use Errno;
   ...

   $select=new IO::Select();
   $select->add(...);

   ...

   while (1) {
      $!=undef;

      while (@ready=$select->can_read()) {
         handle($_) foreach @ready;
      }

      die if $select->count() == 0;  #should always have at least one

      last unless $! == EINTR;       #try again; interrupted by signal
   }

   die if $! == ECHILD;