}

func (wg *WaitGroup) Add(i int32) {
	select {
	case <-wg.done:
		panic("use of an already closed WaitGroup")
	default:
	}
	atomic.AddInt32(&wg.count, i)
}

func (wg *WaitGroup) Done() {
	i := atomic.AddInt32(&wg.count, -1)
	if i == 0 {
		close(wg.done)
	}
}

func (wg *WaitGroup) C() <-chan struct{} {
	return wg.done

// PipeWriter is similar to io.PipeWriter with wait group
type PipeWriter struct {
	*io.PipeWriter
	once sync.Once
	done func()
}

// CloseWithError close with supplied error the writer end.
func (w *PipeWriter) CloseWithError(err error) error {
	err = w.PipeWriter.CloseWithError(err)
	w.once.Do(func() {
		w.done()
	})
	return err
}

// PipeReader is similar to io.PipeReader with wait group
type PipeReader struct {

	select {
	case s.Requests <- b:
		return nil
	case <-s.ctx.Done():
		return context.Cause(s.ctx)
	}
}

// Results returns the results from the remote server one by one.
// If any error is returned by the callback, the stream will be canceled.
// If the context is canceled, the stream will be canceled.
func (s *Stream) Results(next func(b []byte) error) (err error) {
	done := false
	defer func() {
		if s.cancel != nil {

	send := func(result acceptResult) bool {
		select {
		case listener.acceptCh <- result:
			// Successfully written to acceptCh
			return true
		case <-listener.ctx.Done():
			return false
		}
	}

	// Closure to handle TCPListener until done channel is closed.
	handleListener := func(idx int, listener net.Listener) {
		for {
			conn, err := listener.Accept()
			send(acceptResult{conn, err, idx})
		}
	}

	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
}

// DoWithContext is similar to Do except that it accepts a context as an argument to be passed.
func (l *Init) DoWithContext(ctx context.Context, f func(context.Context) error) error {
	if atomic.LoadUint32(&l.done) == 0 {

func (sys *BucketQuotaSys) Init(objAPI ObjectLayer) {
	bucketStorageCache.InitOnce(10*time.Second,
		cachevalue.Opts{ReturnLastGood: true, NoWait: true},
		func() (DataUsageInfo, error) {
			ctx, done := context.WithTimeout(context.Background(), 2*time.Second)
			defer done()

			return loadDataUsageFromBackend(ctx, objAPI)
		},
	)
}

// GetBucketUsageInfo return bucket usage info for a given bucket

			result.Version = Version
			result.Concurrent = concurrency

			select {
			case ch <- result:
			case <-ctx.Done():
				return
			}
		}

		for {
			select {
			case <-ctx.Done():
				// If the client got disconnected stop the speedtest.
				return
			default:
			}

			sopts := speedTestOpts{
				objectSize:   opts.objectSize,

func (x *XDGSCRAMClient) Step(challenge string) (response string, err error) {
	response, err = x.ClientConversation.Step(challenge)
	return
}

// Done returns true if the conversation is completed or has errored.
func (x *XDGSCRAMClient) Done() bool {
	return x.ClientConversation.Done()

			list.currentSendCalls.Add(1)
			list.incCurrentSendCalls(id)
			list.incTotalEvents(id)
			defer list.decCurrentSendCalls(id)
			defer list.currentSendCalls.Add(-1)
			defer wg.Done()

			if err := target.Save(event); err != nil {
				list.eventsErrorsTotal.Add(1)
				list.incFailedEvents(id)
				reqInfo := &logger.ReqInfo{}
				reqInfo.AppendTags("targetID", id.String())

			m := make(map[string]uint64)
			for _, pool := range z.serverPools {
				for _, er := range pool.sets {
					// Load bucket usage prefixes
					ctx, done := context.WithTimeout(context.Background(), 2*time.Second)
					ok := cache.load(ctx, er, bucket+slashSeparator+dataUsageCacheName) == nil
					done()
					if ok {
						root := cache.find(bucket)
						if root == nil {
							// We dont have usage information for this bucket in this