See the [security policy](https://golang.org/security) for details.

The recommended way to file an issue is by running `go bug`.
Otherwise, when filing an issue, make sure to answer these five questions:

1. What version of Go are you using (`go version`)?
2. What operating system and processor architecture are you using?
3. What did you do?
4. What did you expect to see?

type Singleton[T any] struct {
	v   *T
	set chan struct{}
}

// NewSingleton creates a new unset singleton.
func NewSingleton[T any]() *Singleton[T] {
	return &Singleton[T]{set: make(chan struct{}), v: nil}
}

// Get will return the singleton value.
func (s *Singleton[T]) Get() *T {
	<-s.set
	return s.v
}

// GetNonBlocking will return the singleton value or nil if not set yet.

	serviceUnFreeze                           // Un-Freeze previously frozen S3 API calls.
	// Add new service requests here.
)

// Global service signal channel.
var globalServiceSignalCh = make(chan serviceSignal)

// GlobalContext context that is canceled when server is requested to shut down.
// cancelGlobalContext can be used to indicate server shutdown.

			if err != nil {
				err = msgp.WrapError(err, "Resources")
				return
			}
			if cap(z.Resources) >= int(zb0002) {
				z.Resources = (z.Resources)[:zb0002]
			} else {
				z.Resources = make([]string, zb0002)
			}
			for za0001 := range z.Resources {
				z.Resources[za0001], err = dc.ReadString()
				if err != nil {
					err = msgp.WrapError(err, "Resources", za0001)
					return
				}
			}

	if hashedPayload == "" {
		return "", fmt.Errorf("Invalid hashed payload")
	}

	// Set x-amz-date.
	req.Header.Set("x-amz-date", currTime.Format(iso8601Format))

	// Get header map.
	headerMap := make(map[string][]string)
	for k, vv := range req.Header {
		// If request header key is not in ignored headers, then add it.
		if _, ok := ignoredStreamingHeaders[http.CanonicalHeaderKey(k)]; !ok {

	if err != nil {
		return err
	}

	for _, target := range targetList {
		defer target.Close()
	}

	tgts, ok := ctx.Value(config.ContextKeyForTargetFromConfig).(map[string]bool)
	if !ok {
		tgts = make(map[string]bool)
	}
	for _, target := range targetList {
		if tgts[target.ID().ID] {
			// When target set should be online
			yes, err := target.IsActive()
			if err == nil && !yes {
				err = ErrTargetsOffline

func NewConfig() Config {
	cfg := Config{
		// Console logging is on by default
		Console: Console{
			Enabled: true,
		},
		HTTP:         make(map[string]http.Config),
		AuditWebhook: make(map[string]http.Config),
		AuditKafka:   make(map[string]kafka.Config),
	}

	return cfg
}

func getCfgVal(envName, key, defaultValue string) string {
	if key != config.Default {

	var m madmin.OSMetrics
	m.CollectedAt = time.Now()
	m.LifeTimeOps = make(map[string]uint64, osMetricLast)
	for i := range osMetricLast {
		if n := atomic.LoadUint64(&o.operations[i]); n > 0 {
			m.LifeTimeOps[i.String()] = n
		}
	}
	if len(m.LifeTimeOps) == 0 {
		m.LifeTimeOps = nil
	}

	m.LastMinute.Operations = make(map[string]madmin.TimedAction, osMetricLast)
	for i := range osMetricLast {

	// heuristic value that seems like a good starting size.
	b := bytes.NewBuffer(make([]byte, 0, 128))
	if len(c) == 1 {
		for k, v := range c {
			b.WriteString(`{"`)
			escapeStringJSON(b, k)
			b.WriteString(`":"`)
			escapeStringJSON(b, v)
			b.WriteString(`"}`)
		}
		return b.Bytes(), nil
	}

	sortedKeys := make([]string, 0, len(c))
	for k := range c {
		sortedKeys = append(sortedKeys, k)
	}

	c.Assert(err, nil)

	// execute the upload request.
	response, err = s.client.Do(request)
	c.Assert(err, nil)
	// assert the http response.
	c.Assert(response.StatusCode, http.StatusOK)

	// make HTTP request to fetch the object.
	request, err = newTestSignedRequest(http.MethodGet, getGetObjectURL(s.endPoint, bucketName, objectName),
		0, nil, s.accessKey, s.secretKey, s.signer)
	c.Assert(err, nil)