added allocate_rnti method to mac. Useful both during PRACH and handover UE resource allocation

lib/include/srslte/interfaces/enb_interfaces.h

@@ -282,6 +282,9 @@ public:
   virtual void phy_config_enabled(uint16_t rnti, bool enabled)                                     = 0;
   virtual void
   write_mcch(asn1::rrc::sib_type2_s* sib2, asn1::rrc::sib_type13_r9_s* sib13, asn1::rrc::mcch_msg_s* mcch) = 0;
+
+  /* Allocation of C-RNTI during HO */
+  virtual uint16_t allocate_rnti() = 0;
 };
 
 class mac_interface_rlc
@@ -487,8 +490,7 @@ public:
 
 // Combined interface for stack (MAC and RRC) to access PHY
 class phy_interface_stack_lte : public phy_interface_mac_lte, public phy_interface_rrc_lte
-{
-};
+{};
 
 typedef struct {
   uint32_t    enb_id;  // 20-bit id (lsb bits)
@@ -524,8 +526,7 @@ public:
 
 // STACK interface for MAC
 class stack_interface_mac_lte : public srslte::task_handler_interface
-{
-};
+{};
 
 } // namespace srsenb
 

srsenb/hdr/stack/mac/mac.h

@@ -99,11 +99,16 @@ public:
   void
   write_mcch(asn1::rrc::sib_type2_s* sib2, asn1::rrc::sib_type13_r9_s* sib13, asn1::rrc::mcch_msg_s* mcch) override;
 
+  /* Allocate C-RNTI */
+  uint16_t allocate_rnti() final;
+
 private:
   static const int      MAX_LOCATIONS            = 20;
   static const uint32_t cfi                      = 3;
   srslte_dci_location_t locations[MAX_LOCATIONS] = {};
 
+  std::mutex rnti_mutex;
+
   // We use a rwlock in MAC to allow multiple workers to access MAC simultaneously. No conflicts will happen since
   // access for different TTIs
   pthread_rwlock_t rwlock = {};

srsenb/hdr/stack/mac/scheduler_ue.h

@@ -212,7 +212,7 @@ private:
                                           uint32_t               cfi,
                                           const srslte_dci_dl_t& dci);
 
-  static bool bearer_is_ul(ue_bearer_t* lch);
+  static bool bearer_is_ul(const ue_bearer_t* lch);
   static bool bearer_is_dl(const ue_bearer_t* lch);
 
   uint32_t get_pending_ul_old_data_unlocked(uint32_t cc_idx);

srsenb/src/stack/mac/mac.cc

@@ -37,7 +37,10 @@ using namespace asn1::rrc;
 namespace srsenb {
 
 mac::mac() :
-  last_rnti(0), rar_pdu_msg(sched_interface::MAX_RAR_LIST), rar_payload(), common_buffers(SRSLTE_MAX_CARRIERS)
+  last_rnti(0),
+  rar_pdu_msg(sched_interface::MAX_RAR_LIST),
+  rar_payload(),
+  common_buffers(SRSLTE_MAX_CARRIERS)
 {
   pthread_rwlock_init(&rwlock, nullptr);
 }
@@ -445,34 +448,38 @@ int mac::sr_detected(uint32_t tti, uint16_t rnti)
   return ret;
 }
 
+uint16_t mac::allocate_rnti()
+{
+  std::lock_guard<std::mutex> lock(rnti_mutex);
+
+  // Assign a c-rnti
+  uint16_t rnti = last_rnti++;
+  if (last_rnti >= 60000) {
+    last_rnti = 70;
+  }
+
+  return rnti;
+}
+
 void mac::rach_detected(uint32_t tti, uint32_t enb_cc_idx, uint32_t preamble_idx, uint32_t time_adv)
 {
   static srslte::mutexed_tprof<srslte::avg_time_stats> rach_tprof("rach_tprof", "MAC", 1);
   log_h->step(tti);
-  uint16_t rnti;
   auto rach_tprof_meas = rach_tprof.start();
 
-  {
-    srslte::rwlock_write_guard lock(rwlock);
-
-    rnti = last_rnti;
+  uint16_t rnti = allocate_rnti();
 
   // Create new UE
-    if (ue_db.count(rnti) == 0) {
-      ue_db[rnti] =
-          std::unique_ptr<ue>{new ue(rnti, args.nof_prb, &scheduler, rrc_h, rlc_h, phy_h, log_h, cells.size())};
-    }
+  std::unique_ptr<ue> ue_ptr{new ue(rnti, args.nof_prb, &scheduler, rrc_h, rlc_h, phy_h, log_h, cells.size())};
 
   // Set PCAP if available
   if (pcap != nullptr) {
-      ue_db[rnti]->start_pcap(pcap);
+    ue_ptr->start_pcap(pcap);
   }
 
-    // Increase RNTI counter
-    last_rnti++;
-    if (last_rnti >= 60000) {
-      last_rnti = 70;
-    }
+  {
+    srslte::rwlock_write_guard lock(rwlock);
+    ue_db[rnti] = std::move(ue_ptr);
   }
 
   stack_task_queue.push([this, rnti, tti, enb_cc_idx, preamble_idx, time_adv, rach_tprof_meas]() mutable {

srsenb/src/stack/mac/scheduler_ue.cc

@@ -748,7 +748,7 @@ int sched_ue::generate_format0(sched_interface::ul_sched_data_t* data,
  *
  *******************************************************/
 
-bool sched_ue::bearer_is_ul(ue_bearer_t* lch)
+bool sched_ue::bearer_is_ul(const ue_bearer_t* lch)
 {
   return lch->cfg.direction == sched_interface::ue_bearer_cfg_t::UL ||
          lch->cfg.direction == sched_interface::ue_bearer_cfg_t::BOTH;