sched,nr: implementation of main classes for NR scheduler, and basic test for concurrency

srsenb/hdr/stack/mac/nr/sched_nr.h

@@ -0,0 +1,65 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#ifndef SRSRAN_SCHED_NR_H
+#define SRSRAN_SCHED_NR_H
+
+#include "sched_nr_common.h"
+#include "sched_nr_interface.h"
+#include "sched_nr_ue.h"
+#include "sched_nr_worker.h"
+#include "srsran/adt/pool/cached_alloc.h"
+#include "srsran/common/tti_point.h"
+#include <array>
+extern "C" {
+#include "srsran/config.h"
+}
+
+namespace srsenb {
+
+class ue_event_manager;
+
+class sched_nr final : public sched_nr_interface
+{
+public:
+  sched_nr(const sched_nr_cfg& cfg);
+  ~sched_nr() override;
+  void ue_cfg(uint16_t rnti, const sched_nr_ue_cfg& cfg) override;
+
+  void new_tti(tti_point tti_rx) override;
+  int  generate_sched_result(tti_point tti_rx, uint32_t cc, sched_nr_res_t& result);
+
+  void dl_ack_info(tti_point tti_rx, uint16_t rnti, uint32_t cc, uint32_t tb_idx, bool ack) override;
+  void ul_sr_info(tti_point tti_rx, uint16_t rnti) override;
+
+private:
+  void ue_cfg_impl(uint16_t rnti, const sched_nr_ue_cfg& cfg);
+  void run_tti(tti_point tti_rx, uint32_t cc);
+
+  sched_nr_cfg cfg;
+
+  using sched_worker_manager = sched_nr_impl::sched_worker_manager;
+  sched_worker_manager sched_workers;
+
+  std::array<std::array<sched_nr_res_t, SCHED_NR_MAX_CARRIERS>, SCHED_NR_MAX_CARRIERS> sched_results;
+
+  using ue_map_t = sched_nr_impl::ue_map_t;
+  std::mutex ue_db_mutex;
+  ue_map_t   ue_db;
+
+  // management of PHY UE feedback
+  std::unique_ptr<ue_event_manager> pending_events;
+};
+
+} // namespace srsenb
+
+#endif // SRSRAN_SCHED_NR_H

srsenb/hdr/stack/mac/nr/sched_nr_common.h

@@ -0,0 +1,25 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#ifndef SRSRAN_SCHED_NR_COMMON_H
+#define SRSRAN_SCHED_NR_COMMON_H
+
+#include "srsran/adt/circular_map.h"
+
+namespace srsenb {
+
+const static size_t SCHED_NR_MAX_USERS     = 4;
+const static size_t SCHED_NR_NOF_SUBFRAMES = 10;
+
+} // namespace srsenb
+
+#endif // SRSRAN_SCHED_NR_COMMON_H

srsenb/hdr/stack/mac/nr/sched_nr_harq.h

@@ -0,0 +1,61 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#ifndef SRSRAN_SCHED_NR_HARQ_H
+#define SRSRAN_SCHED_NR_HARQ_H
+
+#include "srsran/common/tti_point.h"
+#include <array>
+
+namespace srsenb {
+namespace sched_nr_impl {
+
+template <size_t NofTbs>
+class harq
+{
+public:
+  harq() = default;
+
+  bool empty() const
+  {
+    return std::all_of(tb.begin(), tb.end(), [](const tb_t t) { return not t.active; });
+  }
+  bool empty(uint32_t tb_idx) const { return tb[tb_idx].active; }
+
+private:
+  struct tb_t {
+    bool     active    = false;
+    bool     ack_state = false;
+    bool     ndi       = false;
+    uint32_t n_rtx     = 0;
+    uint32_t mcs       = 0;
+  };
+
+  uint32_t                 id;
+  tti_point                tti_tx;
+  std::array<tb_t, NofTbs> tb;
+};
+
+class harq_entity
+{
+public:
+  void dl_ack_info(tti_point tti_rx, uint32_t tb_idx, bool ack) {}
+
+private:
+  std::array<harq<1>, 16> dl_harqs;
+  std::array<harq<1>, 16> ul_harqs;
+};
+
+} // namespace sched_nr_impl
+} // namespace srsenb
+
+#endif // SRSRAN_SCHED_NR_HARQ_H

