I am working with some laboratory instruments that communicate either through bouilt-in HTTP server or low-level TCP. Both occasionally "freeze". I create the socket thusly: 
my $sock_Zona = IO::Socket::INET->new(
    PeerAddr => $par{addr_Zona},
    PeerPort => $par{port_Zona},
    Proto => "tcp",
    Type => SOCK_STREAM,
    Timeout => $par{conn_tmo}
);

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Here timeout works - an attempt to connect to something that is not listening will fail after the timeout expires. However, setting the read timeout like this: 
unless (defined $sock_Zona) {
    $abort++;
    $sock_Zona = -1;
    ABORT("Zona se ne javlja: $!");
} else {
    IO::Socket::Timeout->enable_timeouts_on($sock_Zona);
    $sock_Zona->read_timeout($par{read_tmo_Zona});    
}

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seems to have no effect. If the instrument for some reason neglects to answer (as they are wont to do), I usually get an empty reply, but sometimes the read from the socket just hangs. I would like to avoid running all reads in separate threads (there are lots of them), if at all possible. Any perl of wisdom greatly appreciated.

In reply to Socket read timeout on Windows by bonzi

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