Working example with 1 slave and 1 master

backend/grisp/grisp_base/files/erl_inetrc

@@ -1,5 +1,5 @@
 % Add hosts
-{host, {X,X,X,X}, ["hostname"]}.
+{host, {10,152,0,13}, ["mainframe1"]}.
 
 % Do not monitor the hosts file
 {hosts_file, ""}.

backend/grisp/grisp_base/files/grisp.ini.mustache

@@ -7,5 +7,5 @@ args = erl.rtems -- -home . -pa . -root conway_game -boot conway_game/releases/0
 [network]
 ip_self = dhcp
 wlan = enable
-hostname = boardX
+hostname = board0002
 wpa = wpa_supplicant.conf

backend/master_vars.config

@@ -1 +1 @@
-{node_name, 'master@host'}.
+{node_name, master}.

backend/rebar.lock

@@ -0,0 +1,26 @@
+{"1.1.0",
+[{<<"cowboy">>,
+  {git,"git://github.com/ninenines/cowboy.git",
+       {ref,"d846827b2a70317914621328bd617e4e5d4d13d8"}},
+  0},
+ {<<"cowlib">>,
+  {git,"https://github.com/ninenines/cowlib",
+       {ref,"75aaeb8415033b07303febbfeba66d6d3413ad06"}},
+  1},
+ {<<"epmd">>,
+  {git,"https://github.com/erlang/epmd",
+       {ref,"4d1a595b9d5c32fc0e55f462da381de62de23bf0"}},
+  0},
+ {<<"grisp">>,{pkg,<<"grisp">>,<<"1.1.4">>},0},
+ {<<"jiffy">>,{pkg,<<"jiffy">>,<<"0.15.2">>},0},
+ {<<"mapz">>,{pkg,<<"mapz">>,<<"0.3.0">>},1},
+ {<<"ranch">>,
+  {git,"https://github.com/ninenines/ranch",
+       {ref,"3190aef88aea04d6dce8545fe9b4574288903f44"}},
+  1}]}.
+[
+{pkg_hash,[
+ {<<"grisp">>, <<"5C22D6F9C0B47A90F132E56AC9D85659B5AC469BAF04B4C98EE1E0EF5894319B">>},
+ {<<"jiffy">>, <<"DE266C390111FD4EA28B9302F0BC3D7472468F3B8E0ACEABFBEFA26D08CD73B7">>},
+ {<<"mapz">>, <<"438D24746CE5A252101E00B2032EFDF7FC69EB32689D3B805DE5E6DD7F52614F">>}]}
+].

backend/slave_vars.config

@@ -1 +1 @@
-{node_name, 'slave@host'}.
+{node_name, 'slave@127.0.0.1'}.

backend/src/conway_game.app.src

@@ -10,7 +10,7 @@
     jiffy,
     runtime_tools
    ]},
-  {env,[ {masterhost, 'master@host'},
+  {env,[ {masterhost, 'master@mainframe1'},
          {slave_n, 1}]},
   {modules, []},
 

backend/src/conway_master_worker.erl

@@ -47,6 +47,7 @@ reset_state() -> gen_server:call(noderef(), reset_state).
 get_state_raw() -> gen_server:call(noderef(), get_state_raw).
 
 init([SlaveN]) ->
+    io:format("Master node ~p~n", [node()]),
     {ok, #state{max_slaves = SlaveN, started = true}}.
 
 handle_call(reset_state, _, #state{ max_slaves = MaxSl }) ->
@@ -102,7 +103,9 @@ handle_cast({update, NodeName, Rect, G}, #state{state = computing,
             {noreply, State#state{current_rects = NewCurrentRects}}
     end;
 handle_cast(M, S) ->
-    io:format("[WARN] Unknown cast: ~p in state ~p~n", [M, S]),
+    io:format("[WARN] Unknown cast: ~p ~n", [M]),
+    io:format("[WARN] in state ~p~n", [S]),
+    io:format("[WARN] State: ~p ~n", [S#state.state]),
     {noreply, S}.
 
 handle_info({'DOWN', Ref, _, _, Reason} = M, S) ->
@@ -116,7 +119,7 @@ handle_info(_, S) ->
 noderef() ->
     {ok, NodeName} = application:get_env(conway_game, masterhost),
     {?MODULE, NodeName}.
-    
+
 inc_generation(#state{goal_generations = N, generation = M} = State) when N == M ->
     NewState = State#state{state = finished, generation = M},
     ws_h:update_state(format_state(NewState)),

backend/src/conway_slave.erl

@@ -1,8 +1,125 @@
+%%% @author zofiapolkowska
+%%% @copyright (C) 2019, zofiapolkowska
+%%% @doc
+%%%
+%%% @end
+%%% Created : 2019-06-04 18:06:41.713061
+
 -module(conway_slave).
 
