Seeing the expression 'non-blocking' immediately makes me think POE.

This is a simple Echo server using POE::Kernel and POE::Wheel::SocketFactory :

use strict;
use warnings;

use POE;
use POE::Wheel::SocketFactory;
use Socket;

POE::Session->create(
  package_states => [ 
    'main' => [ qw(_start _sock_up _sock_err _sock_read) ],
  ],
);

$poe_kernel->run();
exit 0;

sub _start {
  my ($kernel,$heap) = @_[KERNEL,HEAP];

  $heap->{factory} = POE::Wheel::SocketFactory->new(
    SocketProtocol => 'udp',
    BindPort       => 9090,
    SuccessEvent   => '_sock_up',
    FailureEvent   => '_sock_err',
  );

  return;
}

sub _sock_up {
  my ($kernel,$heap,$socket) = @_[KERNEL,HEAP,ARG0];
  delete $heap->{factory};
  $kernel->select_read( $socket, '_sock_read' );
  return;
}

sub _sock_err {
  my ($heap,$op,$errno,$errstr) = @_[HEAP,ARG0..ARG2];
  delete $heap->{factory};
  warn "$op $errno $errstr\n";
  return;
}

sub _sock_read {
  my ($kernel,$socket) = @_[KERNEL,ARG0];

  my $remote_address = recv( $socket, my $message = "", 1024, 0 );
  return unless defined $remote_address;

  send( $socket, $message, 0, $remote_address ) == length($message)
      or warn "Trouble sending response: $!";
  return;
}
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There are many examples in the POE Cookbook