Será llamada por **FastAPI** cuando reciba un request en la URL "`/`" usando una operación `GET`.

En este caso, es una función `async`.

---

También podrías definirla como una función normal en lugar de `async def`:

{* ../../docs_src/first_steps/tutorial003_py39.py hl[7] *}

/// note | Nota

It will be called by **FastAPI** whenever it receives a request to the URL "`/`" using a `GET` operation.

In this case, it is an `async` function.

---

You could also define it as a normal function instead of `async def`:

{* ../../docs_src/first_steps/tutorial003_py39.py hl[7] *}

/// note

Si capturas una excepción usando `except` en una dependencia con `yield` y no la lanzas nuevamente (o lanzas una nueva excepción), FastAPI no podrá notar que hubo una excepción, al igual que sucedería con Python normal:

{* ../../docs_src/dependencies/tutorial008c_an_py39.py hl[15:16] *}

{* ../../docs_src/settings/app02_an_py39/main.py hl[6,12:13] *}

/// tip | Dica

Vamos discutir o `@lru_cache` em breve.

Por enquanto, você pode assumir que `get_settings()` é uma função normal.

///

E então podemos exigi-la na *função de operação de rota* como dependência e usá-la onde for necessário.

{* ../../docs_src/settings/app02_an_py39/main.py hl[17,19:21] *}

     * and the frequency of status checks.
     */
    protected long crawlingExecutionInterval = Constants.DEFAULT_CRAWLING_EXECUTION_INTERVAL;

    /**
     * Thread priority for crawler threads.
     * Defaults to normal thread priority.
     */
    protected int crawlerPriority = Thread.NORM_PRIORITY;

    /**
     * Thread-safe list of active data crawling threads.
     * Used to track and manage all currently running crawler threads.

{* ../../docs_src/settings/app02_an_py39/main.py hl[6,12:13] *}

/// tip

We'll discuss the `@lru_cache` in a bit.

For now you can assume `get_settings()` is a normal function.

///

And then we can require it from the *path operation function* as a dependency and use it anywhere we need it.

{* ../../docs_src/settings/app02_an_py39/main.py hl[17,19:21] *}

    /**
     * Reserve an opportunistic lock filter on the open
     */
    public static final int FILE_RESERVE_OPFILTER = 0x100000;
    /**
     * Open a reparse point and bypass normal reparse point processing
     */
    public static final int FILE_OPEN_REPARSE_POINT = 0x200000;
    /**
     * Open does not cause an opportunistic lock break for the file
     */

    * The router dependencies are executed first, then the [`dependencies` in the decorator](dependencies/dependencies-in-path-operation-decorators.md){.internal-link target=_blank}, and then the normal parameter dependencies.
    * You can also add [`Security` dependencies with `scopes`](../advanced/security/oauth2-scopes.md){.internal-link target=_blank}.

/// tip

            path = "../";
        }
        out.println(dirCount + fileCount + " objects (" + dirCount + " directories, " + fileCount + " files)<br>");
        out.println("<b><a class=\"plain\" href=\".\">normal</a> | <a class=\"plain\" href=\"?fmt=detail\">detailed</a></b>");
        out.println("<p><table border='0' cellspacing='0' cellpadding='0'><tr><td>");

        out.print("<A style=\"width: " + maxLen);

  fun nextFrame(
    requireSettings: Boolean,
    handler: Handler,
  ): Boolean {
    try {
      source.require(9) // Frame header size.
    } catch (e: EOFException) {
      return false // This might be a normal socket close.
    }

    //  0                   1                   2                   3
    //  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1