--export([loop/0]).
+-behaviour(gen_server).
+
+%% API
+-export([start_link/0,
+         init_state/5]).
+
+%% Callbacks
+-export([init/1,
+         handle_call/3,
+         handle_cast/2,
+         handle_info/2,
+         terminate/2,
+         code_change/3]).
+
+-define(SERVER, ?MODULE).
+-define(PRINT(Var), io:format("DEBUG: ~p:~p - ~p~n~n ~p~n~n", [?MODULE, ?LINE, ??Var, Var])).
+
+-record(state, {
+  rect = null,
+  current_gen = 0,
+  max_gen = 1,
+  node_name = ""
+}).
+
+%%% API
+
+start_link() ->
+  gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
+
+init_state(Node, StartingRect, Gens, _Slaves, _W) ->
+  io:format("Init State~n", []),
+  gen_server:call({?MODULE, Node}, {init_state, Node, StartingRect, Gens}),
+  gen_server:cast({?MODULE, Node}, {tick}).
+
+%%% gen_server callbacks
+
+init([]) ->
+  io:format("Slave initialized~p~n", [node()]),
+  conway_master_worker:register_slave(node()),
+
+  {ok, #state{}}.
+
+handle_call({init_state, NodeName, StartingRect, Gens}, _From, State) ->
+  Rect = [],
+  NewState = #state{
+    rect = StartingRect,
+    current_gen = 0,
+    max_gen = Gens,
+    node_name = NodeName
+  },
+  {reply, ok, NewState}.
+
+handle_cast({tick}, #state{max_gen = MaxGen, current_gen = CurrentGen} = State) when CurrentGen >= MaxGen ->
+  {noreply, State};
+
+handle_cast({tick}, State) ->
+  NewGen = State#state.current_gen + 1,
+
+  NewRect = rect:map(fun(X, Y, Value) -> update_cell(X, Y, Value, State#state.rect) end, State#state.rect),
+
+  NewState = State#state{
+    current_gen = NewGen,
+    rect = NewRect},
+
+  conway_master_worker:update_state(
+    NewState#state.node_name,
+    NewState#state.rect,
+    NewState#state.current_gen),
+
+  io:format("Tick: Generation ~p ~n", [NewGen]),
+
+  timer:sleep(300),
+  gen_server:cast({?MODULE, State#state.node_name}, {tick}),
+
+  {noreply, NewState};
+
+handle_cast(_Msg, State) ->
+  {noreply, State}.
+
+handle_info(_Info, State) ->
+  {noreply, State}.
+
+terminate(_Reason, _State) ->
+  ok.
+
+code_change(_OldVsn, State, _Extra) ->
+  {ok, State}.
+
+%%% Internal functions
+
+update_cell(X, Y, Value, Rect) ->
+  Neighbours = [
+    rect:get(Rect, {X-1, Y-1}),
+    rect:get(Rect, {X, Y-1}),
+    rect:get(Rect, {X+1, Y-1}),
+    rect:get(Rect, {X-1, Y}),
+    rect:get(Rect, {X+1, Y}),
+    rect:get(Rect, {X-1, Y+1}),
+    rect:get(Rect, {X, Y+1}),
+    rect:get(Rect, {X+1, Y+1})
+  ],
+
+  Count = length(lists:filter(fun(Value) ->
+    case Value of
+      true -> true;
+      _ -> false
+    end
+  end, Neighbours)),
+
+  NewValue = case {Count, Value} of
+    {2, true} -> true;
+    {3, _} -> true;
+    _ -> false
+  end,
 
-loop() ->
-    io:format("I am alive~n", []),
-    timer:sleep(10000),
-    loop().
+  {{X, Y}, NewValue}.

backend/src/conway_slave_sup.erl

@@ -31,5 +31,5 @@ start_link() ->
 %% Before OTP 18 tuples must be used to specify a child. e.g.
 %% Child :: {Id,StartFunc,Restart,Shutdown,Type,Modules}
 init([]) ->
-    ConwayWorker = #{id => conway_slave, start => {conway_slave, loop, []}},
+    ConwayWorker = #{id => conway_slave, start => {conway_slave, start_link, []}},
     {ok, { {one_for_all, 0, 1}, [ConwayWorker]} }.

backend/src/rest_endpoint.erl

@@ -3,12 +3,13 @@
 -export([init/2]).
 -export([content_types_provided/2]).
 -export([content_types_accepted/2]).
+-export([content_types_accepted/2]).
 -export([allowed_methods/2]).
 -export([to_json/2]).
 
 init(Req, Opts) ->
-    ReqWithCORS = add_cors_headers(Req),
-    {cowboy_rest, ReqWithCORS, Opts}.
+  ReqWithCORS = add_cors_headers(Req),
+	{cowboy_rest, ReqWithCORS, Opts}.
 
 allowed_methods(Req, State) -> {[<<"POST">>, <<"GET">>, <<"OPTIONS">>], Req, State}.
 
@@ -29,7 +30,7 @@ to_json(Req, State) ->
         <<"GET">> ->
             get_state(Req, State);
         <<"OPTIONS">> ->
-            {true, Req, State}
+            {true, Req, State} 
     end.
 
 start_the_game(Req, State) ->
@@ -72,8 +73,8 @@ to_int(B) when is_list(B) ->
 %% Helpers
 
 add_cors_headers(Req) ->
-    Req1 = cowboy_req:set_resp_header(<<"access-control-allow-origin">>, <<"*">>, Req),
-    cowboy_req:set_resp_header(<<"access-control-allow-headers">>, <<"Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With">>, Req1).
+  Req1 = cowboy_req:set_resp_header(<<"access-control-allow-origin">>, <<"*">>, Req),
+  cowboy_req:set_resp_header(<<"access-control-allow-headers">>, <<"Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With">>, Req1).
 
 is_master_node_started() ->
     case maps:get(start_state, conway_master_worker:get_state()) of

backend/vm.args

@@ -1,4 +1,4 @@
--name {{node_name}}
+-sname {{node_name}}
 
 ## Cookie for distributed erlang
 -setcookie conway_game