FileContext Delete on Exit Improvements

    synchronized (DELETE_ON_EXIT) {
      Set<Entry<FileContext, Set<Path>>> set = DELETE_ON_EXIT.entrySet();
      for (Entry<FileContext, Set<Path>> entry : set) {
        FileContext fc = entry.getKey();
        Set<Path> paths = entry.getValue();
        for (Path path : paths) {
          try {
            fc.delete(path, true);
          } catch (IOException e) {
            LOG.warn("Ignoring failure to deleteOnExit for path " + path);
          }
        }
      }
      DELETE_ON_EXIT.clear();