hello, all monks:

I write a simple echo server and client script to test socket timeout. Originally, I think timeout in IO::Socket::INET means the sysread/syswrite will return a ETIMEOUT error if it can't read/write the message within the duration of the timeout. But from the result of my test, it seems that I am very wrong about this. Following is my simple code:

sever:
 #!/usr/bin/perl
 use strict;
 use warnings;

 use IO::Socket::INET;

 my $listenSocket = IO::Socket::INET->new(
     'LocalPort' => '12345',
     'Listen'    => SOMAXCONN,
     'Reuse'     => 1,
     'Proto'     => 'tcp',
 ) or die $@;

 my $conSocket = $listenSocket->accept;

 while ( defined $conSocket ) {
     my $rsp = q{};
     $conSocket->sysread( $rsp, 20 ) or die $@;
     print "recv: $rsp\n";

     $conSocket->syswrite( "hello, client!\n" ) or die $@;

 } ## end while ( defined $conSocket)

[download]
client:
 #!/usr/bin/perl
 use strict;
 use warnings;

 use IO::Socket::INET;

 my $socket = IO::Socket::INET->new(
     'Proto'    => 'tcp',
     'PeerAddr' => '172.16.249.232',
     'PeerPort' => '12345',
 ) or die $@;

 $socket->timeout(2);

 while (1) {
     $socket->syswrite( "hello, server!\n") or die $!;

     my $rsp = q{};
     $socket->sysread( $rsp, 20 ) or die $!;
     print "recv:$rsp\n";

     sleep 1;
 } ## end while (1)

[download]

I run the server side script first, and then run the client side script, when the connection is established, and confirm that the two side can communicate with each other, then I disconnect the client side from the network, and wait for 2 seconds, but the client side didn't complain a ETIMEOUT error:(. So I think I misunderstood the meanning of the timeout in IO::Socket::INET.

Can anyone explain what does timeout means in socket? Thanks in advance.

In reply to what does timeout mean in IO::Socket::INET ? by sunshine_august

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