Hi!
THanks for your suggestion.
I changed my code to:
sub _read_from_socket{
my ($select) = @_;
my ($output, $buffer) = ('', '');
my $socket = undef;
do {
$socket = ($select->can_read(0.1))[0];
} while (!defined $socket);
while(1){
my $status = $socket->read($buffer, 1);
die "Error: $!" if(!defined $status);
$output .= $buffer;
last if $output =~ /\r\n$|^\z/;
}
return $output;
}
Unfortunatelly i'm still getting connections "hanged". This time,
according to wireshark it's when there's a TCP retransmission of a
[FIN,ACK]:
Remote [FIN,ACK] -> Local
Local [FIN,ACK] -> Remote
Remote [ACK] -> Local
Remote [ACK] -> Local
Local [FIN, ACK] -> Remote (TCP Retransmission)
Local [FIN, ACK] -> Remote (TCP Retransmission)
Local [FIN, ACK] -> Remote (TCP Retransmission)
Remote [SYN, ACK] -> Local (TCP Spurious Retransmission)
Local [ACK] -> Remote (TCP Dup Ack #5)
Local [FIN, ACK] -> Remote (TCP Retransmission)
Local [FIN, ACK] -> Remote (TCP Retransmission)
Local [FIN, ACK] -> Remote (TCP Retransmission)
No more exchanges.
On Mon, 12 Oct 2015 20:50:46 -0700
$Bill <dbec...@gmail.com> wrote:
> This failed twice to post - emailing it.
>
> On 10/12/2015 09:58, David Emanuel da Costa Santiago wrote:
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA256
> >
> >
> > Hello all!
> >
> > I'm creating some sockets to a remote server and from time to time,
> > the sockets get "frozen".
> >
> > I'm creating the socket as:
> >
> > $socket = IO::Socket::INET->new (
> > PeerAddr => $server,
> > PeerPort => $port,
> > Blocking => 1,
> > Proto => 'tcp',
> > Timeout => 20, #connection
> > timeout ) or die "Error: Failed to
> > connect : $!\n";
> >
> >
> > So far so good, but when i try to make a first read, the read hangs
> > (always on the first read - If the first read is successfull all the
> > other reads will succeed). No error whatsoever (the connection
> > doesn't even drop!).
> >
> > I'm reading the socket as:
> >
> > sub _read_from_socket{
> > my ($socket) = @_;
> >
> > my ($output, $buffer) = ('', '');
> > while(1){
> > my $status = $socket->read($buffer, 1);
> > die "Error: $!" if(!defined $status);
> > $output .= $buffer;
> > last if $output =~ /\r\n$|^\z/;
> > }
> >
> > return $output;
> > }
> >
> >
> > The same happens even with a sysread (both on windows and linux
> > platforms). This hanging doesn't happen everytime, it's like 1 in 6
> > tries.
> >
> > If i check with netstat i see the connection with state ESTABLISHED.
> >
> > Do you guys know what's going on?
>
> No, but you should be able to avoid the condition by:
> 1) Use non-blocking IO on your new; or
> 2) Use IO::Select can_read to test for data prior to reading; or
> 3) Use an ioctl to test for data or get size of data in input Q
> (FIONREAD); or 4) Use ioctl to reset blocking (FIONBIO) on socket.
>
> I usually use 2) to do my socket IO.
>
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