}
  }

  /**
   * Returns an immediately-executable task for the calling thread to execute, sleeping as necessary
   * until one is ready. If there are no ready queues, or if other threads have everything under
   * control this will return null. If there is more than a single task ready to execute immediately
   * this will start another thread to handle that work.
   */
  fun awaitTaskToRun(): Task? {
    lock.assertHeld()

    factory.close()
  }

  inner class FakePlan(
    val id: Int,
  ) : RoutePlanner.Plan {
    var planningThrowable: Throwable? = null
    var canceled = false
    var connectState = ConnectState.READY
    val connection =
      factory.newConnection(
        pool = pool,
        route = factory.newRoute(address),
        idleAtNanos = defaultConnectionIdleAtNanos,
      )
    var retry: FakePlan? = null

      },
      logger = logger,
    )

  /** Runs all tasks that are ready. Used by the test thread only. */
  fun runTasks() {
    advanceUntil(nanoTime)
  }

  /** Advance the simulated clock, then runs tasks that are ready. Used by the test thread only. */
  fun advanceUntil(newTime: Long) {
    taskRunner.assertThreadDoesntHoldLock()

        it.stageName in listOf(
            StageName.QUICK_FEEDBACK_LINUX_ONLY,
            StageName.QUICK_FEEDBACK,
            StageName.PULL_REQUEST_FEEDBACK,
            StageName.READY_FOR_NIGHTLY,
        )
    }.flatMap { it.functionalTests }.filter { it.os == os }

    if (os == Os.LINUX) {
        steps {
            script {

    }

    var prevStage: Stage? = null
    val previousPerformanceTestPasses: MutableList<PerformanceTestsPass> = mutableListOf()
    model.stages.forEach { stage ->
        if (isSecurityFork() && stage.stageName > StageName.READY_FOR_RELEASE) {
            return@forEach
        }
        val stageProject = StageProject(model, functionalTestBucketProvider, performanceTestBucketProvider, stage, previousPerformanceTestPasses)

              TimeUnit.SECONDS,
              SynchronousQueue(),
              threadFactory("$okHttpName Dispatcher", false),
            )
        }
        return executorServiceOrNull!!
      }

  /** Ready async calls in the order they'll be run. */
  private val readyAsyncCalls = ArrayDeque<AsyncCall>()

  /** Running asynchronous calls. Includes canceled calls that haven't finished yet. */

For production you would use `fastapi run` instead. 🚀

Internally, **FastAPI CLI** uses <a href="https://www.uvicorn.org" class="external-link" target="_blank">Uvicorn</a>, a high-performance, production-ready, ASGI server. 😎

## `fastapi dev`

When you run `fastapi dev`, it will run on development mode.

## In a hurry?

<abbr title="too long; didn't read"><strong>TL;DR:</strong></abbr>

If you are using third party libraries that tell you to call them with `await`, like:

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

Then, declare your *path operation functions* with `async def` like:

```Python hl_lines="2"
@app.get('/')
async def read_results():
    results = await some_library()
    return results

<summary>About the command <code>fastapi dev main.py</code>...</summary>

The command `fastapi dev` reads your `main.py` file, detects the **FastAPI** app in it, and starts a server using <a href="https://www.uvicorn.org" class="external-link" target="_blank">Uvicorn</a>.

By default, `fastapi dev` will start with auto-reload enabled for local development.

    // Close the raw socket so we don't end up doing synchronous I/O.
    rawSocket?.closeQuietly()
  }

  override fun socket(): Socket = socket!!

  /** Returns true if this connection is ready to host new streams. */
  fun isHealthy(doExtensiveChecks: Boolean): Boolean {
    lock.assertNotHeld()

    val nowNs = System.nanoTime()

    val rawSocket = this.rawSocket!!
    val socket = this.socket!!