[23603] Avoid sending duplicated ACKs in DataSharing (backport #5986)

src/cpp/fastdds/subscriber/DataReaderImpl/ReadTakeCommand.hpp

@@ -147,7 +147,6 @@ struct ReadTakeCommand
                     ReturnCode_t previous_return_value = return_value_;
                     bool added = add_sample(*it, remove_change);
                     history_.change_was_processed_nts(change, added);
-                    rtps::BaseReader::downcast(reader_)->end_sample_access_nts(change, wp, added);
 
                     // Check if the payload is dirty
                     if (added && !check_datasharing_validity(change, data_values_.has_ownership()))
@@ -165,7 +164,11 @@ struct ReadTakeCommand
                         added = false;
                     }
 
-                    if (remove_change || (added && take_samples))
+                    // Only send ACK if the change will not be removed to avoid sending the same ACK twice
+                    bool should_remove = remove_change || (added && take_samples);
+                    rtps::BaseReader::downcast(reader_)->end_sample_access_nts(change, wp, added, !should_remove);
+
+                    if (should_remove)
                     {
                         // Remove from history
                         history_.remove_change_sub(change, it);

src/cpp/rtps/reader/BaseReader.hpp

@@ -221,14 +221,16 @@ class BaseReader
     /**
      * @brief Called after the change has been deserialized.
      *
-     * @param [in] change        Pointer to the change being accessed.
-     * @param [in] writer        Writer proxy the @c change belongs to.
-     * @param [in] mark_as_read  Whether the @c change should be marked as read or not.
+     * @param [in] change          Pointer to the change being accessed.
+     * @param [in] writer          Writer proxy the @c change belongs to.
+     * @param [in] mark_as_read    Whether the @c change should be marked as read or not.
+     * @param [in] should_send_ack Whether an ACKNACK should be sent to the writer or not.
      */
     virtual void end_sample_access_nts(
             fastdds::rtps::CacheChange_t* change,
             fastdds::rtps::WriterProxy*& writer,
-            bool mark_as_read) = 0;
+            bool mark_as_read,
+            bool should_send_ack = false) = 0;
 
     /**
      * @brief A method to update the liveliness changed status of the reader

src/cpp/rtps/reader/StatefulReader.cpp

@@ -1467,7 +1467,8 @@ bool StatefulReader::begin_sample_access_nts(
 void StatefulReader::end_sample_access_nts(
         CacheChange_t* change,
         WriterProxy*& writer,
-        bool mark_as_read)
+        bool mark_as_read,
+        bool should_send_ack)
 {
     assert(!writer || change->writerGUID == writer->guid());
 
@@ -1481,7 +1482,7 @@ void StatefulReader::end_sample_access_nts(
         }
     }
 
-    if (mark_as_read)
+    if (should_send_ack && mark_as_read)
     {
         send_ack_if_datasharing(this, history_, writer, change->sequenceNumber);
     }

src/cpp/rtps/reader/StatefulReader.hpp

@@ -295,14 +295,16 @@ class StatefulReader : public fastdds::rtps::BaseReader
 
     /**
      * Called after the change has been deserialized.
-     * @param [in] change        Pointer to the change being accessed.
-     * @param [in] writer        Writer proxy the @c change belongs to.
-     * @param [in] mark_as_read  Whether the @c change should be marked as read or not.
+     * @param [in] change          Pointer to the change being accessed.
+     * @param [in] writer          Writer proxy the @c change belongs to.
+     * @param [in] mark_as_read    Whether the @c change should be marked as read or not.
+     * @param [in] should_send_ack Whether an ACKNACK should be sent to the writer or not.
      */
     void end_sample_access_nts(
             CacheChange_t* change,
             WriterProxy*& writer,
-            bool mark_as_read) override;
+            bool mark_as_read,
+            bool should_send_ack = false) override;
 
     /**
      * @brief Fills the provided vector with the GUIDs of the matched writers.

src/cpp/rtps/reader/StatelessReader.cpp

@@ -513,7 +513,8 @@ bool StatelessReader::begin_sample_access_nts(
 void StatelessReader::end_sample_access_nts(
         CacheChange_t* change,
         WriterProxy*& /*writer*/,
-        bool mark_as_read)
+        bool mark_as_read,
+        bool /*should_send_ack*/)
 {
     // Mark change as read
     if (mark_as_read && !change->isRead)

src/cpp/rtps/reader/StatelessReader.hpp

@@ -218,14 +218,16 @@ class StatelessReader : public fastdds::rtps::BaseReader
 
     /**
      * Called after the change has been deserialized.
-     * @param [in] change        Pointer to the change being accessed.
-     * @param [in] writer        Writer proxy the @c change belongs to.
-     * @param [in] mark_as_read  Whether the @c change should be marked as read or not.
+     * @param [in] change          Pointer to the change being accessed.
+     * @param [in] writer          Writer proxy the @c change belongs to.
+     * @param [in] mark_as_read    Whether the @c change should be marked as read or not.
+     * @param [in] should_send_ack Whether an ACKNACK should be sent to the writer or not.
      */
     void end_sample_access_nts(
             CacheChange_t* change,
             WriterProxy*& writer,
-            bool mark_as_read) override;
+            bool mark_as_read,
+            bool should_send_ack = false) override;
 
     /**
      * @brief Fills the provided vector with the GUIDs of the matched writers.

test/mock/rtps/RTPSReader/rtps/reader/BaseReader.hpp

@@ -154,7 +154,8 @@ class BaseReader : public fastdds::rtps::RTPSReader
     virtual void end_sample_access_nts(
             fastdds::rtps::CacheChange_t* /*change*/,
             fastdds::rtps::WriterProxy*& /*wp*/,
-            bool /*mark_as_read*/)
+            bool /*mark_as_read*/,
+            bool /*should_send_ack*/ = false)
     {
     }