future_utils_test.cc

Go to the documentation of this file.

 
/*
                          Aleph_w
 
  Data structures & Algorithms
  version 2.0.0b
  https://github.com/lrleon/Aleph-w
 
  This file is part of Aleph-w library
 
  Copyright (c) 2002-2026 Leandro Rabindranath Leon
 
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
 
  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
 
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
*/
 
 
 
#include <gtest/gtest.h>
#include <future>
#include <chrono>
#include <thread>
#include <stdexcept>
#include <atomic>
#include <future_utils.H>
 
using namespace Aleph;
 
// =============================================================================
// Test Fixtures
// =============================================================================
 
class FutureUtilsTest : public ::testing::Test
{
protected:
  // Helper to create a simple async task that returns its input
  static std::future<int> make_int_future(int value)
  {
    return std::async(std::launch::async, [value] { return value; });
  }
 
  // Helper to create a delayed async task
  static std::future<int> make_delayed_future(int value, int delay_ms)
  {
    return std::async(std::launch::async, [value, delay_ms] {
      std::this_thread::sleep_for(std::chrono::milliseconds(delay_ms));
      return value;
    });
  }
 
  // Helper to create a void async task
  static std::future<void> make_void_future()
  {
    return std::async(std::launch::async, [] {});
  }
 
  // Helper to create a void async task that modifies a counter
  static std::future<void> make_void_future_with_effect(std::atomic<int> & counter)
  {
    return std::async(std::launch::async, [&counter] { ++counter; });
  }
 
  // Helper to create a failing async task
  static std::future<int> make_failing_future()
  {
    return std::async(std::launch::async, []() -> int {
      throw std::runtime_error("Test exception");
    });
  }
};
 
// =============================================================================
// Basic get_futures Tests (int)
// =============================================================================
 
TEST_F(FutureUtilsTest, GetFuturesEmptyList)
{
  DynList<std::future<int>> futures;
  auto results = get_futures(futures);
 
  EXPECT_TRUE(results.is_empty());
  EXPECT_TRUE(futures.is_empty());
}
 
TEST_F(FutureUtilsTest, GetFuturesSingleElement)
{
  DynList<std::future<int>> futures;
  futures.append(make_int_future(42));
 
  auto results = get_futures(futures);
 
  EXPECT_EQ(results.size(), 1u);
  EXPECT_EQ(results.get_first(), 42);
  EXPECT_TRUE(futures.is_empty());
}
 
TEST_F(FutureUtilsTest, GetFuturesMultipleElements)
{
  DynList<std::future<int>> futures;
  for (int i = 1; i <= 5; ++i)
    futures.append(make_int_future(i * 10));
 
  auto results = get_futures(futures);
 
  EXPECT_EQ(results.size(), 5u);
  EXPECT_TRUE(futures.is_empty());
 
  // Verify order is preserved
  int expected = 10;
  results.traverse([&expected](int val) {
    EXPECT_EQ(val, expected);
    expected += 10;
    return true;
  });
}
 
TEST_F(FutureUtilsTest, GetFuturesPreservesOrder)
{
  DynList<std::future<int>> futures;
  futures.append(make_int_future(1));
  futures.append(make_int_future(2));
  futures.append(make_int_future(3));
 
  auto results = get_futures(futures);
 
  auto it = results.get_it();
  EXPECT_EQ(it.get_curr(), 1); it.next();
  EXPECT_EQ(it.get_curr(), 2); it.next();
  EXPECT_EQ(it.get_curr(), 3);
}
 
TEST_F(FutureUtilsTest, GetFuturesWithDelayedTasks)
{
  DynList<std::future<int>> futures;
  futures.append(make_delayed_future(100, 50));
  futures.append(make_delayed_future(200, 10));
  futures.append(make_delayed_future(300, 30));
 
  auto results = get_futures(futures);
 
  EXPECT_EQ(results.size(), 3u);
 
  // Order should be preserved (100, 200, 300), not completion order
  auto it = results.get_it();
  EXPECT_EQ(it.get_curr(), 100); it.next();
  EXPECT_EQ(it.get_curr(), 200); it.next();
  EXPECT_EQ(it.get_curr(), 300);
}
 
// =============================================================================
// get_futures Rvalue Overload Tests
// =============================================================================
 
TEST_F(FutureUtilsTest, GetFuturesRvalue)
{
  auto make_list = []() {
    DynList<std::future<int>> futures;
    futures.append(std::async(std::launch::async, [] { return 42; }));
    futures.append(std::async(std::launch::async, [] { return 43; }));
    return futures;
  };
 
  auto results = get_futures(make_list());
 
