Merge remote-tracking branch 'remotes/archaelus/master'

.gitignore

@@ -13,3 +13,6 @@ profile
 # Vim
 *.swp
 *.swo
+
+# Emacs
+*~

include/gen_leader_specs.hrl

@@ -0,0 +1,70 @@
+
+-spec init (Args::term()) ->
+                   {'ok', State::term()} |
+                   'ignore' |
+                   {'stop', Reason::term()}.
+
+%% elected(_,_,node()) - captured a single candidate
+%%   reply notifies only the new candidate of the
+%%   sync state, ok notifies all candidates
+%% elected(_,_,undefined) - won a general election
+%%   ok broadcasts sync to all candidates
+-spec elected(State, gen_leader:election(), node() | 'undefined') ->
+                     {'ok', Sync::term(), State} |
+                     {'reply', Sync::term(), State}.
+
+-spec surrendered(State, Sync::term(), gen_leader:election()) ->
+                         {'ok', State}.
+
+-spec handle_leader_call(Request::term(),
+                         From::{pid(), reference()},
+                         State,
+                         gen_leader:election()) ->
+                                {'reply', Reply::term(), State} |
+                                {'reply', Reply::term(), Broadcast::term(), State} |
+                                {'noreply', State} |
+                                {'stop', Reason::term(), Reply::term(), State}.
+
+-spec handle_leader_cast(Msg::term(),
+                         State,
+                         gen_leader:election()) ->
+                                {'ok', Broadcast::term(), State} |
+                                {'noreply', State} |
+                                {'stop', Reason::term(), State}.
+
+-spec from_leader(Msg::term(),
+                  State,
+                  gen_leader:election()) ->
+                         {'noreply', State} |
+                         {'ok', State} |
+                         {'stop', Reason::term(), State}.
+
+-spec handle_call(Request::term(),
+                  From::{pid(), reference()},
+                  State,
+                  gen_leader:election()) ->
+                         {'reply', Reply::term(), State} |
+                         {'noreply', State} |
+                         {'stop', Reason::term(), State} |
+                         {'stop', Reason::term(), Reply::term(), State}.
+
+-spec handle_cast(Msg::term(),
+                  State,
+                  gen_leader:election()) ->
+                         {'noreply', State} |
+                         {'stop', Reason::term(), State}.
+
+-spec handle_DOWN(node(), State, gen_leader:election()) ->
+                         {'ok', State} |
+                         {'ok', Sync::term(), State}.
+
+-spec handle_info(Msg::term(), State) ->
+                         {'noreply', State} |
+                         {'stop', Reason::term(), State} |
+                         {'ok', State}.
+
+-spec terminate(Reason::term(), State::term()) -> any().
+
+-spec code_change(OldVsn::term(), State, gen_leader:election(), Extra::term()) ->
+                         {'ok', State} |
+                         {'ok', State, gen_leader:election()}.

src/gen_leader.erl

@@ -92,18 +92,18 @@
         ]).
 
 
+%% Notification control of candidate membership changes. `all'
+%% means that returns from the handle_DOWN/3 and elected/3 leader's events
+%% will be broadcast to all candidates.
+-type bcast_type() :: 'all' | 'sender'.
+
 -type option() :: {'workers',    Workers::[node()]}
                 | {'vardir',     Dir::string()}
                 | {'bcast_type', Type::bcast_type()}
                 | {'heartbeat',  Seconds::integer()}.
 
 -type options() :: [option()].
 
-%% Notification control of candidate membership changes. `all'
-%% means that returns from the handle_DOWN/3 and elected/3 leader's events
-%% will be broadcast to all candidates.
--type bcast_type() :: 'all' | 'sender'.
-
 -type status() :: 'elec1' | 'elec2' | 'wait' | 'joining' | 'worker' |
                   'waiting_worker' | 'norm'.
 
@@ -156,6 +156,10 @@
           bcast_type                :: bcast_type()
          }).
 
+-opaque election() :: #election{}.
+
+-export_type([election/0]).
+
 -record(server, {
           parent,
           mod,
@@ -242,27 +246,27 @@ start_link(Name, CandidateNodes, OptArgs, Mod, Arg, Options)
 %% Query functions to be used from the callback module
 
 %% @doc Returns list of alive nodes.
--spec alive(#election{}) -> [node()].
+-spec alive(election()) -> [node()].
 alive(E) ->
     candidates(E) -- down(E).
 
 %% @doc Returns list of down nodes.
--spec down(#election{}) -> [node()].
+-spec down(election()) -> [node()].
 down(#election{down = Down}) ->
     Down.
 
 %% @doc Returns the current leader node.
--spec leader_node(#election{}) -> node() | 'none'.
+-spec leader_node(election()) -> node() | 'none'.
 leader_node(#election{leadernode=Leader}) ->
     Leader.
 
