}

	return nil, ErrInvalidDB
}

func (db *PreparedStmtDB) Close() {
	db.Mux.Lock()
	defer db.Mux.Unlock()

	for _, query := range db.PreparedSQL {
		if stmt, ok := db.Stmts[query]; ok {
			delete(db.Stmts, query)
			go stmt.Close()
		}
	}
}

func (sdb *PreparedStmtDB) Reset() {
	sdb.Mux.Lock()
	defer sdb.Mux.Unlock()

	for _, stmt := range sdb.Stmts {
		go stmt.Close()
	}

	list.statLock.Lock()
	defer list.statLock.Unlock()

	stats, ok := list.targetStats[id]
	if !ok {
		// should not happen
		return
	}

	stats.currentSendCalls--
	list.targetStats[id] = stats
	return
}

func (list *TargetList) incFailedEvents(id TargetID) {
	list.statLock.Lock()
	defer list.statLock.Unlock()

	stats, ok := list.targetStats[id]
	if !ok {

func (sys *BucketMetadataSys) Count() int {
	sys.RLock()
	defer sys.RUnlock()

	return len(sys.metadataMap)
}

// Remove bucket metadata from memory.
func (sys *BucketMetadataSys) Remove(buckets ...string) {
	sys.Lock()
	for _, bucket := range buckets {
		delete(sys.metadataMap, bucket)
		globalBucketMonitor.DeleteBucket(bucket)
	}
	sys.Unlock()
}

	if responses == nil {
		return nil, errors.New("RequestStream: responses channel is nil")
	}
	m.init = true
	m.respMu.Lock()
	if m.closed {
		m.respMu.Unlock()
		return nil, ErrDisconnected
	}
	m.respWait = responses // Route directly to output.
	m.respMu.Unlock()

	// Try to grab an initial block.
	m.singleResp = false
	m.RecvSeq = m.SendSeq // Sync
	if cap(requests) > 0 {

	h.mu.RLock()
	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++

}

func (t *tierMetrics) logSuccess(tier string) {
	t.Lock()
	defer t.Unlock()

	stat := t.requestsCount[tier]
	stat.success++
	t.requestsCount[tier] = stat
}

func (t *tierMetrics) logFailure(tier string) {
	t.Lock()
	defer t.Unlock()

	stat := t.requestsCount[tier]
	stat.failure++
	t.requestsCount[tier] = stat
}

var (

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

	}

	// if no update is needed return right away.
	if !update {
		z.poolMetaMutex.Lock()
		z.poolMeta = meta
		z.poolMetaMutex.Unlock()
	} else {
		newMeta := newPoolMeta(z, meta)
		if err = newMeta.save(ctx, z.serverPools); err != nil {
			return err
		}
		z.poolMetaMutex.Lock()
		z.poolMeta = newMeta
		z.poolMetaMutex.Unlock()
	}

	pools := meta.returnResumablePools()

}

func (t *apiConfig) odirectEnabled() bool {
	t.mu.RLock()
	defer t.mu.RUnlock()

	return t.enableODirect
}

func (t *apiConfig) shouldGzipObjects() bool {
	t.mu.RLock()
	defer t.mu.RUnlock()

	return t.gzipObjects
}

func (t *apiConfig) permitRootAccess() bool {
	t.mu.RLock()
	defer t.mu.RUnlock()

	return t.rootAccess
}

			return ctx.Err()
		}
		if opts.Limit > 0 && objsReturned >= opts.Limit {
			return nil
		}

		if s.walkMu != nil {
			s.walkMu.Lock()
		}
		entries, err := s.ListDir(ctx, "", opts.Bucket, current, -1)
		if s.walkMu != nil {
			s.walkMu.Unlock()
		}
		if err != nil {
			// Folder could have gone away in-between
			if err != errVolumeNotFound && err != errFileNotFound {