从大规模用 DispatchLink() 开始 idle timeout 都是交给 outbound 了

ok. perfect, then I'll just implement net.Conn for udp, and depend on that dispatcher will call .Close() on it when idle timeout is reached.

不过 UDP 的话那个“自动清理来源二元组 map”还得留着，因为 outbound 非 UoT 时可能不会把 close 传导过来，我不确定

Well, adding more changes don't make sense then... The whole idea was that udp will be pure net.Conn, only implementing Read/Write/Close/... and lifecycle is controlled the handler, which will close connections that don't have any bytes for some time...

可能非 UoT 时也有 idle timeout close 吧，我真的不确定，@yuhan6665 @Fangliding

Tested it with xHTTP outbound, outbound signal the connections to be closed without a need for additional lifecycle handling on inbound side.

我想起来了，DispatchLink() 靠的是 return 来传导 close，所以只要 outbound 有 idle timeout 就能传导过来