I think with 1.12.2 we revert to the old problem of socket reactor goes in "while(1)" if no socket is sending.
So for example I can reproduce the problem simply using telnet to connect to the server and while(1) starts.
That because it seems that
PollSet::SocketModeMap sm = _pollSet.poll(_timeout);
is not waiting for _timeout but it returns immediately with sm.size()==0 so onTimeout() is called. So I'm going to think if do a trySleep inside onTimeout() but I want to check why poll is not waiting for timeout, I'll keep you updated

ps.using windows 11 compiled with VisualStudio 2022 and using SocketReactor basically to handle FTP command (21 port) sockets