wg     *sync.WaitGroup
	buffer map[int64][]byte
	err    error

	nextOffset int64
	m          sync.Mutex
}

func (w *writerAt) WriteAt(b []byte, offset int64) (n int, err error) {
	w.m.Lock()
	defer w.m.Unlock()

	if w.nextOffset == offset {
		n, err = w.w.Write(b)
		w.nextOffset += int64(n)
	} else {
		w.buffer[offset] = make([]byte, len(b))
		copy(w.buffer[offset], b)
		n = len(b)
	}

				if _, ok := err.(BucketExists); !ok {
					t.Logf("unexpected error: %T: %v", err, err)
					return
				}
				mu.Lock()
				errs++
				mu.Unlock()
				return
			}
			mu.Lock()
			ok++
			mu.Unlock()
		}()
	}
	close(start)
	wg.Wait()
	if ok != 1 {
		t.Fatalf("want 1 ok, got %d", ok)
	}
	if errs != n-1 {

	if err != nil {
		return nil, nil, err
	}

	// Make objLayer available to all internal services via globalObjectAPI.
	globalObjLayerMutex.Lock()
	globalObjectAPI = objLayer
	globalObjLayerMutex.Unlock()
	return objLayer, erasureDirs, nil
}

// cmdType - Represents different service subcomands like status, stop
// and restart.
type cmdType int

const (

	lock := api.NewNSLock(r.Bucket, objInfo.Name)
	lkctx, err := lock.GetLock(ctx, globalOperationTimeout)
	if err != nil {
		return err
	}
	ctx = lkctx.Context()
	defer lock.Unlock(lkctx)

	opts := ObjectOptions{
		VersionID:        objInfo.VersionID,
		Versioned:        versioned,
		VersionSuspended: versionSuspended,
		NoLock:           true,
	}

	var bytesWritten int64
	var bufs [][]byte
	for block := startBlock; block <= endBlock; block++ {
		var blockOffset, blockLength int64
		switch {
		case startBlock == endBlock:
			blockOffset = offset % e.blockSize
			blockLength = length
		case block == startBlock:
			blockOffset = offset % e.blockSize
			blockLength = e.blockSize - blockOffset
		case block == endBlock:
			blockOffset = 0

			old := e.cached.Swap(newAcc)
			var a AccElem
			a.Size = atomic.LoadInt64(&old.Size)
			a.Total = atomic.LoadInt64(&old.Total)
			a.N = atomic.LoadInt64(&old.N)
			e.mu.Lock()
			e.lastMinuteLatency.addAll(t-1, a)
			e.mu.Unlock()
			acc = newAcc
		} else {
			// We may be able to grab the new accumulator by yielding.
			runtime.Gosched()
			acc = e.cached.Load()
		}
	}
	atomic.AddInt64(&acc.N, 1)

func (sCfg *Config) AvailabilityOptimized() bool {
	ConfigLock.RLock()
	defer ConfigLock.RUnlock()
	if !sCfg.initialized {
		return true
	}
	return sCfg.Optimize == "availability" || sCfg.Optimize == ""
}

// Update update storage-class with new config
func (sCfg *Config) Update(newCfg Config) {
	ConfigLock.Lock()
	defer ConfigLock.Unlock()
	sCfg.RRS = newCfg.RRS
	sCfg.Standard = newCfg.Standard

				nil,
			)
			resultsMu.Lock()
			results.NodeResults = append(results.NodeResults, result)
			resultsMu.Unlock()
			return
		}()
	}
	wg.Wait()
	return
}

// GetClusterInfo - returns site replication information.
func (c *SiteReplicationSys) GetClusterInfo(ctx context.Context) (info madmin.SiteReplicationInfo, err error) {
	c.RLock()
	defer c.RUnlock()
	if !c.enabled {
		return info, nil

// returns true if the node changed state from online to offline
func (c *Client) MarkOffline(err error) bool {
	c.Lock()
	c.lastErr = err
	c.lastErrTime = time.Now()
	atomic.StoreInt64(&c.lastConn, time.Now().UnixNano())
	c.Unlock()

	return c.runHealthCheck()

	return func(endpoint Endpoint, err error, once bool) {
		reqInfo := (&logger.ReqInfo{}).AppendTags("endpoint", endpoint.String())
		ctx := logger.SetReqInfo(GlobalContext, reqInfo)
		mutex.Lock()
		defer mutex.Unlock()

		m, ok := printOnce[endpoint]
		if !ok {
			m = make(map[string]int)
			printOnce[endpoint] = m
			if once {
				m[err.Error()]++
				peersLogAlwaysIf(ctx, err)
				return
			}
		}