Fix issue with exclusive ownership and unordered samples (#5182)

* Refs #20866. Regression test.

Signed-off-by: Miguel Company <miguelcompany@eprosima.com>

* Refs #20866. Additional regression test.

Signed-off-by: Miguel Company <miguelcompany@eprosima.com>

* Refs #20866. Fix issue.

Signed-off-by: Miguel Company <miguelcompany@eprosima.com>

* Refs #20866. Fix unit tests.

Signed-off-by: Miguel Company <miguelcompany@eprosima.com>

* Refs #20866. Refactor test to run several cases.

Signed-off-by: Miguel Company <miguelcompany@eprosima.com>

---------

Signed-off-by: Miguel Company <miguelcompany@eprosima.com>
(cherry picked from commit b1a7fe2)
Signed-off-by: JesusPoderoso <jesuspoderoso@eprosima.com>

# Conflicts:
#	test/unittest/dds/subscriber/DataReaderHistoryTests.cpp

src/cpp/fastdds/subscriber/history/DataReaderHistory.cpp

@@ -830,13 +830,39 @@ bool DataReaderHistory::update_instance_nts(
 
     assert(vit != instances_.end());
     assert(false == change->isRead);
+    auto previous_owner = vit->second->current_owner.first;
     ++counters_.samples_unread;
     bool ret =
             vit->second->update_state(counters_, change->kind, change->writerGUID,
                     change->reader_info.writer_ownership_strength);
     change->reader_info.disposed_generation_count = vit->second->disposed_generation_count;
     change->reader_info.no_writers_generation_count = vit->second->no_writers_generation_count;
 
+    auto current_owner = vit->second->current_owner.first;
+    if (current_owner != previous_owner)
+    {
+        assert(current_owner == change->writerGUID);
+
+        // Remove all changes from different owners after the change.
+        DataReaderInstance::ChangeCollection& changes = vit->second->cache_changes;
+        auto it = std::lower_bound(changes.begin(), changes.end(), change, rtps::history_order_cmp);
+        assert(it != changes.end());
+        assert(*it == change);
+        ++it;
+        while (it != changes.end())
+        {
+            if ((*it)->writerGUID != current_owner)
+            {
+                // Remove from history
+                remove_change_sub(*it, it);
+
+                // Current iterator will point to change next to the one removed. Avoid incrementing.
+                continue;
+            }
+            ++it;
+        }
+    }
+
     return ret;
 }
 

test/blackbox/common/DDSBlackboxTestsOwnershipQos.cpp

@@ -2161,6 +2161,142 @@ TEST_P(OwnershipQos, exclusive_kind_keyed_besteffort_disposing_instance)
     exclusive_kind_keyed_disposing_instance(false);
 }
 