 %% @doc Returns a list of known candidates.
--spec candidates(#election{}) -> [node()].
+-spec candidates(election()) -> [node()].
 candidates(#election{candidate_nodes = Cands}) ->
     Cands.
 
 %% @doc Returns a list of known workers.
--spec workers(#election{}) -> [node()].
+-spec workers(election()) -> [node()].
 workers(#election{worker_nodes = Workers}) ->
     Workers.
 
@@ -344,23 +348,23 @@ leader_call(Name, Request, Timeout) ->
 
 
 %% @equiv gen_server:cast/2
--spec cast(Name::name()|pid(), Request::term()) -> 'ok'.
+-spec cast(Name::server_ref(), Request::term()) -> 'ok'.
 cast(Name, Request) ->
     catch do_cast('$gen_cast', Name, Request),
     ok.
 
 %% @doc Similar to <code>gen_server:cast/2</code> but will be forwarded to
 %% the leader via the local gen_leader instance.
--spec leader_cast(Name::name()|pid(), Request::term()) -> 'ok'.
+-spec leader_cast(Name::server_ref(), Request::term()) -> 'ok'.
 leader_cast(Name, Request) ->
     catch do_cast('$leader_cast', Name, Request),
     ok.
 
 
-do_cast(Tag, Name, Request) when is_atom(Name) ->
-    Name ! {Tag, Request};
-do_cast(Tag, Pid, Request) when is_pid(Pid) ->
-    Pid ! {Tag, Request}.
+do_cast(Tag, {global, Name}, Request) ->
+    global:send(Name, {Tag, Request});
+do_cast(Tag, ServerRef, Request) ->
+    ServerRef ! {Tag, Request}.
 
 
 %% @equiv gen_server:reply/2
@@ -446,9 +450,7 @@ init_it(Starter,Parent,Name,Mod,{CandidateNodes,OptArgs,Arg},Options) ->
                     hasBecomeLeader(NewE,Server,{init});
                 false ->
                     %% more than one candidate worker, continue as normal
-                    safe_loop(#server{parent = Parent,mod = Mod,
-                                      state = State,debug = Debug},
-                              candidate, NewE,{init})
+                    safe_loop(Server, candidate, NewE,{init})
             end;
         {{ok, State}, true, true} ->
             Server = #server{parent = Parent,mod = Mod,
@@ -1014,10 +1016,11 @@ handle_msg({'$leader_call', From, Request} = Msg, Server, Role,
 handle_msg({Ref, {leader,reply,Reply}} = Msg, Server, Role,
            #election{buffered = Buffered} = E) ->
     {value, {_,From}} = lists:keysearch(Ref,1,Buffered),
-    NewServer = reply(From, {leader,reply,Reply}, Server, Role,
-                      E#election{buffered =
-                                     lists:keydelete(Ref,1,Buffered)}),
-    loop(NewServer, Role, E, Msg);
+    El = E#election{buffered = lists:keydelete(Ref,1,Buffered)},
+
+    NewServer = reply(From, {leader,reply,Reply}, Server, Role, El),
+
+    loop(NewServer, Role, El, Msg);
 handle_msg({'$gen_call', From, get_candidates} = Msg, Server, Role, E) ->
     NewServer = reply(From, {ok, candidates(E)}, Server, Role, E),
     loop(NewServer, Role, E, Msg);
@@ -1405,11 +1408,23 @@ mon_nodes(E,Nodes,Server) ->
               mon_node(El, Pid, Server)
       end,E1,Nodes -- [node()]).
 
-%% Star monitoring one Process
-mon_node(E,Proc,Server) ->
-    {Ref,Node} = do_monitor(Proc, Server),
-    E#election{monitored = [{Ref,Node} | E#election.monitored]}.
+%% Start monitoring one Process
+mon_node(E,{_RegName, NodeName} = Proc,Server) ->
+    case lists:keymember(NodeName, 2, E#election.monitored) of
+	    true -> E;
+	    false ->
+                {Ref,Node} = do_monitor(Proc, Server),
+                E#election{monitored = [{Ref,Node} | E#election.monitored]}
+    end;
 
+mon_node(E,Proc,Server) when is_pid(Proc) ->
+    case lists:keymember(node(Proc), 2, E#election.monitored) of
+	    true -> E;
+	    false ->
+                {Ref,Node} = do_monitor(Proc, Server),
+                E#election{monitored = [{Ref,Node} | E#election.monitored]}
+    end
+    .
 
 spawn_monitor_proc() ->
     Parent = self(),
@@ -1444,7 +1459,7 @@ mon_handle_req({monitor, P}, From, Refs) ->
                Pid when is_pid(Pid) -> node(Pid)
            end,
     case lists:keyfind(Node, 2, Refs) of
-        {_, Ref} ->
+        {Ref, _} ->
             mon_reply(From, {Ref,Node}),
             Refs;
         false ->