From b5ccbf18919a52806ed9675a449d021a659ecbf7 Mon Sep 17 00:00:00 2001
From: Ismael Gomez <ismagom@gmail.com>
Date: Wed, 20 May 2020 12:16:44 +0200
Subject: [PATCH] Simplify relationship between BSR, SR and RA procedures. Fix
 issue #1346

---
 srsue/hdr/stack/mac/dl_harq.h   |  2 +-
 srsue/hdr/stack/mac/proc_bsr.h  | 11 +++--
 srsue/hdr/stack/mac/proc_sr.h   |  8 ++--
 srsue/src/stack/mac/dl_harq.cc  |  9 ++--
 srsue/src/stack/mac/mac.cc      | 24 ++---------
 srsue/src/stack/mac/proc_bsr.cc | 74 +++++++++++----------------------
 srsue/src/stack/mac/proc_sr.cc  | 21 ++--------
 7 files changed, 47 insertions(+), 102 deletions(-)

diff --git a/srsue/hdr/stack/mac/dl_harq.h b/srsue/hdr/stack/mac/dl_harq.h
index 867f70690..4561d4a09 100644
--- a/srsue/hdr/stack/mac/dl_harq.h
+++ b/srsue/hdr/stack/mac/dl_harq.h
@@ -85,7 +85,7 @@ private:
       // Determine if it's a new transmission 5.3.2.2
       bool calc_is_new_transmission(mac_interface_phy_lte::mac_grant_dl_t grant);
 
-      pthread_mutex_t mutex;
+      std::mutex mutex;
 
       bool            is_initiated;
       dl_harq_entity* harq_entity;
diff --git a/srsue/hdr/stack/mac/proc_bsr.h b/srsue/hdr/stack/mac/proc_bsr.h
index 12724a474..a6fc1fb5a 100644
--- a/srsue/hdr/stack/mac/proc_bsr.h
+++ b/srsue/hdr/stack/mac/proc_bsr.h
@@ -25,6 +25,7 @@
 #include <map>
 #include <stdint.h>
 
+#include "proc_sr.h"
 #include "srslte/common/logmap.h"
 #include "srslte/common/timers.h"
 #include "srslte/interfaces/ue_interfaces.h"
@@ -55,7 +56,8 @@ class bsr_proc : public srslte::timer_callback, public bsr_interface_mux
 {
 public:
   bsr_proc();
-  void init(rlc_interface_mac* rlc, srslte::log_ref log_h, srslte::task_handler_interface* task_handler_);
+  void
+       init(sr_proc* sr_proc, rlc_interface_mac* rlc, srslte::log_ref log_h, srslte::task_handler_interface* task_handler_);
   void step(uint32_t tti);
   void reset();
   void set_config(srslte::bsr_cfg_t& bsr_cfg);
@@ -65,18 +67,16 @@ public:
   uint32_t get_buffer_state();
   bool     need_to_send_bsr_on_ul_grant(uint32_t grant_size, bsr_t* bsr);
   bool     generate_padding_bsr(uint32_t nof_padding_bytes, bsr_t* bsr);
-  bool     need_to_send_sr(uint32_t tti);
-  bool     need_to_reset_sr();
 
 private:
   const static int QUEUE_STATUS_PERIOD_MS = 1000;
 
-  pthread_mutex_t mutex;
+  std::mutex mutex;
 
-  bool                            reset_sr;
   srslte::task_handler_interface* task_handler;
   srslte::log_ref                 log_h;
   rlc_interface_mac*              rlc;
+  sr_proc*                        sr;
 
   srslte::bsr_cfg_t bsr_cfg;
 
@@ -96,7 +96,6 @@ private:
   typedef enum { NONE, REGULAR, PADDING, PERIODIC } triggered_bsr_type_t;
   triggered_bsr_type_t triggered_bsr_type;
 