srsenb/hdr/stack/mac/nr/sched_nr_interface.h

@@ -0,0 +1,58 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#ifndef SRSRAN_SCHED_NR_INTERFACE_H
+#define SRSRAN_SCHED_NR_INTERFACE_H
+
+#include "srsran/adt/bounded_vector.h"
+#include "srsran/common/tti_point.h"
+
+namespace srsenb {
+
+const static size_t   SCHED_NR_MAX_CARRIERS = 4;
+const static uint16_t SCHED_NR_INVALID_RNTI = 0;
+
+struct sched_nr_cell_cfg {};
+
+struct sched_nr_cfg {
+  uint32_t nof_concurrent_subframes = 1;
+
+  srsran::bounded_vector<sched_nr_cell_cfg, SCHED_NR_MAX_CARRIERS> cells;
+};
+
+struct sched_nr_ue_cc_cfg {
+  bool active = false;
+};
+
+struct sched_nr_ue_cfg {
+  srsran::bounded_vector<sched_nr_ue_cc_cfg, SCHED_NR_MAX_CARRIERS> carriers;
+};
+
+struct sched_nr_res_t {
+  struct dl_result {};
+  struct ul_result {};
+};
+
+class sched_nr_interface
+{
+public:
+  virtual ~sched_nr_interface()                                     = default;
+  virtual void ue_cfg(uint16_t rnti, const sched_nr_ue_cfg& ue_cfg) = 0;
+  virtual void new_tti(tti_point tti_rx)                            = 0;
+
+  virtual void dl_ack_info(tti_point tti_rx, uint16_t rnti, uint32_t cc, uint32_t tb_idx, bool ack) = 0;
+  virtual void ul_sr_info(tti_point, uint16_t rnti)                                                 = 0;
+};
+
+} // namespace srsenb
+
+#endif // SRSRAN_SCHED_NR_INTERFACE_H

srsenb/hdr/stack/mac/nr/sched_nr_ue.h

@@ -0,0 +1,101 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#ifndef SRSRAN_SCHED_NR_UE_H
+#define SRSRAN_SCHED_NR_UE_H
+
+#include "sched_nr_common.h"
+#include "sched_nr_harq.h"
+#include "sched_nr_interface.h"
+#include "srsran/adt/move_callback.h"
+#include "srsran/adt/pool/cached_alloc.h"
+
+namespace srsenb {
+
+namespace sched_nr_impl {
+
+class ue_carrier;
+
+class bwp_ue
+{
+public:
+  bwp_ue() = default;
+  explicit bwp_ue(ue_carrier& carrier_, tti_point tti_rx_);
+  ~bwp_ue();
+  bwp_ue(bwp_ue&& other) noexcept : carrier(other.carrier) { other.carrier = nullptr; }
+  bwp_ue& operator=(bwp_ue&& other) noexcept
+  {
+    carrier       = other.carrier;
+    other.carrier = nullptr;
+    return *this;
+  }
+  bool empty() const { return carrier == nullptr; }
+
+  tti_point tti_rx;
+  uint32_t  cc = SCHED_NR_MAX_CARRIERS;
+
+  const sched_nr_ue_cfg* cfg = nullptr;
+  bool                   pending_sr;
+
+private:
+  ue_carrier* carrier = nullptr;
+};
+
+class ue_carrier
+{
+public:
+  ue_carrier(uint16_t rnti, uint32_t cc, const sched_nr_ue_cfg& cfg);
+  bwp_ue try_reserve(tti_point tti_rx);
+  void   push_feedback(srsran::move_callback<void(ue_carrier&)> callback);
+
+  const uint16_t rnti;
+  const uint32_t cc;
+
+  harq_entity harq_ent;
+
+private:
+  friend class bwp_ue;
+  void release() { busy = false; }
+
+  const sched_nr_ue_cfg* cfg;
+
+  srsran::deque<srsran::move_callback<void(ue_carrier&)> > pending_feedback;
+  bool                                                     busy{false};
+};
+
+class ue
+{
+public:
+  ue(uint16_t rnti, const sched_nr_ue_cfg& cfg);
+
+  bwp_ue try_reserve(tti_point tti_rx, uint32_t cc);
+
+  void set_cfg(const sched_nr_ue_cfg& cfg);
+
+  void ul_sr_info(tti_point tti_rx) { pending_sr = true; }
+
+  std::array<std::unique_ptr<ue_carrier>, SCHED_NR_MAX_CARRIERS> carriers;
+
+private:
+  bool pending_sr = false;
+
+  int                            current_idx = 0;
+  std::array<sched_nr_ue_cfg, 4> ue_cfgs;
+};
+
+using ue_map_t = srsran::static_circular_map<uint16_t, std::unique_ptr<ue>, SCHED_NR_MAX_USERS>;
+
+} // namespace sched_nr_impl
+
+} // namespace srsenb
+
+#endif // SRSRAN_SCHED_NR_UE_H

