Merge branch 'dgud/mnesia/sticky-bug/ERL-768/OTP-15979' into maint

* dgud/mnesia/sticky-bug/ERL-768/OTP-15979:
  mnesia: Bump protocol version
  mnesia: Introduce sync_asym_trans protocol

6 files changed, 145 insertions, 115 deletions

diff --git a/lib/mnesia/src/mnesia_locker.erl b/lib/mnesia/src/mnesia_locker.erl
index f68626413e..0222c5b1a0 100644
--- a/lib/mnesia/src/mnesia_locker.erl
+++ b/lib/mnesia/src/mnesia_locker.erl
@@ -774,10 +774,12 @@ do_sticky_lock(Tid, Store, {Tab, Key} = Oid, Lock) ->
     N = node(),
     receive
 	{?MODULE, N, granted} ->
+            ?ets_insert(Store, {sticky, true}),
 	    ?ets_insert(Store, {{locks, Tab, Key}, write}),
 	    [?ets_insert(Store, {nodes, Node}) || Node <- WNodes],
 	    granted;
 	{?MODULE, N, {granted, Val}} -> %% for rwlocks
+            ?ets_insert(Store, {sticky, true}),
 	    case opt_lookup_in_client(Val, Oid, write) of
 		C = #cyclic{} ->
 		    exit({aborted, C});
diff --git a/lib/mnesia/src/mnesia_monitor.erl b/lib/mnesia/src/mnesia_monitor.erl
index 4cfe16dec0..4e50b46da8 100644
--- a/lib/mnesia/src/mnesia_monitor.erl
+++ b/lib/mnesia/src/mnesia_monitor.erl
@@ -83,9 +83,9 @@
 		going_down = [], tm_started = false, early_connects = [],
 		connecting, mq = [], remote_node_status = []}).
 
--define(current_protocol_version,  {8,3}).
+-define(current_protocol_version,  {8,4}).
 
--define(previous_protocol_version, {8,2}).
+-define(previous_protocol_version, {8,3}).
 
 start() ->
     gen_server:start_link({local, ?MODULE}, ?MODULE,
@@ -196,7 +196,7 @@ protocol_version() ->
 %% A sorted list of acceptable protocols the
 %% preferred protocols are first in the list
 acceptable_protocol_versions() ->
-    [protocol_version(), ?previous_protocol_version, {8,1}].
+    [protocol_version(), ?previous_protocol_version].
 
 needs_protocol_conversion(Node) ->
     case {?catch_val({protocol, Node}), protocol_version()} of
diff --git a/lib/mnesia/src/mnesia_schema.erl b/lib/mnesia/src/mnesia_schema.erl
index 4a86aeb375..d0f5d0e07b 100644
--- a/lib/mnesia/src/mnesia_schema.erl
+++ b/lib/mnesia/src/mnesia_schema.erl
@@ -730,7 +730,10 @@ api_list2cs(Other) ->
     mnesia:abort({badarg, Other}).
 
 vsn_cs2list(Cs) ->
-    cs2list(need_old_cstructs(), Cs).
+    cs2list(Cs).
+
+cs2list(false, Cs) ->
+    cs2list(Cs).
 
 cs2list(Cs) when is_record(Cs, cstruct) ->
     Tags = record_info(fields, cstruct),
@@ -755,25 +758,6 @@ cs2list(Cs) when element(1, Cs) == cstruct, tuple_size(Cs) == 19 ->
 	    cookie,version],
     rec2list(Tags, Tags, 2, Cs).
 
