assertThat(timer.elapsed(MILLISECONDS)).isAtLeast(10L);
    // wait for interrupted status and clear it
    while (!Thread.interrupted()) {
      Thread.yield();
    }
  }

  private static class Producer implements Callable<@Nullable Void> {
    final BlockingQueue<Object> q;
    final int elements;
    final CountDownLatch beganProducing = new CountDownLatch(1);

              @SuppressWarnings("ThreadPriorityCheck") // doing our best to test for races
              public void realRun() {
                while (!a.compareAndSet(0, 2.0, 3.0)) {
                  Thread.yield();
                }
              }
            });

    assertTrue(a.compareAndSet(0, 1.0, 2.0));
    awaitTermination(t);
    assertBitEquals(3.0, a.get(0));
  }

      // (in startSignal.await()), and the others waiting for that thread's result.
      while (thread.isAlive() && thread.getState() != Thread.State.WAITING) {
        Thread.yield();
      }
    }
    gettersStartedSignal.countDown();
    gettersComplete.await();

    List<Object> resultList = Lists.newArrayListWithExpectedSize(nThreads);
    for (int i = 0; i < nThreads; i++) {

              @SuppressWarnings("ThreadPriorityCheck") // doing our best to test for races
              public void realRun() {
                while (!a.compareAndSet(0, 2.0, 3.0)) {
                  Thread.yield();
                }
              }
            });

    assertTrue(a.compareAndSet(0, 1.0, 2.0));
    awaitTermination(t);
    assertBitEquals(3.0, a.get(0));
  }

  static void awaitWaiting(Thread t) {
    while (true) {
      Thread.State state = t.getState();
      switch (state) {
        case RUNNABLE:
        case BLOCKED:
          Thread.yield();
          break;
        case WAITING:
          return;
        default:
          throw new AssertionError("unexpected state: " + state);
      }
    }
  }

**`Session`** зберігає **об’єкти в пам’яті** та відстежує зміни у даних, а потім **використовує `engine`** для взаємодії з базою даних.

Ми створимо **залежність** FastAPI з `yield`, яка надаватиме нову `Session` для кожного запиту. Це й гарантує, що ми використовуємо одну сесію на запит. 🤓

Далі створимо залежність `Annotated` - `SessionDep`, щоб спростити решту коду, який її використовуватиме.

Uma **`Session`** é o que armazena os **objetos na memória** e acompanha as alterações necessárias nos dados, para então **usar o `engine`** para se comunicar com o banco de dados.

Vamos criar uma **dependência** do FastAPI com `yield` que fornecerá uma nova `Session` para cada requisição. Isso é o que garante que usamos uma única sessão por requisição. 🤓

  void awaitTimedWaiting(Thread thread) {
    while (true) {
      switch (thread.getState()) {
        case BLOCKED:
        case NEW:
        case RUNNABLE:
        case WAITING:
          Thread.yield();
          break;
        case TIMED_WAITING:
          return;
        case TERMINATED:
          throw new AssertionError();
      }
    }
  }

Bir **`Session`**, **nesneleri memory’de** tutar ve verideki gerekli değişiklikleri takip eder; ardından veritabanıyla iletişim kurmak için **`engine` kullanır**.

`yield` ile, her request için yeni bir `Session` sağlayacak bir FastAPI **dependency** oluşturacağız. Bu da her request’te tek session kullanmamızı garanti eder. 🤓

    void awaitWaiting() {
      while (!isBlocked()) {
        if (getState() == State.TERMINATED) {
          throw new RuntimeException("Thread exited");
        }
        Thread.yield();
      }
    }

    private boolean isBlocked() {
      return getState() == Thread.State.WAITING && LockSupport.getBlocker(this) == future;
    }
  }