set_lock(Tid, Oid, Lock),
+ set_lock(Tid, Oid, Lock, Default),
{granted, Val}
catch _:_Reason ->
%% Table has been deleted from this node,
@@ -303,19 +303,19 @@ grant_lock(Tid, read, Lock, Oid = {Tab, Key})
{not_granted, C}
end
end;
-grant_lock(Tid, {ix_read,IxKey,Pos}, Lock, Oid = {Tab, _}) ->
+grant_lock(Tid, {ix_read,IxKey,Pos}, Lock, Oid = {Tab, _}, Default) ->
try
Res = ix_read_res(Tab, IxKey,Pos),
- set_lock(Tid, Oid, Lock),
+ set_lock(Tid, Oid, Lock, Default),
{granted, Res, [?ALL]}
catch _:_ ->
{not_granted, {no_exists, Tab, {index, [Pos]}}}
end;
-grant_lock(Tid, read, Lock, Oid) ->
- set_lock(Tid, Oid, Lock),
+grant_lock(Tid, read, Lock, Oid, Default) ->
+ set_lock(Tid, Oid, Lock, Default),
{granted, ok};
-grant_lock(Tid, write, Lock, Oid) ->
- set_lock(Tid, Oid, Lock),
+grant_lock(Tid, write, Lock, Oid, Default) ->
+ set_lock(Tid, Oid, Lock, Default),
granted.
%% 1) Impose an ordering on all transactions favour old (low tid) transactions
@@ -325,28 +325,29 @@ grant_lock(Tid, write, Lock, Oid) ->
%% 3) TabLocks is the problem :-) They should not starve and not deadlock
%% handle tablocks in queue as they had locks on unlocked records.
-can_lock(Tid, read, {Tab, Key}, AlreadyQ) when Key /= ?ALL ->
- %% The key is bound, no need for the other BIF
- Oid = {Tab, Key},
- ObjLocks = filter_write(?ets_lookup(mnesia_held_locks, Oid)),
- TabLocks = filter_write(?ets_lookup(mnesia_held_locks, {Tab, ?ALL})),
- check_lock(Tid, Oid, ObjLocks, TabLocks, yes, AlreadyQ, read);
+can_lock(Tid, read, Oid = {Tab, Key}, AlreadyQ) when Key /= ?ALL ->
+ ObjLocks = ?ets_lookup(mnesia_held_locks, Oid),
+ TabLocks = ?ets_lookup(mnesia_held_locks, {Tab, ?ALL}),
+ {check_lock(Tid, Oid,
+ filter_write(ObjLocks),
+ filter_write(TabLocks),
+ yes, AlreadyQ, read),
+ ObjLocks};
can_lock(Tid, read, Oid, AlreadyQ) -> % Whole tab
Tab = element(1, Oid),
ObjLocks = ?ets_match_object(mnesia_held_locks, {{Tab, '_'}, write, '_'}),
- check_lock(Tid, Oid, ObjLocks, [], yes, AlreadyQ, read);
+ {check_lock(Tid, Oid, ObjLocks, [], yes, AlreadyQ, read), undefined};
-can_lock(Tid, write, {Tab, Key}, AlreadyQ) when Key /= ?ALL ->
- Oid = {Tab, Key},
+can_lock(Tid, write, Oid = {Tab, Key}, AlreadyQ) when Key /= ?ALL ->
ObjLocks = ?ets_lookup(mnesia_held_locks, Oid),
TabLocks = ?ets_lookup(mnesia_held_locks, {Tab, ?ALL}),
- check_lock(Tid, Oid, ObjLocks, TabLocks, yes, AlreadyQ, write);
+ {check_lock(Tid, Oid, ObjLocks, TabLocks, yes, AlreadyQ, write), ObjLocks};
can_lock(Tid, write, Oid, AlreadyQ) -> % Whole tab
Tab = element(1, Oid),
ObjLocks = ?ets_match_object(mnesia_held_locks, ?match_oid_held_locks({Tab, '_'})),
- check_lock(Tid, Oid, ObjLocks, [], yes, AlreadyQ, write).
+ {check_lock(Tid, Oid, ObjLocks, [], yes, AlreadyQ, write), undefined}.
filter_write([{_, read, _}]) -> [];
filter_write(Res) -> Res.
