// 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
	loadPolicyDoc(ctx context.Context, policy string, m map[string]PolicyDoc) error

}

// Del - Deletes an entry from the store.
func (store *QueueStore[_]) Del(key Key) error {
	store.Lock()
	defer store.Unlock()
	return store.del(key)
}

// Len returns the entry count.
func (store *QueueStore[_]) Len() int {
	store.RLock()
	l := len(store.entries)
	defer store.RUnlock()
	return l
}

// lockless call
func (store *QueueStore[_]) del(key Key) error {

	"github.com/klauspost/reedsolomon"
)

// getDataBlockLen - get length of data blocks from encoded blocks.
func getDataBlockLen(enBlocks [][]byte, dataBlocks int) int {
	size := 0
	// Figure out the data block length.
	for _, block := range enBlocks[:dataBlocks] {
		size += len(block)
	}
	return size
}

// Writes all the data blocks from encoded blocks until requested
// outSize length. Provides a way to skip bytes until the offset.

	list.Lock()
	defer list.Unlock()

	for id := range targetIDSet {
		target, ok := list.targets[id]
		if ok {
			target.Close()
			delete(list.targets, id)
		}
	}
}

// Targets - list all targets
func (list *TargetList) Targets() []Target {
	if list == nil {
		return []Target{}
	}

	list.RLock()
	defer list.RUnlock()

	if stats == nil {
		return
	}
	stats.Lock()
	defer stats.Unlock()
	if stats.apiStats == nil {
		stats.apiStats = make(map[string]int)
	}
	stats.apiStats[api]++
}

// Dec increments the api stats counter.
func (stats *HTTPAPIStats) Dec(api string) {
	if stats == nil {
		return
	}
	stats.Lock()
	defer stats.Unlock()
	if val, ok := stats.apiStats[api]; ok && val > 0 {
		stats.apiStats[api]--

	// 3. g1 tx exec insert, wait for unlock `conn.PrepareContext(ctx, query)` to finish tx and release.
	stmt, err := conn.PrepareContext(ctx, query)
	if err != nil {
		cacheStmt.prepareErr = err
		db.Mux.Lock()
		delete(db.Stmts, query)
		db.Mux.Unlock()
		return Stmt{}, err
	}

	db.Mux.Lock()
	cacheStmt.Stmt = stmt
	db.Mux.Unlock()

	return cacheStmt, nil
}

		}()
		time.Sleep(1 * time.Millisecond) // wait for goroutine to advance; ref=2

		// Unlock the 1st lock; ref=1 after this line
		nsLk.unlock("volume", "path", false)

		// Taking another lockMapMutex here allows queuing up additional lockers. This should
		// not be required but makes reproduction much easier.
		nsLk.lockMapMutex.Lock()

		// lk3 blocks.
		lk3ch := make(chan bool)
		go func() {

	}
	if m.subroute != nil {
		msg.Flags |= FlagSubroute
	}
	ch := make(chan Response, 1)
	m.respMu.Lock()
	if m.closed {
		m.respMu.Unlock()
		return nil, ErrDisconnected
	}
	m.respWait = ch
	m.respMu.Unlock()
	ctx := m.ctx

	// Add deadline if none.
	if msg.DeadlineMS == 0 {
		msg.DeadlineMS = uint32(defaultSingleRequestTimeout / time.Millisecond)

	defer h.mu.RUnlock()

	return h.Object
}

func (h *healingTracker) setObject(object string) {
	h.mu.Lock()
	defer h.mu.Unlock()

	h.Object = object
}

func (h *healingTracker) updateProgress(success, skipped bool, bytes uint64) {
	h.mu.Lock()
	defer h.mu.Unlock()

	switch {
	case success:
		h.ItemsHealed++
		h.BytesDone += bytes
	case skipped:
		h.ItemsSkipped++

	if r == nil {
		return
	}

	r.Lock()
	defer r.Unlock()
	delete(r.Cache, bucket)
}

// UpdateReplicaStat updates in-memory replica statistics with new values.
func (r *ReplicationStats) UpdateReplicaStat(bucket string, n int64) {
	if r == nil {
		return
	}

	r.Lock()
	defer r.Unlock()
	bs, ok := r.Cache[bucket]
	if !ok {
		bs = newBucketReplicationStats()
	}