diff options
Diffstat (limited to 'lib/mnesia')
| -rw-r--r-- | lib/mnesia/src/mnesia_locker.erl | 74 |
1 files changed, 36 insertions, 38 deletions
diff --git a/lib/mnesia/src/mnesia_locker.erl b/lib/mnesia/src/mnesia_locker.erl index de4811f8e4..6e21332480 100644 --- a/lib/mnesia/src/mnesia_locker.erl +++ b/lib/mnesia/src/mnesia_locker.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 1996-2011. All Rights Reserved. +%% Copyright Ericsson AB 1996-2012. 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 @@ -66,8 +66,8 @@ -record(queue, {oid, tid, op, pid, lucky}). -%% mnesia_held_locks: contain {Oid, Op, Tid} entries (bag) --define(match_oid_held_locks(Oid), {Oid, '_', '_'}). +%% mnesia_held_locks: contain {{Oid,Tid}, Op} entries +-define(match_oid_held_locks(Oid), {{Oid, '_'}, '_'}). %% mnesia_tid_locks: contain {Tid, Oid, Op} entries (bag) -define(match_oid_tid_locks(Tid), {Tid, '_', '_'}). %% mnesia_sticky_locks: contain {Oid, Node} entries and {Tab, Node} entries (set) @@ -83,7 +83,7 @@ start() -> init(Parent) -> register(?MODULE, self()), process_flag(trap_exit, true), - ?ets_new_table(mnesia_held_locks, [bag, private, named_table]), + ?ets_new_table(mnesia_held_locks, [ordered_set, private, named_table]), ?ets_new_table(mnesia_tid_locks, [bag, private, named_table]), ?ets_new_table(mnesia_sticky_locks, [set, private, named_table]), ?ets_new_table(mnesia_lock_queue, [bag, private, named_table, {keypos, 2}]), @@ -237,7 +237,7 @@ loop(State) -> set_lock(Tid, Oid, Op) -> ?dbg("Granted ~p ~p ~p~n", [Tid,Oid,Op]), - ?ets_insert(mnesia_held_locks, {Oid, Op, Tid}), + ?ets_insert(mnesia_held_locks, {{Oid, Tid}, Op}), ?ets_insert(mnesia_tid_locks, {Tid, Oid, Op}). %%%%%%%%%%%%%%%%%%%%%%%%%%% @@ -321,19 +321,19 @@ grant_lock(Tid, write, Lock, Oid) -> can_lock(Tid, read, {Tab, Key}, AlreadyQ) when Key /= ?ALL -> %% The key is bound, no need for the other BIF Oid = {Tab, Key}, - ObjLocks = ?ets_match_object(mnesia_held_locks, {Oid, write, '_'}), - TabLocks = ?ets_match_object(mnesia_held_locks, {{Tab, ?ALL}, write, '_'}), + ObjLocks = ?ets_match_object(mnesia_held_locks, {{Oid, '_'}, write}), + TabLocks = ?ets_match_object(mnesia_held_locks, {{{Tab, ?ALL}, '_'}, write}), check_lock(Tid, Oid, ObjLocks, TabLocks, yes, AlreadyQ, read); can_lock(Tid, read, Oid, AlreadyQ) -> % Whole tab Tab = element(1, Oid), - ObjLocks = ?ets_match_object(mnesia_held_locks, {{Tab, '_'}, write, '_'}), + ObjLocks = ?ets_match_object(mnesia_held_locks, {{{Tab, '_'}, '_'}, write}), check_lock(Tid, Oid, ObjLocks, [], yes, AlreadyQ, read); can_lock(Tid, write, {Tab, Key}, AlreadyQ) when Key /= ?ALL -> Oid = {Tab, Key}, - ObjLocks = ?ets_lookup(mnesia_held_locks, Oid), - TabLocks = ?ets_lookup(mnesia_held_locks, {Tab, ?ALL}), + ObjLocks = ?ets_match_object(mnesia_held_locks, ?match_oid_held_locks(Oid)), + TabLocks = ?ets_match_object(mnesia_held_locks, ?match_oid_held_locks({Tab, ?ALL})), check_lock(Tid, Oid, ObjLocks, TabLocks, yes, AlreadyQ, write); can_lock(Tid, write, Oid, AlreadyQ) -> % Whole tab @@ -342,31 +342,28 @@ can_lock(Tid, write, Oid, AlreadyQ) -> % Whole tab check_lock(Tid, Oid, ObjLocks, [], yes, AlreadyQ, write). %% Check held locks for conflicting locks -check_lock(Tid, Oid, [Lock | Locks], TabLocks, X, AlreadyQ, Type) -> - case element(3, Lock) of - Tid -> - check_lock(Tid, Oid, Locks, TabLocks, X, AlreadyQ, Type); - WaitForTid -> - Queue = allowed_to_be_queued(WaitForTid,Tid), - if Queue == true -> - check_lock(Tid, Oid, Locks, TabLocks, {queue, WaitForTid}, AlreadyQ, Type); - Tid#tid.pid == WaitForTid#tid.pid -> - dbg_out("Spurious lock conflict ~w ~w: ~w -> ~w~n", - [Oid, Lock, Tid, WaitForTid]), - %% Test.. - {Tab, _Key} = Oid, - HaveQ = (ets:lookup(mnesia_lock_queue, Oid) /= []) - orelse (ets:lookup(mnesia_lock_queue,{Tab,?ALL}) /= []), - if - HaveQ -> - {no, WaitForTid}; - true -> - check_lock(Tid,Oid,Locks,TabLocks,{queue,WaitForTid},AlreadyQ,Type) - end; - %%{no, WaitForTid}; Safe solution - true -> - {no, WaitForTid} - end +check_lock(Tid, Oid, [{{_,Tid}, _} | Locks], TabLocks, X, AlreadyQ, Type) -> + check_lock(Tid, Oid, Locks, TabLocks, X, AlreadyQ, Type); +check_lock(Tid, Oid, [Lock = {{_,WaitForTid}, _} | Locks], TabLocks, _X, AlreadyQ, Type) -> + Queue = allowed_to_be_queued(WaitForTid,Tid), + if Queue == true -> + check_lock(Tid, Oid, Locks, TabLocks, {queue, WaitForTid}, AlreadyQ, Type); + Tid#tid.pid == WaitForTid#tid.pid -> + dbg_out("Spurious lock conflict ~w ~w: ~w -> ~w~n", + [Oid, Lock, Tid, WaitForTid]), + %% Test.. + {Tab, _Key} = Oid, + HaveQ = (ets:lookup(mnesia_lock_queue, Oid) /= []) + orelse (ets:lookup(mnesia_lock_queue,{Tab,?ALL}) /= []), + if + HaveQ -> + {no, WaitForTid}; + true -> + check_lock(Tid,Oid,Locks,TabLocks,{queue,WaitForTid},AlreadyQ,Type) + end; + %%{no, WaitForTid}; Safe solution + true -> + {no, WaitForTid} end; check_lock(_, _, [], [], X, {queue, bad_luck}, _) -> @@ -523,9 +520,9 @@ release_lock({Tid, Oid, {queued, _}}) -> release_lock({Tid, Oid, Op}) -> if Op == write -> - ?ets_delete(mnesia_held_locks, Oid); + ?ets_delete(mnesia_held_locks, {Oid, Tid}); Op == read -> - ets:delete_object(mnesia_held_locks, {Oid, Op, Tid}) + ets:delete_object(mnesia_held_locks, {{Oid, Tid}, Op}) end. rearrange_queue([{_Tid, {Tab, Key}, _} | Locks]) -> @@ -1116,7 +1113,8 @@ rec_requests([], _Oid, _Store) -> get_held_locks() -> ?MODULE ! {get_table, self(), mnesia_held_locks}, - receive {mnesia_held_locks, Locks} -> Locks end. + Locks = receive {mnesia_held_locks, Ls} -> Ls end, + [{Oid, Op, Tid} || {{Oid, Tid}, Op} <- Locks]. get_lock_queue() -> ?MODULE ! {get_table, self(), mnesia_lock_queue}, |