File 0162-kernel-Remove-some-obsolete-code-in-the-global-modul.patch of Package erlang
From 865463b67c433b40210458e306a5ed77402989e8 Mon Sep 17 00:00:00 2001
From: Hans Bolinder <hasse@erlang.org>
Date: Wed, 27 Feb 2019 16:01:45 +0100
Subject: [PATCH] kernel: Remove some obsolete code in the global module
erlang:monitor_node() is asynchronous as of Erlang/OTP 21.0. Use that
fact to remove no longer needed code in the global module.
---
lib/kernel/src/global.erl | 80 +++++++++++++++--------------------------------
1 file changed, 25 insertions(+), 55 deletions(-)
diff --git a/lib/kernel/src/global.erl b/lib/kernel/src/global.erl
index a38522eb5c..5bb56f2de6 100644
--- a/lib/kernel/src/global.erl
+++ b/lib/kernel/src/global.erl
@@ -125,16 +125,12 @@
%%% There are also ETS tables used for bookkeeping of locks and names
%%% (the first position is the key):
%%%
-%%% global_locks (set): {ResourceId, LockRequesterId, [{Pid,RPid,ref()]}
+%%% global_locks (set): {ResourceId, LockRequesterId, [{Pid,ref()]}
%%% Pid is locking ResourceId, ref() is the monitor ref.
-%%% RPid =/= Pid if there is an extra process calling erlang:monitor().
-%%% global_names (set): {Name, Pid, Method, RPid, ref()}
+%%% global_names (set): {Name, Pid, Method, ref()}
%%% Registered names. ref() is the monitor ref.
-%%% RPid =/= Pid if there is an extra process calling erlang:monitor().
%%% global_names_ext (set): {Name, Pid, RegNode}
%%% External registered names (C-nodes).
-%%% (The RPid:s can be removed when/if erlang:monitor() returns before
-%%% trying to connect to the other node.)
%%%
%%% Helper tables:
%%% global_pid_names (bag): {Pid, Name} | {ref(), Name}
@@ -310,7 +306,7 @@ re_register_name(Name, Pid, Method0) when is_pid(Pid) ->
-spec registered_names() -> [Name] when
Name :: term().
registered_names() ->
- MS = ets:fun2ms(fun({Name,_Pid,_M,_RP,_R}) -> Name end),
+ MS = ets:fun2ms(fun({Name,_Pid,_M,_R}) -> Name end),
ets:select(global_names, MS).
%%-----------------------------------------------------------------
@@ -1235,7 +1231,7 @@ ins_name_ext(Name, Pid, Method, RegNode, FromPidOrNode, ExtraInfo, S0) ->
where(Name) ->
case ets:lookup(global_names, Name) of
- [{_Name, Pid, _Method, _RPid, _Ref}] ->
+ [{_Name, Pid, _Method, _Ref}] ->
if node(Pid) == node() ->
case is_process_alive(Pid) of
true -> Pid;
@@ -1272,10 +1268,10 @@ can_set_lock({ResourceId, LockRequesterId}) ->
end.
insert_lock({ResourceId, LockRequesterId}=Id, Pid, PidRefs, S) ->
- {RPid, Ref} = do_monitor(Pid),
+ Ref = erlang:monitor(process, Pid),
true = ets:insert(global_pid_ids, {Pid, ResourceId}),
true = ets:insert(global_pid_ids, {Ref, ResourceId}),
- Lock = {ResourceId, LockRequesterId, [{Pid,RPid,Ref} | PidRefs]},
+ Lock = {ResourceId, LockRequesterId, [{Pid,Ref} | PidRefs]},
true = ets:insert(global_locks, Lock),
trace_message(S, {ins_lock, node(Pid)}, [Id, Pid]).
@@ -1293,10 +1289,9 @@ handle_del_lock({ResourceId, LockReqId}, Pid, S0) ->
_ -> S0
end.