srsenb/hdr/stack/mac/nr/sched_nr_worker.h

@@ -0,0 +1,79 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#ifndef SRSRAN_SCHED_NR_WORKER_H
+#define SRSRAN_SCHED_NR_WORKER_H
+
+#include "sched_nr_common.h"
+#include "sched_nr_ue.h"
+#include "srsran/adt/circular_array.h"
+#include "srsran/adt/optional.h"
+#include "srsran/adt/pool/cached_alloc.h"
+#include "srsran/adt/span.h"
+#include <condition_variable>
+#include <mutex>
+#include <semaphore.h>
+
+namespace srsenb {
+namespace sched_nr_impl {
+
+class bwp_worker
+{
+public:
+  explicit bwp_worker(uint32_t cc_, ue_map_t& ue_db_) : cc(cc_), ue_db(ue_db_) {}
+
+  void start(tti_point tti_rx_);
+  void run();
+  void end_tti();
+  bool running() const { return tti_rx.is_valid(); }
+
+private:
+  ue_map_t& ue_db;
+
+  tti_point tti_rx;
+  uint32_t  cc;
+
+  srsran::circular_array<bwp_ue, SCHED_NR_MAX_USERS> bwp_ues;
+};
+
+class sched_worker_manager
+{
+public:
+  explicit sched_worker_manager(ue_map_t& ue_db_, const sched_nr_cfg& cfg_);
+  sched_worker_manager(const sched_worker_manager&) = delete;
+  sched_worker_manager(sched_worker_manager&&)      = delete;
+  ~sched_worker_manager();
+
+  void reserve_workers(tti_point tti_rx, srsran::span<sched_nr_res_t> sf_result_);
+  void start_tti(tti_point tti_rx);
+  bool run_tti(tti_point tti_rx, uint32_t cc);
+  void end_tti(tti_point tti_rx);
+
+private:
+  const sched_nr_cfg& cfg;
+
+  struct sf_worker_ctxt {
+    sem_t                        sf_sem;
+    tti_point                    tti_rx;
+    srsran::span<sched_nr_res_t> sf_result;
+    int                          worker_count = 0;
+    std::vector<bwp_worker>      workers;
+  };
+  std::vector<std::unique_ptr<sf_worker_ctxt> > sf_ctxts;
+
+  sf_worker_ctxt& get_sf(tti_point tti_rx);
+};
+
+} // namespace sched_nr_impl
+} // namespace srsenb
+
+#endif // SRSRAN_SCHED_NR_WORKER_H

srsenb/src/stack/mac/CMakeLists.txt

@@ -14,5 +14,4 @@ set(SOURCES mac.cc ue.cc sched.cc sched_carrier.cc sched_grid.cc sched_ue_ctrl/s
             sched_helpers.cc)
 add_library(srsenb_mac STATIC ${SOURCES} $<TARGET_OBJECTS:mac_schedulers>)
 
