code: public void flushFile(final OFileMMap iFile) {
      lock.readLock().lock();
      try {
        final List<OMMapBufferEntry> entries = bufferPoolPerFile.get(iFile);
        if (entries != null)
          for (OMMapBufferEntry entry : entries)
            entry.flush();
      } finally {
        lock.readLock().unlock();
      }
    }
docs: Flushes all the buffers of the passed file.
  
  @param iFile
  file to flush on disk.