@callback_router3.get("/")
async def callback3(level3: str):
    pass  # pragma: nocover


callback_router4 = APIRouter()


@callback_router4.get("/")
async def callback4(level4: str):
    pass  # pragma: nocover


callback_router5 = APIRouter()


@callback_router5.get("/")
async def callback5(level5: str):
    pass  # pragma: nocover


app = FastAPI(
    dependencies=[Depends(dep0)],

        and:
        1 * callback1.run() >> { throw ex1 }
        1 * callback2.run() >> { throw ex2 }
        1 * callback3.run()
    }

    def 'removed callback is not notified'() {
        def token = new DefaultBuildCancellationToken()

        def callback = Mock(Runnable)
        token.addCallback(callback)
        token.removeCallback(callback)

        when:
        token.cancel()

	var callbacks []*callback
	removedMap := map[string]bool{}
	for _, callback := range p.callbacks {
		if callback.match == nil || callback.match(p.db) {
			callbacks = append(callbacks, callback)
		}
		if callback.remove {
			removedMap[callback.name] = true
		}
	}

	if len(removedMap) > 0 {
		callbacks = removeCallbacks(callbacks, removedMap)
	}
	p.callbacks = callbacks

	createCallback.Clauses = config.CreateClauses

	queryCallback := db.Callback().Query()
	queryCallback.Register("gorm:query", Query)
	queryCallback.Register("gorm:preload", Preload)
	queryCallback.Register("gorm:after_query", AfterQuery)
	queryCallback.Clauses = config.QueryClauses

	deleteCallback := db.Callback().Delete()
	deleteCallback.Match(enableTransaction).Register("gorm:begin_transaction", BeginTransaction)

### Einen Callback-`APIRouter` erstellen

Erstellen Sie zunächst einen neuen `APIRouter`, der einen oder mehrere Callbacks enthält.

```Python hl_lines="3  25"
{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

### Die Callback-*Pfadoperation* erstellen

### Create a callback `APIRouter`

First create a new `APIRouter` that will contain one or more callbacks.

```Python hl_lines="3  25"
{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

### Create the callback *path operation*

To create the callback *path operation* use the same `APIRouter` you created above.

It should look just like a normal FastAPI *path operation*:

	for i := 0; i < P; i++ {
		go func() {
			grow()
			done <- true
		}()
	}
	for i := 0; i < P; i++ {
		<-done
	}
	// now give these stack frames to cgo callbacks
	for i := 0; i < P; i++ {
		go func() {
			C.foo()
			done <- true
		}()
	}
	for i := 0; i < P; i++ {
		<-done
	}

	if e := extraMInUse.Load(); e != 0 {

// compiled with gcc via crosscall2.

// The declaration of crosscall2 is:
//   void crosscall2(void (*fn)(void *), void *, int);
//
// We need to export the symbol crosscall2 in order to support
// callbacks from shared libraries. This applies regardless of
// linking mode.
//
// Compatibility note: SWIG uses crosscall2 in exactly one situation:
// to call _cgo_panic using the pattern shown below. We need to keep

👉 ☝ 👆 ✔️ *⏲ ➡ 🛠️(Ⓜ)* 💪 (1️⃣(Ⓜ) 👈 *🔢 👩‍💻* 🔜 🛠️ *🔢 🛠️*) ⏲ 📻 👆 ✍ 🔛.

🔜 ⚙️ 🔢 `callbacks` *👆 🛠️ ➡ 🛠️ 👨‍🎨* 🚶‍♀️ 🔢 `.routes` (👈 🤙 `list` 🛣/*➡ 🛠️*) ⚪️➡️ 👈 ⏲ 📻:

```Python hl_lines="35"
{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

!!! tip
    👀 👈 👆 🚫 🚶‍♀️ 📻 ⚫️ (`invoices_callback_router`) `callback=`, ✋️ 🔢 `.routes`, `invoices_callback_router.routes`.

### ✅ 🩺

    e: IOException,
  )

  /**
   * Called when the HTTP response was successfully returned by the remote server. The callback may
   * proceed to read the response body with [Response.body]. The response is still live until its
   * response body is [closed][ResponseBody]. The recipient of the callback may consume the response
   * body on another thread.
   *