lib,rlc_am_nr: don't enqueue segment retx if already pending for retx.

lib/src/rlc/rlc_am_nr.cc

@@ -811,7 +811,7 @@ void rlc_am_nr_tx::handle_control_pdu(uint8_t* payload, uint32_t nof_bytes)
           bool segment_found = false;
           for (const rlc_amd_tx_pdu_nr::pdu_segment& segm : pdu.segment_list) {
             if (segm.so >= nack.so_start && segm.so <= nack.so_end) {
-              // FIXME: Check if this segment is not already queued for retransmission
+              if (not retx_queue->has_sn(nack_sn, segm.so)) {
                 rlc_amd_retx_nr_t& retx = retx_queue->push();
                 retx.sn                 = nack_sn;
                 retx.is_segment         = true;
@@ -823,6 +823,12 @@ void rlc_am_nr_tx::handle_control_pdu(uint8_t* payload, uint32_t nof_bytes)
                         retx.sn,
                         retx.so_start,
                         retx.segment_length);
+              } else {
+                RlcInfo("Skip already scheduled RETX of SDU segment SN=%d, so_start=%d, segment_length=%d",
+                        nack_sn,
+                        segm.so,
+                        segm.payload_len);
+              }
               segment_found = true;
             }
           }

lib/test/rlc/rlc_am_nr_test.cc

@@ -1110,7 +1110,7 @@ int segment_retx_and_loose_segments_test(rlc_am_nr_sn_size_t sn_size)
     rlc1.write_pdu(status_buf.msg, status_buf.N_bytes);
 
     // Write status PDU duplicate to RLC1
-    // rlc1.write_pdu(status_buf.msg, status_buf.N_bytes);
+    rlc1.write_pdu(status_buf.msg, status_buf.N_bytes);
 
     // Check there are two Retx segments
     TESTASSERT_EQ(header_size + payload_size, rlc1.get_buffer_state()); // Fixme: get_buffer_state()
@@ -1153,9 +1153,12 @@ int segment_retx_and_loose_segments_test(rlc_am_nr_sn_size_t sn_size)
   uint32_t total_tx_pdu_bytes1 = NBUFS * data_pdu_size + 2 * pdu_size_first + 3 * pdu_size_continued;
   uint32_t total_rx_pdu_bytes1 = status_pdu_ack_size +                                 // ACK, no NACK
                                  (status_pdu_ack_size + status_pdu_nack_size) +        // ACK + NACK full SDU
-                                 (status_pdu_ack_size + 2 * status_pdu_nack_size + // ACK + NACK two segments
+                                 2 * (status_pdu_ack_size + 2 * status_pdu_nack_size + // 2 * (ACK + NACK two segments)
+                                      2 * status_pdu_so_size);
+  uint32_t total_tx_pdu_bytes2 = status_pdu_ack_size +                                 // ACK, no NACK
+                                 (status_pdu_ack_size + status_pdu_nack_size) +        // ACK + NACK full SDU
+                                 1 * (status_pdu_ack_size + 2 * status_pdu_nack_size + // 1 * (ACK + NACK two segments)
                                       2 * status_pdu_so_size);
-  uint32_t total_tx_pdu_bytes2 = total_rx_pdu_bytes1;
   uint32_t total_rx_pdu_bytes2 = (NBUFS - 1) * data_pdu_size + pdu_size_first + 2 * pdu_size_continued;
 
   // SDU metrics
@@ -1166,7 +1169,7 @@ int segment_retx_and_loose_segments_test(rlc_am_nr_sn_size_t sn_size)
   TESTASSERT_EQ(0, metrics1.num_lost_sdus);
   // PDU metrics
   TESTASSERT_EQ(5 + 3 + 2, metrics1.num_tx_pdus); // 5 + (3 + 2) re-transmissions
-  TESTASSERT_EQ(3, metrics1.num_rx_pdus);         // 3 status PDU
+  TESTASSERT_EQ(4, metrics1.num_rx_pdus);         // 4 status PDU
   TESTASSERT_EQ(total_tx_pdu_bytes1, metrics1.num_tx_pdu_bytes);
   TESTASSERT_EQ(total_rx_pdu_bytes1, metrics1.num_rx_pdu_bytes);
   TESTASSERT_EQ(0, metrics1.num_lost_sdus); // No lost SDUs