@@ -366,8 +367,7 @@ check_lock(_, _, [], [], X, {queue, bad_luck}, _) ->
check_lock(_, _, [], [], X = {queue, _Tid}, _AlreadyQ, _) ->
X;
-check_lock(Tid, Oid, [], [], X, AlreadyQ, Type) ->
- {Tab, Key} = Oid,
+check_lock(Tid, Oid = {Tab, Key}, [], [], X, AlreadyQ, Type) ->
if
Type == write ->
check_queue(Tid, Tab, X, AlreadyQ);
@@ -467,14 +467,14 @@ set_read_lock_on_all_keys(Tid, From, Tab, IxKey, Pos) ->
Op = {ix_read,IxKey, Pos},
Lock = read,
case can_lock(Tid, Lock, Oid, {no, bad_luck}) of
- yes ->
- Reply = grant_lock(Tid, Op, Lock, Oid),
+ {yes, Default} ->
+ Reply = grant_lock(Tid, Op, Lock, Oid, Default),
reply(From, Reply);
- {no, Lucky} ->
+ {{no, Lucky},_} ->
C = #cyclic{op = Op, lock = Lock, oid = Oid, lucky = Lucky},
?dbg("Rejected ~p ~p ~p ~p ~n", [Tid, Oid, Lock, Lucky]),
reply(From, {not_granted, C});
- {queue, Lucky} ->
+ {{queue, Lucky},_} ->
?dbg("Queued ~p ~p ~p ~p ~n", [Tid, Oid, Lock, Lucky]),
%% Append to queue: Nice place for trace output
?ets_insert(mnesia_lock_queue,
@@ -531,11 +531,11 @@ release_locks([]) ->
release_lock({Tid, Oid, {queued, _}}) ->
?ets_match_delete(mnesia_lock_queue, #queue{oid=Oid, tid = Tid, op = '_',
pid = '_', lucky = '_'});
-release_lock({This, Oid, Op}) ->
+release_lock({Tid, Oid, Op}) ->
case ?ets_lookup(mnesia_held_locks, Oid) of
[] -> ok;
[{Oid, Prev, Locks0}] ->
- Locks = [{TOp, Tid} || {TOp, Tid} <- Locks0, Tid =/= This],
+ Locks = remove_tid(Locks0, Tid, []),
if Locks =:= [] ->
?ets_delete(mnesia_held_locks, Oid);
Op =:= read ->
@@ -550,6 +550,12 @@ release_lock({This, Oid, Op}) ->
end
end.
+remove_tid([{_Op, Tid}|Ls], Tid, Acc) ->
+ remove_tid(Ls,Tid, Acc);
+remove_tid([Keep|Ls], Tid, Acc) ->
+ remove_tid(Ls,Tid, [Keep|Acc]);
+remove_tid([], _, Acc) -> Acc.
+
rearrange_queue([{_Tid, {Tab, Key}, _} | Locks]) ->
if
Key /= ?ALL->
@@ -614,18 +620,18 @@ try_waiter({queue, Oid, Tid, Op, ReplyTo, _}) ->
try_waiter(Oid, Op, SimpleOp, Lock, ReplyTo, Tid) ->
case can_lock(Tid, Lock, Oid, {queue, bad_luck}) of
- yes ->
+ {yes, Default} ->
%% Delete from queue: Nice place for trace output
?ets_match_delete(mnesia_lock_queue,
#queue{oid=Oid, tid = Tid, op = Op,
pid = ReplyTo, lucky = '_'}),
- Reply = grant_lock(Tid, SimpleOp, Lock, Oid),
+ Reply = grant_lock(Tid, SimpleOp, Lock, Oid, Default),
reply(ReplyTo,Reply),
locked;
- {queue, _Why} ->
+ {{queue, _Why}, _} ->
?dbg("Keep ~p ~p ~p ~p~n", [Tid, Oid, Lock, _Why]),
queued; % Keep waiter in queue
- {no, Lucky} ->
+ {{no, Lucky}, _} ->
C = #cyclic{op = SimpleOp, lock = Lock, oid = Oid, lucky = Lucky},
verbose("** WARNING ** Restarted transaction, possible deadlock in lock queue ~w: cyclic = ~w~n",
[Tid, C]),
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 04:01:34 +0000