你是对的。在这种情况下你肯定需要{active, false}
在侦听套接字选项之间传递。考虑一下这段代码:
-define(TCP_OPTIONS, [binary, {active, false}, ...]).
...
start(Port) ->
{ok, Socket} = gen_tcp:listen(Port, ?TCP_OPTIONS),
accept(Socket).
accept(ListenSocket) ->
case gen_tcp:accept(ListenSocket) of
{ok, Socket} ->
Pid = spawn(fun() ->
io:format("Connection accepted ~n", []),
enter_loop(Socket)
end),
gen_tcp:controlling_process(Socket, Pid),
Pid ! ack,
accept(ListenSocket);
Error ->
exit(Error)
end.
enter_loop(Sock) ->
%% make sure to acknowledge owner rights transmission finished
receive ack -> ok end,
loop(Sock).
loop(Sock) ->
%% set soscket options to receive messages directly into itself
inet:setopts(Sock, [{active, once}]),
receive
{tcp, Socket, Data} ->
io:format("Got packet: ~p~n", [Data]),
...,
loop(Socket);
{tcp_closed, Socket} ->
io:format("Socket ~p closed~n", [Socket]);
{tcp_error, Socket, Reason} ->
io:format("Error on socket ~p reason: ~p~n", [Socket, Reason])
end.
因此,您不会失去任何东西,直到controlling_process
成功了。众所周知,这个问题在互联网上已经被广泛讨论。
如果您想使用现成的解决方案,您肯定需要看看Ranch https://github.com/extend/ranch项目。