use IO::Socket qw( );

my $sel = new IO::Select();

my %clients;
for my $sock ($sock1, $sock2) {
   $clients{$sock} = {
      buf => '',
      # ...
   };

   $sel->add( $sock );
}

while ( my @ready = $sel->can_read() ) {
   foreach my $sock (@ready) {
      my $client = $clients{$sock};

      our $buf; local *buf = \( $client->{buf} );

      sysread( $sock, $buf, 32*1024, length($buf) )
         or do { $sel->remove( $sock );
                 delete $clients{$sock};
                 next;
               };

      while ( my ($msg) = $buf =~ s/^(...)// ) {
         process($msg);
      }
   }
}