Function TEST

cpp/src/arrow/util/async_util_test.cc:46–83

constexpr std::string_view kDummyName = "unit test";

TEST(AsyncTaskScheduler, ShouldScheduleConcurrentTasks) {
  // A basic test to make sure we schedule the right number of concurrent tasks
  constexpr int kMaxConcurrentTasks = 2;
  constexpr int kTotalNumTasks = kMaxConcurrentTasks + 1;
  Future<> futures[kTotalNumTasks];
  bool submitted[kTotalNumTasks];
  Future<> finished = AsyncTaskScheduler::Make([&](AsyncTaskScheduler* scheduler) {
    std::shared_ptr<ThrottledAsyncTaskScheduler> throttled =
        ThrottledAsyncTaskScheduler::Make(scheduler, kMaxConcurrentTasks);
    for (int i = 0; i < kTotalNumTasks; i++) {
      futures[i] = Future<>::Make();
      submitted[i] = false;
      throttled->AddSimpleTask(
          [&, i] {
            submitted[i] = true;
            return futures[i];
          },
          kDummyName);
    }
    return Status::OK();
  });
  AssertNotFinished(finished);
  for (int i = 0; i < kTotalNumTasks; i++) {
    if (i < kMaxConcurrentTasks) {
      ASSERT_TRUE(submitted[i]);
    } else {
      ASSERT_FALSE(submitted[i]);
    }
  }

  for (int j = 0; j < kTotalNumTasks; j++) {
    futures[j].MarkFinished();
    if (j + kMaxConcurrentTasks < kTotalNumTasks) {
      ASSERT_TRUE(submitted[j + kMaxConcurrentTasks]);
    }
  }
  ASSERT_FINISHES_OK(finished);
}

TEST(AsyncTaskScheduler, CancelWaitsForTasksToFinish) {
  StopSource stop_source;