  EXPECT_EQ(results.size(), 2u);
}
 
// =============================================================================
// Void Future Tests
// =============================================================================
 
TEST_F(FutureUtilsTest, GetVoidFuturesEmptyList)
{
  DynList<std::future<void>> futures;
  EXPECT_NO_THROW(get_futures(futures));
  EXPECT_TRUE(futures.is_empty());
}
 
TEST_F(FutureUtilsTest, GetVoidFuturesSingleElement)
{
  DynList<std::future<void>> futures;
  futures.append(make_void_future());
 
  EXPECT_NO_THROW(get_futures(futures));
  EXPECT_TRUE(futures.is_empty());
}
 
TEST_F(FutureUtilsTest, GetVoidFuturesMultipleElements)
{
  std::atomic<int> counter{0};
  DynList<std::future<void>> futures;
 
  for (int i = 0; i < 5; ++i)
    futures.append(make_void_future_with_effect(counter));
 
  get_futures(futures);
 
  EXPECT_EQ(counter.load(), 5);
  EXPECT_TRUE(futures.is_empty());
}
 
TEST_F(FutureUtilsTest, GetVoidFuturesRvalue)
{
  std::atomic<int> counter{0};
 
  auto make_list = [&counter]() {
    DynList<std::future<void>> futures;
    futures.append(std::async(std::launch::async, [&counter] { ++counter; }));
    futures.append(std::async(std::launch::async, [&counter] { ++counter; }));
    return futures;
  };
 
  get_futures(make_list());
 
  EXPECT_EQ(counter.load(), 2);
}
 
// =============================================================================
// Exception Handling Tests
// =============================================================================
 
TEST_F(FutureUtilsTest, GetFuturesPropagatesException)
{
  DynList<std::future<int>> futures;
  futures.append(make_int_future(1));
  futures.append(make_failing_future());
  futures.append(make_int_future(3));
 
  EXPECT_THROW(get_futures(futures), std::runtime_error);
}
 
TEST_F(FutureUtilsTest, GetVoidFuturesPropagatesException)
{
  DynList<std::future<void>> futures;
  futures.append(make_void_future());
  futures.append(std::async(std::launch::async, [] {
    throw std::logic_error("Void exception");
  }));
 
  EXPECT_THROW(get_futures(futures), std::logic_error);
}
 
// =============================================================================
// all_ready Tests
// =============================================================================
 
TEST_F(FutureUtilsTest, AllReadyEmptyList)
{
  DynList<std::future<int>> futures;
  EXPECT_TRUE(all_ready(futures));
}
 
TEST_F(FutureUtilsTest, AllReadyWithReadyFutures)
{
  DynList<std::future<int>> futures;
  futures.append(make_int_future(1));
  futures.append(make_int_future(2));
 
  // Give futures time to complete
  std::this_thread::sleep_for(std::chrono::milliseconds(50));
 
  EXPECT_TRUE(all_ready(futures));
}
 
TEST_F(FutureUtilsTest, AllReadyWithPendingFutures)
{
  DynList<std::future<int>> futures;
  futures.append(make_delayed_future(1, 500)); // Long delay
 
  // Check immediately - should not be ready
  EXPECT_FALSE(all_ready(futures));
 
  // Clean up
  get_futures(futures);
}
 
TEST_F(FutureUtilsTest, AllReadyMixed)
{
  DynList<std::future<int>> futures;
  futures.append(make_int_future(1)); // Ready immediately
  futures.append(make_delayed_future(2, 500)); // Still pending
 
  // Give first future time but not second
  std::this_thread::sleep_for(std::chrono::milliseconds(50));
 
  EXPECT_FALSE(all_ready(futures));
 
  // Clean up
  get_futures(futures);
}
 
// =============================================================================
// count_ready Tests
// =============================================================================
 
TEST_F(FutureUtilsTest, CountReadyEmptyList)
{
  DynList<std::future<int>> futures;
  EXPECT_EQ(count_ready(futures), 0u);
}
 
TEST_F(FutureUtilsTest, CountReadyAllReady)
{
  DynList<std::future<int>> futures;
  for (int i = 0; i < 5; ++i)
    futures.append(make_int_future(i));
 
  // Give futures time to complete
  std::this_thread::sleep_for(std::chrono::milliseconds(50));
 
  EXPECT_EQ(count_ready(futures), 5u);
 
  // Clean up
  get_futures(futures);
}
 
TEST_F(FutureUtilsTest, CountReadyNoneReady)
{
  DynList<std::future<int>> futures;
  for (int i = 0; i < 3; ++i)
    futures.append(make_delayed_future(i, 500));
 
  // Check immediately
  EXPECT_EQ(count_ready(futures), 0u);
 
