use IO::Socket qw( );

my $sel = new IO::Select( $sock1, $sock2 );

while ( my @ready = $sel->can_read() ) {
   foreach my $sock (@ready) {
      if ($sock == $sock1) {
         ...do someththing...

         if (...done...) {
            $sel->remove( $sock1 );
         }
      }

      elsif ($sock == $sock2) {
         ...do someththing...

         if (...done...) {
            $sel->remove( $sock2 );
         }
      }
   }
}