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()
}

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;

/** Forwarding wrapper around a {@code Lock}. */
@J2ktIncompatible
@GwtIncompatible
abstract class ForwardingLock implements Lock {
  abstract Lock delegate();

  @Override
  public void lock() {
    delegate().lock();
  }

  @Override
  public void lockInterruptibly() throws InterruptedException {

}

// Empty returns true if targetList is empty.
func (list *TargetList) Empty() bool {
	list.RLock()
	defer list.RUnlock()

	return len(list.targets) == 0
}

// List - returns available target IDs.
func (list *TargetList) List(region string) []ARN {
	list.RLock()
	defer list.RUnlock()

	keys := make([]ARN, 0, len(list.targets))
	for k := range list.targets {

		logger.Info("bucketMetacache.findCache: bucket %s does not match this bucket %s", o.Bucket, b.bucket)
		debug.PrintStack()
		return metacache{}
	}

	// Grab a write lock, since we create one if we cannot find one.
	b.mu.Lock()
	defer b.mu.Unlock()

	// Check if exists already.
	if c, ok := b.caches[o.ID]; ok {
		c.lastHandout = time.Now()
		b.caches[o.ID] = c
		b.debugf("returning existing %v", o.ID)
		return c

	if err == nil {
		return
	}

	nerr := unwrapErrs(err)
	l.Lock()
	shouldLog := true
	prev, ok := l.IDMap[id]
	if !ok {
		l.IDMap[id] = onceErr{
			Err:   nerr,
			Count: 1,
		}
	} else if prev.Err.Error() == nerr.Error() {
		// if errors are equal do not log.
		prev.Count++
		l.IDMap[id] = prev
		shouldLog = false
	}
	l.Unlock()

	if shouldLog {
		consoleLogIf(ctx, subsystem, err, errKind...)
	}

type IAMStorageAPI interface {
	// The role of the read-write lock is to prevent go routines from
	// concurrently reading and writing the IAM storage. The (r)lock()
	// functions return the iamCache. The cache can be safely written to
	// only when returned by `lock()`.
	lock() *iamCache
	unlock()
	rlock() *iamCache
	runlock()
	getUsersSysType() UsersSysType

func (r *ReqInfo) AppendTags(key, val string) *ReqInfo {
	if r == nil {
		return nil
	}
	r.Lock()
	defer r.Unlock()
	r.tags = append(r.tags, KeyVal{key, val})
	return r
}

// SetTags - sets key/val to ReqInfo.tags
func (r *ReqInfo) SetTags(key, val string) *ReqInfo {
	if r == nil {
		return nil
	}
	r.Lock()
	defer r.Unlock()
	// Search of tag key already exists in tags
	var updated bool
	for _, tag := range r.tags {

func (m *bucketMeasurement) updateExponentialMovingAverage(endTime time.Time) {
	// Calculate aggregate avg bandwidth and exp window avg
	m.lock.Lock()
	defer func() {
		m.startTime = endTime
		m.lock.Unlock()
	}()

	if m.startTime.IsZero() {
		return
	}

	if endTime.Before(m.startTime) {
		return
	}

	duration := endTime.Sub(m.startTime)

		srQueueStats: newInQueueStats(r, "site"),
	}
}

func (q *queueCache) update() {
	q.Lock()
	defer q.Unlock()
	q.srQueueStats.update()
	for _, s := range q.bucketStats {
		s.update()
	}
}

func (q *queueCache) getBucketStats(bucket string) InQueueMetric {
	q.RLock()
	defer q.RUnlock()
	v, ok := q.bucketStats[bucket]
	if !ok {
		return InQueueMetric{}
	}
	return InQueueMetric{

		t.Fatalf("unexpected error: %v", err)
	}
	if err := ps.Subscribe(MaskAll, ch2, doneCh, nil); err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	ps.Lock()
	defer ps.Unlock()

	if len(ps.subs) != 2 || ps.NumSubscribers(MaskAll) != 2 || ps.Subscribers() != 2 {
		t.Fatalf("expected 2 subscribers")
	}
}

func TestNumSubscribersMask(t *testing.T) {
	ps := New[Maskable, Mask](2)