Make the CRE master deal only with worker PIDs, instead of registered…

… names internally and also increase its verbosity.

src/cre_master.erl

@@ -123,9 +123,9 @@ stop( CreName ) ->
 %% gen_server callback functions
 %%====================================================================
 
-code_change( _OldVsn, CreState, _Extra )  -> {ok, CreState}.
+code_change( _OldVsn, CreState, _Extra ) -> {ok, CreState}.
 handle_call( _Request, _From, CreState ) -> {reply, {error, bad_msg}, CreState}.
-terminate( _Reason, _CreState )           -> ok.
+terminate( _Reason, _CreState )          -> ok.
 
 init( _Arg ) ->
   process_flag( trap_exit, true ),
@@ -134,30 +134,39 @@ init( _Arg ) ->
 
 handle_cast( {add_worker, P}, CreState ) ->
 
-  error_logger:info_report(
-    [{info, "new worker"},
-     {application, cre},
-     {cre_master_pid, self()},
-     {worker_pid, P}] ),
+  #cre_state{ idle_lst = IdleLst, busy_map = BusyMap } = CreState,
 
+  % extract pid because link/1 cannot deal with registered names
   Pid =
     if
       is_pid( P ) -> P;
       true        -> whereis( P )
     end,
 
-  true = link( Pid ),
+  error_logger:info_report(
+    [{info, "new worker"},
+     {application, cre},
+     {cre_master_pid, self()},
+     {worker_pid, Pid},
+     {nworker, length( IdleLst )+maps:size( BusyMap )+1}] ),
 
-  #cre_state{ idle_lst = IdleLst } = CreState,
 
-  CreState1 = CreState#cre_state{ idle_lst = [P|IdleLst] },
+  true = link( Pid ),
+
+  CreState1 = CreState#cre_state{ idle_lst = [Pid|IdleLst] },
 
   CreState2 = attempt_progress( CreState1 ),
 
   {noreply, CreState2};
 
 handle_cast( {worker_result, P, A, Delta}, CreState ) ->
 
+  Pid =
+    if
+      is_pid( P ) -> P;
+      true        -> whereis( P )
+    end,
+
   #cre_state{ subscr_map = SubscrMap,
               idle_lst   = IdleLst,
               busy_map   = BusyMap,
@@ -170,10 +179,10 @@ handle_cast( {worker_result, P, A, Delta}, CreState ) ->
 
   case maps:get( A, BusyMap, undefined ) of
 
-    P ->
+    Pid ->
       lists:foreach( F, maps:get( A, SubscrMap ) ),
       CreState1 = CreState#cre_state{ subscr_map = maps:remove( A, SubscrMap ),
-                                      idle_lst   = [P|IdleLst],
+                                      idle_lst   = [Pid|IdleLst],
                                       busy_map   = maps:remove( A, BusyMap ),
                                       cache      = Cache#{ A => Delta } },
       CreState2 = attempt_progress( CreState1 ),
@@ -224,9 +233,14 @@ handle_info( {'EXIT', P, _Reason}, CreState ) ->
               busy_map = BusyMap,
               queue    = Queue } = CreState,
 
-
+  Pid =
+    if
+      is_pid( P ) -> P;
+      true        -> whereis( P )
+    end,
+
 
-  case lists:member( P, IdleLst ) of
+  case lists:member( Pid, IdleLst ) of
 
     % an idle worker died
     true ->
@@ -235,23 +249,25 @@ handle_info( {'EXIT', P, _Reason}, CreState ) ->
         [{info, "idle worker down"},
          {application, cre},
          {cre_master_pid, self()},
-         {worker_pid, P}] ),
+         {worker_pid, Pid},
+         {nworker, length( IdleLst )+maps:size( BusyMap )-1}] ),
 
-      CreState1 = CreState#cre_state{ idle_lst = IdleLst--[P] },
+      CreState1 = CreState#cre_state{ idle_lst = IdleLst--[Pid] },
 
       {noreply, CreState1};
 
     false ->
-      case lists:keyfind( P, 2, maps:to_list( BusyMap ) ) of
+      case lists:keyfind( Pid, 2, maps:to_list( BusyMap ) ) of
 
         % a busy worker died    
-        {A, P} ->
+        {A, Pid} ->
 
           error_logger:info_report(
             [{info, "busy worker down"},
              {application, cre},
              {cre_master_pid, self()},
-             {worker_pid, P}] ),
+             {worker_pid, Pid},
+             {nworker, length( IdleLst )+maps:size( BusyMap )-1}] ),
 
           CreState1 = CreState#cre_state{ queue    = [A|Queue],
                                           busy_map = maps:remove( A, BusyMap ) },
@@ -265,7 +281,7 @@ handle_info( {'EXIT', P, _Reason}, CreState ) ->
             [{info, "exit signal received"},
              {application, cre},
              {cre_master_pid, self()},
-             {from_pid, P}] ),
+             {from_pid, Pid}] ),
 
           {stop, exit, CreState}
       end
@@ -278,6 +294,8 @@ handle_info( _Info, CreState ) -> {noreply, CreState}.
 %% Internal functions
 %%====================================================================
 
+-spec attempt_progress( CreState :: #cre_state{} ) -> #cre_state{}.
+
 attempt_progress( CreState ) ->
 
   #cre_state{ idle_lst   = IdleLst,
@@ -298,11 +316,11 @@ attempt_progress( CreState ) ->
 
         [_|_] ->
 
-          P = lib_combin:pick_from( IdleLst ),
-          IdleLst1 = IdleLst--[P],
-          BusyMap1 = BusyMap#{ A => P },
+          Pid = lib_combin:pick_from( IdleLst ),
+          IdleLst1 = IdleLst--[Pid],
+          BusyMap1 = BusyMap#{ A => Pid },
 
-          cre_worker:worker_request( P, A ),
+          cre_worker:worker_request( Pid, A ),
 
           CreState#cre_state{ idle_lst = IdleLst1,
                               busy_map = BusyMap1,