-remove_lock(ResourceId, LockRequesterId, Pid, [{Pid,RPid,Ref}], Down, S0) ->
+remove_lock(ResourceId, LockRequesterId, Pid, [{Pid,Ref}], Down, S0) ->
?trace({remove_lock_1, {id,ResourceId},{pid,Pid}}),
true = erlang:demonitor(Ref, [flush]),
- kill_monitor_proc(RPid, Pid),
true = ets:delete(global_locks, ResourceId),
true = ets:delete_object(global_pid_ids, {Pid, ResourceId}),
true = ets:delete_object(global_pid_ids, {Ref, ResourceId}),
@@ -1309,9 +1304,8 @@ remove_lock(ResourceId, LockRequesterId, Pid, [{Pid,RPid,Ref}], Down, S0) ->
remove_lock(ResourceId, LockRequesterId, Pid, PidRefs0, _Down, S) ->
?trace({remove_lock_2, {id,ResourceId},{pid,Pid}}),
PidRefs = case lists:keyfind(Pid, 1, PidRefs0) of
- {Pid, RPid, Ref} ->
+ {Pid, Ref} ->
true = erlang:demonitor(Ref, [flush]),
- kill_monitor_proc(RPid, Pid),
true = ets:delete_object(global_pid_ids,
{Ref, ResourceId}),
lists:keydelete(Pid, 1, PidRefs0);
@@ -1324,11 +1318,6 @@ remove_lock(ResourceId, LockRequesterId, Pid, PidRefs0, _Down, S) ->
trace_message(S, {rem_lock, node(Pid)},
[{ResourceId, LockRequesterId}, Pid]).
-kill_monitor_proc(Pid, Pid) ->
- ok;
-kill_monitor_proc(RPid, _Pid) ->
- exit(RPid, kill).
-
do_ops(Ops, ConnNode, Names_ext, ExtraInfo, S0) ->
?trace({do_ops, {ops,Ops}}),
@@ -1394,8 +1383,8 @@ sync_other(Node, N) ->
% exit(normal).
insert_global_name(Name, Pid, Method, FromPidOrNode, ExtraInfo, S) ->
- {RPid, Ref} = do_monitor(Pid),
- true = ets:insert(global_names, {Name, Pid, Method, RPid, Ref}),
+ Ref = erlang:monitor(process, Pid),
+ true = ets:insert(global_names, {Name, Pid, Method, Ref}),
true = ets:insert(global_pid_names, {Pid, Name}),
true = ets:insert(global_pid_names, {Ref, Name}),
case lock_still_set(FromPidOrNode, ExtraInfo, S) of
@@ -1437,7 +1426,7 @@ extra_info(Tag, ExtraInfo) ->
del_name(Ref, S) ->
NameL = [Name ||
{_, Name} <- ets:lookup(global_pid_names, Ref),
- {_, _Pid, _Method, _RPid, Ref1} <-
+ {_, _Pid, _Method, Ref1} <-
ets:lookup(global_names, Name),
Ref1 =:= Ref],
case NameL of
@@ -1450,24 +1439,23 @@ del_name(Ref, S) ->
%% Keeps the entry in global_names for whereis_name/1.
delete_global_name_keep_pid(Name, S) ->
case ets:lookup(global_names, Name) of
- [{Name, Pid, _Method, RPid, Ref}] ->
- delete_global_name2(Name, Pid, RPid, Ref, S);
+ [{Name, Pid, _Method, Ref}] ->
+ delete_global_name2(Name, Pid, Ref, S);
[] ->
S
end.
delete_global_name2(Name, S) ->
case ets:lookup(global_names, Name) of
- [{Name, Pid, _Method, RPid, Ref}] ->
+ [{Name, Pid, _Method, Ref}] ->
true = ets:delete(global_names, Name),
- delete_global_name2(Name, Pid, RPid, Ref, S);
+ delete_global_name2(Name, Pid, Ref, S);
[] ->
S
end.
