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-rw-r--r--lib/kernel/src/pg2.erl50
1 files changed, 27 insertions, 23 deletions
diff --git a/lib/kernel/src/pg2.erl b/lib/kernel/src/pg2.erl
index 1ff10eb303..edf4aedde2 100644
--- a/lib/kernel/src/pg2.erl
+++ b/lib/kernel/src/pg2.erl
@@ -1,18 +1,19 @@
%%
%% %CopyrightBegin%
%%
-%% Copyright Ericsson AB 1997-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2016. 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
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
%%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
%%
%% %CopyrightEnd%
%%
@@ -45,7 +46,7 @@ start() ->
-spec create(Name :: name()) -> 'ok'.
create(Name) ->
- ensure_started(),
+ _ = ensure_started(),
case ets:member(pg2_table, {group, Name}) of
false ->
global:trans({{?MODULE, Name}, self()},
@@ -60,7 +61,7 @@ create(Name) ->
-spec delete(Name :: name()) -> 'ok'.
delete(Name) ->
- ensure_started(),
+ _ = ensure_started(),
global:trans({{?MODULE, Name}, self()},
fun() ->
gen_server:multi_call(?MODULE, {delete, Name})
@@ -71,7 +72,7 @@ delete(Name) ->
when Name :: name().
join(Name, Pid) when is_pid(Pid) ->
- ensure_started(),
+ _ = ensure_started(),
case ets:member(pg2_table, {group, Name}) of
false ->
{error, {no_such_group, Name}};
@@ -88,7 +89,7 @@ join(Name, Pid) when is_pid(Pid) ->
when Name :: name().
leave(Name, Pid) when is_pid(Pid) ->
- ensure_started(),
+ _ = ensure_started(),
case ets:member(pg2_table, {group, Name}) of
false ->
{error, {no_such_group, Name}};
@@ -105,7 +106,7 @@ leave(Name, Pid) when is_pid(Pid) ->
when Name :: name().
get_members(Name) ->
- ensure_started(),
+ _ = ensure_started(),
case ets:member(pg2_table, {group, Name}) of
true ->
group_members(Name);
@@ -117,7 +118,7 @@ get_members(Name) ->
when Name :: name().
get_local_members(Name) ->
- ensure_started(),
+ _ = ensure_started(),
case ets:member(pg2_table, {group, Name}) of
true ->
local_group_members(Name);
@@ -128,7 +129,7 @@ get_local_members(Name) ->
-spec which_groups() -> [Name :: name()].
which_groups() ->
- ensure_started(),
+ _ = ensure_started(),
all_groups().
-spec get_closest_pid(Name) -> pid() | {'error', Reason} when
@@ -140,19 +141,22 @@ get_closest_pid(Name) ->
[Pid] ->
Pid;
[] ->
- {_,_,X} = erlang:now(),
case get_members(Name) of
[] -> {error, {no_process, Name}};
Members ->
- lists:nth((X rem length(Members))+1, Members)
+ random_element(Members)
end;
Members when is_list(Members) ->
- {_,_,X} = erlang:now(),
- lists:nth((X rem length(Members))+1, Members);
+ random_element(Members);
Else ->
Else
end.
+random_element(List) ->
+ X = abs(erlang:monotonic_time()
+ bxor erlang:unique_integer()),
+ lists:nth((X rem length(List)) + 1, List).
+
%%%
%%% Callback functions from gen_server
%%%
@@ -165,7 +169,7 @@ get_closest_pid(Name) ->
init([]) ->
Ns = nodes(),
- net_kernel:monitor_nodes(true),
+ ok = net_kernel:monitor_nodes(true),
lists:foreach(fun(N) ->
{?MODULE, N} ! {new_pg2, node()},
self() ! {nodeup, N}
@@ -283,7 +287,7 @@ member_died(Ref) ->
join_group(Name, Pid) ->
Ref_Pid = {ref, Pid},
- try _ = ets:update_counter(pg2_table, Ref_Pid, {4, +1})
+ try _ = ets:update_counter(pg2_table, Ref_Pid, {4, +1}), true
catch _:_ ->
{RPid, Ref} = do_monitor(Pid),
true = ets:insert(pg2_table, {Ref_Pid, RPid, Ref, 1}),