+/*!
+ * This is a regression test for redmine issue 20866.
+ *
+ * This test checks that a reader keeping a long number of samples and with an exclusive ownership policy only
+ * returns the data from the writer with the highest strength.
+ *
+ * @param use_keep_all_history  Whether to use KEEP_ALL history or KEEP_LAST(20).
+ * @param mixed_data            Whether to send data from both writers in an interleaved way.
+ */
+static void test_exclusive_kind_big_history(
+        bool use_keep_all_history,
+        bool mixed_data)
+{
+    PubSubReader<KeyedHelloWorldPubSubType> reader(TEST_TOPIC_NAME);
+    PubSubWriter<KeyedHelloWorldPubSubType> low_strength_writer(TEST_TOPIC_NAME);
+    PubSubWriter<KeyedHelloWorldPubSubType> high_strength_writer(TEST_TOPIC_NAME);
+
+    // Configure history QoS.
+    if (use_keep_all_history)
+    {
+        reader.history_kind(eprosima::fastdds::dds::KEEP_ALL_HISTORY_QOS);
+        low_strength_writer.history_kind(eprosima::fastdds::dds::KEEP_ALL_HISTORY_QOS);
+        high_strength_writer.history_kind(eprosima::fastdds::dds::KEEP_ALL_HISTORY_QOS);
+    }
+    else
+    {
+        reader.history_kind(eprosima::fastdds::dds::KEEP_LAST_HISTORY_QOS).history_depth(20);
+        low_strength_writer.history_kind(eprosima::fastdds::dds::KEEP_LAST_HISTORY_QOS).history_depth(20);
+        high_strength_writer.history_kind(eprosima::fastdds::dds::KEEP_LAST_HISTORY_QOS).history_depth(20);
+    }
+
+    // Prepare data.
+    std::list<KeyedHelloWorld> generated_data = default_keyedhelloworld_data_generator(20);
+    auto middle = std::next(generated_data.begin(), 10);
+    std::list<KeyedHelloWorld> low_strength_data(generated_data.begin(), middle);
+    std::list<KeyedHelloWorld> high_strength_data(middle, generated_data.end());
+    auto expected_data = high_strength_data;
+
+    if (mixed_data)
+    {
+        // Expect reception of the first two samples from the low strength writer (one per instance).
+        auto it = low_strength_data.begin();
+        expected_data.push_front(*it++);
+        expected_data.push_front(*it);
+    }
+
+    // Initialize writers.
+    low_strength_writer.ownership_strength(3)
+            .reliability(eprosima::fastdds::dds::RELIABLE_RELIABILITY_QOS)
+            .init();
+    ASSERT_TRUE(low_strength_writer.isInitialized());
+
+    // High strength writer will use a custom transport to ensure its data is received after the low strength data.
+    auto test_transport = std::make_shared<test_UDPv4TransportDescriptor>();
+    std::atomic<bool> drop_messages(false);
+    test_transport->messages_filter_ = [&drop_messages](eprosima::fastdds::rtps::CDRMessage_t&)
+            {
+                return drop_messages.load();
+            };
+    high_strength_writer.ownership_strength(4)
+            .reliability(eprosima::fastdds::dds::RELIABLE_RELIABILITY_QOS)
+            .disable_builtin_transport()
+            .add_user_transport_to_pparams(test_transport)
+            .init();
+    ASSERT_TRUE(high_strength_writer.isInitialized());
+
+    // Initialize reader.
+    reader.ownership_exclusive()
+            .reliability(eprosima::fastdds::dds::RELIABLE_RELIABILITY_QOS)
+            .init();
+    ASSERT_TRUE(reader.isInitialized());
+
+    // Wait for discovery.
+    low_strength_writer.wait_discovery();
+    high_strength_writer.wait_discovery();
+    reader.wait_discovery(std::chrono::seconds::zero(), 2);
+
+    // Drop the messages from the high strength writer, so they arrive later to the reader.
+    drop_messages.store(true);
+
+    if (mixed_data)
+    {
+        // Send one sample from each writer, with low strength data first.
+        while (!low_strength_data.empty() && !high_strength_data.empty())
+        {
+            EXPECT_TRUE(low_strength_writer.send_sample(low_strength_data.front()));
+            EXPECT_TRUE(high_strength_writer.send_sample(high_strength_data.front()));
+            low_strength_data.pop_front();
+            high_strength_data.pop_front();
+        }
+    }
+    else
+    {
+        // Send high strength data first, so it has the lowest source timestamps, but drop the messages, so they arrive
+        // later to the reader.
+        high_strength_writer.send(high_strength_data);
+        EXPECT_TRUE(high_strength_data.empty());
+
+        // Send low strength data, so it has the highest source timestamps.
+        low_strength_writer.send(low_strength_data);
+        EXPECT_TRUE(low_strength_data.empty());
+    }
+
+    // Wait for the reader to receive the low strength data.
+    EXPECT_TRUE(low_strength_writer.waitForAllAcked(std::chrono::seconds(1)));
+
+    // Let high strength writer send the data, and wait for the reader to receive it.
+    drop_messages.store(false);
+    EXPECT_TRUE(high_strength_writer.waitForAllAcked(std::chrono::seconds(1)));
+
+    // Make the reader process the data, expecting only the required data.
+    // The issue was reproduced by the reader complaining about reception of unexpected data.
+    reader.startReception(expected_data);
+    reader.block_for_all();
+}
+
+TEST(OwnershipQos, exclusive_kind_keep_all_reliable)
+{
+    test_exclusive_kind_big_history(true, false);
+}
+
+TEST(OwnershipQos, exclusive_kind_keep_all_reliable_mixed)
+{
+    test_exclusive_kind_big_history(true, true);
+}
+
+TEST(OwnershipQos, exclusive_kind_keep_last_reliable)
+{
+    test_exclusive_kind_big_history(false, false);
+}
+
+TEST(OwnershipQos, exclusive_kind_keep_last_reliable_mixed)
+{
+    test_exclusive_kind_big_history(false, true);
+}
+
 #ifdef INSTANTIATE_TEST_SUITE_P
 #define GTEST_INSTANTIATE_TEST_MACRO(x, y, z, w) INSTANTIATE_TEST_SUITE_P(x, y, z, w)
 #else