db.Mux.RLock()
	if stmt, ok := db.Stmts[query]; ok && (!stmt.Transaction || isTransaction) {
		db.Mux.RUnlock()
		// wait for other goroutines prepared
		<-stmt.prepared
		if stmt.prepareErr != nil {
			return Stmt{}, stmt.prepareErr
		}

		return *stmt, nil
	}
	db.Mux.RUnlock()

	db.Mux.Lock()
	// double check

		srs.Failed.addsize(st.TransferSize, st.Err)
	case st.Pending:
	}
	sr.M[dID] = srs
}

func (sr *SRStats) get() map[string]SRMetric {
	epMap := globalBucketTargetSys.healthStats()

	sr.lock.RLock()
	defer sr.lock.RUnlock()
	m := make(map[string]SRMetric, len(sr.M))
	for dID, v := range sr.M {
		t := newXferStats()
		mx := make(map[RMetricName]XferStats)

		if v.XferRateLrg != nil {

	if ri == nil {
		return
	}

	ri.mu.Lock()
	defer ri.mu.Unlock()

	if success {
		ri.Bucket = bucket
		ri.Object = info.Name
	}
	ri.countItem(info.Size, info.DeleteMarker, success, attempt)
}

func (ri *batchJobInfo) trackCurrentBucketBatch(bucket string, batch []ObjectInfo) {
	if ri == nil {
		return
	}

	ri.mu.Lock()
	defer ri.mu.Unlock()

	ri.Bucket = bucket

	sets []*erasureObjects

	// Reference format.
	format *formatErasureV3

	// erasureDisks mutex to lock erasureDisks.
	erasureDisksMu sync.RWMutex

	// Re-ordered list of disks per set.
	erasureDisks [][]StorageAPI

	// Distributed locker clients.
	erasureLockers setsDsyncLockers

	// Distributed lock owner (constant per running instance).
	erasureLockOwner string

	// List of endpoints provided on the command line.

	}
}

func (n *netPerfRX) ActiveConnections() uint64 {
	n.RLock()
	defer n.RUnlock()
	return n.activeConnections
}

func (n *netPerfRX) Reset() {
	n.Lock()
	defer n.Unlock()
	n.RX = 0
	n.RXSample = 0
	n.lastToConnect = time.Time{}
	n.firstToDisconnect = time.Time{}
}

// Reader to read random data.
type netperfReader struct {
	n   uint64
	eof chan struct{}

<p class="rule">
For any call to <code>l.RLock</code> on a <code>sync.RWMutex</code> variable <code>l</code>,
there is an <i>n</i> such that the <i>n</i>th call to <code>l.Unlock</code>
is synchronized before the return from <code>l.RLock</code>,
and the matching call to <code>l.RUnlock</code> is synchronized before the return from call <i>n</i>+1 to <code>l.Lock</code>.
</p>

<p class="rule">

			return err
		}
		pk.add(key.Kid, pkey)
	}

	return nil
}

func (pk *publicKeys) add(keyID string, key interface{}) {
	pk.Lock()
	defer pk.Unlock()

	pk.pkMap[keyID] = key
}

func (pk *publicKeys) get(kid string) interface{} {
	pk.RLock()
	defer pk.RUnlock()
	return pk.pkMap[kid]
}

// PopulatePublicKey - populates a new publickey from the JWKS URL.

		objAPI:       objAPI,
		usersSysType: usersSysType,
	}
}

func (iamOS *IAMObjectStore) rlock() *iamCache {
	iamOS.RLock()
	return iamOS.iamCache
}

func (iamOS *IAMObjectStore) runlock() {
	iamOS.RUnlock()
}

func (iamOS *IAMObjectStore) lock() *iamCache {
	iamOS.Lock()
	return iamOS.iamCache
}

func (iamOS *IAMObjectStore) unlock() {
	iamOS.Unlock()
}

// Metadata has data stripped, if any.
func (s *xlStorage) WalkDir(ctx context.Context, opts WalkDirOptions, wr io.Writer) (err error) {
	legacyFS := !(s.fsType == xfs || s.fsType == ext4)

	s.RLock()
	legacy := s.formatLegacy
	s.RUnlock()

	// Verify if volume is valid and it exists.
	volumeDir, err := s.getVolDir(opts.Bucket)
	if err != nil {
		return err
	}

	if !skipAccessChecks(opts.Bucket) {

		return nil, errCorruptedBackend
	}
	return fi, nil
}

// GetDiskID - returns the cached disk uuid
func (s *xlStorage) GetDiskID() (string, error) {
	s.RLock()
	diskID := s.diskID
	fileInfo := s.formatFileInfo
	lastCheck := s.formatLastCheck

	// check if we have a valid disk ID that is less than 1 seconds old.