-set(SOURCES mac_nr.cc)
+add_subdirectory(nr)
-add_library(srsgnb_mac STATIC ${SOURCES})

srsenb/src/stack/mac/nr/CMakeLists.txt

@@ -0,0 +1,11 @@
+#
+# Copyright 2013-2021 Software Radio Systems Limited
+#
+# By using this file, you agree to the terms and conditions set
+# forth in the LICENSE file which can be found at the top level of
+# the distribution.
+#
+
+set(SOURCES mac_nr.cc sched_nr.cc sched_nr_ue.cc sched_nr_worker.cc)
+
+add_library(srsgnb_mac STATIC ${SOURCES})

srsenb/src/stack/mac/nr/sched_nr.cc

@@ -0,0 +1,154 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#include "srsenb/hdr/stack/mac/nr/sched_nr.h"
+#include "srsran/common/thread_pool.h"
+
+namespace srsenb {
+
+using sched_nr_impl::bwp_worker;
+using sched_nr_impl::sched_worker_manager;
+using sched_nr_impl::ue;
+using sched_nr_impl::ue_carrier;
+using sched_nr_impl::ue_map_t;
+
+class ue_event_manager
+{
+  using callback_t    = srsran::move_callback<void()>;
+  using callback_list = srsran::deque<callback_t>;
+
+public:
+  explicit ue_event_manager(ue_map_t& ue_db_) : ue_db(ue_db_) {}
+
+  void push_event(srsran::move_callback<void()> event)
+  {
+    std::lock_guard<std::mutex> lock(common_mutex);
+    common_events.push_back(std::move(event));
+  }
+  void push_cc_feedback(uint16_t rnti, uint32_t cc, srsran::move_callback<void(ue_carrier&)> event)
+  {
+    std::lock_guard<std::mutex> lock(common_mutex);
+    feedback_list.emplace_back();
+    feedback_list.back().rnti     = rnti;
+    feedback_list.back().cc       = cc;
+    feedback_list.back().callback = std::move(event);
+  }
+  void new_tti()
+  {
+    {
+      std::lock_guard<std::mutex> lock(common_mutex);
+      common_events.swap(common_events_tmp); // reuse memory
+      feedback_list.swap(feedback_list_tmp);
+    }
+    while (not common_events_tmp.empty()) {
+      common_events_tmp.front()();
+      common_events_tmp.pop_front();
+    }
+    while (not feedback_list_tmp.empty()) {
+      auto& e = feedback_list_tmp.front();
+      if (ue_db.contains(e.rnti) and ue_db[e.rnti]->carriers[e.cc] != nullptr) {
+        ue_db[e.rnti]->carriers[e.cc]->push_feedback(std::move(e.callback));
+      }
+    }
+  }
+
+private:
+  ue_map_t& ue_db;
+
+  std::mutex    common_mutex;
+  callback_list common_events;
+  struct ue_feedback {
+    uint16_t                                 rnti = SCHED_NR_INVALID_RNTI;
+    uint32_t                                 cc   = SCHED_NR_MAX_CARRIERS;
+    srsran::move_callback<void(ue_carrier&)> callback;
+  };
+  srsran::deque<ue_feedback> feedback_list;
+  callback_list              common_events_tmp;
+  srsran::deque<ue_feedback> feedback_list_tmp;
+};
+
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+sched_nr::sched_nr(const sched_nr_cfg& cfg_) :
+  cfg(cfg_), pending_events(new ue_event_manager(ue_db)), sched_workers(ue_db, cfg)
+{}
+
+sched_nr::~sched_nr() {}
+
+void sched_nr::ue_cfg(uint16_t rnti, const sched_nr_ue_cfg& uecfg)
+{
+  pending_events->push_event([this, rnti, uecfg]() { ue_cfg_impl(rnti, uecfg); });
+}
+
+void sched_nr::ue_cfg_impl(uint16_t rnti, const sched_nr_ue_cfg& uecfg)
+{
+  if (not ue_db.contains(rnti)) {
+    ue_db.insert(rnti, std::unique_ptr<ue>(new ue{rnti, uecfg}));
+  } else {
+    ue_db[rnti]->set_cfg(uecfg);
+  }
+}
+
+void sched_nr::new_tti(tti_point tti_rx)
+{
+  // Lock subframe workers to provided tti_rx
+  sched_workers.reserve_workers(tti_rx, sched_results[tti_rx.sf_idx()]);
+
+  {
+    // synchronize {tti,cc} state. e.g. reserve UE resources for {tti,cc} decision, process feedback
+    std::lock_guard<std::mutex> lock(ue_db_mutex);
+    // Process pending events
+    pending_events->new_tti();
+
+    sched_workers.start_tti(tti_rx);
+  }
+}
+
+int sched_nr::generate_sched_result(tti_point tti_rx, uint32_t cc, sched_nr_res_t& result)
+{
+  // Generate {tti,cc} scheduling decision
+  run_tti(tti_rx, cc);
+
+  // copy scheduling decision result
+  result = sched_results[tti_rx.sf_idx()][cc];
+
+  return SRSRAN_SUCCESS;
+}
+
+void sched_nr::run_tti(tti_point tti_rx, uint32_t cc)
+{
+  // unlocked, parallel region
+  bool all_workers_finished = sched_workers.run_tti(tti_rx, cc);
+
+  if (all_workers_finished) {
+    // once all workers of the same subframe finished, synchronize sched outcome with ue_db
+    std::lock_guard<std::mutex> lock(ue_db_mutex);
+    sched_workers.end_tti(tti_rx);
+  }
+}
+
+void sched_nr::dl_ack_info(tti_point tti_rx, uint16_t rnti, uint32_t cc, uint32_t tb_idx, bool ack)
+{
+  pending_events->push_cc_feedback(
+      rnti, cc, [tti_rx, tb_idx, ack](ue_carrier& ue_cc) { ue_cc.harq_ent.dl_ack_info(tti_rx, tb_idx, ack); });
+}
+
+void sched_nr::ul_sr_info(tti_point tti_rx, uint16_t rnti)
+{
+  pending_events->push_event([this, rnti, tti_rx]() {
+    if (ue_db.contains(rnti)) {
+      ue_db[rnti]->ul_sr_info(tti_rx);
+    }
+  });
+}
+
+} // namespace srsenb

