enb,mac: fix concurrent access to cell structs

this patch moves the rwlock that protects the UE database outside
to also protect the cell struct.

It also adds a missing write guard when setting the cell

srsenb/src/stack/mac/mac.cc

@@ -228,6 +228,7 @@ int mac::ue_set_crnti(uint16_t temp_crnti, uint16_t crnti, const sched_interface
 
 int mac::cell_cfg(const std::vector<sched_interface::cell_cfg_t>& cell_cfg_)
 {
+  srsran::rwlock_write_guard lock(rwlock);
   cell_config = cell_cfg_;
   return scheduler.cell_cfg(cell_config);
 }
@@ -576,6 +577,8 @@ int mac::get_dl_sched(uint32_t tti_tx_dl, dl_sched_list_t& dl_sched_res_list)
     add_padding();
   }
 
+  srsran::rwlock_read_guard lock(rwlock);
+
   for (uint32_t enb_cc_idx = 0; enb_cc_idx < cell_config.size(); enb_cc_idx++) {
     // Run scheduler with current info
     sched_interface::dl_sched_res_t sched_result = {};
@@ -587,9 +590,6 @@ int mac::get_dl_sched(uint32_t tti_tx_dl, dl_sched_list_t& dl_sched_res_list)
     int         n            = 0;
     dl_sched_t* dl_sched_res = &dl_sched_res_list[enb_cc_idx];
 
-    {
-      srsran::rwlock_read_guard lock(rwlock);
-
     // Copy data grants
     for (uint32_t i = 0; i < sched_result.data.size(); i++) {
       uint32_t tb_count = 0;
@@ -648,9 +648,6 @@ int mac::get_dl_sched(uint32_t tti_tx_dl, dl_sched_list_t& dl_sched_res_list)
       }
     }
 
-      // No more uses of shared ue_db beyond here
-    }
-
     // Copy RAR grants
     for (uint32_t i = 0; i < sched_result.rar.size(); i++) {
       // Copy dci info
@@ -728,12 +725,9 @@ int mac::get_dl_sched(uint32_t tti_tx_dl, dl_sched_list_t& dl_sched_res_list)
   }
 
   // Count number of TTIs for all active users
-  {
-    srsran::rwlock_read_guard lock(rwlock);
   for (auto& u : ue_db) {
     u.second->metrics_cnt();
   }
-  }
 
   return SRSRAN_SUCCESS;
 }