lock.lock();
      try {
        locked.countDown();
        finishLatch.await(1, MINUTES);
      } catch (InterruptedException e) {
        fail(e.toString());
      } finally {
        lock.unlock();
      }
    }

    void waitUntilHoldingLock() throws InterruptedException {
      locked.await(1, MINUTES);
    }

    void releaseLockAndFinish() throws InterruptedException {

      lock.lock();
      try {
        locked.countDown();
        finishLatch.await(1, MINUTES);
      } catch (InterruptedException e) {
        fail(e.toString());
      } finally {
        lock.unlock();
      }
    }

    void waitUntilHoldingLock() throws InterruptedException {
      locked.await(1, MINUTES);
    }

    void releaseLockAndFinish() throws InterruptedException {

	wg := sync.WaitGroup{}
	wg.Add(1000)
	for i := 0; i < 1000; i++ {
		go func(i int) {
			lc.Add(fmt.Sprintf("key-%d", i/10), fmt.Sprintf("val-%d", i/10))
			wg.Done()
		}(i)
	}
	wg.Wait()
	if lc.Len() != 100 {
		t.Fatalf("length differs from expected")
	}
}

func TestLRUInvalidateAndEvict(t *testing.T) {
	var evicted int
	lc := lru.NewLRU(-1, func(_, _ string) { evicted++ }, 0)

    }

    @Test
    void testExpiration() throws InterruptedException {
        // Registration should not be expired initially with long timeout
        assertFalse(registration.isExpired(60000));

        // Wait a bit to ensure some time has passed
        Thread.sleep(50);
        // Should be expired with very short timeout (shorter than sleep time)
        assertTrue(registration.isExpired(10));
    }

    @Test

				UserDefined:      userDefined,
			})
			if err != nil {
				errs[idx] = err
				return
			}
			objInfos[idx] = objInfo
		}(i, req)
	}
	wg.Wait()

	return objInfos, errs

rd island and mcdonald islands","honduras","hong kong","hungary","iceland","india","indonesia","iran","iraq","ireland","isle of man","israel","italy","jamaica","japan","jersey","jordan","kazakhstan","kenya","kiribati","north korea","south korea","kuwait","kyrgyzstan","laos","latvia","lebanon","lesotho","liberia","libya","liechtenstein","lithuania","luxembourg","macao","macedonia","madagascar","malawi","malaysia","maldives","mali","malta","marshall islands","martinique","mauritania","mauritius","...

                    if (delayTime <= 0) {
                        lastTime.set(currentTime);
                        break;
                    }
                    lastTime.wait(delayTime);
                }
            }
        } catch (final InterruptedException e) {
            throw new InterruptedRuntimeException(e);
        } catch (final Exception e) {

En este caso, la función de tarea escribirá en un archivo (simulando el envío de un email).

Y como la operación de escritura no usa `async` y `await`, definimos la función con un `def` normal:

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## Agregar la tarea en segundo plano

        directoryLeaseManager.updateDirectoryCache(directoryPath, files);

        assertTrue(entry.isComplete());
        assertFalse(entry.needsRefresh());

        // Wait for expiration
        Thread.sleep(100);

        assertTrue(entry.isExpired());
        assertTrue(entry.needsRefresh());

        // After expiration, cache should be treated as invalid by manager

	var wg sync.WaitGroup
	for i := 0; i < 5; i++ {
		wg.Add(1)
		go func(i int) {
			defer wg.Done()
			var buf [1]byte
			r.ReadAt(buf[:], int64(i))
		}(i)
	}
	wg.Wait()
}

func TestEmptyReaderConcurrent(t *testing.T) {
	// Test for the race detector, to verify a Read that doesn't yield any bytes
	// is okay to use from multiple goroutines. This was our historic behavior.