where_to_wlock optimization + change_table_majority/2

5 files changed, 96 insertions, 29 deletions

diff --git a/lib/mnesia/src/mnesia.erl b/lib/mnesia/src/mnesia.erl
index 43953f9ad4..980a9c6213 100644
--- a/lib/mnesia/src/mnesia.erl
+++ b/lib/mnesia/src/mnesia.erl
@@ -93,7 +93,7 @@
 	 add_table_copy/3, del_table_copy/2, move_table_copy/3,
 	 add_table_index/2, del_table_index/2,
 	 transform_table/3, transform_table/4,
-	 change_table_copy_type/3,
+	 change_table_copy_type/3, change_table_majority/2,
 	 read_table_property/2, write_table_property/2, delete_table_property/2,
 	 change_table_frag/2,
 	 clear_table/1, clear_table/4,
@@ -2461,6 +2461,9 @@ change_table_access_mode(T, Access) ->
 change_table_load_order(T, O) -> 
     mnesia_schema:change_table_load_order(T, O).
 
+change_table_majority(T, M) ->
+    mnesia_schema:change_table_majority(T, M).
+
 set_master_nodes(Nodes) when is_list(Nodes) ->
     UseDir = system_info(use_dir),
     IsRunning = system_info(is_running),
diff --git a/lib/mnesia/src/mnesia_controller.erl b/lib/mnesia/src/mnesia_controller.erl
index 0254769758..d4b2c7b5cc 100644
--- a/lib/mnesia/src/mnesia_controller.erl
+++ b/lib/mnesia/src/mnesia_controller.erl
@@ -72,6 +72,7 @@
 	 add_active_replica/4,
 	 update/1,
 	 change_table_access_mode/1,
+	 change_table_majority/1,
 	 del_active_replica/2,
 	 wait_for_tables/2,
 	 get_network_copy/2,
@@ -690,7 +691,8 @@ handle_call({update_where_to_write, [add, Tab, AddNode], _From}, _Dummy, State)
 	case lists:member(AddNode, Current) and 
 	    (State#state.schema_is_merged == true) of
 	    true ->
-		mnesia_lib:add_lsort({Tab, where_to_write}, AddNode);
+		mnesia_lib:add_lsort({Tab, where_to_write}, AddNode),
+		update_where_to_wlock(Tab);
 	    false ->
 		ignore
 	end,
@@ -1690,6 +1692,8 @@ add_active_replica(Tab, Node, Storage, AccessMode) ->
 	    set(Var, mark_blocked_tab(Blocked, Del)),
 	    mnesia_lib:del({Tab, where_to_write}, Node)
     end,
+
+    update_where_to_wlock(Tab),
     add({Tab, active_replicas}, Node).
 
 del_active_replica(Tab, Node) ->
@@ -1699,7 +1703,8 @@ del_active_replica(Tab, Node) ->
     New = lists:sort(Del),
     set(Var, mark_blocked_tab(Blocked, New)),      % where_to_commit
     mnesia_lib:del({Tab, active_replicas}, Node),
-    mnesia_lib:del({Tab, where_to_write}, Node).
+    mnesia_lib:del({Tab, where_to_write}, Node),
+    update_where_to_wlock(Tab).
 
 change_table_access_mode(Cs) ->
     W = fun() -> 
@@ -1708,7 +1713,22 @@ change_table_access_mode(Cs) ->
 			      val({Tab, active_replicas}))
 	end,
     update(W).
-	    
+
+change_table_majority(Cs) ->
+    W = fun() ->
+		Tab = Cs#cstruct.name,
+		set({Tab, majority}, Cs#cstruct.majority),
+		update_where_to_wlock(Tab)
+	end,
+    update(W).
+
+update_where_to_wlock(Tab) ->
+    WNodes = val({Tab, where_to_write}),
+    Majority = case catch val({Tab, majority}) of
+		   true -> true;
+		   _    -> false
+	       end,
+    set({Tab, where_to_wlock}, {WNodes, Majority}).
 
