our %WA: shared;
  our $WAlock: shared;
...
  my ($key, $dtg, $bytes) = @_;
  if (!defined $WA{$key}) {
    {
      lock $WAlock;
      $WA{$key} = &share({}); #hook shared anon hash;
    
      {
        lock $WA{$key};
        $WA{$key}{PS}=$dtg;          # PS period Start
        $WA{$key}{PE}=$dtg + $secs;  # PE period End
        $WA{$key}{PT}=0;             # PT period Total
        $WA{$key}{stgs} =();         # list of decaying values
        for my $i (0..$rnds-1){
          $WA{$key}{stags}[$i]=0;    # init all stages to 0
        }
      }
    }
  } # end of (! defined) entry being initialized