code: public static int epollBusyWait(FileDescriptor epollFd, EpollEventArray events) throws IOException {
          int ready = epollBusyWait0(epollFd.intValue(), events.memoryAddress(), events.length());
          if (ready < 0) {
              throw newIOException("epoll_wait", ready);
          }
          return ready;
      }
docs: Non-blocking variant of
  {@link #epollWait(FileDescriptor, EpollEventArray, FileDescriptor, int, int)}
  that will also hint to processor we are in a busy-wait loop.