private Instance createInstance(ThreadContext callContext, BeanContext beanContext)
      throws ApplicationException {
    try {
      initializeDependencies(beanContext);

      final InstanceContext context = beanContext.newInstance();

      if (context.getBean() instanceof SessionBean) {

        final Operation originalOperation = callContext.getCurrentOperation();
        try {
          callContext.setCurrentOperation(Operation.CREATE);
          final Method create = beanContext.getCreateMethod();
          final InterceptorStack ejbCreate =
              new InterceptorStack(
                  context.getBean(),
                  create,
                  Operation.CREATE,
                  new ArrayList<InterceptorData>(),
                  new HashMap());
          ejbCreate.invoke();
        } finally {
          callContext.setCurrentOperation(originalOperation);
        }
      }

      ReadWriteLock lock;
      if (beanContext.isBeanManagedConcurrency()) {
        // Bean-Managed Concurrency
        lock = new BeanManagedLock();
      } else {
        // Container-Managed Concurrency
        lock = new ReentrantReadWriteLock();
      }

      return new Instance(
          context.getBean(), context.getInterceptors(), context.getCreationalContext(), lock);
    } catch (Throwable e) {
      if (e instanceof java.lang.reflect.InvocationTargetException) {
        e = ((java.lang.reflect.InvocationTargetException) e).getTargetException();
      }
      String t =
          "The bean instance " + beanContext.getDeploymentID() + " threw a system exception:" + e;
      logger.error(t, e);
      throw new ApplicationException(
          new NoSuchEJBException("Singleton failed to initialize").initCause(e));
    }
  }
  public void freeInstance(ThreadContext callContext) {
    BeanContext beanContext = callContext.getBeanContext();
    Data data = (Data) beanContext.getContainerData();
    Future<Instance> instanceFuture = data.singleton.get();

    // Possible the instance was never created
    if (instanceFuture == null) return;

    Instance instance;
    try {
      instance = instanceFuture.get();
    } catch (InterruptedException e) {
      Thread.interrupted();
      logger.error(
          "Singleton shutdown failed because the thread was interrupted: "
              + beanContext.getDeploymentID(),
          e);
      return;
    } catch (ExecutionException e) {
      // Instance was never initialized
      return;
    }

    try {
      callContext.setCurrentOperation(Operation.PRE_DESTROY);
      callContext.setCurrentAllowedStates(null);

      Method remove = instance.bean instanceof SessionBean ? beanContext.getCreateMethod() : null;

      List<InterceptorData> callbackInterceptors = beanContext.getCallbackInterceptors();
      InterceptorStack interceptorStack =
          new InterceptorStack(
              instance.bean,
              remove,
              Operation.PRE_DESTROY,
              callbackInterceptors,
              instance.interceptors);

      // Transaction Demarcation for Singleton PostConstruct method
      TransactionType transactionType;

      if (beanContext.getComponentType() == BeanType.SINGLETON) {
        Set<Method> callbacks =
            callbackInterceptors.get(callbackInterceptors.size() - 1).getPreDestroy();
        if (callbacks.isEmpty()) {
          transactionType = TransactionType.RequiresNew;
        } else {
          transactionType = beanContext.getTransactionType(callbacks.iterator().next());
          if (transactionType == TransactionType.Required) {
            transactionType = TransactionType.RequiresNew;
          }
        }
      } else {
        transactionType =
            beanContext.isBeanManagedTransaction()
                ? TransactionType.BeanManaged
                : TransactionType.NotSupported;
      }
      TransactionPolicy transactionPolicy =
          EjbTransactionUtil.createTransactionPolicy(transactionType, callContext);
      try {
        // Call the chain
        interceptorStack.invoke();
        if (instance.creationalContext != null) {
          instance.creationalContext.release();
        }
      } catch (Throwable e) {
        // RollBack Transaction
        EjbTransactionUtil.handleSystemException(transactionPolicy, e, callContext);
      } finally {
        EjbTransactionUtil.afterInvoke(transactionPolicy, callContext);
      }

    } catch (Throwable re) {
      logger.error("Singleton shutdown failed: " + beanContext.getDeploymentID(), re);
    }
  }