你和你的戀人去速食店，排隊等候時，收銀員正在幫排在你前面的人點餐。😍

<img src="/img/async/concurrent-burgers/concurrent-burgers-01.png" class="illustration">

輪到你了，你給你與你的戀人點了兩個豪華漢堡。🍔🍔

<img src="/img/async/concurrent-burgers/concurrent-burgers-02.png" class="illustration">

收銀員通知廚房準備你的漢堡（儘管他們還在為前面其他顧客準備食物）。

<img src="/img/async/concurrent-burgers/concurrent-burgers-03.png" class="illustration">

之後你完成付款。💸

收銀員給你一個號碼牌。

你和你的恋人一起去快餐店，你排队在后面，收银员从你前面的人接单。😍

<img src="/img/async/concurrent-burgers/concurrent-burgers-01.png" class="illustration">

然后轮到你了，你为你的恋人和你选了两个非常豪华的汉堡。🍔🍔

<img src="/img/async/concurrent-burgers/concurrent-burgers-02.png" class="illustration">

收银员对厨房里的厨师说了一些话，让他们知道他们必须为你准备汉堡（尽管他们目前正在为之前的顾客准备汉堡）。

<img src="/img/async/concurrent-burgers/concurrent-burgers-03.png" class="illustration">

你付钱了。 💸

收银员给你轮到的号码。

```Python hl_lines="1"
async def get_burgers(number: int):
    # Do some asynchronous stuff to create the burgers
    return burgers
```

...`def`를 사용하는 대신:

```Python hl_lines="2"
# This is not asynchronous
def get_sequential_burgers(number: int):
    # Do some sequential stuff to create the burgers
    return burgers
```

```Python
# get_burgersはasync defで定義されているので動作しない
burgers = get_burgers(2)
```

---

したがって、 `await` で呼び出すことができるライブラリを使用している場合は、次のように `async def` を使用して、それを使用する*path operation 関数*を作成する必要があります:

```Python hl_lines="2-3"
@app.get('/burgers')
async def read_burgers():
    burgers = await get_burgers(2)
    return burgers
```

### より発展的な技術詳細

`await` は `async def` で定義された関数内でのみ使用できることがわかったかと思います。

* ✨ Add illustrations for Concurrent burgers and Parallel burgers. PR [#5277](https://github.com/tiangolo/fastapi/pull/5277) by [@tiangolo](https://github.com/tiangolo). Updated docs at: [Concurrency and Burgers](https://fastapi.tiangolo.com/async/#concurrency-and-burgers).

### Translations

            buffers.add(buffer);
        }

        // When - Release all buffers back
        for (byte[] buffer : buffers) {
            BufferCache.releaseBuffer(buffer);
        }

        // Then - Should be able to get buffers again
        byte[] newBuffer = BufferCache.getBuffer();

        "/items/",
        headers={"X-Token": "coneofsilence"},
        json={"id": "foobar", "title": "Foo Bar", "description": "The Foo Barters"},
    )
    assert response.status_code == 200
    assert response.json() == {
        "id": "foobar",
        "title": "Foo Bar",
        "description": "The Foo Barters",
    }


def test_create_item_bad_token():
    response = client.post(
        "/items/",

	go func() {
		for {
			rb.Read(buf)
		}
	}()

	for b.Loop() {
		rb.Write(data)
	}
}

func BenchmarkRingBuffer_AsyncReadBlocking(b *testing.B) {
	const sz = 512
	const buffers = 10
	rb := New(sz * buffers)
	rb.SetBlocking(true)
	data := []byte(strings.Repeat("a", sz))
	buf := make([]byte, sz)

	go func() {
		for {
			rb.Read(buf)
		}
	}()

	for b.Loop() {
		rb.Write(data)
	}

package cmd

import (
	"context"
)

const (
	memTotal     = "total"
	memUsed      = "used"
	memFree      = "free"
	memBuffers   = "buffers"
	memCache     = "cache"
	memUsedPerc  = "used_perc"
	memShared    = "shared"
	memAvailable = "available"
)

var (
	memTotalMD     = NewGaugeMD(memTotal, "Total memory on the node")

        // When & Then
        assertDoesNotThrow(() -> {
            mockBufferCache.releaseBuffer(buffer);
        }, "releaseBuffer should handle valid buffers");
    }

    @Test
    @DisplayName("getBuffer should return buffers for use")
    void testGetBufferBasicUsage() {
        // When
        byte[] buffer1 = testCache.getBuffer();
        byte[] buffer2 = testCache.getBuffer();

        // Then