  // Clean up
  get_futures(futures);
}
 
TEST_F(FutureUtilsTest, CountReadyPartiallyReady)
{
  DynList<std::future<int>> futures;
  futures.append(make_int_future(1));
  futures.append(make_int_future(2));
  futures.append(make_delayed_future(3, 500));
 
  // Give fast futures time to complete
  std::this_thread::sleep_for(std::chrono::milliseconds(50));
 
  size_t ready_count = count_ready(futures);
  EXPECT_GE(ready_count, 2u);
  EXPECT_LE(ready_count, 3u);
 
  // Clean up
  get_futures(futures);
}
 
// =============================================================================
// Different Types Tests
// =============================================================================
 
TEST_F(FutureUtilsTest, GetFuturesWithStrings)
{
  DynList<std::future<std::string>> futures;
  futures.append(std::async(std::launch::async, [] { return std::string("hello"); }));
  futures.append(std::async(std::launch::async, [] { return std::string("world"); }));
 
  auto results = get_futures(futures);
 
  EXPECT_EQ(results.size(), 2u);
 
  auto it = results.get_it();
  EXPECT_EQ(it.get_curr(), "hello"); it.next();
  EXPECT_EQ(it.get_curr(), "world");
}
 
TEST_F(FutureUtilsTest, GetFuturesWithDoubles)
{
  DynList<std::future<double>> futures;
  futures.append(std::async(std::launch::async, [] { return 3.14; }));
  futures.append(std::async(std::launch::async, [] { return 2.71; }));
 
  auto results = get_futures(futures);
 
  EXPECT_EQ(results.size(), 2u);
 
  auto it = results.get_it();
  EXPECT_DOUBLE_EQ(it.get_curr(), 3.14); it.next();
  EXPECT_DOUBLE_EQ(it.get_curr(), 2.71);
}
 
TEST_F(FutureUtilsTest, GetFuturesWithVectors)
{
  DynList<std::future<std::vector<int>>> futures;
  futures.append(std::async(std::launch::async, [] {
    return std::vector<int>{1, 2, 3};
  }));
  futures.append(std::async(std::launch::async, [] {
    return std::vector<int>{4, 5};
  }));
 
  auto results = get_futures(futures);
 
  EXPECT_EQ(results.size(), 2u);
 
  auto it = results.get_it();
  EXPECT_EQ(it.get_curr().size(), 3u);
  it.next();
  EXPECT_EQ(it.get_curr().size(), 2u);
}
 
// =============================================================================
// Stress Tests
// =============================================================================
 
TEST_F(FutureUtilsTest, ManyFutures)
{
  DynList<std::future<int>> futures;
  constexpr int N = 100;
 
  for (int i = 0; i < N; ++i)
    futures.append(make_int_future(i));
 
  auto results = get_futures(futures);
 
  EXPECT_EQ(results.size(), static_cast<size_t>(N));
  EXPECT_TRUE(futures.is_empty());
 
  // Verify all values
  int expected = 0;
  results.traverse([&expected](int val) {
    EXPECT_EQ(val, expected++);
    return true;
  });
}
 
TEST_F(FutureUtilsTest, ManyVoidFutures)
{
  std::atomic<int> counter{0};
  DynList<std::future<void>> futures;
  constexpr int N = 100;
 
  for (int i = 0; i < N; ++i)
    futures.append(make_void_future_with_effect(counter));
 
  get_futures(futures);
 
  EXPECT_EQ(counter.load(), N);
  EXPECT_TRUE(futures.is_empty());
}
 
// =============================================================================
// Edge Cases
// =============================================================================
 
TEST_F(FutureUtilsTest, FutureWithZeroValue)
{
  DynList<std::future<int>> futures;
  futures.append(make_int_future(0));
 
  auto results = get_futures(futures);
 
  EXPECT_EQ(results.size(), 1u);
  EXPECT_EQ(results.get_first(), 0);
}
 
TEST_F(FutureUtilsTest, FutureWithNegativeValue)
{
  DynList<std::future<int>> futures;
  futures.append(make_int_future(-42));
 
  auto results = get_futures(futures);
 
  EXPECT_EQ(results.size(), 1u);
  EXPECT_EQ(results.get_first(), -42);
}
 
TEST_F(FutureUtilsTest, FutureWithEmptyString)
{
  DynList<std::future<std::string>> futures;
  futures.append(std::async(std::launch::async, [] { return std::string(); }));
 
  auto results = get_futures(futures);
 
  EXPECT_EQ(results.size(), 1u);
  EXPECT_TRUE(results.get_first().empty());
}
 
// =============================================================================
// Main
// =============================================================================
 
int main(int argc, char ** argv)
{
  ::testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}