-  bool     sr_is_sent;
   uint32_t current_tti;
   uint32_t trigger_tti;
 
diff --git a/srsue/hdr/stack/mac/proc_sr.h b/srsue/hdr/stack/mac/proc_sr.h
index f0237611b..59f721866 100644
--- a/srsue/hdr/stack/mac/proc_sr.h
+++ b/srsue/hdr/stack/mac/proc_sr.h
@@ -30,16 +30,18 @@
 
 namespace srsue {
 
+// Forward-declare ra_proc
+class ra_proc;
+
 class sr_proc
 {
 public:
   sr_proc();
-  void init(phy_interface_mac_lte* phy_h, rrc_interface_mac* rrc, srslte::log_ref log_h);
+  void init(ra_proc* ra, phy_interface_mac_lte* phy_h, rrc_interface_mac* rrc, srslte::log_ref log_h);
   void step(uint32_t tti);
   void set_config(srslte::sr_cfg_t& cfg);
   void reset();
   void start();
-  bool need_random_access();
 
 private:
   bool need_tx(uint32_t tti);
@@ -49,12 +51,12 @@ private:
 
   srslte::sr_cfg_t sr_cfg;
 
+  ra_proc*               ra;
   rrc_interface_mac*     rrc;
   phy_interface_mac_lte* phy_h;
   srslte::log_ref        log_h;
 
   bool initiated;
-  bool do_ra;
 };
 
 } // namespace srsue
diff --git a/srsue/src/stack/mac/dl_harq.cc b/srsue/src/stack/mac/dl_harq.cc
index ca0aa8a09..2760b9780 100644
--- a/srsue/src/stack/mac/dl_harq.cc
+++ b/srsue/src/stack/mac/dl_harq.cc
@@ -175,7 +175,6 @@ dl_harq_entity::dl_harq_process::dl_tb_process::dl_tb_process()
   n_retx       = 0;
   bzero(&cur_grant, sizeof(mac_interface_phy_lte::mac_grant_dl_t));
   payload_buffer_ptr = NULL;
-  pthread_mutex_init(&mutex, NULL);
 }
 
 dl_harq_entity::dl_harq_process::dl_tb_process::~dl_tb_process()
@@ -211,7 +210,7 @@ bool dl_harq_entity::dl_harq_process::dl_tb_process::init(int pid, dl_harq_entit
 void dl_harq_entity::dl_harq_process::dl_tb_process::reset(bool lock)
 {
   if (lock) {
-    pthread_mutex_lock(&mutex);
+    mutex.lock();
   }
 
   bzero(&cur_grant, sizeof(mac_interface_phy_lte::mac_grant_dl_t));
@@ -231,7 +230,7 @@ void dl_harq_entity::dl_harq_process::dl_tb_process::reset(bool lock)
   }
 
   if (lock) {
-    pthread_mutex_unlock(&mutex);
+    mutex.unlock();
   }
 }
 
@@ -244,7 +243,7 @@ void dl_harq_entity::dl_harq_process::dl_tb_process::new_grant_dl(mac_interface_
                                                                   mac_interface_phy_lte::tb_action_dl_t* action)
 {
 
-  pthread_mutex_lock(&mutex);
+  mutex.lock();
 
   // Compute RV for BCCH when not specified in PDCCH format
   if (is_bcch && grant.tb[tid].rv == -1) {
@@ -369,7 +368,7 @@ void dl_harq_entity::dl_harq_process::dl_tb_process::tb_decoded(mac_interface_ph
          cur_grant.tb[tid].ndi);
   }
 
-  pthread_mutex_unlock(&mutex);
+  mutex.unlock();
 
   if (ack && is_bcch) {
     reset();
diff --git a/srsue/src/stack/mac/mac.cc b/srsue/src/stack/mac/mac.cc
index 93d6aa338..e299242e5 100644
--- a/srsue/src/stack/mac/mac.cc
+++ b/srsue/src/stack/mac/mac.cc
@@ -85,12 +85,12 @@ bool mac::init(phy_interface_mac_lte*  phy,
   // Create Stack task dispatch queue
   stack_task_dispatch_queue = stack_h->make_task_queue();
 