-cs2list(false, Cs) ->
-    cs2list(Cs);
-cs2list({8,3}, Cs) ->
-    cs2list(Cs);
-cs2list({8,Minor}, Cs) when Minor =:= 2; Minor =:= 1 ->
-    Orig = record_info(fields, cstruct),
-    Tags = [name,type,ram_copies,disc_copies,disc_only_copies,
-	    load_order,access_mode,majority,index,snmp,local_content,
-	    record_name,attributes,
-	    user_properties,frag_properties,storage_properties,
-	    cookie,version],
-    CsList = rec2list(Tags, Orig, 2, Cs),
-    case proplists:get_value(index, CsList, []) of
-	[] -> CsList;
-	NewFormat ->
-	    OldFormat = [Pos || {Pos, _Pref} <- NewFormat],
-	    lists:keyreplace(index, 1, CsList, {index, OldFormat})
-    end.
-
 rec2list([index | Tags], [index|Orig], Pos, Rec) ->
     Val = element(Pos, Rec),
     [{index, lists:map(
@@ -796,19 +780,8 @@ rec2list([], _, _Pos, _Rec) ->
 rec2list(Tags, [_|Orig], Pos, Rec) ->
     rec2list(Tags, Orig, Pos+1, Rec).
 
-normalize_cs(Cstructs, Node) ->
-    %% backward-compatibility hack; normalize before returning
-    case need_old_cstructs([Node]) of
-	false ->
-	    Cstructs;
-	Version ->
-	    %% some other format
-	    [convert_cs(Version, Cs) || Cs <- Cstructs]
-    end.
-
-convert_cs(Version, Cs) ->
-    Fields = [Value || {_, Value} <- cs2list(Version, Cs)],
-    list_to_tuple([cstruct|Fields]).
+normalize_cs(Cstructs, _Node) ->
+    Cstructs.
 
 list2cs(List) ->
     list2cs(List, get_ext_types()).
@@ -1864,11 +1837,7 @@ do_move_table(schema, _FromNode, _ToNode) ->
     mnesia:abort({bad_type, schema});
 do_move_table(Tab, FromNode, ToNode) when is_atom(FromNode), is_atom(ToNode) ->
     TidTs = get_tid_ts_and_lock(schema, write),
-    AnyOld = lists:any(fun(Node) -> mnesia_monitor:needs_protocol_conversion(Node) end,
-		       [ToNode|val({Tab, where_to_write})]),
-    if AnyOld -> ignore;  %% Leads to deadlock on old nodes
-       true -> get_tid_ts_and_lock(Tab, write)
-    end,
+    get_tid_ts_and_lock(Tab, write),
     insert_schema_ops(TidTs, make_move_table(Tab, FromNode, ToNode));
 do_move_table(Tab, FromNode, ToNode) ->
     mnesia:abort({badarg, Tab, FromNode, ToNode}).
@@ -3438,15 +3407,14 @@ do_merge_schema(LockTabs0) ->
                                                   mnesia_lib:intersect(Ns,NeedsLock))
                      || {T,Ns} <- LockTabs],
 
-		    NeedsConversion = need_old_cstructs(NeedsLock ++ LockedAlready),
 		    {value, SchemaCs} = lists:keysearch(schema, #cstruct.name, Cstructs),
-		    SchemaDef = cs2list(NeedsConversion, SchemaCs),
+		    SchemaDef = cs2list(false, SchemaCs),
 		    %% Announce that Node is running
 		    A = [{op, announce_im_running, node(), SchemaDef, Running, RemoteRunning}],
 		    do_insert_schema_ops(Store, A),
 
 		    %% Introduce remote tables to local node
-		    do_insert_schema_ops(Store, make_merge_schema(Node, NeedsConversion, Cstructs)),
+		    do_insert_schema_ops(Store, make_merge_schema(Node, false, Cstructs)),
 
 		    %% Introduce local tables to remote nodes
 		    Tabs = val({schema, tables}),
@@ -3471,23 +3439,7 @@ do_merge_schema(LockTabs0) ->
     end.
 
 fetch_cstructs(Node) ->
-    Convert = mnesia_monitor:needs_protocol_conversion(Node),
-    case rpc:call(Node, mnesia_controller, get_remote_cstructs, [])  of
-	{cstructs, Cs0, RemoteRunning1} when Convert ->
-	    {cstructs, [list2cs(cs2list(Cs)) || Cs <- Cs0], RemoteRunning1};
-	Result ->
-	    Result
-    end.
-
-need_old_cstructs() ->
-    need_old_cstructs(val({schema, where_to_write})).
-
-need_old_cstructs(Nodes) ->
-    Filter = fun(Node) -> mnesia_monitor:needs_protocol_conversion(Node) end,
-    case lists:filter(Filter, Nodes) of
-	[] -> false;
-	Ns -> lists:min([element(1, ?catch_val({protocol, Node})) || Node <- Ns])
-    end.
+    rpc:call(Node, mnesia_controller, get_remote_cstructs, []).
 
 tab_to_nodes(Tab) when is_atom(Tab) ->
     Cs = val({Tab, cstruct}),
diff --git a/lib/mnesia/src/mnesia_tm.erl b/lib/mnesia/src/mnesia_tm.erl
index 8b79fca1d7..8a4113422a 100644
--- a/lib/mnesia/src/mnesia_tm.erl
+++ b/lib/mnesia/src/mnesia_tm.erl
@@ -26,7 +26,7 @@
 	 init/1,
 	 non_transaction/5,
 	 transaction/6,
-	 commit_participant/5,
+	 commit_participant/6,
 	 dirty/2,
 	 display_info/2,
 	 do_update_op/3,
@@ -62,13 +62,14 @@
 %% Format on coordinators is [{Tid, EtsTabList} .....
 
 -record(prep, {protocol = sym_trans,
-	       %% async_dirty | sync_dirty | sym_trans | sync_sym_trans | asym_trans
+	       %% async_dirty | sync_dirty | sym_trans | sync_sym_trans | asym_trans | sync_asym_trans
 	       records = [],
 	       prev_tab = [], % initiate to a non valid table name
 	       prev_types,
 	       prev_snmp,
 	       types,
-	       majority = []
+	       majority = [],
+               sync = false
 	      }).
 
 -record(participant, {tid, pid, commit, disc_nodes = [],
@@ -250,11 +251,13 @@ doit_loop(#state{coordinators=Coordinators,participants=Participants,supervisor=
 	    mnesia_checkpoint:tm_enter_pending(Tid, DiscNs, RamNs),
 	    Commit = new_cr_format(Commit0),
 	    Pid =
-		case Protocol of
-		    asym_trans when node(Tid#tid.pid) /= node() ->
-			Args = [tmpid(From), Tid, Commit, DiscNs, RamNs],
+                if
+                    node(Tid#tid.pid) =:= node() ->
+                        error({internal_error, local_node});
+                    Protocol =:= asym_trans orelse Protocol =:= sync_asym_trans ->
+			Args = [Protocol, tmpid(From), Tid, Commit, DiscNs, RamNs],
 			spawn_link(?MODULE, commit_participant, Args);
-		    _ when node(Tid#tid.pid) /= node() -> %% *_sym_trans
+                    true -> %% *_sym_trans
 			reply(From, {vote_yes, Tid}),
 			nopid
 		end,
@@ -1190,7 +1193,15 @@ do_arrange(Tid, Store, RestoreKey, Prep, N) when RestoreKey == restore_op ->
     P2 = Prep#prep{protocol = asym_trans, records = Recs2},
     do_arrange(Tid, Store, ?ets_next(Store, RestoreKey), P2, N + 1);
 do_arrange(_Tid, _Store, '$end_of_table', Prep, N) ->
-    {N, Prep};
+    case Prep of
+        #prep{sync=true, protocol=asym_trans} ->
+            {N, Prep#prep{protocol=sync_asym_trans}};
+        _ ->
+            {N, Prep}
+    end;
+do_arrange(Tid, Store, sticky, Prep, N) ->
+    P2 = Prep#prep{sync=true},
+    do_arrange(Tid, Store, ?ets_next(Store, sticky), P2, N);
 do_arrange(Tid, Store, IgnoredKey, Prep, N) -> %% locks, nodes ... local atoms...
     do_arrange(Tid, Store, ?ets_next(Store, IgnoredKey), Prep, N).
 
