plan.then(segment);
            }

            // Create plan, setup and teardown
            for (MavenProject project : plan.getAllProjects().keySet()) {
                BuildStep pplan = new BuildStep(PLAN, project, null);
                pplan.status.set(PLANNING); // the plan step always need planning

{* ../../docs_src/background_tasks/tutorial002.py hl[13,15,22,25] *}

Dans cet exemple, les messages seront écrits dans le fichier `log.txt` après que la réponse soit envoyée.

S'il y avait une `query` (paramètre nommé `q`) dans la requête, alors elle sera écrite dans `log.txt` via une tâche d'arrière-plan.

    if (plan is FailedPlan) return plan.result

    // Connect TCP asynchronously.
    tcpConnectsInFlight += plan
    val taskName = "$okHttpName connect ${routePlanner.address.url.redact()}"
    taskRunner.newQueue().schedule(
      object : Task(taskName) {
        override fun runOnce(): Long {
          val connectResult =
            try {
              plan.connectTcp()

    fun handleSuccess(): RealConnection

    fun cancel()

    /**
     * Returns a plan to attempt if canceling this plan was a mistake! The returned plan is not
     * canceled, even if this plan is canceled.
     */
    fun retry(): Plan?
  }

  /**
   * What to do once a plan has executed.
   *
   * If [nextPlan] is not-null, another attempt should be made by following it. If [throwable] is

    public void writePlan(BuildPlan plan) {
        if (logger.isDebugEnabled()) {
            writePlan(logger::debug, plan);
        }
    }

    public void writePlan(BuildPlan plan, MavenProject project) {
        if (logger.isDebugEnabled()) {
            writePlan(logger::debug, plan, project);
        }
    }

    public void writePlan(Consumer<String> writer, BuildPlan plan) {

        return plan.keySet().stream();
    }

    public void addProject(MavenProject project, Map<String, BuildStep> steps) {
        plan.put(project, steps);
    }

    public void addStep(MavenProject project, String name, BuildStep step) {
        plan.get(project).put(name, step);
    }

    public Stream<BuildStep> allSteps() {
        return plan.values().stream().flatMap(m -> m.values().stream());

  private val call: RealCall,
  private val routePlanner: RealRoutePlanner,
  // Specifics to this plan.
  override val route: Route,
  internal val routes: List<Route>?,
  private val attempt: Int,
  private val tunnelRequest: Request?,
  internal val connectionSpecIndex: Int,
  internal val isTlsFallback: Boolean,
) : RoutePlanner.Plan,
  ExchangeCodec.Carrier {
  /** True if this connect was canceled; typically because it lost a race. */

        canceled -> {
          events += "plan $id TCP connect canceled"
          ConnectResult(this, nextPlan = connectTcpNextPlan, throwable = IOException("canceled"))
        }
        connectTcpNextPlan != null -> {
          events += "plan $id needs follow-up"
          ConnectResult(this, nextPlan = connectTcpNextPlan)
        }
        else -> {
          events += "plan $id TCP connected"

        // There is only a single threadsafe plugin here...
        assertEquals(plan.size() - 1, unSafePlugins.size());
    }

    @Test
    void testFindLastWhenFirst() throws Exception {
        MavenExecutionPlan plan = LifecycleExecutionPlanCalculatorStub.getProjectAExecutionPlan();

        ExecutionPlanItem beerPhase = plan.findLastInPhase(

  private var routeSelector: RouteSelector? = null
  private var nextRouteToTry: Route? = null

  override val deferredPlans = ArrayDeque<Plan>()

  override fun isCanceled(): Boolean = call.isCanceled()

  @Throws(IOException::class)
  override fun plan(): Plan {
    val reuseCallConnection = planReuseCallConnection()
    if (reuseCallConnection != null) return reuseCallConnection