thumbnailTaskQueue = new LinkedBlockingQueue<>(thumbnailTaskQueueSize);
        generating = !Constants.TRUE.equalsIgnoreCase(System.getProperty("fess.thumbnail.process"));
        thumbnailQueueThread = new Thread((Runnable) () -> {
            final List<Tuple3<String, String, String>> taskList = new ArrayList<>();
            while (generating) {
                try {

	// cache is the internal map that backs the cache.
	cache map[interface{}]entry
	// generation is used as a cheap resource version for cache entries. Cleanups
	// are scheduled with a key and generation. When the cleanup runs, it first
	// compares its generation with the current generation of the entry. It
	// deletes the entry iff the generation matches. This prevents cleanups

	Strategy.PrepareForUpdate(ctx, updatedLabel, podTemplate)
	if updatedLabel.Generation != 1 {
		t.Errorf("expected Generation=1, got %d", updatedLabel.Generation)
	}

	updatedTemplate := podTemplate.DeepCopy()
	updatedTemplate.ResourceVersion = "10"
	updatedTemplate.Generation = 999
	updatedTemplate.Template.Spec.RestartPolicy = api.RestartPolicyNever

	// ensure generation is updated for spec changes

import org.gradle.platform.base.*

// tag::component-registration[]
// tag::binary-registration[]
// tag::binaries-generation[]
// tag::text-tasks-generation[]
class DocumentationPlugin extends RuleSource {
// end::binary-registration[]
// end::binaries-generation[]
// end::text-tasks-generation[]
    @ComponentType
    void registerComponent(TypeBuilder<DocumentationComponent> builder) {}
// end::component-registration[]

Их тяжелее настраивать, также им нужен брокер сообщений наподобие RabbitMQ или Redis, но зато они позволяют вам запускать фоновые задачи в нескольких процессах и даже на нескольких серверах.

Для примера, посмотрите [Project Generators](../project-generation.md){.internal-link target=_blank}, там есть проект с уже настроенным Celery.

	ProcRange(ctx *traceContext, ev *trace.Event)
	ProcTransition(ctx *traceContext, ev *trace.Event)

	// User annotations.
	Log(ctx *traceContext, ev *trace.Event)

	// Finish indicates the end of the trace and finalizes generation.
	Finish(ctx *traceContext)
}

// runGenerator produces a trace into ctx by running the generator over the parsed trace.
func runGenerator(ctx *traceContext, g generator, parsed *parsedTrace, opts *genOpts) {

	ready.set(false)
	ready.set(false)
	ready.set(false)
	if generation, ok := ready.checkAndReadGeneration(); generation != 0 || ok {
		t.Errorf("unexpected state: generation=%v ready=%v", generation, ok)
	}
	ready.set(true)
	if generation, ok := ready.checkAndReadGeneration(); generation != 1 || !ok {
		t.Errorf("unexpected state: generation=%v ready=%v", generation, ok)
	}
	ready.set(true)
	ready.set(true)

//
// The issue is that the parser reads ahead to the first batch of the
// next generation to find generation boundaries, but if it finds an
// error, it needs to delay handling that error until later. Previously
// it would handle that error immediately and a totally valid generation
// would be skipped for parsing and rejected because of an error in a
// batch in the following generation.
//
// This test captures this behavior by making both the first generation

		t.Errorf("CronJob does not allow setting status on create")
	}
	if cronJob.Generation != 1 {
		t.Errorf("expected Generation=1, got %d", cronJob.Generation)
	}
	errs := Strategy.Validate(ctx, cronJob)
	if len(errs) != 0 {
		t.Errorf("Unexpected error validating %v", errs)
	}
	now := metav1.Now()

	// ensure we do not change generation for non-spec updates
	updatedLabelCronJob := cronJob.DeepCopy()

				ResourceVersion:   obj.ResourceVersion,
				CreationTimestamp: obj.CreationTimestamp.Time,
				OwnerReferences:   obj.OwnerReferences,
				UID:               string(obj.UID),
				Generation:        obj.Generation,
			},
			Spec:   &obj.Spec,
			Status: &obj.Status,
		}
	},
	gvk.CertificateSigningRequest: func(r runtime.Object) config.Config {
		obj := r.(*k8sioapicertificatesv1.CertificateSigningRequest)