I am trying to pass a routine to another subroutine within a Perl module. But when I pass the sub reference the passed in ref no longer has the object data. Maybe its not possible to do it this way. The line I have a question about is the "unless" lines below:

sub get_flag_end {
   my $self = shift;
   return ( -e "$self->{file}" );
}

sub wait_for_end {
   my $self = shift;
   my $timeout = shift;
   my $poll_interval = shift;

   # Is it even possible to pass the oject subroutine and retain the objects data?
   #unless ( $self->timeout( $timeout, $poll_interval, $self->get_flag_end ) ) { # does not work
   unless ( $self->timeout( $timeout, $poll_interval, \&get_flag_end ) ) {       # call happens but members are empty
      die "!!!ERROR!!! Timed out while waiting for wait_for_end: timeout=$timeout, poll_interval=$poll_interval \n";
   }
}

sub timeout {
   my $self = shift;
   my $timeout = shift;
   my $poll_interval = shift;
   my $test_condition = shift;
   until ($test_condition->() || $timeout <= 0) {
      $timeout -= $poll_interval;
      sleep $poll_interval;
   }
   return $timeout > 0; # condition was met before timeout
}

I know that I could change the "get_flag_end" routine to take the value as an argument to the subroutine but what if there was a bunch of stuff done in "get_flag_end" and I needed more members from the object. I simplified the code a bit to make it a little easier to follow.