}
    }

    /**
     * Sets the thread pool for executing the request.
     *
     * @param threadPool the thread pool
     * @return this CurlRequest instance
     */
    public CurlRequest threadPool(final ForkJoinPool threadPool) {
        this.threadPool = threadPool;
        return this;
    }

    /**
     * Sets the connection and read timeouts for the request.
     *

        To be awaitable, compatible with async, this is run in threadpool.
        """
        return await super().seek(offset)

    async def close(self) -> None:
        """
        Close the file.

        To be awaitable, compatible with async, this is run in threadpool.
        """
        return await super().close()

    @classmethod

        ForkJoinPool pool1 = new ForkJoinPool(2);
        ForkJoinPool pool2 = new ForkJoinPool(4);

        // Multiple threadPool calls should work
        request.threadPool(pool1);
        request.threadPool(pool2);

        assertNotNull(request);
    }

    @Test
    public void testOnConnectWithNull() {

        ForkJoinPool pool = new ForkJoinPool(1);
        req.threadPool(pool);

        // ## Act ##
        // execute() should force synchronous execution but restore threadPool afterward
        try (CurlResponse response = req.execute()) {
            assertEquals(200, response.getHttpStatusCode());
        }

        // ## Assert ##
        // After execute(), the threadPool should be restored

    ExecutorService threadPool = newFixedThreadPool(nThreads);
    CountDownLatch tasksFinished = new CountDownLatch(nTasks);
    for (int i = 0; i < nTasks; i++) {
      String s = "a" + i;
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
      Future<?> possiblyIgnoredError =
          threadPool.submit(
              () -> {

    ExecutorService threadPool = newFixedThreadPool(nThreads);
    CountDownLatch tasksFinished = new CountDownLatch(nTasks);
    for (int i = 0; i < nTasks; i++) {
      String s = "a" + i;
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
      Future<?> possiblyIgnoredError =
          threadPool.submit(
              () -> {

而且在許多情況下，讀取它們會是阻塞操作（可能阻塞事件迴圈），因為資料是從磁碟或網路讀取。

/// info

上面的範例其實是例外，因為 `io.BytesIO` 物件已在記憶體中，讀取不會阻塞任何東西。

但在多數情況下，讀取檔案或類檔案物件會造成阻塞。

///

為了避免阻塞事件迴圈，你可以將路徑操作函式宣告為一般的 `def`（而非 `async def`），這樣 FastAPI 會在 threadpool worker 上執行它，避免阻塞主事件迴圈。

{* ../../docs_src/stream_data/tutorial002_py310.py ln[30:34] hl[31] *}

/// tip

如果你需要在 async 函式內呼叫阻塞程式碼，或在阻塞函式中呼叫 async 函式，你可以使用 [Asyncer](https://asyncer.tiangolo.com)，它是 FastAPI 的姊妹函式庫。

common:mkl_threadpool --define=build_with_mkl=true --define=enable_mkl=true
common:mkl_threadpool --define=tensorflow_mkldnn_contraction_kernel=0
common:mkl_threadpool --define=build_with_mkl_opensource=true
common:mkl_threadpool -c opt

# Config setting to build oneDNN with Compute Library for the Arm Architecture (ACL).
# with Eigen threadpool support

這裡是有關 FastAPI 內部技術細節。

如果你有相當多的技術背景（例如協程、執行緒、阻塞等），並且對 FastAPI 如何處理 `async def` 與常規 `def` 感到好奇，請繼續閱讀。

///

### 路徑操作函式 { #path-operation-functions }

當你使用 `def` 而不是 `async def` 宣告*路徑操作函式*時，該函式會在外部的執行緒池（threadpool）中執行，然後等待結果，而不是直接呼叫（因為這樣會阻塞伺服器）。

    // Fesen Client
    //

    /**
     * Gets the thread pool used by the client.
     *
     * @return the thread pool
     */
    @Override
    public ThreadPool threadPool() {
        return client.threadPool();
    }

    /**
     * Gets the admin client for cluster and index administration.
     *
     * @return the admin client
     */
    @Override