-  bsr_procedure.init(rlc_h, log_h, stack_h);
+  bsr_procedure.init(&sr_procedure, rlc_h, log_h, stack_h);
   phr_procedure.init(phy_h, log_h, stack_h);
   mux_unit.init(rlc_h, &bsr_procedure, &phr_procedure);
   demux_unit.init(phy_h, rlc_h, this, &timer_alignment);
   ra_procedure.init(phy_h, rrc, log_h, &uernti, &timer_alignment, &mux_unit, stack_h);
-  sr_procedure.init(phy_h, rrc, log_h);
+  sr_procedure.init(&ra_procedure, phy_h, rrc, log_h);
 
   // Create UL/DL unique HARQ pointers
   ul_harq.at(0)->init(log_h, &uernti, &ra_procedure, &mux_unit);
@@ -214,28 +214,12 @@ void mac::run_tti(const uint32_t tti)
 
   /* Warning: Here order of invocation of procedures is important!! */
 
-  // Step all procedures
+  // Step all procedures (must follow this order)
   Debug("Running MAC tti=%d\n", tti);
   mux_unit.step();
   bsr_procedure.step(tti);
-  phr_procedure.step();
-
-  // Check if BSR procedure need to start SR
-  if (bsr_procedure.need_to_send_sr(tti)) {
-    Debug("Starting SR procedure by BSR request, PHY TTI=%d\n", tti);
-    sr_procedure.start();
-  }
-  if (bsr_procedure.need_to_reset_sr()) {
-    Debug("Resetting SR procedure by BSR request\n");
-    sr_procedure.reset();
-  }
   sr_procedure.step(tti);
-
-  // Check SR if we need to start RA
-  if (sr_procedure.need_random_access()) {
-    ra_procedure.start_mac_order();
-  }
-
+  phr_procedure.step();
   ra_procedure.step(tti);
   ra_procedure.update_rar_window(ra_window_start, ra_window_length);
 
diff --git a/srsue/src/stack/mac/proc_bsr.cc b/srsue/src/stack/mac/proc_bsr.cc
index 96d020a62..e2b2a1676 100644
--- a/srsue/src/stack/mac/proc_bsr.cc
+++ b/srsue/src/stack/mac/proc_bsr.cc
@@ -31,14 +31,16 @@ bsr_proc::bsr_proc()
   current_tti        = 0;
   trigger_tti        = 0;
   triggered_bsr_type = NONE;
-
-  pthread_mutex_init(&mutex, NULL);
 }
 
-void bsr_proc::init(rlc_interface_mac* rlc_, srslte::log_ref log_h_, srslte::task_handler_interface* task_handler_)
+void bsr_proc::init(sr_proc*                        sr_,
+                    rlc_interface_mac*              rlc_,
+                    srslte::log_ref                 log_h_,
+                    srslte::task_handler_interface* task_handler_)
 {
   log_h        = log_h_;
   rlc          = rlc_;
+  sr           = sr_;
   task_handler = task_handler_;
 
   timer_periodic           = task_handler->get_unique_timer();
@@ -77,8 +79,6 @@ void bsr_proc::reset()
   timer_periodic.stop();
   timer_retx.stop();
 
-  reset_sr           = false;
-  sr_is_sent         = false;
   triggered_bsr_type = NONE;
 
   trigger_tti = 0;
@@ -86,7 +86,7 @@ void bsr_proc::reset()
 
 void bsr_proc::set_config(srslte::bsr_cfg_t& bsr_cfg_)
 {
-  pthread_mutex_lock(&mutex);
+  std::lock_guard<std::mutex> lock(mutex);
 
   bsr_cfg = bsr_cfg_;
 
