unsupported/test/cxx11_tensor_notification.cpp

// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2015 Vijay Vasudevan <vrv@google.com>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#define EIGEN_USE_THREADS

#include <atomic>

#include <stdlib.h>
#include "main.h"
#include <Eigen/CXX11/Tensor>

static void test_notification_single() {
  ThreadPool thread_pool(1);

  std::atomic<int> counter(0);
  Eigen::Notification n;
  auto func = [&n, &counter]() {
    n.Wait();
    ++counter;
  };
  thread_pool.Schedule(func);
  std::this_thread::sleep_for(std::chrono::milliseconds(1000));

  // The thread should be waiting for the notification.
  VERIFY_IS_EQUAL(counter, 0);

  // Unblock the thread
  n.Notify();

  std::this_thread::sleep_for(std::chrono::milliseconds(1000));

  // Verify the counter has been incremented
  VERIFY_IS_EQUAL(counter, 1);
}

// Like test_notification_single() but enqueues multiple threads to
// validate that all threads get notified by Notify().
static void test_notification_multiple() {
  ThreadPool thread_pool(1);

  std::atomic<int> counter(0);
  Eigen::Notification n;
  auto func = [&n, &counter]() {
    n.Wait();
    ++counter;
  };
  thread_pool.Schedule(func);
  thread_pool.Schedule(func);
  thread_pool.Schedule(func);
  thread_pool.Schedule(func);
  std::this_thread::sleep_for(std::chrono::milliseconds(1000));
  VERIFY_IS_EQUAL(counter, 0);
  n.Notify();
  std::this_thread::sleep_for(std::chrono::milliseconds(1000));
  VERIFY_IS_EQUAL(counter, 4);
}

EIGEN_DECLARE_TEST(cxx11_tensor_notification) {
  CALL_SUBTEST(test_notification_single());
  CALL_SUBTEST(test_notification_multiple());
}