// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package dsync

import (
	"math/rand"
	"sync"
)

// lockedRandSource provides protected rand source, implements rand.Source interface.
type lockedRandSource struct {
	lk  sync.Mutex
	src rand.Source
}

// Int63 returns a non-negative pseudo-random 63-bit integer as an int64.
func (r *lockedRandSource) Int63() (n int64) {

package dsync

import (
	"math/rand"
	"time"
)

func backoffWait(min, unit, cap time.Duration) func(*rand.Rand, uint) time.Duration {
	if unit > time.Hour {
		// Protect against integer overflow
		panic("unit cannot exceed one hour")
	}
	return func(r *rand.Rand, attempt uint) time.Duration {
		sleep := min
		sleep += unit * time.Duration(attempt)

package cmd

import (
	"context"
	"fmt"
	"io"
	"math/rand"
	"sync"
	"time"

	"github.com/minio/pkg/v2/sync/errgroup"
)

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)) {
		i := i
		wg.Add(1)

import (
	"context"
	"fmt"
	"math/rand"
	"time"

	"github.com/tidwall/gjson"
)

const (
	licUpdateCycle = 24 * time.Hour * 30
	licRenewPath   = "/api/cluster/renew-license"
)

// initlicenseUpdateJob start the periodic license update job in the background.
func initLicenseUpdateJob(ctx context.Context, objAPI ObjectLayer) {
	go func() {
		r := rand.New(rand.NewSource(time.Now().UnixNano()))

	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 i := 0; i < 100; i++ {
				for j := 0; j < 100; j++ {
					timeout.LogSuccess(time.Duration(float64(time.Second) * rng.Float64()))
				}
				to := timeout.Timeout()
				if to < time.Millisecond || to > time.Second {

type ObjectKey [32]byte

// GenerateKey generates a unique ObjectKey from a 256 bit external key
// and a source of randomness. If random is nil the default PRNG of the
// system (crypto/rand) is used.
func GenerateKey(extKey []byte, random io.Reader) (key ObjectKey) {
	if random == nil {
		random = rand.Reader
	}
	if len(extKey) != 32 { // safety check

			return &testResponse{
				OrgNum:    req.Num,
				OrgString: req.String,
				Embedded:  *req,
			}, nil
		}))
		errFatal(err)
	}
	const payloadSize = 512
	rng := rand.New(rand.NewSource(time.Now().UnixNano()))
	payload := make([]byte, payloadSize)
	_, err = rng.Read(payload)
	errFatal(err)

	// Wait for all to connect
	// Parallel writes per server.
	b.Run("bytes", func(b *testing.B) {

	dm := NewDRWMutex(ds, "test")

	dm.Lock(id, source)
	time.Sleep(time.Duration(10+(rand.Float32()*50)) * time.Millisecond)
	dm.Unlock(context.Background())

	dm.Lock(id, source)
	time.Sleep(time.Duration(10+(rand.Float32()*50)) * time.Millisecond)
	dm.Unlock(context.Background())

	dm.Lock(id, source)
	time.Sleep(time.Duration(10+(rand.Float32()*50)) * time.Millisecond)
	dm.Unlock(context.Background())

	dm.Lock(id, source)

				}
				mu.Unlock()
			}(clnt)
		}
		wg.Wait()

		select {
		case <-ctx.Done():
			return ctx.Err()
		default:
			// Sleep and stagger to avoid blocked CPU and thundering
			// herd upon start up sequence.
			time.Sleep(25*time.Millisecond + time.Duration(rand.Int63n(int64(100*time.Millisecond))))
			retries++
			// after 20 retries start logging that servers are not reachable yet
			if retries >= 20 {

	if err != nil {
		return err
	}

	pollIntervalBase := time.Millisecond
	nextPollInterval := func() time.Duration {
		// Add 10% jitter.
		interval := pollIntervalBase + time.Duration(rand.Intn(int(pollIntervalBase/10)))
		// Double and clamp for next time.
		pollIntervalBase *= 2
		if pollIntervalBase > shutdownPollIntervalMax {
			pollIntervalBase = shutdownPollIntervalMax
		}
		return interval
	}