srsenb/src/stack/mac/nr/sched_nr_ue.cc

@@ -0,0 +1,80 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#include "srsenb/hdr/stack/mac/nr/sched_nr_ue.h"
+
+namespace srsenb {
+namespace sched_nr_impl {
+
+bwp_ue::bwp_ue(ue_carrier& carrier_, tti_point tti_rx_) : carrier(&carrier_), tti_rx(tti_rx_), cc(carrier_.cc) {}
+
+bwp_ue::~bwp_ue()
+{
+  if (carrier != nullptr) {
+    carrier->release();
+  }
+}
+
+ue_carrier::ue_carrier(uint16_t rnti_, uint32_t cc_, const sched_nr_ue_cfg& cfg_) : rnti(rnti_), cc(cc_), cfg(&cfg_) {}
+
+void ue_carrier::push_feedback(srsran::move_callback<void(ue_carrier&)> callback)
+{
+  pending_feedback.push_back(std::move(callback));
+}
+
+bwp_ue ue_carrier::try_reserve(tti_point tti_rx)
+{
+  if (busy) {
+    return bwp_ue();
+  }
+  // successfully acquired
+  busy = true;
+  while (not pending_feedback.empty()) {
+    pending_feedback.front()(*this);
+    pending_feedback.pop_front();
+  }
+  return bwp_ue(*this, tti_rx);
+}
+
+ue::ue(uint16_t rnti, const sched_nr_ue_cfg& cfg)
+{
+  for (uint32_t cc = 0; cc < cfg.carriers.size(); ++cc) {
+    if (cfg.carriers[cc].active) {
+      carriers[cc].reset(new ue_carrier(rnti, cc, cfg));
+    }
+  }
+}
+
+void ue::set_cfg(const sched_nr_ue_cfg& cfg)
+{
+  current_idx          = (current_idx + 1) % ue_cfgs.size();
+  ue_cfgs[current_idx] = cfg;
+}
+
+bwp_ue ue::try_reserve(tti_point tti_rx, uint32_t cc)
+{
+  if (carriers[cc] == nullptr) {
+    return bwp_ue();
+  }
+  bwp_ue sfu = carriers[cc]->try_reserve(tti_rx);
+  if (sfu.empty()) {
+    return bwp_ue();
+  }
+  // set UE-common parameters
+  sfu.pending_sr = pending_sr;
+  sfu.cfg        = &ue_cfgs[current_idx];
+
+  return sfu;
+}
+
+} // namespace sched_nr_impl
+} // namespace srsenb

