Thanks for the reply, all. I searched through the threads you referenced and saw good examples of setting non-blocking mode. I'm not sure I'm using this right, tho. If I place the statement after establishing the socket and before the while statement (while recv), the receive evaluates false and the while statement doesn't execute.

    my $hSocket = IO::Socket::INET->new(
      LocalPort=>$intListenPort, 
      Proto=>$strProtocol
      ) or die "Can't create UDP socket: $@";
    ioctl($hSocket, 0x8004667e, pack("I", 1));
    my ($datagram,$flags);
    # Wait for a datagram, then open a response port,
      respond, then close both ports.
    while ($hSocket->recv($datagram,42,$flags)) {
...

[download]
So, I'm wondering if this is the right approach. I think the core of the problem is that I'm waiting for incoming data to determine if a connection has been established.

Is there another way to watch for client connection (and corresponding technique to time-out), before establishing the recv loop? For instance, doesn't IO::Socket call an accept method on connection? So couldn't I check $hSocket for a value (undef?) until timeout, and then launch the recv loop once I have a client? Or maybe using the accept method directly, like

until ($hSocket->accept()) {
        ...check for timeout
        ...close socket and exit if timeout
        }
        while ($hSocket->recv($datagram,42,$flags)) {
        ...

[download]

I guess I'm asking if blocking is really the problem or my approach to checking for connection. I think...

In reply to Re^2: Timeout Socket recv on UDP... on windows by shunyun
in thread Timeout Socket recv on UDP... on windows by shunyun

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