### **API Machinery**

*   The kube-apiserver `--etcd-quorum-read` flag is deprecated and the ability to switch off quorum read will be removed in a future release. ([#53795](https://github.com/kubernetes/kubernetes/pull/53795),[ @xiangpengzhao](https://github.com/xiangpengzhao))

  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST read this before you upgrade)](#no-really-you-must-read-this-before-you-upgrade)
  - [Changes by Kind](#changes-by-kind-13)
    - [Deprecation](#deprecation)
    - [API Change](#api-change-3)
    - [Feature](#feature-11)

    - [Summary API in kubelet doesn't have accelerator metrics](#summary-api-in-kubelet-doesnt-have-accelerator-metrics)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST read this before you upgrade)](#no-really-you-must-read-this-before-you-upgrade)
  - [Changes by Kind](#changes-by-kind-14)
    - [Deprecation](#deprecation)
    - [API Change](#api-change-4)
    - [Feature](#feature-6)

}

var errUnreadByte = errors.New("bytes.Buffer: UnreadByte: previous operation was not a successful read")

// UnreadByte unreads the last byte returned by the most recent successful
// read operation that read at least one byte. If a write has happened since
// the last read, if the last read returned an error, or if the read read zero
// bytes, UnreadByte returns an error.
func (b *Buffer) UnreadByte() error {

      while (curr != null) {
        succ = curr.next;
        if (curr.thread != null) { // we aren't unlinking this node, update pred.
          pred = curr;
        } else if (pred != null) { // We are unlinking this node and it has a predecessor.
          pred.next = succ;
          if (pred.thread == null) { // We raced with another node that unlinked pred. Restart.
            continue restart;
          }

                            return -1;
                        }
                        int toRead = Math.min(length, remaining);
                        System.arraycopy(includeContent, index[0], buffer, offset, toRead);
                        index[0] += toRead;
                        return toRead;
                    });
                })) {

  }

  /** Receive frames until there are no more. Invoked only by the reader thread. */
  @Throws(IOException::class)
  fun loopReader(response: Response) {
    try {
      listener.onOpen(this@RealWebSocket, response)
      while (receivedCloseCode == -1) {
        // This method call results in one or more onRead* methods being called on this thread.
        reader!!.processNextFrame()
      }
    } catch (e: Exception) {

    @Override
    public boolean offer(E o) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.offer(o);
    }

    @Override
    public @Nullable E poll() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.poll();
    }

    @Override
    public E remove() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.remove();
    }

    @Override

        InputStreamThread thread = new InputStreamThread(is, StandardCharsets.UTF_8, 10, null);
        thread.start();

        Thread.sleep(50);

        String output1 = thread.getOutput();
        boolean contains1 = thread.contains("concurrent1");

        thread.join(1000);

        String output2 = thread.getOutput();
        boolean contains2 = thread.contains("concurrent1");

          @Override
          public Thread newThread(Runnable r) {
            Thread thread = new Thread(r);
            thread.setName(THREAD_NAME);
            thread.setPriority(THREAD_PRIORITY);
            thread.setDaemon(THREAD_DAEMON);
            thread.setUncaughtExceptionHandler(UNCAUGHT_EXCEPTION_HANDLER);
            return thread;
          }
        };

    Thread thread =