TestMap<K, V> inner = new TestMap<>(innermost, mutex);
    NavigableMap<K, V> outer = Synchronized.navigableMap(inner, mutex);
    return outer;
  }

  static class TestEntry<K, V> extends ForwardingMapEntry<K, V> implements Serializable {
    private final Entry<K, V> delegate;
    private final Object mutex;

    TestEntry(Entry<K, V> delegate, Object mutex) {
      this.delegate = delegate;
      this.mutex = mutex;

  private volatile @Nullable Object mutexDoNotUseDirectly;

  private Object mutex() {
    Object mutex = mutexDoNotUseDirectly;
    if (mutex == null) {
      synchronized (this) {
        mutex = mutexDoNotUseDirectly;
        if (mutex == null) {
          mutexDoNotUseDirectly = mutex = new Object();
        }
      }
    }
    return mutex;
  }

  RateLimiter(SleepingStopwatch stopwatch) {

	writers         atomic.Int32
	lastCleanup     atomic.Pointer[time.Time]
	locksOverloaded atomic.Int64
}

// getMutex will lock the mutex.
// Call the returned function to unlock.
func (l *localLocker) getMutex() func() {
	l.waitMutex.Add(1)
	l.mutex.Lock()
	l.waitMutex.Add(-1)
	return l.mutex.Unlock
}

func (l *localLocker) String() string {
	return globalEndpoints.Localhost()
}

	Cache             map[string]*BucketReplicationStats
	mostRecentStats   BucketStatsMap
	registry          metrics.Registry
	sync.RWMutex                 // mutex for Cache
	mostRecentStatsMu sync.Mutex // mutex for mostRecentStats

	wlock sync.RWMutex // mutex for active workers

	movingAvgTicker *time.Ticker // Ticker for calculating moving averages
	wTimer          *time.Ticker // ticker for calculating active workers

	benchmarkMutex(b, true, true)
}

func BenchmarkMutexNoSpin(b *testing.B) {
	b.ResetTimer()
	b.ReportAllocs()

	// This benchmark models a situation where spinning in the mutex should be
	// non-profitable and allows to confirm that spinning does not do harm.
	// To achieve this we create excess of goroutines most of which do local work.
	// These goroutines yield during local work, so that switching from

	writeLocks           []string // Array of nodes that granted a write lock
	readLocks            []string // Array of array of nodes that granted reader locks
	rng                  *rand.Rand
	m                    sync.Mutex // Mutex to prevent multiple simultaneous locks from this node
	clnt                 *Dsync
	cancelRefresh        context.CancelFunc
	refreshInterval      time.Duration
	lockRetryMinInterval time.Duration
}

)

// rateMeasurement captures the transfer details for one bucket/target
//msgp:ignore rateMeasurement

type rateMeasurement struct {
	lock                 sync.Mutex
	bytesSinceLastWindow uint64    // Total bytes since last window was processed
	startTime            time.Time // Start time for window
	expMovingAvg         float64   // Previously calculated exponential moving average
}

    or a <i>synchronizing operation</i> such as an atomic data access,
	a mutex operation, or a channel operation,</li>
	<li>its location in the program,</li>
	<li>the memory location or variable being accessed, and</li>
	<li>the values read or written by the operation.</li>
</ul>
<p>
Some memory operations are <i>read-like</i>, including read, atomic read, mutex lock, and channel receive.

)

var printEndpointError = func() func(Endpoint, error, bool) {
	var mutex sync.Mutex
	printOnce := make(map[Endpoint]map[string]int)

	return func(endpoint Endpoint, err error, once bool) {
		reqInfo := (&logger.ReqInfo{}).AppendTags("endpoint", endpoint.String())
		ctx := logger.SetReqInfo(GlobalContext, reqInfo)
		mutex.Lock()
		defer mutex.Unlock()

		m, ok := printOnce[endpoint]
		if !ok {
			m = make(map[string]int)

	var count int64
	h.mutex.RLock()
	defer h.mutex.RUnlock()

	for _, v := range h.scannedItemsMap {
		count += v
	}
	return count
}

// getScannedItemsMap - returns map of all scanned items against type
func (h *healSequence) getScannedItemsMap() map[madmin.HealItemType]int64 {
	h.mutex.RLock()
	defer h.mutex.RUnlock()

	// Make a copy before returning the value