bucketCh <- b
		}
	}
	xioutil.SafeClose(bucketCh)

	bucketResults := make(chan dataUsageEntryInfo, len(disks))

	// Start async collector/saver.
	// This goroutine owns the cache.
	var saverWg sync.WaitGroup
	saverWg.Add(1)
	go func() {
		// Add jitter to the update time so multiple sets don't sync up.

	ctx, cancel := context.WithCancel(context.Background())
	go func() {
		select {
		case <-ctx1.Done():
		case <-ctx2.Done():
		// The lock acquirer decides to cancel, exit this goroutine
		case <-ctx.Done():
		}

		cancel()
	}()
	return ctx, cancel
}

func (ld sharedLock) GetLock(ctx context.Context) (context.Context, context.CancelFunc) {
	l := <-ld.lockContext

// TestPreparedStmtConcurrentClose test calling close and executing SQL concurrently
// for example: one goroutine found error and just close the database, and others are executing SQL
// this test making sure that the gorm would not get a Segmentation Fault,
// and the only error cause by this is using a closed Stmt or gorm.ErrInvalidDB
// and all of the goroutine must got gorm.ErrInvalidDB after database close
func TestPreparedStmtConcurrentClose(t *testing.T) {

	closedMu sync.Mutex
	closer   io.ReadCloser
	closed   bool
}

func (pr *progressReader) Read(p []byte) (n int, err error) {
	// This ensures that Close will block until Read has completed.
	// This allows another goroutine to close the reader.
	pr.closedMu.Lock()
	defer pr.closedMu.Unlock()
	if pr.closed {
		return 0, errors.New("progressReader: read after Close")
	}
	return pr.processedReader.Read(p)
}

	neededFrags = make(map[urlFrag][]string) // URL#frag -> who needs it
)

var aRx = regexp.MustCompile(`<a href=['"]?(/[^\s'">]+)`)

// Owned by crawlLoop goroutine:
var (
	linkSources = make(map[string][]string) // url no fragment -> sources
	fragExists  = make(map[urlFrag]bool)
	problems    []string
)

func localLinks(body string) (links []string) {

		// lk2
		lk2ch := make(chan struct{})
		go func() {
			defer close(lk2ch)
			nsLk.lock(ctx, "volume", "path", "source", "opsID", false, 1*time.Millisecond)
		}()
		time.Sleep(1 * time.Millisecond) // wait for goroutine to advance; ref=2

		// Unlock the 1st lock; ref=1 after this line
		nsLk.unlock("volume", "path", false)

		// Taking another lockMapMutex here allows queuing up additional lockers. This should

)

// RingBuffer is a circular buffer that implement io.ReaderWriter interface.
// It operates like a buffered pipe, where data written to a RingBuffer
// and can be read back from another goroutine.
// It is safe to concurrently read and write RingBuffer.
type RingBuffer struct {
	buf       []byte
	size      int
	r         int // next position to read
	w         int // next position to write
	isFull    bool

		if sleep > cap {
			sleep = cap
		}
		sleep -= time.Duration(r.Float64() * float64(sleep-unit))
		return sleep
	}
}

func (c *Client) runHealthCheck() bool {
	// Start goroutine that will attempt to reconnect.
	// If server is already trying to reconnect this will have no effect.
	if c.HealthCheckFn != nil && atomic.CompareAndSwapInt32(&c.connected, online, offline) {
		go func() {

	}

	result := &serviceResult{}
	if err := json.Unmarshal(resp, result); err != nil {
		t.Error(err)
	}
	_ = result

	// Wait until testServiceSignalReceiver() called in a goroutine quits.
	wg.Wait()
}

// Test for service restart management REST API.
func TestServiceRestartHandler(t *testing.T) {
	testServicesCmdHandler(restartCmd, t)
}

			return buf.Bytes(), err
		}
	case madmin.ProfilerGoroutines:
		prof.ext = "txt"
		prof.record("goroutine", 1, "before")
		prof.record("goroutine", 2, "before,debug=2")
		prof.stopFn = func() ([]byte, error) {
			var buf bytes.Buffer
			err := pprof.Lookup("goroutine").WriteTo(&buf, 1)
			return buf.Bytes(), err
		}
	case madmin.ProfilerTrace:
		dirPath, err := os.MkdirTemp("", "profile")