type PubSub[T Maskable, M Maskable] struct {
	// atomics, keep at top:
	types          uint64
	numSubscribers int32
	maxSubscribers int32

	// not atomics:
	subs []*Sub[T]
	sync.RWMutex
}

// Publish message to the subscribers.
// Note that publish is always non-blocking send so that we don't block on slow receivers.
// Hence receivers should use buffered channel so as not to miss the published events.

		Curr: qm.Curr.add(o.Curr),
		Avg:  qm.Avg.add(o.Avg),
		Max:  qm.Max.add(o.Max),
	}
}

type queueCache struct {
	srQueueStats InQueueStats
	bucketStats  map[string]InQueueStats
	sync.RWMutex // mutex for queue stats
}

func newQueueCache(r metrics.Registry) queueCache {
	return queueCache{
		bucketStats:  make(map[string]InQueueStats),
		srQueueStats: newInQueueStats(r, "site"),
	}
}

	Proxy string `json:"proxy"`

	// Transport configured with proxy_url if set optionally.
	transport http.RoundTripper

	// The subnet base URL
	BaseURL string
}

var configLock sync.RWMutex

// Registered indicates if cluster is registered or not
func (c *Config) Registered() bool {
	configLock.RLock()
	defer configLock.RUnlock()

	return len(c.APIKey) > 0
}

	}
	c = Config{
		Enabled:            false,
		arnProviderCfgsMap: map[arn.ARN]*providerCfg{},
		ProviderCfgs:       map[string]*providerCfg{},
		pubKeys: publicKeys{
			RWMutex: &sync.RWMutex{},
			pkMap:   map[string]any{},
		},
		roleArnPolicyMap: map[arn.ARN]string{},
		transport:        openIDClientTransport,
		closeRespFn:      closeRespFn,
	}

	seenClientIDs := set.NewStringSet()

	Cache             map[string]*BucketReplicationStats
	mostRecentStats   BucketStatsMap
	registry          metrics.Registry
	sync.RWMutex                 // mutex for Cache
	mostRecentStatsMu sync.Mutex // mutex for mostRecentStats

	wlock sync.RWMutex // mutex for active workers

	movingAvgTicker *time.Ticker // Ticker for calculating moving averages

	Init(ctx context.Context) error
	IsOnline(ctx context.Context) bool
	Cancel()
	Send(ctx context.Context, entry any) error
	Type() types.TargetType
}

type targetsList struct {
	list []Target
	mu   sync.RWMutex
}

func newTargetsList() *targetsList {
	return &targetsList{}
}

func (tl *targetsList) get() []Target {
	tl.mu.RLock()
	defer tl.mu.RUnlock()

	return tl.list
}

	resourceMetricsMapMu sync.RWMutex
	// resourceMetricsHelpMap maps metric name to its help string
	resourceMetricsHelpMap map[MetricName]string
	resourceMetricsGroups  []*MetricsGroupV2
	// initial values for drives (at the time  of server startup)
	// used for calculating avg values for drive metrics
	latestDriveStats      map[string]madmin.DiskIOStats
	latestDriveStatsMu    sync.RWMutex
	lastDriveStatsRefresh time.Time
)

	EnvBitrot       = "MINIO_HEAL_BITROTSCAN"
	EnvSleep        = "MINIO_HEAL_MAX_SLEEP"
	EnvIOCount      = "MINIO_HEAL_MAX_IO"
	EnvDriveWorkers = "MINIO_HEAL_DRIVE_WORKERS"
)

var configMutex sync.RWMutex

// Config represents the heal settings.
type Config struct {
	// Bitrot will perform bitrot scan on local disk when checking objects.
	Bitrot string `json:"bitrotscan"`

	"github.com/minio/minio/internal/pubsub"
	"github.com/minio/pkg/v3/policy"
)

// EventNotifier - notifies external systems about events in MinIO.
type EventNotifier struct {
	sync.RWMutex
	targetList     *event.TargetList
	bucketRulesMap map[string]event.RulesMap
}

// NewEventNotifier - creates new event notification object.
func NewEventNotifier(ctx context.Context) *EventNotifier {

// Therefore no cluster locks are required.
var localMetacacheMgr = &metacacheManager{
	buckets: make(map[string]*bucketMetacache),
	trash:   make(map[string]metacache),
}

type metacacheManager struct {
	mu      sync.RWMutex
	init    sync.Once
	buckets map[string]*bucketMetacache
	trash   map[string]metacache // Recently deleted lists.
}

const metacacheMaxEntries = 5000

// initManager will start async saving the cache.