import (
	"context"
	"math/rand"
	"sync"
	"time"
)

func (er erasureObjects) getOnlineDisks() (newDisks []StorageAPI) {
	disks := er.getDisks()
	var wg sync.WaitGroup
	var mu sync.Mutex
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	for _, i := range r.Perm(len(disks)) {
		wg.Add(1)
		go func() {
			defer wg.Done()
			if disks[i] == nil {
				return
			}

// initCallhome will start the callhome task in the background.
func initCallhome(ctx context.Context, objAPI ObjectLayer) {
	if !globalCallhomeConfig.Enabled() {
		return
	}

	go func() {
		r := rand.New(rand.NewSource(time.Now().UnixNano()))
		// Leader node (that successfully acquires the lock inside runCallhome)
		// will keep performing the callhome. If the leader goes down for some reason,

	var wg sync.WaitGroup
	disks := er.getDisks()
	infos := make([]DiskInfo, len(disks))
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	for _, i := range r.Perm(len(disks)) {
		wg.Add(1)
		go func() {
			defer wg.Done()

			disk := disks[i]
			if disk == nil {
				infos[i].Error = errDiskNotFound.Error()

	// Race test.
	timeout := newDynamicTimeout(time.Second, time.Millisecond)
	var wg sync.WaitGroup
	for i := 0; i < runtime.GOMAXPROCS(0); i++ {
		wg.Add(1)
		rng := rand.New(rand.NewSource(int64(i)))
		go func() {
			defer wg.Done()
			for range 100 {
				for range 100 {
					timeout.LogSuccess(time.Duration(float64(time.Second) * rng.Float64()))
				}
				to := timeout.Timeout()

	}
	if len(l.lockUID) != 0 {
		t.Fatalf("lockUID len, got %d, want %d + %d", len(l.lockUID), 0, 0)
	}
}

func Test_localLocker_expireOldLocksExpire(t *testing.T) {
	rng := rand.New(rand.NewSource(0))
	quorum := 0
	// Numbers of unique locks
	for _, locks := range []int{100, 1000, 1e6} {
		if testing.Short() && locks > 100 {
			continue
		}
		t.Run(fmt.Sprintf("%d-locks", locks), func(t *testing.T) {

	testShuffleDisks(t, z)
}

func Test_hashOrder(t *testing.T) {
	for x := 1; x < 17; x++ {
		t.Run(fmt.Sprintf("%d", x), func(t *testing.T) {
			var first [17]int
			rng := rand.New(rand.NewSource(0))
			var tmp [16]byte
			rng.Read(tmp[:])
			prefix := hex.EncodeToString(tmp[:])
			for range 10000 {
				rng.Read(tmp[:])

				y := hashOrder(fmt.Sprintf("%s/%x", prefix, hex.EncodeToString(tmp[:3])), x)

		peerResyncMap: make(map[string]resyncState),
	}
	go s.save(ctx)
	go s.init(ctx)
	return &s
}

// init site resync metrics
func (sm *siteResyncMetrics) init(ctx context.Context) {
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	// Run the site resync metrics load in a loop
	for {
		if err := sm.load(ctx, newObjectLayerFn()); err == nil {
			<-ctx.Done()
			return
		}

func getRandomRange(minN, maxN int, seed int64) int {
	// special value -1 means no explicit seeding.
	if seed == -1 {
		return rand.New(rand.NewSource(time.Now().UnixNano())).Intn(maxN-minN) + minN
	}
	return rand.New(rand.NewSource(seed)).Intn(maxN-minN) + minN
}

// Randomizes the order of bytes in the byte array
// using Knuth Fisher-Yates shuffle algorithm.

		retryAttempts = batchKeyRotateJobDefaultRetries
	}
	delay := job.KeyRotate.Flags.Retry.Delay
	if delay <= 0 {
		delay = batchKeyRotateJobDefaultRetryDelay
	}

	rnd := rand.New(rand.NewSource(time.Now().UnixNano()))

	selectObj := func(info FileInfo) (ok bool) {
		if r.Flags.Filter.OlderThan > 0 && time.Since(info.ModTime) < r.Flags.Filter.OlderThan {

		Tiers:       make(map[string]madmin.TierConfig),
	}
}

func (config *TierConfigMgr) refreshTierConfig(ctx context.Context, objAPI ObjectLayer) {
	const tierCfgRefresh = 15 * time.Minute
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	randInterval := func() time.Duration {
		return time.Duration(r.Float64() * 5 * float64(time.Second))
	}

	// To avoid all MinIO nodes reading the tier config object at the same
	// time.