select {
			case sub.ch <- item:
			default:
			}
		}
	}
}

// Subscribe - Adds a subscriber to pubsub system
func (ps *PubSub[T, M]) Subscribe(mask M, subCh chan T, doneCh <-chan struct{}, filter func(entry T) bool) error {
	totalSubs := atomic.AddInt32(&ps.numSubscribers, 1)
	if ps.maxSubscribers > 0 && totalSubs > ps.maxSubscribers {
		atomic.AddInt32(&ps.numSubscribers, -1)

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 {

func (w *metacacheWriter) stream() (chan<- metaCacheEntry, error) {
	if w.creator != nil {
		err := w.creator()
		w.creator = nil
		if err != nil {
			return nil, fmt.Errorf("metacacheWriter: unable to create writer: %w", err)
		}
		if w.mw == nil {
			return nil, errors.New("metacacheWriter: writer not initialized")
		}
	}
	objs := make(chan metaCacheEntry, 100)
	w.streamErr = nil

func (er erasureObjects) nsScanner(ctx context.Context, buckets []BucketInfo, wantCycle uint32, updates chan<- dataUsageCache, healScanMode madmin.HealScanMode) error {
	if len(buckets) == 0 {
		return nil
	}

	// Collect disks we can use.
	disks, healing := er.getOnlineDisksWithHealing(false)
	if len(disks) == 0 {

	"strings"
	"time"

	"github.com/coreos/go-systemd/v22/daemon"
	"github.com/minio/minio/internal/logger"
)

func shutdownHealMRFWithTimeout() {
	const shutdownTimeout = time.Minute

	finished := make(chan struct{})
	go func() {
		globalMRFState.shutdown()
		close(finished)
	}()
	select {
	case <-time.After(shutdownTimeout):
	case <-finished:
	}
}

func handleSignals() {
	// Custom exit function

	if handler == nil {
		return nil, ErrUnknownHandler
	}

	var requests chan []byte
	var responses chan Response
	if handler.InCapacity > 0 {
		requests = make(chan []byte, handler.InCapacity)
	}
	if handler.OutCapacity > 0 {
		responses = make(chan Response, handler.OutCapacity)
	} else {
		responses = make(chan Response, 1)
	}

	cl, err := c.newMuxClient(ctx)
	if err != nil {

// Its value is the maximum value of the int64 type, which means that when the cache size is not specified,
// the cache can theoretically store as many elements as possible.
// (1 << 63) - 1 is the maximum value that an int64 type can represent.
const (
	defaultMaxSize = math.MaxInt
	// defaultTTL defines the default time-to-live (TTL) for each cache entry.

	// 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.

in an unspecified order.
This means that races on multiword data structures
can lead to inconsistent values not corresponding to a single write.
When the values depend on the consistency
of internal (pointer, length) or (pointer, type) pairs,
as can be the case for interface values, maps,
slices, and strings in most Go implementations,
such races can in turn lead to arbitrary memory corruption.
</p>

<p>

// 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() {