feat(08): ring of processes

.github/workflows/ci.yml

@@ -16,5 +16,5 @@ jobs:
         run: |
           rebar3 dialyzer
           rebar3 eunit -v
-          rebar3 proper -c true --module prop_boolean,prop_create,prop_manipulating,prop_sorting,prop_db,prop_echo,prop_positive_echo
+          rebar3 proper -c true --module prop_boolean,prop_create,prop_manipulating,prop_sorting,prop_db,prop_echo,prop_positive_echo,prop_ring
           # rebar3 cover -m 100

apps/08-anillo-de-procesos/src/ring.erl

@@ -2,11 +2,47 @@
 
 % Public API
 -export([start/3]).
+-export([init/4, loop/2]).
 
 %%--------------------------------------------------------------------
 %% @doc Start function.
 %% @spec start(ProcNum :: pos_integer(), MsgNum :: pos_integer(), Message :: term()) -> ok
 %% @end
 %%--------------------------------------------------------------------
-start(_ProcNum, _MsgNum, _Message) ->
-    erlang:throw(not_implemented).
+start(ProcNum, MsgNum, Message) ->
+    register(master, spawn(?MODULE, init, [ProcNum, MsgNum, Message, self()])),
+    receive
+        ring_close ->
+            ok
+    end.
+
+%%%-------------------------------------------------------------------
+%%% INTERNAL FUNCTIONS
+%%%-------------------------------------------------------------------
+init(0, _MsgNum, _Message, _From)->
+    ok;
+init(1, MsgNum, Message, From) ->
+    master ! {MsgNum - 1, Message},
+    loop(master, From);
+init(ProcNum, MsgNum, Message, From) ->
+    Next = spawn(?MODULE, init, [ProcNum - 1, MsgNum, Message, From]),
+    loop(Next, From).
+
+loop(finish, From) ->
+    receive
+        stop ->
+            From ! ring_close
+    end;
+loop(Next, From) ->
+    receive 
+        {0, Message} ->
+            io:format("~p~n", [Message]),
+            Next ! stop,
+            loop(finish, From);
+        {MsgNum, Message} ->
+            io:format("~p~n", [Message]),
+            Next ! {MsgNum - 1, Message},
+            loop(Next, From);
+        stop ->
+            Next ! stop
+    end.

apps/08-anillo-de-procesos/test/prop_ring.erl

@@ -49,7 +49,7 @@ prop_ring() ->
 %% Sub-propiedades
 % (1) Comprobamos que se crean tantos procesos como se indica
 creacion(NProcs, Trazas) ->
-    ParentsAndChildren = [{Parent, Child} || {trace, Parent, spawn, Child, _Fun} <- Trazas],
+    ParentsAndChildren = [{Parent, Child} || {trace, Parent, spawn, Child, {ring, _, _}} <- Trazas],
     length(ParentsAndChildren) == NProcs.
 
 % (2) Comprobamos que se envía a mensaxe o número de veces axeitado
@@ -64,9 +64,10 @@ recepcion(NMsgs, Msg, Trazas) ->
 
 % (4) Comprobamos que se destrúen os procesos
 destruccion(NProcs, Trazas) ->
+    RingProcs = [Child || {trace, _Parent, spawn, Child, {ring, _, _}} <- Trazas],
     Stoppers = [{From, To} || {trace, From, send, stop, To} <- Trazas],
     Stopped =  [Who || {trace, Who, 'receive', stop} <- Trazas],
-    Exited =  [Who || {trace, Who, exit, normal} <- Trazas],
+    Exited =  [Who || {trace, Who, exit, normal} <- Trazas, lists:member(Who, RingProcs)],
     (length(Stoppers) == length(Stopped)) andalso (length(Exited) == NProcs).
 
 % Outras posibles sub-propiedades: