since we moved cell search to the background thread, cell reselection prints a error message that it cannot start. In fact it already started. It is just waiting for the cell search to finish. This PR fixes this

srsue/hdr/stack/rrc/rrc.h

@@ -615,6 +615,7 @@ private:
   class plmn_search_proc;
   class process_pcch_proc;
   class go_idle_proc;
+  class cell_reselection_proc;
   srslte::proc_t<cell_search_proc>         cell_searcher;
   srslte::proc_t<si_acquire_proc>          si_acquirer;
   srslte::proc_t<serving_cell_config_proc> serv_cell_cfg;
@@ -623,6 +624,7 @@ private:
   srslte::proc_t<process_pcch_proc>        pcch_processor;
   srslte::proc_t<connection_request_proc>  conn_req_proc;
   srslte::proc_t<plmn_search_proc>         plmn_searcher;
+  srslte::proc_t<cell_reselection_proc>    cell_reselector;
 
   srslte::callback_list_t callback_list;
 

srsue/hdr/stack/rrc/rrc_procedures.h

@@ -205,6 +205,17 @@ private:
   uint32_t rlc_flush_counter;
 };
 
+class rrc::cell_reselection_proc : public srslte::proc_impl_t
+{
+public:
+  srslte::proc_outcome_t init(rrc* rrc_);
+  srslte::proc_outcome_t step() final;
+  static const char*     name() { return "Cell Reselection"; }
+
+private:
+  rrc* rrc_ptr;
+};
+
 } // namespace srsue
 
 #endif // SRSLTE_RRC_PROCEDURES_H

srsue/src/stack/rrc/rrc.cc

@@ -1445,40 +1445,15 @@ void rrc::start_cell_reselection()
     return;
   }
 
-  if (not cell_selector.launch(this)) {
-    rrc_log->error("Failed to initiate a Cell Selection procedure...\n");
+  if (cell_reselector.is_active()) {
+    // it is already running
     return;
   }
 
-  rrc_log->info("Cell Reselection - Starting...\n");
-  callback_list.defer_task([this]() {
-    if (cell_selector.run()) {
-      return srslte::proc_outcome_t::yield;
+  if (not cell_reselector.launch(this)) {
+    rrc_log->error("Failed to initiate a Cell Reselection procedure...\n");
   }
-    cell_selection_proc ret = cell_selector.pop();
-    if (ret.is_error()) {
-      rrc_log->error("Cell Reselection - Error while selecting a cell\n");
-      return srslte::proc_outcome_t::error;
-    } else {
-      switch (ret.get_cs_result()) {
-        case cs_result_t::changed_cell:
-          // New cell has been selected, start receiving PCCH
-          mac->pcch_start_rx();
-          break;
-        case cs_result_t::no_cell:
-          rrc_log->warning("Could not find any cell to camp on\n");
-          break;
-        case cs_result_t::same_cell:
-          if (!phy->cell_is_camping()) {
-            rrc_log->warning("Did not reselect cell but serving cell is out-of-sync.\n");
-            serving_cell->in_sync = false;
-          }
-          break;
-      }
-    }
-    rrc_log->info("Cell Reselection - Finished successfully\n");
-    return srslte::proc_outcome_t::success;
-  });
+  callback_list.defer_proc(cell_reselector);
 }
 
 void rrc::cell_search_completed(const phy_interface_rrc_lte::cell_search_ret_t& cs_ret,

srsue/src/stack/rrc/rrc_procedures.cc

@@ -826,4 +826,51 @@ proc_outcome_t rrc::go_idle_proc::step()
   return proc_outcome_t::yield;
 }
 
+/**************************************
+ *    Cell Reselection procedure
+ *************************************/
+
+proc_outcome_t rrc::cell_reselection_proc::init(srsue::rrc* rrc_)
+{
+  rrc_ptr = rrc_;
+
+  Info("Cell Reselection - Starting...\n");
+  if (not rrc_ptr->cell_selector.launch(rrc_ptr)) {
+    Error("Failed to initiate a Cell Selection procedure...\n");
+    return proc_outcome_t::error;
+  }
+
+  return proc_outcome_t::yield;
+}
+
+proc_outcome_t rrc::cell_reselection_proc::step()
+{
+  if (rrc_ptr->cell_selector.run()) {
+    return srslte::proc_outcome_t::yield;
+  }
+  cell_selection_proc ret = rrc_ptr->cell_selector.pop();
+  if (ret.is_error()) {
+    Error("Cell Reselection - Error while selecting a cell\n");
+    return srslte::proc_outcome_t::error;
+  }
+
+  switch (ret.get_cs_result()) {
+    case cs_result_t::changed_cell:
+      // New cell has been selected, start receiving PCCH
+      rrc_ptr->mac->pcch_start_rx();
+      break;
+    case cs_result_t::no_cell:
+      Warning("Could not find any cell to camp on\n");
+      break;
+    case cs_result_t::same_cell:
+      if (!rrc_ptr->phy->cell_is_camping()) {
+        Warning("Did not reselect cell but serving cell is out-of-sync.\n");
+        rrc_ptr->serving_cell->in_sync = false;
+      }
+      break;
+  }
+  Info("Cell Reselection - Finished successfully\n");
+  return srslte::proc_outcome_t::success;
+}
+
 } // namespace srsue