From 581a99c616dde3833828bcd67874c8ee3c7b979d Mon Sep 17 00:00:00 2001
From: Francisco <francisco.paisana@softwareradiosystems.com>
Date: Tue, 15 Feb 2022 12:44:14 +0000
Subject: [PATCH] nr,gnb: use memory pool to allocate scheduler UEs

---
 .../srsran/adt/pool/circular_stack_pool.h        | 16 ++++++++++++++++
 srsgnb/hdr/stack/mac/sched_nr.h                  |  5 ++++-
 srsgnb/hdr/stack/mac/sched_nr_ue.h               |  4 +++-
 srsgnb/src/stack/mac/sched_nr.cc                 | 10 ++++++++--
 4 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/lib/include/srsran/adt/pool/circular_stack_pool.h b/lib/include/srsran/adt/pool/circular_stack_pool.h
index 2228e8d29..640ff6b13 100644
--- a/lib/include/srsran/adt/pool/circular_stack_pool.h
+++ b/lib/include/srsran/adt/pool/circular_stack_pool.h
@@ -107,6 +107,22 @@ private:
   srslog::basic_logger&                               logger;
 };
 
+template <typename T, size_t N, typename... Args>
+unique_pool_ptr<T> make_pool_obj_with_fallback(circular_stack_pool<N>& pool, size_t key, Args&&... args)
+{
+  void* block = pool.allocate(key, sizeof(T), alignof(T));
+  if (block == nullptr) {
+    // allocated with "new" as a fallback
+    return unique_pool_ptr<T>(new T(std::forward<Args>(args)...), std::default_delete<T>());
+  }
+  // allocation using memory pool was successful
+  new (block) T(std::forward<Args>(args)...);
+  return unique_pool_ptr<T>(static_cast<T*>(block), [key, &pool](T* ptr) {
+    ptr->~T();
+    pool.deallocate(key, ptr);
+  });
+}
+
 } // namespace srsran
 
 #endif // SRSRAN_CIRCULAR_MAP_STACK_POOL_H
diff --git a/srsgnb/hdr/stack/mac/sched_nr.h b/srsgnb/hdr/stack/mac/sched_nr.h
index 2041d09d4..144d9261d 100644
--- a/srsgnb/hdr/stack/mac/sched_nr.h
+++ b/srsgnb/hdr/stack/mac/sched_nr.h
@@ -17,6 +17,7 @@
 #include "sched_nr_interface.h"
 #include "sched_nr_ue.h"
 #include "srsran/adt/pool/cached_alloc.h"
+#include "srsran/adt/pool/circular_stack_pool.h"
 #include "srsran/common/slot_point.h"
 #include <array>
 extern "C" {
@@ -61,7 +62,7 @@ public:
 
 private:
   int ue_cfg_impl(uint16_t rnti, const ue_cfg_t& cfg);
-  int add_ue_impl(uint16_t rnti, std::unique_ptr<sched_nr_impl::ue> u);
+  int add_ue_impl(uint16_t rnti, sched_nr_impl::unique_ue_ptr u);
 
   // args
   sched_nr_impl::sched_params_t cfg;
@@ -74,6 +75,8 @@ private:
   using slot_cc_worker = sched_nr_impl::cc_worker;
   std::vector<std::unique_ptr<sched_nr_impl::cc_worker> > cc_workers;
 
+  // UE Database
+  std::unique_ptr<srsran::circular_stack_pool<SRSENB_MAX_UES> > ue_pool;
   using ue_map_t = sched_nr_impl::ue_map_t;
   ue_map_t ue_db;
 
diff --git a/srsgnb/hdr/stack/mac/sched_nr_ue.h b/srsgnb/hdr/stack/mac/sched_nr_ue.h
index b6cd93699..0fd4eb123 100644
--- a/srsgnb/hdr/stack/mac/sched_nr_ue.h
+++ b/srsgnb/hdr/stack/mac/sched_nr_ue.h
@@ -22,6 +22,7 @@
 #include "srsran/adt/circular_map.h"
 #include "srsran/adt/move_callback.h"
 #include "srsran/adt/pool/cached_alloc.h"
+#include "srsran/adt/pool/pool_interface.h"
 
 namespace srsenb {
 
@@ -205,7 +206,8 @@ private:
   ue_carrier* ue = nullptr;
 };
 
-using ue_map_t      = rnti_map_t<std::unique_ptr<ue> >;
+using unique_ue_ptr = srsran::unique_pool_ptr<ue>;
+using ue_map_t      = rnti_map_t<unique_ue_ptr>;
 using slot_ue_map_t = rnti_map_t<slot_ue>;
 
 } // namespace sched_nr_impl
diff --git a/srsgnb/src/stack/mac/sched_nr.cc b/srsgnb/src/stack/mac/sched_nr.cc
index 9176611a3..0c95a0739 100644
--- a/srsgnb/src/stack/mac/sched_nr.cc
+++ b/srsgnb/src/stack/mac/sched_nr.cc
@@ -295,6 +295,9 @@ int sched_nr::config(const sched_args_t& sched_cfg, srsran::const_span<sched_nr_
   cfg    = sched_params_t{sched_cfg};
   logger = &srslog::fetch_basic_logger(sched_cfg.logger_name);
 
+  // Initiate UE memory pool
+  ue_pool.reset(new srsran::circular_stack_pool<SRSENB_MAX_UES>(8, sizeof(ue), 4));
+
   // Initiate Common Sched Configuration
   cfg.cells.reserve(cell_list.size());
   for (uint32_t cc = 0; cc < cell_list.size(); ++cc) {
@@ -333,7 +336,7 @@ void sched_nr::ue_rem(uint16_t rnti)
   });
 }
 
-int sched_nr::add_ue_impl(uint16_t rnti, std::unique_ptr<sched_nr_impl::ue> u)
+int sched_nr::add_ue_impl(uint16_t rnti, sched_nr_impl::unique_ue_ptr u)
 {
   logger->info("SCHED: New user rnti=0x%x, cc=%d", rnti, cfg.cells[0].cc);
   return ue_db.insert(rnti, std::move(u)).has_value() ? SRSRAN_SUCCESS : SRSRAN_ERROR;
@@ -342,6 +345,8 @@ int sched_nr::add_ue_impl(uint16_t rnti, std::unique_ptr<sched_nr_impl::ue> u)
 int sched_nr::ue_cfg_impl(uint16_t rnti, const ue_cfg_t& uecfg)
 {
   if (not ue_db.contains(rnti)) {
+    // create user object
+    unique_ue_ptr u = srsran::make_pool_obj_with_fallback<ue>(*ue_pool, rnti, rnti, uecfg, cfg);
     return add_ue_impl(rnti, std::make_unique<ue>(rnti, uecfg, cfg));
   }
   ue_db[rnti]->set_cfg(uecfg);
@@ -416,7 +421,8 @@ void sched_nr::get_metrics(mac_metrics_t& metrics)
 int sched_nr::dl_rach_info(const rar_info_t& rar_info)
 {
   // create user object outside of sched main thread
-  std::unique_ptr<ue> u = std::make_unique<ue>(rar_info.temp_crnti, rar_info.cc, cfg);
+  unique_ue_ptr u =
+      srsran::make_pool_obj_with_fallback<ue>(*ue_pool, rar_info.temp_crnti, rar_info.temp_crnti, rar_info.cc, cfg);
 
   // enqueue UE creation event + RACH handling
   auto add_ue = [this, rar_info, u = std::move(u)](event_manager::logger& ev_logger) mutable {