continue@eachQueue
          }

          // If we already have more than one task, that's enough work for now. Stop searching.
          readyTask != null -> {
            multipleReadyTasks = true
            break@eachQueue
          }

          // We have a task to execute when we complete the loop.
          else -> {
            readyTask = candidate
          }

    taskRunner.lock.withLock {
      check(currentTask == TestThreadSerialTask)
      nanoTime = newTime
      yieldUntil(ResumePriority.AfterOtherTasks)
    }
  }

  /** Confirm all tasks have completed. Used by the test thread only. */
  fun assertNoMoreTasks() {
    taskRunner.assertThreadDoesntHoldLock()

    taskRunner.lock.withLock {
      assertThat(activeThreads).isEqualTo(0)
    }
  }

      "FINE: Q10000 scheduled after 100 µs: task",
      "FINE: Q10000 starting              : task",
      "FINE: Q10000 finished run in   0 µs: task",
    )
  }

  /** Inspect how many runnables have been enqueued. If none then we're truly sequential. */
  @Test fun singleQueueIsSerial() {
    redQueue.execute("task one", 100.µs) {
      log += "one:run@${taskFaker.nanoTime} parallel=${taskFaker.isParallel}"
    }