Merge branch 'master' of http://github.com/abecciu/gen_leader_revival

Conflicts:
	.gitignore

.gitignore

@@ -2,6 +2,7 @@
 ebin/*.beam
 erl_crash.dump
 doc/*
+
 # Xcode
 build/*
 *.xcodeproj/*

README.markdown

@@ -14,7 +14,13 @@ Use the version in combined_version.
 What Exactly Does It Do?
 ========================
 
-Let us get back to you on that.
+Leader election behavior.
+-------------------------
+
+This application implements a leader election behavior modeled after
+gen_server. This behavior intends to make it reasonably
+straightforward to implement a fully distributed server with
+master-slave semantics.
 
 Current Participants
 ====================

doc/skeleton.erl

@@ -0,0 +1,230 @@
+-module(skeleton).
+
+-behaviour(gen_leader).
+
+%% API
+-export([start_link/1, start_link/2]).
+
+%% gen_leader callbacks
+-export([init/1,
+         handle_cast/3,
+         handle_call/4,
+         handle_info/2,
+         handle_leader_call/4,
+         handle_leader_cast/3,
+         handle_DOWN/3,
+         elected/3,
+         surrendered/3,
+         from_leader/3,
+         code_change/4,
+         terminate/2]).
+
+
+-define(SERVER, ?MODULE).
+
+-record(state, {}).
+
+%%%===================================================================
+%%% API
+%%%===================================================================
+
+%%--------------------------------------------------------------------
+%% @doc
+%% Starts the server
+%%
+%% @spec start_link() -> {ok, Pid} | ignore | {error, Error}
+%% @end
+%%--------------------------------------------------------------------
+start_link(Nodes) ->
+    start_link(Nodes, []).
+
+start_link(Nodes, Seed) when is_list(Nodes), is_atom(Seed) ->
+    start_link(Nodes, {seed_node, Seed});
+
+start_link(Nodes, Opts) ->
+    gen_leader:start_link(?SERVER, Nodes, Opts, ?MODULE, [], []).
+
+%%%===================================================================
+%%% gen_leader callbacks
+%%%===================================================================
+
+%%--------------------------------------------------------------------
+%% @private
+%% @doc
+%% Initializes the server
+%%
+%% @spec init(Args) -> {ok, State} |
+%%                     ignore |
+%%                     {stop, Reason}
+%% @end
+%%--------------------------------------------------------------------
+init([]) ->
+    {ok, #state{}}.
+
+%%--------------------------------------------------------------------
+%% @private
+%% @doc
+%% Called only in the leader process when it is elected. The Synch
+%% term will be broadcasted to all the nodes in the cluster.
+%%
+%% @spec elected(State, Election, undefined) -> {ok, Synch, State}
+%% @end
+%%--------------------------------------------------------------------
+elected(State, _Election, undefined) ->
+    Synch = [],
+    {ok, Synch, State};
+
+%%--------------------------------------------------------------------
+%% @private
+%% @doc
+%% Called only in the leader process when a new candidate joins the
+%% cluster. The Synch term will be sent to Node.
+%%
+%% @spec elected(State, Election, Node) -> {ok, Synch, State}
+%% @end
+%%--------------------------------------------------------------------
+elected(State, _Election, _Node) ->
+    {reply, [], State}.
+
+%%--------------------------------------------------------------------
+%% @private
+%% @doc
+%% Called in all members of the cluster except the leader. Synch is a
+%% term returned by the leader in the elected/3 callback.
+%%
+%% @spec surrendered(State, Synch, Election) -> {ok, State}
+%% @end
+%%--------------------------------------------------------------------
+surrendered(State, _Synch, _Eelection) ->
+    {ok, State}.
+
+%%--------------------------------------------------------------------
+%% @private
+%% @doc
+%% Handling call messages. Called in the leader.
+%%
+%% @spec handle_leader_call(Request, From, State, Election) ->
+%%                                            {reply, Reply, Broadcast, State} |
+%%                                            {reply, Reply, State} |
+%%                                            {noreply, State} |
+%%                                            {stop, Reason, Reply, State} |
+%%                                            {stop, Reason, State}
+%% @end
+%%--------------------------------------------------------------------
+handle_leader_call(_Request, _From, State, _Election) ->
+    {reply, ok, State}.
+
+%%--------------------------------------------------------------------
+%% @private