 %% node To now has tab loaded, but this must be undone
 %% This code is rpc:call'ed from the tab_copier process
diff --git a/lib/mnesia/src/mnesia_dumper.erl b/lib/mnesia/src/mnesia_dumper.erl
index 644133cf5d..9a0a2c4dcc 100644
--- a/lib/mnesia/src/mnesia_dumper.erl
+++ b/lib/mnesia/src/mnesia_dumper.erl
@@ -896,6 +896,14 @@ insert_op(Tid, _, {op, change_table_access_mode,TabDef, _OldAccess, _Access}, In
     end,
     insert_cstruct(Tid, Cs, true, InPlace, InitBy);
 
+insert_op(Tid, _, {op, change_table_majority,TabDef, _OldAccess, _Access}, InPlace, InitBy) ->
+    Cs = mnesia_schema:list2cs(TabDef),
+    case InitBy of
+	startup -> ignore;
+	_ -> mnesia_controller:change_table_majority(Cs)
+    end,
+    insert_cstruct(Tid, Cs, true, InPlace, InitBy);
+
 insert_op(Tid, _, {op, change_table_load_order, TabDef, _OldLevel, _Level}, InPlace, InitBy) ->
     Cs = mnesia_schema:list2cs(TabDef),
     insert_cstruct(Tid, Cs, true, InPlace, InitBy);
diff --git a/lib/mnesia/src/mnesia_locker.erl b/lib/mnesia/src/mnesia_locker.erl
index 635668ff59..0492d794f3 100644
--- a/lib/mnesia/src/mnesia_locker.erl
+++ b/lib/mnesia/src/mnesia_locker.erl
@@ -657,17 +657,17 @@ rwlock(Tid, Store, Oid) ->
 	    Lock = write,
 	    case need_lock(Store, Tab, Key, Lock)  of
 		yes ->
-		    Ns = w_nodes(Tab),
-		    check_majority(Tab, Ns),
+		    {Ns, Majority} = w_nodes(Tab),
+		    check_majority(Majority, Tab, Ns),
 		    Res = get_rwlocks_on_nodes(Ns, rwlock, Node, Store, Tid, Oid),
 		    ?ets_insert(Store, {{locks, Tab, Key}, Lock}),
 		    Res;
 		no ->
 		    if
 			Key == ?ALL ->
-			    w_nodes(Tab);
+			    element(2, w_nodes(Tab));
 			Tab == ?GLOBAL ->
-			    w_nodes(Tab);
+			    element(2, w_nodes(Tab));
 			true ->
 			    dirty_rpc(Node, Tab, Key, Lock)
 		    end
@@ -679,9 +679,8 @@ rwlock(Tid, Store, Oid) ->
 %% in the local store under the key == nodes
 
 w_nodes(Tab) ->
-    Nodes = ?catch_val({Tab, where_to_write}),
-    case Nodes of
-	[_ | _] -> Nodes;
+    case ?catch_val({Tab, where_to_wlock}) of
+	{[_ | _], _} = Where -> Where;
 	_ ->  mnesia:abort({no_exists, Tab})
     end.
 
@@ -733,8 +732,8 @@ sticky_lock(Tid, Store, {Tab, Key} = Oid, Lock) ->
     end.
 
 do_sticky_lock(Tid, Store, {Tab, Key} = Oid, Lock) ->
-    WNodes = w_nodes(Tab),
-    sticky_check_majority(Lock, Tab, WNodes),
+    {WNodes, Majority} = w_nodes(Tab),
+    sticky_check_majority(Lock, Tab, Majority, WNodes),
     ?MODULE ! {self(), {test_set_sticky, Tid, Oid, Lock}},
     N = node(),
     receive
@@ -764,20 +763,15 @@ do_sticky_lock(Tid, Store, {Tab, Key} = Oid, Lock) ->
 	    dirty_sticky_lock(Tab, Key, [N], Lock)
     end.
 
