pf：gen_*不能call自己

src/gen_call.erl

@@ -41,7 +41,12 @@ do_call(Process, Label, Request, Timeout) ->
          %% Local without timeout; no need to use alias since we unconditionally
          %% will wait for either a reply or a down message which corresponds to
          %% the process being terminated (as opposed to 'noconnection')...
-         Process ! {Label, {self(), Mref}, Request},
+         case self() of
+            Process ->
+               exit(calling_self);
+            _ ->
+               Process ! {Label, {self(), Mref}, Request},
+         end,
          receive
             {Mref, Reply} ->
                erlang:demonitor(Mref, [flush]),