@@ -1448,7 +1459,8 @@ multi_commit(sync_sym_trans, _Maj = [], Tid, CR, Store) ->
 		    [{tid, Tid}, {outcome, Outcome}]),
     Outcome;
 
-multi_commit(asym_trans, Majority, Tid, CR, Store) ->
+multi_commit(Protocol, Majority, Tid, CR, Store)
+  when Protocol =:= asym_trans; Protocol =:= sync_asym_trans ->
     %% This more expensive commit protocol is used when
     %% table definitions are changed (schema transactions).
     %% It is also used when the involved tables are
@@ -1515,7 +1527,7 @@ multi_commit(asym_trans, Majority, Tid, CR, Store) ->
     end,
     Pending = mnesia_checkpoint:tm_enter_pending(Tid, DiscNs, RamNs),
     ?ets_insert(Store, Pending),
-    {WaitFor, Local} = ask_commit(asym_trans, Tid, CR2, DiscNs, RamNs),
+    {WaitFor, Local} = ask_commit(Protocol, Tid, CR2, DiscNs, RamNs),
     SchemaPrep = ?CATCH(mnesia_schema:prepare_commit(Tid, Local, {coord, WaitFor})),
     {Votes, Pids} = rec_all(WaitFor, Tid, do_commit, []),
 
@@ -1563,38 +1575,38 @@ multi_commit(asym_trans, Majority, Tid, CR, Store) ->
 
 %% Returns do_commit or {do_abort, Reason}
 rec_acc_pre_commit([Pid | Tail], Tid, Store, Commit, Res, DumperMode,
-		   GoodPids, SchemaAckPids) ->
+		   GoodPids, AckPids) ->
     receive
 	{?MODULE, _, {acc_pre_commit, Tid, Pid, true}} ->
 	    rec_acc_pre_commit(Tail, Tid, Store, Commit, Res, DumperMode,
-			       [Pid | GoodPids], [Pid | SchemaAckPids]);
+			       [Pid | GoodPids], [Pid | AckPids]);
 
 	{?MODULE, _, {acc_pre_commit, Tid, Pid, false}} ->
 	    rec_acc_pre_commit(Tail, Tid, Store, Commit, Res, DumperMode,
-			       [Pid | GoodPids], SchemaAckPids);
+			       [Pid | GoodPids], AckPids);
 
 	{?MODULE, _, {acc_pre_commit, Tid, Pid}} ->
 	    %% Kept for backwards compatibility. Remove after Mnesia 4.x
 	    rec_acc_pre_commit(Tail, Tid, Store, Commit, Res, DumperMode,
-			       [Pid | GoodPids], [Pid | SchemaAckPids]);
+			       [Pid | GoodPids], [Pid | AckPids]);
 	{?MODULE, _, {do_abort, Tid, Pid, _Reason}} ->
 	    AbortRes = {do_abort, {bad_commit, node(Pid)}},
 	    rec_acc_pre_commit(Tail, Tid, Store, Commit, AbortRes, DumperMode,
-			       GoodPids, SchemaAckPids);
+			       GoodPids, AckPids);
 	{mnesia_down, Node} when Node == node(Pid) ->
 	    AbortRes = {do_abort, {bad_commit, Node}},
 	    ?SAFE(Pid ! {Tid, AbortRes}),  %% Tell him that he has died
 	    rec_acc_pre_commit(Tail, Tid, Store, Commit, AbortRes, DumperMode,
-			       GoodPids, SchemaAckPids)
+			       GoodPids, AckPids)
     end;
-rec_acc_pre_commit([], Tid, Store, {Commit,OrigC}, Res, DumperMode, GoodPids, SchemaAckPids) ->
+rec_acc_pre_commit([], Tid, Store, {Commit,OrigC}, Res, DumperMode, GoodPids, AckPids) ->
     D = Commit#commit.decision,
     case Res of
 	do_commit ->
 	    %% Now everybody knows that the others
 	    %% has voted yes. We also know that
 	    %% everybody are uncertain.
-	    prepare_sync_schema_commit(Store, SchemaAckPids),
+	    prepare_sync_schema_commit(Store, AckPids),
 	    tell_participants(GoodPids, {Tid, committed}),
 	    D2 = D#decision{outcome = committed},
 	    mnesia_recover:log_decision(D2),
@@ -1606,7 +1618,7 @@ rec_acc_pre_commit([], Tid, Store, {Commit,OrigC}, Res, DumperMode, GoodPids, Sc
 	    do_commit(Tid, Commit, DumperMode),
             ?eval_debug_fun({?MODULE, rec_acc_pre_commit_done_commit},
 			    [{tid, Tid}]),
-	    sync_schema_commit(Tid, Store, SchemaAckPids),
+	    sync_schema_commit(Tid, Store, AckPids),
 	    mnesia_locker:release_tid(Tid),
 	    ?MODULE ! {delete_transaction, Tid};
 