@@ -98,13 +98,13 @@ void bsr_proc::set_config(srslte::bsr_cfg_t& bsr_cfg_)
     timer_retx.set(bsr_cfg_.retx_timer, [this](uint32_t tid) { timer_expired(tid); });
     Info("BSR:   Configured timer reTX %d ms\n", bsr_cfg_.retx_timer);
   }
-  pthread_mutex_unlock(&mutex);
 }
 
 /* Process Periodic BSR */
 void bsr_proc::timer_expired(uint32_t timer_id)
 {
-  pthread_mutex_lock(&mutex);
+  std::lock_guard<std::mutex> lock(mutex);
+
   // periodicBSR-Timer
   if (timer_id == timer_periodic.id()) {
     if (triggered_bsr_type == NONE) {
@@ -119,10 +119,8 @@ void bsr_proc::timer_expired(uint32_t timer_id)
     if (check_any_channel()) {
       set_trigger(REGULAR);
       Debug("BSR:   Triggering BSR reTX\n");
-      sr_is_sent = false;
     }
   }
-  pthread_mutex_unlock(&mutex);
 }
 
 uint32_t bsr_proc::get_buffer_state()
@@ -275,12 +273,12 @@ bool bsr_proc::generate_bsr(bsr_t* bsr, uint32_t nof_padding_bytes)
 // Periodic BSR is triggered by the expiration of the timers
 void bsr_proc::step(uint32_t tti)
 {
+  std::lock_guard<std::mutex> lock(mutex);
+
   if (!initiated) {
     return;
   }
 
-  pthread_mutex_lock(&mutex);
-
   current_tti = tti;
 
   update_new_data();
@@ -292,7 +290,12 @@ void bsr_proc::step(uint32_t tti)
 
   update_buffer_state();
 
-  pthread_mutex_unlock(&mutex);
+  // Trigger SR if Regular BSR is triggered
+  if (triggered_bsr_type == REGULAR) {
+    set_trigger(NONE);
+    Debug("BSR:   Triggering SR procedure: tti=%d, trigger_tti=%d\n", tti, trigger_tti);
+    sr->start();
+  }
 }
 
 char* bsr_proc::bsr_type_tostring(triggered_bsr_type_t type)
@@ -325,9 +328,9 @@ char* bsr_proc::bsr_format_tostring(bsr_format_t format)
 
 bool bsr_proc::need_to_send_bsr_on_ul_grant(uint32_t grant_size, bsr_t* bsr)
 {
-  bool bsr_included = false;
+  std::lock_guard<std::mutex> lock(mutex);
 
-  pthread_mutex_lock(&mutex);
+  bool bsr_included = false;
 
   uint32_t bsr_sz = 0;
   if (triggered_bsr_type == PERIODIC || triggered_bsr_type == REGULAR) {
@@ -362,22 +365,22 @@ bool bsr_proc::need_to_send_bsr_on_ul_grant(uint32_t grant_size, bsr_t* bsr)
   }
 
   // Cancel SR if an Uplink grant is received
-  reset_sr = true;
+  Debug("BSR:   Cancelling SR procedure due to uplink grant\n");
+  sr->reset();
 
   // Restart or Start ReTX timer upon indication of a grant
   if (timer_retx.duration()) {
     timer_retx.run();
     Debug("BSR:   Started retxBSR-Timer\n");
   }
-  pthread_mutex_unlock(&mutex);
   return bsr_included;
 }
 
 bool bsr_proc::generate_padding_bsr(uint32_t nof_padding_bytes, bsr_t* bsr)
 {
-  bool ret = false;
+  std::lock_guard<std::mutex> lock(mutex);
 
-  pthread_mutex_lock(&mutex);
+  bool ret = false;
 