+%% @doc
+%% Handling cast messages. Called in the leader.
+%%
+%% @spec handle_leader_cast(Request, State, Election) ->
+%%                                            {ok, Broadcast, State} |
+%%                                            {noreply, State} |
+%%                                            {stop, Reason, State}
+%% @end
+%%--------------------------------------------------------------------
+handle_leader_cast(_Request, State, _Election) ->
+    {noreply, State}.
+
+%%--------------------------------------------------------------------
+%% @private
+%% @doc
+%% Handling messages from leader.
+%%
+%% @spec from_leader(Request, State, Election) ->
+%%                                    {ok, State} |
+%%                                    {noreply, State} |
+%%                                    {stop, Reason, State}
+%% @end
+%%--------------------------------------------------------------------
+from_leader(_Synch, State, _Election) ->
+    {ok, State}.
+
+%%--------------------------------------------------------------------
+%% @private
+%% @doc
+%% Handling nodes going down. Called in the leader only.
+%%
+%% @spec handle_DOWN(Node, State, Election) ->
+%%                                  {ok, State} |
+%%                                  {ok, Broadcast, State} |
+%% @end
+%%--------------------------------------------------------------------
+handle_DOWN(_Node, State, _Election) ->
+    {ok, State}.
+
+%%--------------------------------------------------------------------
+%% @private
+%% @doc
+%% Handling call messages
+%%
+%% @spec handle_call(Request, From, State, Election) ->
+%%                                   {reply, Reply, State} |
+%%                                   {noreply, State} |
+%%                                   {stop, Reason, Reply, State} |
+%%                                   {stop, Reason, State}
+%% @end
+%%--------------------------------------------------------------------
+handle_call(_Request, _From, State, _Election) ->
+    Reply = ok,
+    {reply, Reply, State}.
+
+%%--------------------------------------------------------------------
+%% @private
+%% @doc
+%% Handling cast messages
+%%
+%% @spec handle_cast(Msg, State, Election) ->
+%%                                  {noreply, State} |
+%%                                  {stop, Reason, State}
+%% @end
+%%--------------------------------------------------------------------
+handle_cast(_Msg, State, _Election) ->
+    {noreply, State}.
+
+%%--------------------------------------------------------------------
+%% @private
+%% @doc
+%% Handling all non call/cast messages
+%%
+%% @spec handle_info(Info, State) -> {noreply, State} |
+%%                                   {stop, Reason, State}
+%% @end
+%%--------------------------------------------------------------------
+handle_info(_Info, State) ->
+    {noreply, State}.
+
+%%--------------------------------------------------------------------
+%% @private
+%% @doc
+%% This function is called by a gen_leader when it is about to
+%% terminate. It should be the opposite of Module:init/1 and do any
+%% necessary cleaning up. When it returns, the gen_leader terminates
+%% with Reason. The return value is ignored.
+%%
+%% @spec terminate(Reason, State) -> void()
+%% @end
+%%--------------------------------------------------------------------
+terminate(_Reason, _State) ->
+    ok.
+
+%%--------------------------------------------------------------------
+%% @private
+%% @doc
+%% Convert process state when code is changed
+%%
+%% @spec code_change(OldVsn, State, Election, Extra) ->
+%%                                          {ok, NewState} |
+%%                                          {ok, NewState, NewElection}
+%% @end
+%%--------------------------------------------------------------------
+code_change(_OldVsn, State, _Election, _Extra) ->
+    {ok, State}.
+
+
+%%%===================================================================
+%%% Internal functions
+%%%===================================================================
+

ebin/gen_leader.app

@@ -1,4 +1,13 @@
-{application, gen_leader, [
-	{vsn, "1.0"},
-	{modules, [gen_leader]}
-]}.
+%%% -*- mode: erlang -*-
+
+{application, gen_leader,
+ [
+  {description, "The gen_leader behaviour"},
+  {vsn, "1.0"},
+  {id, "gen_leader"},
+  {modules, [gen_leader]},
+  {registered, [ ]},
+  %% NOTE: do not list applications which are load-only!
+  {applications, [ kernel, stdlib ] }
+ ]
+}.

src/Makefile

@@ -0,0 +1,2 @@
+all:
+	cd .. && $(MAKE)