@@ -1623,6 +1635,7 @@ rec_acc_pre_commit([], Tid, Store, {Commit,OrigC}, Res, DumperMode, GoodPids, Sc
     Res.
 
 %% Note all nodes in case of mnesia_down mgt
+%% sync_schema_commit is (ab)used for sync_asym_trans as well.
 prepare_sync_schema_commit(_Store, []) ->
     ok;
 prepare_sync_schema_commit(Store, [Pid | Pids]) ->
@@ -1648,17 +1661,17 @@ tell_participants([Pid | Pids], Msg) ->
 tell_participants([], _Msg) ->
     ok.
 
--spec commit_participant(_, _, _, _, _) -> no_return().
+-spec commit_participant(_, _, _, _, _, _) -> no_return().
 %% Trap exit because we can get a shutdown from application manager
-commit_participant(Coord, Tid, Bin, DiscNs, RamNs) when is_binary(Bin) ->
+commit_participant(Protocol, Coord, Tid, Bin, DiscNs, RamNs) when is_binary(Bin) ->
     process_flag(trap_exit, true),
     Commit = binary_to_term(Bin),
-    commit_participant(Coord, Tid, Bin, Commit, DiscNs, RamNs);
-commit_participant(Coord, Tid, C = #commit{}, DiscNs, RamNs) ->
+    commit_participant(Protocol, Coord, Tid, Bin, Commit, DiscNs, RamNs);
+commit_participant(Protocol, Coord, Tid, C = #commit{}, DiscNs, RamNs) ->
     process_flag(trap_exit, true),
-    commit_participant(Coord, Tid, C, C, DiscNs, RamNs).
+    commit_participant(Protocol, Coord, Tid, C, C, DiscNs, RamNs).
 
-commit_participant(Coord, Tid, Bin, C0, DiscNs, _RamNs) ->
+commit_participant(Protocol, Coord, Tid, Bin, C0, DiscNs, _RamNs) ->
     ?eval_debug_fun({?MODULE, commit_participant, pre}, [{tid, Tid}]),
     try mnesia_schema:prepare_commit(Tid, C0, {part, Coord}) of
 	{Modified, C = #commit{}, DumperMode} ->
@@ -1683,8 +1696,9 @@ commit_participant(Coord, Tid, Bin, C0, DiscNs, _RamNs) ->
 		    mnesia_recover:log_decision(D#decision{outcome = unclear}),
 		    ?eval_debug_fun({?MODULE, commit_participant, pre_commit},
 				    [{tid, Tid}]),
-		    Expect_schema_ack = C#commit.schema_ops /= [],
-		    reply(Coord, {acc_pre_commit, Tid, self(), Expect_schema_ack}),
+		    ExpectAck = C#commit.schema_ops /= []
+                        orelse Protocol =:= sync_asym_trans,
+		    reply(Coord, {acc_pre_commit, Tid, self(), ExpectAck}),
 
