var wg sync.WaitGroup
	for i := 0; i < 5; i++ {
		wg.Add(1)
		go func(i int) {
			defer wg.Done()
			var buf [1]byte
			r.ReadAt(buf[:], int64(i))
		}(i)
	}
	wg.Wait()
}

func TestEmptyReaderConcurrent(t *testing.T) {
	// Test for the race detector, to verify a Read that doesn't yield any bytes
	// is okay to use from multiple goroutines. This was our historic behavior.

MC_CONFIG_DIR="{{ .Values.configPathmc }}"
MC="/usr/bin/mc --insecure --config-dir ${MC_CONFIG_DIR}"
{{- else }}
MC="/usr/bin/mc --insecure"
{{- end }}

# connectToMinio
# Use a check-sleep-check loop to wait for MinIO service to be available
connectToMinio() {
	SCHEME=$1
	ATTEMPTS=0
	LIMIT=29 # Allow 30 attempts
	set -e   # fail if we can't read the keys.
	ACCESS=$(cat /config/rootUser)
	SECRET=$(cat /config/rootPassword)

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_py310.py hl[6:9] *}

## Add the background task { #add-the-background-task }

   同樣地，你可以把 `dataclasses` 與標準型別註記組合使用。
8. 注意這個「路徑操作函式」使用的是一般的 `def` 而非 `async def`。

   一如往常，在 FastAPI 中你可以視需要混用 `def` 與 `async def`。

   如果需要複習何時用哪個，請參考文件中關於 [`async` 與 `await`](../async.md#in-a-hurry) 的章節「In a hurry?」。
9. 這個「路徑操作函式」回傳的不是 dataclass（雖然也可以），而是一個包含內部資料的字典清單。

   FastAPI 會使用 `response_model` 參數（其中包含 dataclass）來轉換回應。

你可以把 `dataclasses` 與其他型別註記以多種方式組合，形成複雜的資料結構。

  /**
   * Asserts that a prior call that had caused this thread to block or wait has since returned
   * normally.
   */
  public void assertPriorCallReturns(@Nullable String methodName) throws Exception {
    assertThat(getResponse(methodName).getResult()).isNull();
  }

  /**
   * Asserts that a prior call that had caused this thread to block or wait has since returned the
   * expected boolean value.
   */

                } finally {
                    latch.countDown();
                }
            });
        }

        assertTrue(latch.await(10, TimeUnit.SECONDS));
        executor.shutdown();
    }

    @Test
    @DisplayName("Test invalid session ID handling")
    public void testInvalidSessionIdHandling() {

# Special characters for example : ',",<,>,{,}
MINIO_ACCESSKEY_SECRETKEY_TMP="/tmp/accessKey_and_secretKey_svcacct_tmp"

# connectToMinio
# Use a check-sleep-check loop to wait for MinIO service to be available
connectToMinio() {
  SCHEME=$1
  ATTEMPTS=0 ; LIMIT=29 ; # Allow 30 attempts
  set -e ; # fail if we can't read the keys.

}

// TryLockedOpenFile - tries a new write lock, functionality
// it is similar to LockedOpenFile with with syscall.LOCK_EX
// mode but along with syscall.LOCK_NB such that the function
// doesn't wait forever but instead returns if it cannot
// acquire a write lock.
func TryLockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
	return lockedOpenFile(path, flag, perm, syscall.LOCK_NB)
}

        };

        InputStreamThread thread = new InputStreamThread(is, StandardCharsets.UTF_8, 100, callback);
        thread.start();

        assertTrue("Should process all lines within timeout", latch.await(3, TimeUnit.SECONDS));

        thread.join(1000);

        assertEquals("All lines should be processed", 5000, receivedLines.size());
        assertEquals("First line", "Line number 0", receivedLines.get(0));

```Python
with open("file.txt") as file:
    file.read()
```

最近の Python には「非同期コンテキストマネージャ」もあります。`async with` で使います:

```Python
async with lifespan(app):
    await do_stuff()
```

このようにコンテキストマネージャ（または非同期コンテキストマネージャ）を作ると、`with` ブロックに入る前に `yield` より前のコードが実行され、`with` ブロックを出た後に `yield` より後ろのコードが実行されます。

上のコード例では直接それを使ってはいませんが、FastAPI に渡して内部で使ってもらいます。