/// tip | İpucu

Sonraki bölümler **mutlaka "gelişmiş" olmak zorunda değildir**.

Kullanım şeklinize bağlı olarak, çözümünüz bu bölümlerden birinde olabilir.

///

## Önce Öğreticiyi Okuyun

[Tutorial - User Guide](../tutorial/index.md){.internal-link target=_blank} sayfasındaki bilgilerle **FastAPI**'nın çoğu özelliğini kullanabilirsiniz.

   * segments, each governed by its own write lock. The segment lock is taken once for each explicit
   * write, and twice for each cache loading computation (once prior to loading the new value, and
   * once after loading completes). Much internal cache management is performed at the segment

#   DefaultVersionResolverRequest    - Version resolution results (session/soft, less critical than artifacts)
#   RgavCacheKey                     - BOM import caching (session/soft, typically resolved once)
#   DefaultModelBuilderRequest       - Model building operations (none, ensures fresh dynamic builds)
#   *                                - Fallback for all other requests (request/soft for temporary child request caching)
#

This provider might be charging you per request, and calling it might take some extra time than if you had a fixed mock user for tests.

You probably want to test the external provider once, but not necessarily call it for every test that runs.

In this case, you can override the dependency that calls that provider, and use a custom dependency that returns a mock user, only for your tests.

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

## Query Parameters with a Pydantic Model { #query-parameters-with-a-pydantic-model }

      // If the worker is not yet running, the delegate Executor might reject our attempt to start
      // it. To preserve FIFO order and failure atomicity of rejected execution when the same
      // Runnable is executed more than once, allocate a wrapper that we know is safe to remove by
      // object identity.
      // A data structure that returned a removal handle from add() would allow eliminating this
      // allocation.
      submittedTask =

      // If the worker is not yet running, the delegate Executor might reject our attempt to start
      // it. To preserve FIFO order and failure atomicity of rejected execution when the same
      // Runnable is executed more than once, allocate a wrapper that we know is safe to remove by
      // object identity.
      // A data structure that returned a removal handle from add() would allow eliminating this
      // allocation.
      submittedTask =

You can define logic (code) that should be executed before the application **starts up**. This means that this code will be executed **once**, **before** the application **starts receiving requests**.

The same way, you can define logic (code) that should be executed when the application is **shutting down**. In this case, this code will be executed **once**, **after** having handled possibly **many requests**.

### Installing xl-meta

To install, [Go](https://golang.org/dl/) must be installed. Once installed, execute this to install the binary:

```bash
go install github.com/minio/minio/docs/debugging/xl-meta@latest
```

### Using xl-meta

	// wait for sys.boot_completed.
	if err := adb("wait-for-device", "exec-out", "while [[ -z $(getprop sys.boot_completed) ]]; do sleep 1; done;"); err != nil {
		return 0, err
	}

	// Done once per make.bash.
	if err := adbCopyGoroot(); err != nil {
		return 0, err
	}

	// Prepare a temporary directory that will be cleaned up at the end.
	// Binary names can conflict.