func TestDynamicTimeoutConcurrent(t *testing.T) {
	// 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 i := 0; i < 100; i++ {
				for j := 0; j < 100; j++ {
					timeout.LogSuccess(time.Duration(float64(time.Second) * rng.Float64()))
				}

// 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) {

// 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
		logger.CriticalIf(context.Background(), errors.New("crypto: invalid key length"))
	}
	var nonce [32]byte

	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)

// is given, it sets default dial function.
//
// You can use returned dial function for `http.Transport.DialContext`.
//
// In this function, it uses functions from `rand` package. To make it really random,
// you MUST call `rand.Seed` and change the value from the default in your application
func DialContextWithLookupHost(lookupHost LookupHost, baseDialCtx DialContext) DialContext {
	if lookupHost == nil {

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

package cmd

import (
	"bytes"
	"context"
	crand "crypto/rand"
	"io"
	"math/rand"
	"testing"

	"github.com/dustin/go-humanize"
)

func (a badDisk) ReadFile(ctx context.Context, volume string, path string, offset int64, buf []byte, verifier *BitrotVerifier) (n int64, err error) {

	}
	return hosts
}

// returns an online host (and corresponding port) from a slice of DNS records
func getHostFromSrv(records []dns.SrvRecord) (host string) {
	hosts := getHostsSlice(records)
	rng := rand.New(rand.NewSource(time.Now().UTC().UnixNano()))
	var d net.Dialer
	var retry int
	for retry < len(hosts) {
		ctx, cancel := context.WithTimeout(GlobalContext, 300*time.Millisecond)

		host = hosts[rng.Intn(len(hosts))]

	}

	globalBatchJobsMetrics.save(job.ID, ri)
	lastObject := ri.Object

	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 {

	// special value -1 means no explicit seeding.
	if seed != -1 {
		rand.Seed(seed)
	}
	return rand.Intn(max-min) + min
}

// Randomizes the order of bytes in the byte array
// using Knuth Fisher-Yates shuffle algorithm.
func randomizeBytes(s []byte, seed int64) []byte {
	// special value -1 means no explicit seeding.
	if seed != -1 {
		rand.Seed(seed)
	}
	n := len(s)
	var j int

	if err != nil {
		return err
	}
	return wsutil.WriteMessage(conn, c.side, ws.OpBinary, dst)
}

func (c *Connection) connect() {
	c.updateState(StateConnecting)
	rng := rand.New(rand.NewSource(time.Now().UnixNano()))
	// Runs until the server is shut down.
	for {
		if c.State() == StateShutdown {
			return
		}
		toDial := strings.Replace(c.Remote, "http://", "ws://", 1)