*LockedFile
	mutex sync.Mutex
	refs  int // Holds read lock refs.
}

// IsClosed - Check if the rlocked file is already closed.
func (r *RLockedFile) IsClosed() bool {
	r.mutex.Lock()
	defer r.mutex.Unlock()
	return r.refs == 0
}

// IncLockRef - is used by called to indicate lock refs.
func (r *RLockedFile) IncLockRef() {
	r.mutex.Lock()
	r.refs++
	r.mutex.Unlock()
}

	sys.aMutex.Lock()
	defer sys.aMutex.Unlock()
	if v, ok := sys.arnErrsMap[arn]; !ok {
		sys.arnErrsMap[arn] = arnErrs{
			updateInProgress: true,
			count:            v.count + 1,
			bucket:           bucket,
		}
	}
}

func (sys *BucketTargetSys) markRefreshDone(bucket, arn string) {
	sys.aMutex.Lock()
	defer sys.aMutex.Unlock()
	if v, ok := sys.arnErrsMap[arn]; ok {

			ok = true
		}
	}
	if ok {
		lock := z.serverPools[0].NewNSLock(minioMetaBucket, rebalMetaName)
		lkCtx, err := lock.GetLock(ctx, globalOperationTimeout)
		if err != nil {
			rebalanceLogIf(ctx, fmt.Errorf("failed to acquire write lock on %s/%s: %w", minioMetaBucket, rebalMetaName, err))
			return err
		}
		defer lock.Unlock(lkCtx)

		ctx = lkCtx.Context()

func SystemTargets() []Target {
	swapSystemMuRW.RLock()
	defer swapSystemMuRW.RUnlock()

	res := systemTargets
	return res
}

// AuditTargets returns active audit targets.
// Returned slice may not be modified in any way.
func AuditTargets() []Target {
	swapAuditMuRW.RLock()
	defer swapAuditMuRW.RUnlock()

	res := auditTargets
	return res
}

	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 (r *lockedRandSource) Int63() (n int64) {
	r.lk.Lock()
	n = r.src.Int63()
	r.lk.Unlock()
	return
}

// Seed uses the provided seed value to initialize the generator to a
// deterministic state.
func (r *lockedRandSource) Seed(seed int64) {
	r.lk.Lock()
	r.src.Seed(seed)
	r.lk.Unlock()

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()

}

// 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 {

// if it is not successful yet.
func (l *Init) Do(f func() error) error {
	if atomic.LoadUint32(&l.done) == 0 {
		return l.do(f)
	}
	return nil
}

func (l *Init) do(f func() error) error {
	l.m.Lock()
	defer l.m.Unlock()
	if atomic.LoadUint32(&l.done) == 0 {
		if err := f(); err != nil {
			return err
		}
		// Mark as done only when f() is successful
		atomic.StoreUint32(&l.done, 1)
	}
	return nil
}

		t.Fatal(err)
	}

	erasureDisks := xl.getDisks()
	z.serverPools[0].erasureDisksMu.Lock()
	xl.getDisks = func() []StorageAPI {
		for i := range erasureDisks[:6] {
			erasureDisks[i] = newNaughtyDisk(erasureDisks[i], nil, errFaultyDisk)
		}
		return erasureDisks
	}

	z.serverPools[0].erasureDisksMu.Unlock()
	_, err = obj.DeleteObject(ctx, bucket, object, ObjectOptions{})