問題gen_tcp：接受

Question

我做了一個tcp服務器產生一個進程監聽傳入的連接。下面是示例代碼（從我的原代碼中刪除了一些東西）：

模塊：

main([]) -> 
    { ok, Pid } = b:start(), 
    receive 
      _ -> 
        ok 
    end. 

模塊B：

-define(TCP_OPTIONS, [binary, { active, false}, { packet, 0 } , {reuseaddr, true}]). 

... 

start_link(Port) -> 
    Pid = spawn_link(server_listener, init, [ Port ]), 
    { ok , self() }. 

init(Port, Processor) -> 
    case gen_tcp:listen(Port, ?TCP_OPTIONS) of 
    { ok , LSocket } -> 
      accept_loop(LSocket); 
    { error, Reason } -> 
     { stop, Reason } 
    end. 

accept_loop(LSocket) -> 
    ?LOG("Current socket acceptor PID [~w]~n", [self()]), 
    case gen_tcp:accept(LSocket) of 
     { ok, Socket } -> 
     %do stuff here 
     spawn(server_listener , accept_loop, [ LSocket ]); 
     { error, Reason } -> 
     ?LOG("Error accepting socket! [ ~s ]~n", [ Reason ]) 
    end. 

的問題是：每一次當我嘗試在此端口上從telnet連接，我在gen_tcp：accept上收到錯誤{error，closed}。這已經迫使我試圖弄清楚發生了什麼。

感謝，

Answer 1

你「接受環」是不是一個真正的環...它是人爲的。

您可能想要「do_accept_loop」和適當的「server_loop」來處理連接。看看this。

你想沿着線的東西：

% Call echo:listen(Port) to start the service. 
listen(Port) -> 
    {ok, LSocket} = gen_tcp:listen(Port, ?TCP_OPTIONS), 
    accept(LSocket). 

% Wait for incoming connections and spawn the echo loop when we get one. 
accept(LSocket) -> 
    {ok, Socket} = gen_tcp:accept(LSocket), 
    spawn(fun() -> loop(Socket) end), 
    accept(LSocket). 

% Echo back whatever data we receive on Socket. 
loop(Socket) -> 
    case gen_tcp:recv(Socket, 0) of 
     {ok, Data} -> 
      gen_tcp:send(Socket, Data), 
      loop(Socket); 
     {error, closed} -> 
      ok 
    end.