//
//go:linkname readMetricNames runtime/metrics_test.runtime_readMetricNames
func readMetricNames() []string {
	metricsLock()
	initMetrics()
	n := len(metrics)
	metricsUnlock()

	list := make([]string, 0, n)

	metricsLock()
	for name := range metrics {
		list = append(list, name)
	}
	metricsUnlock()

	return list
}

func ReadMetricsSlow(memStats *MemStats, samplesp unsafe.Pointer, len, cap int) {
	stw := stopTheWorld(stwForTestReadMetricsSlow)

	// Initialize the metrics beforehand because this could
	// allocate and skew the stats.
	metricsLock()
	initMetrics()

	systemstack(func() {
		// Donate the racectx to g0. readMetricsLocked calls into the race detector
		// via map access.
		getg().racectx = getg().m.curg.racectx

	servermetrics "k8s.io/kubernetes/pkg/kubelet/server/metrics"
)

var _ MetricsProvider = &metricsBlock{}

// metricsBlock represents a MetricsProvider that detects the size of the
// BlockMode Volume.
type metricsBlock struct {
	// the device node where the volume is attached to.
	device string
}

// NewMetricsStatfs creates a new metricsBlock with the device node of the
// Volume.
func NewMetricsBlock(device string) MetricsProvider {

	expected := &Metrics{}
	if !volumetest.MetricsEqualIgnoreTimestamp(actual, expected) {
		t.Errorf("Expected empty Metrics from uninitialized MetricsBlock, actual %v", *actual)
	}
	if err == nil {
		t.Errorf("Expected error when calling GetMetrics on uninitialized MetricsBlock, actual nil")
	}

	metrics = NewMetricsBlock("/nonexistent/device/node")
	actual, err = metrics.GetMetrics()