-delete_global_name2(Name, Pid, RPid, Ref, S) ->
+delete_global_name2(Name, Pid, Ref, S) ->
true = erlang:demonitor(Ref, [flush]),
- kill_monitor_proc(RPid, Pid),
delete_global_name(Name, Pid),
?trace({delete_global_name,{item,Name},{pid,Pid}}),
true = ets:delete_object(global_pid_names, {Pid, Name}),
@@ -1929,9 +1917,9 @@ reset_node_state(Node) ->
%% from the same partition.
exchange_names([{Name, Pid, Method} | Tail], Node, Ops, Res) ->
case ets:lookup(global_names, Name) of
- [{Name, Pid, _Method, _RPid2, _Ref2}] ->
+ [{Name, Pid, _Method, _Ref2}] ->
exchange_names(Tail, Node, Ops, Res);
- [{Name, Pid2, Method2, _RPid2, _Ref2}] when node() < Node ->
+ [{Name, Pid2, Method2, _Ref2}] when node() < Node ->
%% Name clash! Add the result of resolving to Res(olved).
%% We know that node(Pid) =/= node(), so we don't
%% need to link/unlink to Pid.
@@ -1960,7 +1948,7 @@ exchange_names([{Name, Pid, Method} | Tail], Node, Ops, Res) ->
Op = {delete, Name},
exchange_names(Tail, Node, [Op | Ops], [Op | Res])
end;
- [{Name, _Pid2, _Method, _RPid, _Ref}] ->
+ [{Name, _Pid2, _Method, _Ref}] ->
%% The other node will solve the conflict.
exchange_names(Tail, Node, Ops, Res);
_ ->
@@ -2036,7 +2024,7 @@ pid_is_locking(Pid, PidRefs) ->
delete_lock(Ref, S0) ->
Locks = pid_locks(Ref),
F = fun({ResourceId, LockRequesterId, PidRefs}, S) ->
- {Pid, _RPid, Ref} = lists:keyfind(Ref, 3, PidRefs),
+ {Pid, Ref} = lists:keyfind(Ref, 2, PidRefs),
remove_lock(ResourceId, LockRequesterId, Pid, PidRefs, true, S)
end,
lists:foldl(F, S0, Locks).
@@ -2046,10 +2034,10 @@ pid_locks(Ref) ->
ets:lookup(global_locks, ResourceId)
end, ets:lookup(global_pid_ids, Ref)),
[Lock || Lock = {_Id, _Req, PidRefs} <- L,
- rpid_is_locking(Ref, PidRefs)].
+ ref_is_locking(Ref, PidRefs)].
-rpid_is_locking(Ref, PidRefs) ->
- lists:keyfind(Ref, 3, PidRefs) =/= false.
+ref_is_locking(Ref, PidRefs) ->
+ lists:keyfind(Ref, 2, PidRefs) =/= false.
handle_nodedown(Node, S) ->
%% DOWN signals from monitors have removed locks and registered names.
@@ -2062,7 +2050,7 @@ handle_nodedown(Node, S) ->
get_names() ->
ets:select(global_names,
- ets:fun2ms(fun({Name, Pid, Method, _RPid, _Ref}) ->
+ ets:fun2ms(fun({Name, Pid, Method, _Ref}) ->
{Name, Pid, Method}
end)).
@@ -2205,24 +2193,6 @@ unexpected_message(Message, What) ->
%%% Utilities
-%% When/if erlang:monitor() returns before trying to connect to the
-%% other node this function can be removed.
-do_monitor(Pid) ->
- case (node(Pid) =:= node()) orelse lists:member(node(Pid), nodes()) of
- true ->
- %% Assume the node is still up
- {Pid, erlang:monitor(process, Pid)};
- false ->
- F = fun() ->
- Ref = erlang:monitor(process, Pid),
- receive
- {'DOWN', Ref, process, Pid, _Info} ->
- exit(normal)
- end
- end,
- erlang:spawn_monitor(F)
- end.
-
intersection(_, []) ->
[];
intersection(L1, L2) ->
--
2.16.4