srsenb/src/stack/mac/nr/sched_nr_worker.cc

@@ -0,0 +1,139 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#include "srsenb/hdr/stack/mac/nr/sched_nr_worker.h"
+
+namespace srsenb {
+namespace sched_nr_impl {
+
+/// Called at the beginning of TTI in a locked context, to reserve available UE resources
+void bwp_worker::start(tti_point tti_rx_)
+{
+  srsran_assert(not running(), "scheduler worker::start() called for active worker");
+  // Try reserve UE cells for this worker
+  for (auto& ue_pair : ue_db) {
+    uint16_t rnti = ue_pair.first;
+    ue&      u    = *ue_pair.second;
+
+    bwp_ue sfu0 = u.try_reserve(tti_rx, cc);
+    if (sfu0.empty()) {
+      // Failed to synchronize because UE is being used by another worker
+      continue;
+    }
+    // Synchronization of UE for this {tti, cc} was successful
+    bwp_ues[rnti] = std::move(sfu0);
+  }
+
+  tti_rx = tti_rx_;
+}
+
+void bwp_worker::run()
+{
+  srsran_assert(running(), "scheduler worker::run() called for non-active worker");
+}
+
+void bwp_worker::end_tti()
+{
+  srsran_assert(running(), "scheduler worker::end() called for non-active worker");
+
+  // releases UE resources
+  for (bwp_ue& u : bwp_ues) {
+    if (not u.empty()) {
+      u = {};
+    }
+  }
+
+  tti_rx = {};
+}
+
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+sched_worker_manager::sched_worker_manager(ue_map_t& ue_db_, const sched_nr_cfg& cfg_) : cfg(cfg_)
+{
+  // Note: For now, we only allow parallelism at the sector level
+  sf_ctxts.resize(cfg.nof_concurrent_subframes);
+  for (size_t i = 0; i < cfg.nof_concurrent_subframes; ++i) {
+    sf_ctxts[i].reset(new sf_worker_ctxt());
+    sem_init(&sf_ctxts[i]->sf_sem, 0, 1);
+    sf_ctxts[i]->workers.reserve(cfg.cells.size());
+    for (uint32_t cc = 0; cc < cfg.cells.size(); ++cc) {
+      sf_ctxts[i]->workers.emplace_back(cc, ue_db_);
+    }
+  }
+}
+
+sched_worker_manager::~sched_worker_manager()
+{
+  for (uint32_t sf = 0; sf < sf_ctxts.size(); ++sf) {
+    sem_destroy(&sf_ctxts[sf]->sf_sem);
+  }
+}
+
+sched_worker_manager::sf_worker_ctxt& sched_worker_manager::get_sf(tti_point tti_rx)
+{
+  return *sf_ctxts[tti_rx.to_uint() % sf_ctxts.size()];
+}
+
+void sched_worker_manager::reserve_workers(tti_point tti_rx_, srsran::span<sched_nr_res_t> sf_result_)
+{
+  // lock if slot worker is already being used
+  auto& sf_worker_ctxt = get_sf(tti_rx_);
+  sem_wait(&sf_worker_ctxt.sf_sem);
+
+  sf_worker_ctxt.sf_result    = sf_result_;