 		    %% Now we are vulnerable for failures, since
 		    %% we cannot decide without asking others
@@ -1694,7 +1708,7 @@ commit_participant(Coord, Tid, Bin, C0, DiscNs, _RamNs) ->
 			    ?eval_debug_fun({?MODULE, commit_participant, log_commit},
 					    [{tid, Tid}]),
 			    do_commit(Tid, C, DumperMode),
-			    case Expect_schema_ack of
+			    case ExpectAck of
 				false -> ignore;
 				true -> reply(Coord, {schema_commit, Tid, self()})
 			    end,
@@ -1978,7 +1992,7 @@ sync_send_dirty(Tid, [Head | Tail], Tab, WaitFor) ->
 	    Res =  do_dirty(Tid, Head),
 	    {WF, Res};
 	true ->
-	    {?MODULE, Node} ! {self(), {sync_dirty, Tid, ext_format(Head), Tab}},
+	    {?MODULE, Node} ! {self(), {sync_dirty, Tid, Head, Tab}},
 	    sync_send_dirty(Tid, Tail, Tab, [Node | WaitFor])
     end;
 sync_send_dirty(_Tid, [], _Tab, WaitFor) ->
@@ -1997,11 +2011,11 @@ async_send_dirty(Tid, [Head | Tail], Tab, ReadNode, WaitFor, Res) ->
 	    NewRes =  do_dirty(Tid, Head),
 	    async_send_dirty(Tid, Tail, Tab, ReadNode, WaitFor, NewRes);
 	ReadNode == Node ->
-	    {?MODULE, Node} ! {self(), {sync_dirty, Tid, ext_format(Head), Tab}},
+	    {?MODULE, Node} ! {self(), {sync_dirty, Tid, Head, Tab}},
 	    NewRes = {'EXIT', {aborted, {node_not_running, Node}}},
 	    async_send_dirty(Tid, Tail, Tab, ReadNode, [Node | WaitFor], NewRes);
 	true ->
-	    {?MODULE, Node} ! {self(), {async_dirty, Tid, ext_format(Head), Tab}},
+	    {?MODULE, Node} ! {self(), {async_dirty, Tid, Head, Tab}},
 	    async_send_dirty(Tid, Tail, Tab, ReadNode, WaitFor, Res)
     end;
 async_send_dirty(_Tid, [], _Tab, _ReadNode, WaitFor, Res) ->
@@ -2058,24 +2072,20 @@ ask_commit(Protocol, Tid, [Head | Tail], DiscNs, RamNs, WaitFor, Local) ->
 	Node == node() ->
 	    ask_commit(Protocol, Tid, Tail, DiscNs, RamNs, WaitFor, Head);
 	true ->
-	    CR = ext_format(Head),
-	    Msg = {ask_commit, Protocol, Tid, CR, DiscNs, RamNs},
+	    Msg = {ask_commit, convert_old(Protocol, Node), Tid, Head, DiscNs, RamNs},
 	    {?MODULE, Node} ! {self(), Msg},
 	    ask_commit(Protocol, Tid, Tail, DiscNs, RamNs, [Node | WaitFor], Local)
     end;
 ask_commit(_Protocol, _Tid, [], _DiscNs, _RamNs, WaitFor, Local) ->
     {WaitFor, Local}.
 
