private void checkRelease(){
  List<PartitionReader> toRelease=new ArrayList<PartitionReader>();
  for (  PartitionReader p : hold) {
    if (!p.isTaken()) {
      toRelease.add(p);
      finish(p);
    }
  }
  hold.removeAll(toRelease);
}

private void checkRelease ( ) { List < PartitionReader > toRelease = new ArrayList < PartitionReader > ( ) ; for ( PartitionReader p : hold ) { if ( ! p . isTaken ( ) ) { toRelease . add ( p ) ; finish ( p ) ; } } hold . removeAll ( toRelease ) ; }
check whether to release the hold partitions
