// save the content of the cache to minioMetaBackgroundOpsBucket with the provided name.
// Note that no locking is done when saving.
func (d *dataUsageCache) save(ctx context.Context, store objectIO, name string) error {
	select {
	case <-ctx.Done():
		return ctx.Err()
	case maxConcurrentScannerSaves <- struct{}{}:
	}

	buf := bytebufferpool.Get()
	defer func() {

	resourceMetricsMapMu.Unlock()
	metricsTimer := time.NewTimer(resourceMetricsCollectionInterval)
	defer metricsTimer.Stop()

	collectLocalResourceMetrics()

	for {
		select {
		case <-GlobalContext.Done():
			return
		case <-metricsTimer.C:
			collectLocalResourceMetrics()

			// Reset the timer for next cycle.
			metricsTimer.Reset(resourceMetricsCollectionInterval)
		}
	}
}

	workers := []chan expiryOp{make(chan expiryOp)}
	es.workers.Store(&workers)
	globalExpiryState = es
	var wg sync.WaitGroup
	wg.Add(1)
	expired := make([]ObjectToDelete, 0, 5)
	go func() {
		defer wg.Done()
		workers := globalExpiryState.workers.Load()
		for t := range (*workers)[0] {
			if t, ok := t.(newerNoncurrentTask); ok {
				expired = append(expired, t.versions...)
			}
		}
	}()
	lc := lifecycle.Lifecycle{

Then your API will (let's imagine):

* Send the invoice to some customer of the external developer.
* Collect the money.
* Send a notification back to the API user (the external developer).
    * This will be done by sending a POST request (from *your API*) to some *external API* provided by that external developer (this is the "callback").

## The normal **FastAPI** app

	r.input = make(chan *queueItem, runtime.GOMAXPROCS(0))
	r.readerWg.Add(1)

	// Start splitter
	go func() {
		defer close(r.input)
		defer close(r.queue)
		defer r.readerWg.Done()
		for {
			q := queueItem{
				input: next,
				dst:   make(chan [][]string, 1),
				err:   nextErr,
			}
			select {
			case <-r.close:
				return
			case r.queue <- &q:
			}

		}
		if sizeS.tiers != nil {
			sizeS.tiers[storageclass.STANDARD] = tierStats{}
			sizeS.tiers[storageclass.RRS] = tierStats{}
		}

		done := globalScannerMetrics.time(scannerMetricApplyAll)
		objInfos, err := item.applyVersionActions(ctx, objAPI, fivs.Versions, globalExpiryState)
		done()

		if err != nil {
			res["err"] = err.Error()
			return sizeSummary{}, errSkipFile
		}

		defer cancel()

		wg := sync.WaitGroup{}
		for i, disk := range disks {
			if disk == nil {
				done <- false
				continue
			}
			if !disk.IsOnline() {
				done <- false
				continue
			}
			wg.Add(1)
			go func(i int, disk StorageAPI) {
				defer wg.Done()

				var (
					fi  FileInfo
					rfi RawFileInfo
					err error
				)

				if opts.VersionID != "" {

	return jpool
}

func (j *BatchJobPool) cleanupReports(randomWait func() time.Duration) {
	t := time.NewTimer(randomWait())
	defer t.Stop()

	for {
		select {
		case <-GlobalContext.Done():
			return
		case <-t.C:
			results := make(chan itemOrErr[ObjectInfo], 100)
			ctx, cancel := context.WithCancel(j.ctx)
			defer cancel()

		closeWithErr: rb.CloseWithError,
		h:            h,
		shardSize:    shardSize,
		canClose:     &sync.WaitGroup{},
		byteBuf:      buf,
	}
	bw.canClose.Add(1)
	go func() {
		defer bw.canClose.Done()

		totalFileSize := int64(-1) // For compressed objects length will be unknown (represented by length=-1)
		if length != -1 {

	target := &WebhookTarget{
		id:         event.TargetID{ID: id, Name: "webhook"},
		args:       args,
		loggerOnce: loggerOnce,
		transport:  transport,
		cancel:     cancel,
		cancelCh:   ctx.Done(),
	}

	return target, nil