}
  }

  interface Backend {
    fun nanoTime(): Long

    fun coordinatorNotify(taskRunner: TaskRunner)

    fun coordinatorWait(
      taskRunner: TaskRunner,
      nanos: Long,
    )

    fun <T> decorate(queue: BlockingQueue<T>): BlockingQueue<T>

    fun execute(
      taskRunner: TaskRunner,
      runnable: Runnable,
    )
  }

  private var contextSwitchCount = 0

  /** Guarded by [TaskRunner.lock]. */
  private var activeThreads = 0

  /** A task runner that posts tasks to this fake. Tasks won't be executed until requested. */
  val taskRunner: TaskRunner =
    TaskRunner(
      object : TaskRunner.Backend {
        override fun execute(
          taskRunner: TaskRunner,
          runnable: Runnable,
        ) {

    if (isLoom()) {
      val backend = TaskRunner.RealBackend(loomThreadFactory())
      val taskRunner = TaskRunner(backend)

      OkHttpClient.Builder()
        .connectionPool(
          buildConnectionPool(
            connectionListener = connectionListener,
            taskRunner = taskRunner,
          ),
        )
        .dispatcher(Dispatcher(backend.executor))

  private val taskRunner = taskFaker.taskRunner

  /**
   * Note that we don't use the same [TaskFaker] for this factory. That way off-topic tasks like
   * connection pool maintenance tasks don't add noise to route planning tests.
   */
  private val routePlanner = FakeRoutePlanner(taskFaker = taskFaker)
  private val finder = FastFallbackExchangeFinder(routePlanner, taskRunner)

  @AfterEach
  fun tearDown() {

    // Can't allocate once a leak has been detected.
    assertThat(c1.noNewExchanges).isTrue()
  }

  @Test fun interruptStopsThread() {
    val realTaskRunner = TaskRunner.INSTANCE
    val pool =
      factory.newConnectionPool(
        taskRunner = TaskRunner.INSTANCE,
        maxIdleConnections = 2,
      )
    factory.newConnection(pool, routeA1)
    assertThat(realTaskRunner.activeQueues()).isNotEmpty()

    fun newTestConnection(
      taskRunner: TaskRunner,
      connectionPool: RealConnectionPool,
      route: Route,
      socket: Socket,
      idleAtNs: Long,
    ): RealConnection {
      val result =
        RealConnection(
          taskRunner = taskRunner,
          connectionPool = connectionPool,
          route = route,
          rawSocket = null,

import okhttp3.internal.concurrent.TaskQueue
import okhttp3.internal.concurrent.TaskRunner
import okhttp3.internal.connection.Locks.withLock
import okhttp3.internal.connection.RealCall.CallReference
import okhttp3.internal.okHttpName
import okhttp3.internal.platform.Platform
import okio.IOException

class RealConnectionPool(
  private val taskRunner: TaskRunner,
  /**
   * The maximum number of idle connections across all addresses.

 *
 * Each step may fail. If a retry is possible, a new instance is created with the next plan, which
 * will be configured differently.
 */
class ConnectPlan(
  private val taskRunner: TaskRunner,
  private val connectionPool: RealConnectionPool,
  private val readTimeoutMillis: Int,
  private val writeTimeoutMillis: Int,
  private val socketConnectTimeoutMillis: Int,

  /** For scheduling everything asynchronous. */
  private val taskRunner = builder.taskRunner

  /** Asynchronously writes frames to the outgoing socket. */
  private val writerQueue = taskRunner.newQueue()

  /** Ensures push promise callbacks events are sent in order per stream. */
  private val pushQueue = taskRunner.newQueue()

  /** Notifies the listener of settings changes. */

import okhttp3.internal.closeQuietly
import okhttp3.internal.concurrent.TaskRunner
import okhttp3.internal.connection.Locks.withLock
import okhttp3.internal.connection.RoutePlanner.Plan
import okhttp3.internal.platform.Platform
import okhttp3.internal.toHostHeader

class RealRoutePlanner(
  private val taskRunner: TaskRunner,
  private val connectionPool: RealConnectionPool,
  private val readTimeoutMillis: Int,