🌾 💲 ⚫️❔ 💉 🔘 *➡ 🛠️* & 🎏 🔗:

{* ../../docs_src/dependencies/tutorial007.py hl[4] *}

📟 📄 `yield` 📄 🛠️ ⏮️ 📨 ✔️ 🚚:

{* ../../docs_src/dependencies/tutorial007.py hl[5:6] *}

/// tip

👆 💪 ⚙️ `async` ⚖️ 😐 🔢.

**FastAPI** 🔜 ▶️️ 👜 ⏮️ 🔠, 🎏 ⏮️ 😐 🔗.

///

## 🔗 ⏮️ `yield` & `try`

🚥 👆 ⚙️ `try` 🍫 🔗 ⏮️ `yield`, 👆 🔜 📨 🙆 ⚠ 👈 🚮 🕐❔ ⚙️ 🔗.

package stmt_store

import (
	"context"
	"database/sql"
	"math"
	"sync"
	"time"

	"gorm.io/gorm/internal/lru"
)

type Stmt struct {
	*sql.Stmt
	Transaction bool
	prepared    chan struct{}
	prepareErr  error
}

func (stmt *Stmt) Error() error {
	return stmt.prepareErr
}

func (stmt *Stmt) Close() error {
	<-stmt.prepared

	if stmt.Stmt != nil {
		return stmt.Stmt.Close()
	}
	return nil

<details markdown="1">
<summary>Or use <code>async def</code>...</summary>

If your code uses `async` / `await`, use `async def`:

```Python hl_lines="9  14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
async def read_item(item_id: int, q: Union[str, None] = None):

    // ThreadLocal is not available to GWT, so we always reuse the same
    // instance.  It is always safe to return the same instance because
    // javascript is single-threaded, and only used by blocks that doesn't
    // involve async callbacks.
    return CHAR_BUFFER;
  }

  private Platform() {}

```java
import org.codelibs.curl.Curl;

Curl.post("https://api.example.com/items")
    .body("{\"name\":\"item1\"}")
    .header("Content-Type", "application/json")
    .execute(
        response -> System.out.println("Async status: " + response.getHttpStatusCode()),
        error -> error.printStackTrace());
```

## API Overview

- `org.codelibs.curl.Curl`: entry point for HTTP methods (GET, POST, PUT, DELETE, HEAD, OPTIONS, CONNECT, TRACE).

//go:build unix

package tar

import (
	"io/fs"
	"os/user"
	"runtime"
	"strconv"
	"sync"
	"syscall"
)

func init() {
	sysStat = statUnix
}

// userMap and groupMap caches UID and GID lookups for performance reasons.
// The downside is that renaming uname or gname by the OS never takes effect.
var userMap, groupMap sync.Map // map[int]string

func statUnix(fi fs.FileInfo, h *Header, doNameLookups bool) error {

package clause_test

import (
	"sync"
	"testing"

	"gorm.io/gorm"
	"gorm.io/gorm/clause"
	"gorm.io/gorm/schema"
	"gorm.io/gorm/utils/tests"
)

func TestJoin(t *testing.T) {
	results := []struct {
		name string
		join clause.Join
		sql  string
	}{
		{
			name: "LEFT JOIN",
			join: clause.Join{
				Type:  clause.LeftJoin,
				Table: clause.Table{Name: "user"},
				ON: clause.Where{

package gorm

import (
	"context"
	"database/sql"
	"database/sql/driver"
	"errors"
	"reflect"
	"sync"
	"time"

	"gorm.io/gorm/internal/stmt_store"
)

type PreparedStmtDB struct {
	Stmts stmt_store.Store
	Mux   *sync.RWMutex
	ConnPool
}

// NewPreparedStmtDB creates and initializes a new instance of PreparedStmtDB.
//
// Parameters:

	Cache             map[string]*BucketReplicationStats
	mostRecentStats   BucketStatsMap
	registry          metrics.Registry
	sync.RWMutex                 // mutex for Cache
	mostRecentStatsMu sync.Mutex // mutex for mostRecentStats

	wlock sync.RWMutex // mutex for active workers

	movingAvgTicker *time.Ticker // Ticker for calculating moving averages

It is just a standard function that can receive parameters.

It can be an `async def` or normal `def` function, **FastAPI** will know how to handle it correctly.

In this case, the task function will write to a file (simulating sending an email).

And as the write operation doesn't use `async` and `await`, we define the function with normal `def`:

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}