# 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('/')

                        },
                    }
                }
            },
            "required": True,
        },
    },
)
async def create_item(request: Request):
    raw_body = await request.body()
    data = magic_data_reader(raw_body)

import time

from fastapi import FastAPI, Request

app = FastAPI()


@app.middleware("http")
async def add_process_time_header(request: Request, call_next):
    start_time = time.time()
    response = await call_next(request)
    process_time = time.time() - start_time
    response.headers["X-Process-Time"] = str(process_time)

import pytest
from httpx import AsyncClient

from .main import app


@pytest.mark.anyio
async def test_root():
    async with AsyncClient(app=app, base_url="http://test") as ac:
        response = await ac.get("/")
    assert response.status_code == 200

                doLast {
                  startLatch.countDown() // allow b to finish
                  stopLatch.await() // wait for d to start
                }
              }
            }

            project(":b") {
              task t {
                doLast {
                  startLatch.await() // wait for a to start
                }
              }
            }

            client.connection.connect()
            client.outgoingService1.doStuff("from client 1")
            client.outgoingService1.doStuff("from client 2")
        }
        received.await()
        client.stop()
        server.stop()

        then:
        1 * serverService.doStuff("from client 1")
        1 * serverService.doStuff("from client 2") >> { received.countDown() }

            }
        }

        // Wait for all asynchronous work submitted to this queue to complete before continuing
        workQueue.await()
        logger.lifecycle("Created ${outputDir.get().asFile.listFiles().size} reversed files in ${outputDir.get().asFile.toRelativeString(projectLayout.projectDirectory.asFile)}")
        // end::wait-for-completion[]
    }
}

        "requestBody": {
            "content": {"application/x-yaml": {"schema": Item.schema()}},
            "required": True,
        },
    },
)
async def create_item(request: Request):
    raw_body = await request.body()
    try:
        data = yaml.safe_load(raw_body)
    except yaml.YAMLError:
        raise HTTPException(status_code=422, detail="Invalid YAML")
    try:
        item = Item.parse_obj(data)

    }

    @Override
    public void await() throws InterruptedException {
      lock.lock();
      try {
        condition.await();
      } finally {
        lock.unlock();
      }
    }

    @Override
    public boolean await(long time, TimeUnit unit) throws InterruptedException {
      lock.lock();
      try {
        return condition.await(time, unit);
      } finally {

 * limitations under the License.
 */

package org.gradle.kotlin.dsl.concurrent

import org.awaitility.Duration.ONE_SECOND
import org.awaitility.kotlin.atMost
import org.awaitility.kotlin.await
import org.awaitility.kotlin.untilNotNull

import org.gradle.kotlin.dsl.support.useToRun

import org.hamcrest.CoreMatchers.equalTo
import org.hamcrest.CoreMatchers.instanceOf