When Go 1.23 builds older programs, the old behaviors remain in effect.
The new [GODEBUG setting](/doc/godebug) [`asynctimerchan=1`](/pkg/time/#NewTimer)
can be used to revert back to asynchronous channel behaviors

      // interact poorly with the reentrancy-avoiding behavior of this executor - when the operation
      // before the cancelled future completes, it will synchronously complete both the newFuture
      // from the cancelled operation and its own. This can cause one runnable to queue two tasks,
      // breaking the invariant this method relies on to iteratively run the next task after the

   */
  fun cancel()

  fun interface Factory {
    /**
     * Creates a new event source and immediately returns it. Creating an event source initiates an
     * asynchronous process to connect the socket. Once that succeeds or fails, `listener` will be
     * notified. The caller must cancel the returned event source when it is no longer in use.
     */
    fun newEventSource(

            }
        };
    }

    // ===================================================================================
    //                                                                        Asynchronous
    //                                                                        ============
    protected void async(final AsyncManager asyncManager, final Runnable runnable) {

    title: JWT Authentication with FastAPI and AWS Cognito
  - author: Ankush Thakur
    author_link: https://geekflare.com/author/ankush/
    link: https://geekflare.com/python-asynchronous-web-frameworks/
    title: Top 5 Asynchronous Web Frameworks for Python
  - author: Nico Axtmann
    author_link: https://www.linkedin.com/in/nico-axtmann

以及如何[使用 `CORSMiddleware` 处理 CORS](../tutorial/cors.md){.internal-link target=_blank}。

本章学习如何使用其它中间件。

## 添加 ASGI 中间件

因为 **FastAPI** 基于 Starlette，且执行 <abbr title="Asynchronous Server Gateway Interface，异步服务器网关界面">ASGI</abbr> 规范，所以可以使用任意 ASGI 中间件。

中间件不必是专为 FastAPI 或 Starlette 定制的，只要遵循 ASGI 规范即可。

总之，ASGI 中间件是类，并把 ASGI 应用作为第一个参数。

因此，有些第三方 ASGI 中间件的文档推荐以如下方式使用中间件：

```Python

 *
 * Other exception types cancel the current call:
 *
 *  * For synchronous calls made with [Call.execute], the exception is propagated to the caller.
 *
 *  * For asynchronous calls made with [Call.enqueue], an [IOException] is propagated to the caller
 *    indicating that the call was canceled. The interceptor's exception is delivered to the current

In diesem Abschnitt werden wir sehen, wie man andere Middlewares verwendet.

## ASGI-Middleware hinzufügen

Da **FastAPI** auf Starlette basiert und die <abbr title="Asynchronous Server Gateway Interface">ASGI</abbr>-Spezifikation implementiert, können Sie jede ASGI-Middleware verwenden.

		}
	}

	for i, version := range x.versions {
		if version.header.VersionID != uv || version.header.Type != ObjectType {
			continue
		}
		// if uv has tiered content we add a
		// free-version to track it for asynchronous
		// deletion via scanner.
		ver, err := x.getIdx(i)
		if err != nil {
			return err
		}

		if freeVersion, toFree := ver.ObjectV2.InitFreeVersion(fi); toFree {
			return x.addVersion(freeVersion)

   */
  fun cancel()

  fun interface Factory {
    /**
     * Creates a new web socket and immediately returns it. Creating a web socket initiates an
     * asynchronous process to connect the socket. Once that succeeds or fails, `listener` will be
     * notified. The caller must either close or cancel the returned web socket when it is no longer
     * in use.
     */