-ext_format(#commit{ext=[]}=CR) -> CR;
-ext_format(#commit{node=Node, ext=Ext}=CR) ->
+convert_old(sync_asym_trans, Node) ->
     case mnesia_monitor:needs_protocol_conversion(Node) of
-	true  ->
-	    case lists:keyfind(snmp, 1, Ext) of
-		false -> CR#commit{ext=[]};
-		{snmp, List} -> CR#commit{ext=List}
-	    end;
-	false -> CR
-    end.
+        true -> asym_trans;
+        false -> sync_asym_trans
+    end;
+convert_old(Protocol, _) ->
+    Protocol.
 
 new_cr_format(#commit{ext=[]}=Cr) -> Cr;
 new_cr_format(#commit{ext=[{_,_}|_]}=Cr) -> Cr;
@@ -2304,7 +2314,7 @@ reconfigure_participants(_, []) ->
 %% tell mnesia_tm on all involved nodes (including the local node)
 %% about the outcome.
 tell_outcome(Tid, Protocol, Node, CheckNodes, TellNodes) ->
-    Outcome = mnesia_recover:what_happened(Tid, Protocol, CheckNodes),
+    Outcome = mnesia_recover:what_happened(Tid, proto(Protocol), CheckNodes),
     case Outcome of
 	aborted ->
 	    rpc:abcast(TellNodes, ?MODULE, {Tid,{do_abort, {mnesia_down, Node}}});
@@ -2313,6 +2323,9 @@ tell_outcome(Tid, Protocol, Node, CheckNodes, TellNodes) ->
     end,
     Outcome.
 
+proto(sync_asym_trans) -> asym_trans;
+proto(Proto) -> Proto.
+
 do_stop(#state{coordinators = Coordinators}) ->
     Msg = {mnesia_down, node()},
     lists:foreach(fun({Tid, _}) -> Tid#tid.pid ! Msg end, gb_trees:to_list(Coordinators)),
diff --git a/lib/mnesia/test/mnesia_isolation_test.erl b/lib/mnesia/test/mnesia_isolation_test.erl
index 98a7840b72..c99158945d 100644
--- a/lib/mnesia/test/mnesia_isolation_test.erl
+++ b/lib/mnesia/test/mnesia_isolation_test.erl
@@ -29,7 +29,7 @@
 -export([no_conflict/1, simple_queue_conflict/1,
          advanced_queue_conflict/1, simple_deadlock_conflict/1,
          advanced_deadlock_conflict/1, schema_deadlock/1, lock_burst/1,
-         nasty/1, basic_sticky_functionality/1,
+         nasty/1, basic_sticky_functionality/1, sticky_sync/1,
          unbound1/1, unbound2/1,
          create_table/1, delete_table/1, move_table_copy/1,
          add_table_index/1, del_table_index/1, transform_table/1,
@@ -71,7 +71,8 @@ groups() ->
        advanced_deadlock_conflict, schema_deadlock, lock_burst,
        {group, sticky_locks}, {group, unbound_locking},
        {group, admin_conflict}, nasty]},
-     {sticky_locks, [], [basic_sticky_functionality]},
+     {sticky_locks, [],
+      [basic_sticky_functionality,sticky_sync]},
      {unbound_locking, [], [unbound1, unbound2]},
      {admin_conflict, [],
       [create_table, delete_table, move_table_copy,
@@ -594,9 +595,49 @@ get_held() ->
     mnesia_locker ! {get_table, self(), mnesia_sticky_locks},
     receive {mnesia_sticky_locks, Locks} -> Locks end.
 
