opts      madmin.HealOpts
	// Healing response will be sent here
	respCh chan healResult
}

// healResult represents a healing result with a possible error
type healResult struct {
	result madmin.HealResultItem
	err    error
}

// healRoutine receives heal tasks, to heal buckets, objects and format.json
type healRoutine struct {
	tasks   chan healTask
	workers int
}

func activeListeners() int {

	mrfMU      sync.Mutex
	resyncer   *replicationResyncer

	// workers:
	workers    []chan ReplicationWorkerOperation
	lrgworkers []chan ReplicationWorkerOperation

	// mrf:
	mrfWorkerKillCh chan struct{}
	mrfReplicaCh    chan ReplicationWorkerOperation
	mrfSaveCh       chan MRFReplicateEntry
	mrfStopCh       chan struct{}
	mrfWorkerSize   int
}

	es := &expiryState{
		ctx:    ctx,
		objAPI: objAPI,
	}
	workers := make([]chan expiryOp, 0, n)
	es.workers.Store(&workers)
	es.ResizeWorkers(n)
	return es
}

func (es *expiryState) getWorkerCh(h uint64) chan<- expiryOp {
	w := es.workers.Load()
	if w == nil || len(*w) == 0 {
		return nil
	}
	workers := *w

)

var sharedLockTimeout = newDynamicTimeoutWithOpts(dynamicTimeoutOpts{
	timeout:       30 * time.Second,
	minimum:       10 * time.Second,
	retryInterval: time.Minute,
})

type sharedLock struct {
	lockContext chan LockContext
}

func (ld sharedLock) backgroundRoutine(ctx context.Context, objAPI ObjectLayer, lockName string) {
	for {
		locker := objAPI.NewNSLock(minioMetaBucket, lockName)

	// All responses *must* be read by the caller until either an error is returned or the channel is closed.
	// Canceling the context will cause the context cancellation error to be returned.
	responses <-chan Response
	cancel    context.CancelCauseFunc

	// Requests sent to the server.
	// If the handler is defined with 0 incoming capacity this will be nil.
	// Channel *must* be closed to signal the end of the stream.

type BytePoolCap struct {
	c    chan []byte
	w    int
	wcap int
}

// NewBytePoolCap creates a new BytePool bounded to the given maxSize, with new
// byte arrays sized based on width.
func NewBytePoolCap(maxSize uint64, width int, capwidth int) (bp *BytePoolCap) {
	if capwidth > 0 && capwidth < 64 {
		panic("buffer capped with smaller than 64 bytes is not supported")
	}

// The returned function should always be called to release resources.
// An optional error can be sent which will be picked as text only error,
// without its original type by the receiver.
// waitForHTTPStream should be used to the receiving side.
func streamHTTPResponse(w http.ResponseWriter) *httpStreamResponse {
	doneCh := make(chan error)
	blockCh := make(chan []byte)
	h := httpStreamResponse{done: doneCh, block: blockCh}
	go func() {

func getDeadline(d time.Duration) time.Duration {
	if d < time.Millisecond {
		return 0
	}
	if d > MaxDeadline {
		return MaxDeadline
	}
	return d
}

type writerWrapper struct {
	ch  chan<- []byte
	ctx context.Context
}

func (w *writerWrapper) Write(p []byte) (n int, err error) {
	buf := GetByteBufferCap(len(p))
	buf = buf[:len(p)]
	copy(buf, p)
	select {
	case w.ch <- buf:

The handler function has this signature.

Sample handler:
```go
    handler :=  func(ctx context.Context, payload []byte, in <-chan []byte, out chan<- []byte) *RemoteErr {
        fmt.Println("Got request with initial payload", p, "from", GetCaller(ctx context.Context))
        fmt.Println("Subroute:", GetSubroute(ctx))
        for {
            select {

// Borrowed from mutex_test.go
func HammerMutex(m *DRWMutex, loops int, cdone chan bool) {
	for i := 0; i < loops; i++ {
		m.Lock(id, source)
		m.Unlock(context.Background())
	}
	cdone <- true
}

// Borrowed from mutex_test.go
func TestMutex(t *testing.T) {
	loops := 200
	if testing.Short() {
		loops = 5
	}
	c := make(chan bool)
	m := NewDRWMutex(ds, "test")
	for i := 0; i < 10; i++ {