add byte tx counter to the set of metrics being measured in RLC

lib/include/srslte/upper/rlc_am_lte.h

@@ -185,7 +185,8 @@ private:
     pthread_mutex_t mutex;
 
     // Metrics
-    srslte::rolling_average<float> mean_pdu_latency_us;
+    uint64_t                        tx_byte_count = 0;
+    srslte::rolling_average<double> mean_pdu_latency_us;
   };
 
   // Receiver sub-class

lib/include/srslte/upper/rlc_um_lte.h

@@ -65,7 +65,8 @@ private:
     uint32_t vt_us = 0; // Send state. SN to be assigned for next PDU.
 
     // Metrics
-    srslte::rolling_average<float> mean_pdu_latency_us;
+    uint64_t                        tx_byte_count = 0;
+    srslte::rolling_average<double> mean_pdu_latency_us;
 
     void debug_state();
   };

lib/src/upper/rlc_am_lte.cc

@@ -946,6 +946,8 @@ int rlc_am_lte::rlc_am_lte_tx::build_data_pdu(uint8_t* payload, uint32_t nof_byt
   log->info_hex(payload, total_len, "%s Tx PDU SN=%d (%d B)\n", RB_NAME, header.sn, total_len);
   log->debug("%s\n", rlc_amd_pdu_header_to_string(header).c_str());
   debug_state();
+
+  tx_byte_count += buffer_ptr->N_bytes;
   return total_len;
 }
 

lib/src/upper/rlc_um_lte.cc

@@ -208,6 +208,7 @@ int rlc_um_lte::rlc_um_lte_tx::build_data_pdu(unique_byte_buffer_t pdu, uint8_t*
   log->info_hex(payload, pdu->N_bytes, "%s Tx PDU SN=%d (%d B)\n", rb_name.c_str(), header.sn, pdu->N_bytes);
 
   debug_state();
+  tx_byte_count += pdu->N_bytes;
 
   return pdu->N_bytes;
 }