# 並行処理と async / await

*path operation 関数*のための `async def` に関する詳細と非同期 (asynchronous) コード、並行処理 (Concurrency)、そして、並列処理 (Parallelism) の背景について。

## 急いでいますか？

<abbr title="too long; didn't read (長すぎて読めない人のための要約という意味のスラング)"><strong>TL;DR:</strong></abbr>

次のような、`await` を使用して呼び出すべきサードパーティライブラリを使用している場合:

```Python
results = await some_library()
```

以下の様に `async def` を使用して*path operation 関数*を宣言します。

```Python hl_lines="2"
@app.get('/')

      // (in startSignal.await()), and the others waiting for that thread's result.
      while (thread.isAlive() && thread.getState() != Thread.State.WAITING) {
        Thread.yield();
      }
    }
    gettersStartedSignal.countDown();
    gettersComplete.await();

    List<Object> resultList = Lists.newArrayListWithExpectedSize(nThreads);

  const repo = context.payload.repository.name;
  console.log(`Original PR: ${pr_number} and Rollback Commit: ${rollback_commit}`);
  // Get the Original PR Details
  const pr_resp = await github.rest.pulls.get({
    owner,
    repo,
    pull_number: pr_number
  });
  if (pr_resp.status != 200 || pr_resp.data.state != 'closed') {

* `seek(offset)`: Goes to the byte position `offset` (`int`) in the file.
    * E.g., `await myfile.seek(0)` would go to the start of the file.
    * This is especially useful if you run `await myfile.read()` once and then need to read the contents again.
* `close()`: Closes the file.

As all these methods are `async` methods, you need to "await" them.

For example, inside of an `async` *path operation function* you can get the contents with:

      throw RuntimeException("boom!")
    }

    queue.schedule("task", TimeUnit.MILLISECONDS.toNanos(200)) {
      log.put("normal task running")
      return@schedule -1L
    }

    queue.idleLatch().await(500, TimeUnit.MILLISECONDS)

    assertThat(log.take()).isEqualTo("failing task running")
    assertThat(log.take()).isEqualTo("uncaught exception: java.lang.RuntimeException: boom!")

        content={"detail": jsonable_encoder(exc.errors())},
    )


async def websocket_request_validation_exception_handler(
    websocket: WebSocket, exc: WebSocketRequestValidationError
) -> None:
    await websocket.close(
        code=WS_1008_POLICY_VIOLATION, reason=jsonable_encoder(exc.errors())

 * Object x = new MyClass() {
 *   ...
 *   protected void finalize() { latch.countDown(); ... }
 * };
 * x = null;  // Hint to the JIT that x is stack-unreachable
 * GcFinalization.await(latch);
 * }</pre>
 *
 * <p>Here's an example that uses a user-defined finalization predicate:
 *
 * <pre>{@code
 * final WeakHashMap<Object, Object> map = new WeakHashMap<>();
 * map.put(new Object(), Boolean.TRUE);

import pytest

from docs_src.async_tests.test_main import test_root


@pytest.mark.anyio
async def test_async_testing():

  //      */
  //     public void await(AtomicBoolean flag) {
  //         await(flag, LONG_DELAY_MS);
  //     }

  //     /**
  //      * Spin-waits up to the specified timeout until flag becomes true.
  //      */
  //     public void await(AtomicBoolean flag, long timeoutMillis) {
  //         long startTime = System.nanoTime();
  //         while (!flag.get()) {

          inetSocketAddress: InetSocketAddress,
          proxy: Proxy,
        ) {
          try {
            // Wait for request2 to guarantee we make 2 separate connections to the server.
            latch1.await()
          } catch (e: InterruptedException) {
            throw AssertionError(e)
          }
        }

        override fun connectionAcquired(
          call: Call,
          connection: Connection,