+  sf_worker_ctxt.tti_rx       = tti_rx_;
+  sf_worker_ctxt.worker_count = sf_worker_ctxt.workers.size();
+}
+
+void sched_worker_manager::start_tti(tti_point tti_rx_)
+{
+  auto& sf_worker_ctxt = get_sf(tti_rx_);
+  srsran_assert(sf_worker_ctxt.tti_rx == tti_rx_, "invalid run_tti(tti, cc) arguments");
+
+  for (uint32_t cc = 0; cc < sf_worker_ctxt.workers.size(); ++cc) {
+    sf_worker_ctxt.workers[cc].start(sf_worker_ctxt.tti_rx);
+  }
+}
+
+bool sched_worker_manager::run_tti(tti_point tti_rx_, uint32_t cc)
+{
+  auto& sf_worker_ctxt = get_sf(tti_rx_);
+  srsran_assert(sf_worker_ctxt.tti_rx == tti_rx_, "invalid run_tti(tti, cc) arguments");
+  if (not sf_worker_ctxt.workers[cc].running()) {
+    // run for this tti and cc was already called
+    return false;
+  }
+
+  // Get {tti, cc} scheduling decision
+  sf_worker_ctxt.workers[cc].run();
+
+  // decrement the number of active workers
+  --sf_worker_ctxt.worker_count;
+  srsran_assert(sf_worker_ctxt.worker_count >= 0, "invalid number of calls to run_tti(tti, cc)");
+  return sf_worker_ctxt.worker_count == 0;
+}
+
+void sched_worker_manager::end_tti(tti_point tti_rx_)
+{
+  auto& sf_worker_ctxt = get_sf(tti_rx_);
+  srsran_assert(sf_worker_ctxt.tti_rx == tti_rx_, "invalid run_tti(tti, cc) arguments");
+  srsran_assert(sf_worker_ctxt.worker_count == 0, "invalid number of calls to run_tti(tti, cc)");
+
+  // All the workers of the same TTI have finished. Synchronize scheduling decisions with UEs state
+  for (auto& worker : sf_worker_ctxt.workers) {
+    worker.end_tti();
+  }
+  sem_post(&sf_worker_ctxt.sf_sem);
+}
+
+} // namespace sched_nr_impl
+} // namespace srsenb

srsenb/test/mac/CMakeLists.txt

@@ -74,3 +74,5 @@ add_test(sched_cqi_test sched_cqi_test)
 add_executable(sched_phy_resource_test sched_phy_resource_test.cc)
 target_link_libraries(sched_phy_resource_test srsran_common srsenb_mac srsran_mac sched_test_common)
 add_test(sched_phy_resource_test sched_phy_resource_test)
+
+add_subdirectory(nr)

srsenb/test/mac/nr/CMakeLists.txt

@@ -0,0 +1,15 @@
+#
+# Copyright 2013-2021 Software Radio Systems Limited
+#
+# By using this file, you agree to the terms and conditions set
+# forth in the LICENSE file which can be found at the top level of
+# the distribution.
+#
+
+add_executable(sched_nr_test sched_nr_test.cc)
+target_link_libraries(sched_nr_test
+        srsgnb_mac
+        srsran_common
+        ${CMAKE_THREAD_LIBS_INIT}
+        ${Boost_LIBRARIES})
+add_test(sched_nr_test sched_nr_test)