+sticky_sync(suite) -> [];
+sticky_sync(Config) when is_list(Config) ->
+    %% BUG ERIERL-768
+    Nodes = [N1, N2] = ?acquire_nodes(2, Config),
+
+    mnesia:create_table(dc, [{type, ordered_set}, {disc_copies, Nodes}]),
+    mnesia:create_table(ec, [{type, ordered_set}, {ram_copies, [N2]}]),
+
+    TestFun =
+        fun(I) ->
+                %% In first transaction we initialise {dc, I} record with value 0
+                First = fun() ->
+                                %% Do a lot of writes into ram copies table
+                                %% which on the Slave in do_commit will be
+                                %% processed first
+                                lists:foreach(fun(J) -> ok = mnesia:write(ec, {ec, J, 0}, write) end,
+                                              lists:seq(1, 750)),
+                                %% Then set initial value of {dc, I} record to 0 with sticky_write
+                                mnesia:write(dc, {dc, I, 0}, sticky_write)
+                        end,
+                ok = mnesia:activity(transaction, First),
+                %% In second transaction we set value of {dc, I} record to 1
+                Upd = fun() ->
+                              %% Modify a single ram copies record with ensured lock grant
+                              %% (key not used in previous transactions)
+                              %% we use this second table only to force asym_trans protocol
+                              mnesia:write(ec, {ec, 1001 + I, 0}, write),
+                              %% And set final version of {dc, I} record to 1 with sticky_write
+                              mnesia:write(dc, {dc, I, 1}, sticky_write)
+                    end,
+                ok = mnesia:activity(transaction, Upd)
+        end,
+
+    %% Fill 1000 dc records. At the end all dc records should have value 1.
+    lists:foreach(TestFun, lists:seq(1,1000)),
+    io:format("Written, check content~n",[]),
+    All = fun() -> mnesia:select(dc, [ {{dc, '_', 0}, [] ,['$_']} ]) end,
+    ?match({atomic, []}, rpc:call(N1, mnesia, sync_transaction, [All])),
+    ?match({atomic, []}, rpc:call(N2, mnesia, sync_transaction, [All])),
 
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+    ?verify_mnesia(Nodes, []).
 
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 unbound1(suite) -> [];
 unbound1(Config) when is_list(Config) ->
diff --git a/lib/mnesia/test/mt b/lib/mnesia/test/mt
index a398ee0422..b169734f56 100755
--- a/lib/mnesia/test/mt
+++ b/lib/mnesia/test/mt
@@ -34,8 +34,35 @@ erlcmd="erl -sname a $p $args -mnesia_test_timeout"
 erlcmd1="erl -sname a1 $p $args"
 erlcmd2="erl -sname a2 $p $args"
 
-xterm -geometry 70x20+0+550 -T a1 -e $erlcmd1 &
-xterm -geometry 70x20+450+550 -T a2 -e $erlcmd2 &
+if test z"$MT_TERM" = z ; then
+    MT_TERM=xterm
+fi
+
+case $MT_TERM in
+    xterm)
+	geom0="-geometry 142x40+0+0"
+	geom1="-geometry 70x20+0+550"
+	geom2="-geometry 70x20+480+550"
+	title="-T"
+	exec="-e"
+	;;
+    gnome-terminal)
+	geom0="--geometry 142x40+0+0"
+	geom1="--geometry 70x20+0+740"
+	geom2="--geometry 70x20+700+740"
+	title="--title"
+	exec="--hide-menubar --"
+	;;
+    *rxvt)
+	geom0="-geometry 142x40+0+0"
+	geom1="-geometry 70x20+0+680"
+	geom2="-geometry 70x20+630+680"
+	title="-title"
+	exec="-e"
+esac
+
+$MT_TERM $geom1 $title a1 $exec $erlcmd1 &
+$MT_TERM $geom2 $title a2 $exec $erlcmd2 &
 
 rm "$latest" 2>/dev/null
 ln -s "$log" "$latest"
@@ -51,11 +78,6 @@ echo "Give the following command in order to see the outcome from node a@$h"":"
 echo ""
 echo "	less test_log$$"
 
-ostype=`uname -s`
-if [ "$ostype" = "SunOS" ] ; then 
-  /usr/openwin/bin/xterm -geometry 145x40+0+0 -T a -l -lf "$log" -e $erlcmd &
-else
-  xterm -geometry 145x40+0+0 -T a -e script -f -c "$erlcmd" "$log"  &
-fi
+$MT_TERM $geom0 $title a $exec script -f -c "$erlcmd" "$log"  &
 tail -f "$log" | egrep 'Eval|<>ERROR|NYI'