-sticky_check_majority(read, _, _) ->
-    ok;
-sticky_check_majority(write, Tab, WNodes) ->
-    case ?catch_val({Tab, majority}) of
+sticky_check_majority(W, Tab, true, WNodes) when W==write; W==read_write ->
+    case mnesia_lib:have_majority(Tab, WNodes) of
 	true ->
-	    case mnesia_lib:have_majority(Tab, WNodes) of
-		true ->
-		    ok;
-		false ->
-		    mnesia:abort({no_majority, Tab})
-	    end;
-	_ ->
-	    ok
-    end.
+	    ok;
+	false ->
+	    mnesia:abort({no_majority, Tab})
+    end;
+sticky_check_majority(_, _, _, _) ->
+    ok.
 
 not_stuck(Tid, Store, Tab, _Key, Oid, _Lock, N) ->
     rlock(Tid, Store, {Tab, ?ALL}),   %% needed?
@@ -821,15 +815,19 @@ wlock(Tid, Store, Oid, CheckMajority) ->
     {Tab, Key} = Oid,
     case need_lock(Store, Tab, Key, write) of
 	yes ->
-	    Ns = w_nodes(Tab),
-	    check_majority(CheckMajority, Tab, Ns),
+	    {Ns, Majority} = w_nodes(Tab),
+	    if CheckMajority ->
+		    check_majority(Majority, Tab, Ns);
+	       true ->
+		    ignore
+	    end,
 	    Op = {self(), {write, Tid, Oid}},
 	    ?ets_insert(Store, {{locks, Tab, Key}, write}),
 	    get_wlocks_on_nodes(Ns, Ns, Store, Op, Oid);
 	no when Key /= ?ALL, Tab /= ?GLOBAL ->
 	    [];
 	no ->
-	    w_nodes(Tab)
+	    element(2, w_nodes(Tab))
     end.
 
 wlock_table(Tid, Store, Tab) ->
diff --git a/lib/mnesia/src/mnesia_schema.erl b/lib/mnesia/src/mnesia_schema.erl
index b3f06322d9..360da8a17d 100644
--- a/lib/mnesia/src/mnesia_schema.erl
+++ b/lib/mnesia/src/mnesia_schema.erl
@@ -37,6 +37,7 @@
          change_table_copy_type/3,
          change_table_access_mode/2,
          change_table_load_order/2,
+	 change_table_majority/2,
 	 change_table_frag/2,
 	 clear_table/1,
          create_table/1,
@@ -1508,6 +1509,43 @@ make_change_table_load_order(Tab, LoadOrder) ->
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
+change_table_majority(Tab, Majority) when is_boolean(Majority) ->
+    schema_transaction(fun() -> do_change_table_majority(Tab, Majority) end).
+
+do_change_table_majority(schema, _Majority) ->
+    mnesia:abort({bad_type, schema});
+do_change_table_majority(Tab, Majority) ->
+    TidTs = get_tid_ts_and_lock(schema, write),
+    get_tid_ts_and_lock(Tab, none),
+    insert_schema_ops(TidTs, make_change_table_majority(Tab, Majority)).
+
+make_change_table_majority(Tab, Majority) ->
+    ensure_writable(schema),
+    Cs = incr_version(val({Tab, cstruct})),
+    ensure_active(Cs),
+    OldMajority = Cs#cstruct.majority,
+    Cs2 = Cs#cstruct{majority = Majority},
+    FragOps = case lists:keyfind(base_table, 1, Cs#cstruct.frag_properties) of
+		  {_, Tab} ->
+		      FragNames = mnesia_frag:frag_names(Tab) -- [Tab],
+		      lists:map(
+			fun(T) ->
+				get_tid_ts_and_lock(Tab, none),
+				CsT = incr_version(val({T, cstruct})),
+				ensure_active(CsT),
+				CsT2 = CsT#cstruct{majority = Majority},
+				verify_cstruct(CsT2),
+				{op, change_table_majority, cs2list(CsT2),
+				 OldMajority, Majority}
+			end, FragNames);
+		  false    -> [];
+		  {_, _}   -> mnesia:abort({bad_type, Tab})
+	      end,
+    verify_cstruct(Cs2),
+    [{op, change_table_majority, cs2list(Cs2), OldMajority, Majority} | FragOps].
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
 write_table_property(Tab, Prop) when is_tuple(Prop), size(Prop) >= 1 ->
     schema_transaction(fun() -> do_write_table_property(Tab, Prop) end);
 write_table_property(Tab, Prop) ->