* Bug fixes:

  * Fix corner-case with OnlyLocal Service healthchecks. ([#44313](https://github.com/kubernetes/kubernetes/pull/44313), [@thockin](https://github.com/thockin))

     *
     * <p>Note that because of concurrent set calls and uses of atomics, this bitCount is a (very)
     * close *estimate* of the actual number of bits set. It's not possible to do better than an
     * estimate without locking. Note that the number, if not exactly accurate, is *always*
     * underestimating, never overestimating.
     */
    long bitCount() {
      return bitCount.sum();
    }

    LockFreeBitArray copy() {

------------------------------

#### OkHttpClient final methods

`OkHttpClient` has 26 accessors like `interceptors()` and `writeTimeoutMillis()` that were non-final
in OkHttp 3.x and are final in 4.x. These were made non-final for use with mocking frameworks like
[Mockito][mockito]. We believe subtyping `OkHttpClient` is the wrong way to test with OkHttp. If
you must, mock `Call.Factory` which is the interface that `OkHttpClient` implements.

#### Internal API changes

func TestFailedRefreshLock(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping test in short mode.")
	}

	// Simulate Refresh response to return no locking found
	for i := range lockServers[:3] {
		lockServers[i].setRefreshReply(false)
		defer lockServers[i].setRefreshReply(true)
	}

	dm := NewDRWMutex(ds, "aap")
	dm.refreshInterval = 500 * time.Millisecond

  }

  private fun connectHttp2(
    peer: MockHttp2Peer,
    realConnection: RealConnection,
    maxConcurrentStreams: Int,
  ): Http2Connection {
    // Write the mocking script.
    val settings1 = Settings()
    settings1[Settings.MAX_CONCURRENT_STREAMS] = maxConcurrentStreams
    peer.sendFrame().settings(settings1)
    peer.acceptFrame() // ACK
    peer.sendFrame().ping(false, 2, 0)

#### Secure Erasure and Locking

    // way for it to return a false negative would be for the target value to jump around in the map
    // such that none of the subsequent iterations observed it, despite the fact that at every point
    // in time it was present somewhere int the map. This becomes increasingly unlikely as
    // CONTAINS_VALUE_RETRIES increases, though without locking it is theoretically possible.

Versioning must be explicitly enabled on a bucket, versioning is not enabled by default. Object locking enabled buckets have versioning enabled automatically. Enabling and suspending versioning is done at the bucket level.

		m.closeLocked()
		return false
	}
}

func (m *muxClient) close() {
	if debugPrint {
		fmt.Println("closing outgoing mux", m.MuxID)
	}
	if !m.respMu.TryLock() {
		// Cancel before locking - will unblock any pending sends.
		if m.cancelFn != nil {
			m.cancelFn(context.Canceled)
		}
		// Wait for senders to release.
		m.respMu.Lock()
	}

	defer m.respMu.Unlock()
	m.closeLocked()
}

 * multiple routes to be attempted simultaneously.
 *
 * Events and sequences of events may be repeated for retries and follow-ups.
 *
 * All event methods must execute fast, without external locking, cannot throw exceptions, attempt
 * to mutate the event parameters, or be re-entrant back into the client. Any IO - writing to files
 * or network should be done asynchronously.
 */
abstract class EventListener {
  /**