r  io.Reader
	mu sync.Mutex
}

func (d *disconnectReader) Read(p []byte) (n int, err error) {
	d.mu.Lock()
	defer d.mu.Unlock()
	if d.r != nil {
		return d.r.Read(p)
	}
	return 0, errors.New("reader closed")
}

func (d *disconnectReader) Close() error {
	d.mu.Lock()
	d.r = nil
	d.mu.Unlock()
	return nil
}

func (srv *Server) Shutdown() error {
	srv.listenerMutex.Lock()
	if srv.listener == nil {
		srv.listenerMutex.Unlock()
		return http.ErrServerClosed
	}
	srv.listenerMutex.Unlock()

	if atomic.AddUint32(&srv.inShutdown, 1) > 1 {
		// shutdown in progress
		return http.ErrServerClosed
	}

	// Close underneath HTTP listener.
	srv.listenerMutex.Lock()
	err := srv.listener.Close()
	srv.listenerMutex.Unlock()

 *
 * <ul>
 *   <li>for an unnested {@code lock()} and {@code unlock()}, a cycle detecting lock takes 38ns as
 *       opposed to the 24ns taken by a plain lock.
 *   <li>for nested locking, the cost increases with the depth of the nesting:
 *       <ul>
 *         <li>2 levels: average of 64ns per lock()/unlock()
 *         <li>3 levels: average of 77ns per lock()/unlock()
 *         <li>4 levels: average of 99ns per lock()/unlock()

func (evnot *EventNotifier) RemoveNotification(bucketName string) {
	evnot.Lock()
	defer evnot.Unlock()

	delete(evnot.bucketRulesMap, bucketName)
}

// RemoveAllBucketTargets - closes and removes all notification targets.
func (evnot *EventNotifier) RemoveAllBucketTargets() {
	evnot.Lock()
	defer evnot.Unlock()

	targetIDSet := event.NewTargetIDSet()
	for k := range evnot.targetList.TargetMap() {

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 {

		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

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

}

// 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 {

	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()
}

	}
	return l.makeResp(resp, err)
}

// UnlockHandler - releases the acquired lock.
func (l *lockRESTServer) UnlockHandler(args *dsync.LockArgs) (*dsync.LockResp, *grid.RemoteErr) {
	resp := lockRPCUnlock.NewResponse()
	_, err := l.ll.Unlock(context.Background(), *args)
	// Ignore the Unlock() "reply" return value because if err == nil, "reply" is always true
	// Consequently, if err != nil, reply is always false