lib,rlc_am_nr: starting to order segments to be able to receive them out-of-order

lib/include/srsran/rlc/rlc_am_nr.h

@@ -221,7 +221,9 @@ public:
   int  handle_segment_data_sdu(const rlc_am_nr_pdu_header_t& header, const uint8_t* payload, uint32_t nof_bytes);
   bool inside_rx_window(uint32_t sn);
   void write_to_upper_layers(uint32_t lcid, unique_byte_buffer_t sdu);
-  bool have_all_segments_been_received(const std::list<rlc_amd_rx_pdu_nr>& segment_list);
+  void insert_received_segment(rlc_amd_rx_pdu_nr                                   segment,
+                               std::set<rlc_amd_rx_pdu_nr, rlc_amd_rx_pdu_nr_cmp>& segment_list);
+  bool have_all_segments_been_received(const std::set<rlc_amd_rx_pdu_nr, rlc_amd_rx_pdu_nr_cmp>& segment_list);
 
   // Metrics
   uint32_t get_sdu_rx_latency_ms() final;

lib/include/srsran/rlc/rlc_am_nr_packing.h

@@ -15,6 +15,7 @@
 
 #include "srsran/common/string_helpers.h"
 #include "srsran/rlc/rlc_am_base.h"
+#include <set>
 
 namespace srsran {
 
@@ -52,11 +53,15 @@ struct rlc_amd_rx_pdu_nr {
   explicit rlc_amd_rx_pdu_nr(uint32_t rlc_sn_) : rlc_sn(rlc_sn_) {}
 };
 
+struct rlc_amd_rx_pdu_nr_cmp {
+  bool operator()(const rlc_amd_rx_pdu_nr& a, const rlc_amd_rx_pdu_nr& b) const { return a.header.so < b.header.so; }
+};
+
 struct rlc_amd_rx_sdu_nr_t {
-  uint32_t                     rlc_sn         = 0;
-  bool                         fully_received = false;
-  unique_byte_buffer_t         buf;
-  std::list<rlc_amd_rx_pdu_nr> segments;
+  uint32_t                                           rlc_sn         = 0;
+  bool                                               fully_received = false;
+  unique_byte_buffer_t                               buf;
+  std::set<rlc_amd_rx_pdu_nr, rlc_amd_rx_pdu_nr_cmp> segments;
 
   rlc_amd_rx_sdu_nr_t() = default;
   explicit rlc_amd_rx_sdu_nr_t(uint32_t rlc_sn_) : rlc_sn(rlc_sn_) {}

lib/src/rlc/rlc_am_nr.cc

@@ -1112,8 +1112,8 @@ int rlc_am_nr_rx::handle_segment_data_sdu(const rlc_am_nr_pdu_header_t& header,
   memcpy(pdu_segment.buf->msg, payload + hdr_len, nof_bytes - hdr_len); // Don't copy header
   pdu_segment.buf->N_bytes = nof_bytes - hdr_len;
 
-  // Store SDU segment. TODO sort by SO and check for duplicate bytes.
-  rx_sdu.segments.push_back(std::move(pdu_segment));
+  // Store SDU segment. Sort by SO and check for duplicate bytes.
+  insert_received_segment(std::move(pdu_segment), rx_sdu.segments);
 
   // Check weather all segments have been received
   rx_sdu.fully_received = have_all_segments_been_received(rx_sdu.segments);
@@ -1301,14 +1301,21 @@ uint32_t rlc_am_nr_rx::get_rx_buffered_bytes()
   return 0;
 }
 
-bool rlc_am_nr_rx::have_all_segments_been_received(const std::list<rlc_amd_rx_pdu_nr>& segment_list)
+void rlc_am_nr_rx::insert_received_segment(rlc_amd_rx_pdu_nr                                   segment,
+                                           std::set<rlc_amd_rx_pdu_nr, rlc_amd_rx_pdu_nr_cmp>& segment_list)
+{
+  segment_list.insert(std::move(segment));
+}
+
+bool rlc_am_nr_rx::have_all_segments_been_received(
+    const std::set<rlc_amd_rx_pdu_nr, rlc_amd_rx_pdu_nr_cmp>& segment_list)
 {
   if (segment_list.empty()) {
     return false;
   }
 
   // Check if we have received the last segment
-  if ((--segment_list.end())->header.si != rlc_nr_si_field_t::last_segment) {
+  if (segment_list.rbegin()->header.si != rlc_nr_si_field_t::last_segment) {
     return false;
   }