first_otp.erl

-module(server1).
-export([start/2, rpc/2]).
start(Name, Mod) ->
  register(Name, spawn(fun() -> loop(Name, Mod, Mod:init()) end)).

rpc(Name, Request) ->
  io:format(" self at rpc is ~p~n", [self()]),
  io:format(" Name at rpc is ~p~n", [Name]),

  Name ! { self(), Request },
  receive
    { Name, Response } -> 
      io:format(" self is  ~p~n", [self()]),
      Response
  end.

loop(Name, Mod, State) ->
  io:format(" self at loop is ~p~n", [self()]),
  receive
    { From, Request } ->
      io:format(" From in loop is ~p~n", [From]),

      { Response, State1 } = Mod:handle(Request, State),
      From ! { Name, Response},
      loop(Name, Mod, State1)
    end.
    
    
    
-module(name_server).
-export([init/0, add/2, find/1, handle/2]).
-import(server1, [rpc/2]).

add(Name, Place) -> 
  io:format(" self in add is ~p~n", [self()]),
  rpc(name_server, { add, Name, Place}).

find(Name) -> 
  io:format(" self at find is ~p~n", [self()]),
  rpc(name_server, {find, Name}).

init() -> dict:new().

handle({add, Name, Place}, Dict) -> 
  io:format(" self at handle add is ~p~n", [self()]),
  {ok, dict:store(Name, Place, Dict)};

handle({find, Name}, Dict) -> 
  io:format(" self at handle find is ~p~n", [self()]),
  {dict:find(Name, Dict), Dict}.    

使用以下命令查看进程信息

observer:start()