code: static void releaseDirectByteBuffer(final ByteBuffer buffer)
      {
          assert buffer != null && buffer.isDirect();
  
          if (CLEAN_HANDLE != null && DIRECT_BUFFER_CLAZZ.isInstance(buffer)) {
              try {
                  final PrivilegedExceptionAction<Void> pea = new PrivilegedExceptionAction<Void>() {
                      @Override
                      public Void run() throws Exception {
                          try {
                              CLEAN_HANDLE.invokeExact(buffer);
                          } catch (Exception e) {
                              throw e;
                          } catch (Throwable t) {
                              //this will be an error
                              throw new RuntimeException(t);
                          }
                          return null;
                      }
                  };
                  AccessController.doPrivileged(pea);
              } catch (Throwable t) {
                  Logger.getLogger(SnappyFramed.class.getName()).log(Level.FINE, "Exception occurred attempting to clean up Sun specific DirectByteBuffer.", t);
              }
          }
      }
docs: Provides jvm implementation specific operation to aggressively release resources associated with <i>buffer</i>.
  
  @param buffer The {@code ByteBuffer} to release. Must not be {@code null}. Must be  {@link ByteBuffer#isDirect() direct}.