Erlang TCP 服务器总是在接受时关闭

Question

我是 Erlang 的新手，我正在尝试设置一个简单的多客户端聊天服务器来了解有关该语言的更多信息。但是，每当我尝试运行它时，我都会从侦听套接字上的 gen_tcp:accept 调用中得到一个套接字关闭错误。我尝试了许多不同的端口号均无济于事。我错过了什么？

代码如下：

-define(TCP_OPTIONS, [binary, {packet, 2}, {active, false}, {reuseaddr, true}]).

listen(Portno, DictPid) -> 
  case gen_tcp:listen(Portno, ?TCP_OPTIONS) of
    {ok, ListenSocket} ->
      spawn_link(fun() -> accept_connections(ListenSocket, DictPid) end),
      io:format("Listening on ~p~n", [ListenSocket]);
    {error, Error} ->
      io:format("Listen Error: ~w~n", [Error])
  end.

accept_connections(ListenSocket, DictPid) ->
  case gen_tcp:accept(ListenSocket) of
    {ok, ClientSocket} ->
      io:format("Accepting:~w~n", [ClientSocket]),
      gen_tcp:send(ClientSocket, "Welcome! Enter your name~n"),
      ClientPid = spawn(fun() -> io:format("Client connected"),
                                 setup_user(ClientSocket, DictPid) end),
      gen_tcp:controlling_process(ClientSocket, ClientPid),
      accept_connections(ListenSocket, DictPid);
    {error, Error} ->
      io:format("Accept Error: ~w~n", [Error])
  end.
  
setup_user(ClientSocket, DictPid) ->
  {ok, Username} = gen_tcp:recv(ClientSocket, 0),
  DictPid ! {add_new_pair, ClientSocket, Username},
  ClientDict = get_dict(DictPid),
  broadcast_message(dict:fetch_keys(ClientDict), "[" ++ Username ++ "has entered the chat]"),
  client_loop(ClientSocket, Username, DictPid).

[rest of program]

Answer 1

这里的问题是ListenSocket的控制器终止，导致ListenSocket被关闭。