srsenb/test/mac/nr/sched_nr_test.cc

@@ -0,0 +1,120 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#include "srsenb/hdr/stack/mac/nr/sched_nr.h"
+#include "srsran/common/test_common.h"
+#include "srsran/common/thread_pool.h"
+
+namespace srsenb {
+
+void sched_nr_cfg_serialized_test()
+{
+  sched_nr_cfg cfg;
+  cfg.cells.resize(1);
+
+  sched_nr sched(cfg);
+
+  sched_nr_ue_cfg uecfg;
+  uecfg.carriers.resize(1);
+  uecfg.carriers[0].active = true;
+  sched.ue_cfg(0x46, uecfg);
+
+  for (uint32_t nof_ttis = 0; nof_ttis < 1000; ++nof_ttis) {
+    tti_point tti(nof_ttis % 10240);
+    sched.new_tti(tti);
+    for (uint32_t cc = 0; cc < cfg.cells.size(); ++cc) {
+      sched_nr_res_t res;
+      TESTASSERT(sched.generate_sched_result(tti, cc, res) == SRSRAN_SUCCESS);
+    }
+  }
+}
+
+void sched_nr_cfg_parallel_cc_test()
+{
+  std::atomic<int> tasks{0};
+
+  sched_nr_cfg cfg;
+  cfg.cells.resize(4);
+
+  sched_nr sched(cfg);
+
+  sched_nr_ue_cfg uecfg;
+  uecfg.carriers.resize(cfg.cells.size());
+  for (uint32_t cc = 0; cc < cfg.cells.size(); ++cc) {
+    uecfg.carriers[cc].active = true;
+  }
+  sched.ue_cfg(0x46, uecfg);
+
+  for (uint32_t nof_ttis = 0; nof_ttis < 1000; ++nof_ttis) {
+    tti_point tti(nof_ttis % 10240);
+    sched.new_tti(tti);
+    ++tasks;
+    srsran::get_background_workers().push_task([&cfg, &sched, tti, &tasks]() {
+      for (uint32_t cc = 0; cc < cfg.cells.size(); ++cc) {
+        sched_nr_res_t res;
+        TESTASSERT(sched.generate_sched_result(tti, cc, res) == SRSRAN_SUCCESS);
+      }
+      --tasks;
+    });
+  }
+
+  while (tasks > 0) {
+    usleep(100);
+  }
+}
+
+void sched_nr_cfg_parallel_sf_test()
+{
+  uint32_t         nof_sectors = 2;
+  std::atomic<int> tasks{0};
+
+  sched_nr_cfg cfg;
+  cfg.nof_concurrent_subframes = 2;
+  cfg.cells.resize(nof_sectors);
+
+  sched_nr sched(cfg);
+
+  sched_nr_ue_cfg uecfg;
+  uecfg.carriers.resize(cfg.cells.size());
+  for (uint32_t cc = 0; cc < cfg.cells.size(); ++cc) {
+    uecfg.carriers[cc].active = true;
+  }
+  sched.ue_cfg(0x46, uecfg);
+
+  for (uint32_t nof_ttis = 0; nof_ttis < 1000; ++nof_ttis) {
+    tti_point tti(nof_ttis % 10240);
+    sched.new_tti(tti);
+    ++tasks;
+    srsran::get_background_workers().push_task([&cfg, &sched, tti, &tasks]() {
+      for (uint32_t cc = 0; cc < cfg.cells.size(); ++cc) {
+        sched_nr_res_t res;
+        TESTASSERT(sched.generate_sched_result(tti, cc, res) == SRSRAN_SUCCESS);
+      }
+      --tasks;
+    });
+  }
+
+  while (tasks > 0) {
+    usleep(100);
+  }
+}
+
+} // namespace srsenb
+
+int main()
+{
+  srsran::get_background_workers().set_nof_workers(4);
+
+  srsenb::sched_nr_cfg_serialized_test();
+  srsenb::sched_nr_cfg_parallel_cc_test();
+  srsenb::sched_nr_cfg_parallel_sf_test();
+}