jesuashok,
Actually, I am using select eg:

    # Activate socket
    $read_handles = IO::Select->new();
    $read_handles->add($cfg::listen_socket);


    # Main loop: check reads/accepts, check writes, check ready to pro
+cess

    # Loop forever, listening for incoming msgs
    while (1)
    {
        # check for new information on the connections we have
        # NB: use blocking handles.
        ($new_read_handles) =
                        IO::Select->select($read_handles, undef, undef
+);
[download]

When I said blocking socket, I mean it's declared so that it waits on the socket instead of busy waiting round the above loop, wasting cpu.
Here's the declaration:

    $cfg::listen_socket =
                IO::Socket::INET->new(LocalPort => $cfg::params{'RPS_P
+ORT'},
                                      Type      => SOCK_STREAM,
                                      Proto     => 'tcp',
                                      Listen    => SOMAXCONN,
                                      Reuse     => 1,
                                      Blocking  => 1 )  # Blocking is 
+on
[download]

As I understand ALRM (which occurred to me), I was going to use it in the ctrl thread to give up waiting for the listen thr to shutdown after X seconds, but it seems to me that's more or less equiv to just ignoring the listen thr anyway, as it (listen thr) won't actually shutdown.

tye: I suppose I could use the shutdown cmd as long as I make the socket declaration threads::shared::share($cfg::listen_socket). At the moment it's only global within the listen thr.

Cheers
Chris