   // This function is called by MUX only if Regular BSR has not been triggered before
   if (nof_padding_bytes >= 2) {
@@ -387,43 +390,15 @@ bool bsr_proc::generate_padding_bsr(uint32_t nof_padding_bytes, bsr_t* bsr)
     set_trigger(NONE);
     ret = true;
   }
-  pthread_mutex_unlock(&mutex);
 
   return ret;
 }
 
-bool bsr_proc::need_to_reset_sr()
-{
-  bool ret = false;
-  pthread_mutex_lock(&mutex);
-  if (reset_sr) {
-    reset_sr   = false;
-    sr_is_sent = false;
-    Debug("BSR:   SR reset. sr_is_sent and reset_rs false\n");
-    ret = true;
-  }
-  pthread_mutex_unlock(&mutex);
-  return ret;
-}
-
-bool bsr_proc::need_to_send_sr(uint32_t tti)
-{
-  bool ret = false;
-  pthread_mutex_lock(&mutex);
-  if (!sr_is_sent && triggered_bsr_type == REGULAR) {
-    reset_sr   = false;
-    sr_is_sent = true;
-    Debug("BSR:   Need to send sr: sr_is_sent=true, reset_sr=false, tti=%d, trigger_tti=%d\n", tti, trigger_tti);
-    ret = true;
-  }
-  pthread_mutex_unlock(&mutex);
-  return ret;
-}
-
 void bsr_proc::setup_lcid(uint32_t lcid, uint32_t new_lcg, uint32_t priority)
 {
+  std::lock_guard<std::mutex> lock(mutex);
+
   if (new_lcg < NOF_LCG) {
-    pthread_mutex_lock(&mutex);
     // First see if it already exists and eliminate it
     for (int i = 0; i < NOF_LCG; i++) {
       if (lcgs[i].count(lcid)) {
@@ -433,7 +408,6 @@ void bsr_proc::setup_lcid(uint32_t lcid, uint32_t new_lcg, uint32_t priority)
     // Now add it
     lcgs[new_lcg][lcid].priority   = priority;
     lcgs[new_lcg][lcid].old_buffer = 0;
-    pthread_mutex_unlock(&mutex);
   } else {
     Error("BSR:   Invalid lcg=%d for lcid=%d\n", new_lcg, lcid);
   }
diff --git a/srsue/src/stack/mac/proc_sr.cc b/srsue/src/stack/mac/proc_sr.cc
index ad305b733..4785b1792 100644
--- a/srsue/src/stack/mac/proc_sr.cc
+++ b/srsue/src/stack/mac/proc_sr.cc
@@ -25,6 +25,7 @@
 #define Debug(fmt, ...) log_h->debug(fmt, ##__VA_ARGS__)
 
 #include "srsue/hdr/stack/mac/proc_sr.h"
+#include "srsue/hdr/stack/mac/proc_ra.h"
 
 namespace srsue {
 
@@ -33,14 +34,14 @@ sr_proc::sr_proc()
   initiated = false;
 }
 
-void sr_proc::init(phy_interface_mac_lte* phy_h_, rrc_interface_mac* rrc_, srslte::log_ref log_h_)
+void sr_proc::init(ra_proc* ra_, phy_interface_mac_lte* phy_h_, rrc_interface_mac* rrc_, srslte::log_ref log_h_)
 {
   log_h      = log_h_;
   rrc        = rrc_;
+  ra         = ra_;
   phy_h      = phy_h_;
   initiated  = true;
   sr_counter = 0;
-  do_ra      = false;
 }
 
 void sr_proc::reset()
@@ -90,32 +91,18 @@ void sr_proc::step(uint32_t tti)
                  sr_cfg.dsr_transmax);
             log_h->console("Scheduling request failed: releasing RRC connection...\n");
             rrc->release_pucch_srs();
-            do_ra         = true;
             is_pending_sr = false;
           }
         }
       } else {
         Info("SR:    PUCCH not configured. Starting RA procedure\n");
-        do_ra = true;
+        ra->start_mac_order();
         reset();
       }
     }
   }
 }
 
-bool sr_proc::need_random_access()
-{
-  if (initiated) {
-    if (do_ra) {
-      do_ra = false;
-      return true;
-    } else {
-      return false;
-    }
-  }
-  return false;
-}
-
 void sr_proc::start()
 {
   if (initiated) {