code: void close() {
      acquireExclusiveLock();
      try {
  
        if (buffer != null) {
          if (dirty)
            buffer.force();
  
          if (sunClass != null) {
            // USE SUN JVM SPECIAL METHOD TO FREE RESOURCES
            try {
              final Method m = sunClass.getMethod("cleaner");
              final Object cleaner = m.invoke(buffer);
              cleaner.getClass().getMethod("clean").invoke(cleaner);
            } catch (Exception e) {
              OLogManager.instance().error(this, "Error on calling Sun's MMap buffer clean", e);
            }
          }
  
          buffer = null;
        }
        counter = 0;
        file = null;
  
      } finally {
        releaseExclusiveLock();
      }
    }
docs: Force closing of file if it's opened yet.