Changes on srsENB mutexing logic to fix general race condition and deadlock issues (#229)

* fixed some issues with the UL scheduling

* Hack to fix UL scheduler

* minor fix

* Cleaned up code and fixed issue with the update_allocation function

* fixed the console printing in the enb

* log/console fix

* fixed the log print

* added a normalization factor

* RLC: entity uses dynamic instances. Simplified stop/reset/reestablish procedure. Added non-blocking interface

* Limit decimals in metrics stdout

* Changed mutexes to rwlock in RLC/RRC/MAC/PDCP to fix race conditions when removing users

* Fix deadlock bug for MIMO

* Remove headers

* Fix missing unlock causing overflows

* Do not decrease CQI when PUCCH (this is a temporal fix, requires to reduce the maximum MCS)

* Fix mutex unlock in worker

* Configurable RLC tx buffer. Default to 512 for enodeb

* Check NULL SDU in write_sdu()

* Protect RLC objects and tx_queue from being destroyed while using it

* Remove superfluous code

* Disable SIB logging

* Fix block_queue for enb

lib/include/srslte/common/block_queue.h

@@ -42,6 +42,8 @@
 #include <pthread.h>
 #include <stdio.h>
 #include <stdint.h>
+#include <unistd.h>
+#include <strings.h>
 
 namespace srslte {
 
@@ -63,6 +65,28 @@ public:
     pthread_cond_init(&cv_full, NULL);
     this->capacity = capacity;
     mutexed_callback = NULL;
+    enable = true;
+    num_threads = 0;
+  }
+  ~block_queue() {
+    // Unlock threads waiting at push or pop
+    pthread_mutex_lock(&mutex);
+    enable = false;
+    pthread_cond_signal(&cv_full);
+    pthread_cond_signal(&cv_empty);
+    pthread_mutex_unlock(&mutex);
+
+    // Wait threads blocked in push/pop to exit
+    while(num_threads>0) {
+      usleep(100);
+    }
+    
+    // Wait them to exit and destroy cv and mutex
+    pthread_mutex_lock(&mutex);
+    pthread_cond_destroy(&cv_full);
+    pthread_cond_destroy(&cv_empty);
+    pthread_mutex_unlock(&mutex);
+    pthread_mutex_destroy(&mutex);
   }
   void set_mutexed_itf(call_mutexed_itf *itf) {
     mutexed_callback = itf;
@@ -70,26 +94,6 @@ public:
   void resize(int new_capacity) {
     capacity = new_capacity;
   }
-  bool push_(const myobj& value, bool block) {
-    pthread_mutex_lock(&mutex);
-    if (capacity > 0) {
-      if (block) {
-        while(q.size() > (uint32_t) capacity) {
-          pthread_cond_wait(&cv_full, &mutex);
-        }
-      } else {
-        pthread_mutex_unlock(&mutex);
-        return false;
-      }
-    }
-    q.push(value);
-    if (mutexed_callback) {
-      mutexed_callback->pushing(value);
-    }
-    pthread_cond_signal(&cv_empty);
-    pthread_mutex_unlock(&mutex);
-    return true;
-  }
 
   void push(const myobj& value) {
     push_(value, true);
@@ -99,36 +103,14 @@ public:
     return push_(value, false);
   }
 
-  bool try_pop(myobj *value) { 
+  bool try_pop(myobj *value) {
-    pthread_mutex_lock(&mutex);
+    return pop_(value, false);
-    if (q.empty()) {
-      pthread_mutex_unlock(&mutex);
-      return false;
-    }
-    if (value) {
-      *value = q.front(); 
-      q.pop();
-    }
-    if (mutexed_callback) {
-      mutexed_callback->popping(*value);
-    }
-    pthread_cond_signal(&cv_full);
-    pthread_mutex_unlock(&mutex);
-    return true;
   }
 
   myobj wait_pop() { // blocking pop
-    pthread_mutex_lock(&mutex);
+    myobj value;
-    while(q.empty()) {
+    bzero(&value, sizeof(myobj));
-      pthread_cond_wait(&cv_empty, &mutex);
+    pop_(&value, true);
-    }
-    myobj value = q.front();
-    q.pop();
-    if (mutexed_callback) {
-      mutexed_callback->popping(value);
-    }
-    pthread_cond_signal(&cv_full);
-    pthread_mutex_unlock(&mutex);
     return value;
   }
 
@@ -153,12 +135,77 @@ public:
   }
 
 private:
+
+  bool pop_(myobj *value, bool block) {
+    if (!enable) {
+      return false;
+    }
+    pthread_mutex_lock(&mutex);
+    num_threads++;
+    bool ret = false;
+    if (q.empty() && !block) {
+      goto exit;
+    }
+    while (q.empty() && enable) {
+      pthread_cond_wait(&cv_empty, &mutex);
+    }
+    if (!enable) {
+      goto exit;
+    }
+    if (value) {
+      *value = q.front();
+      q.pop();
+    }
+    ret = true;
+    if (mutexed_callback) {
+      mutexed_callback->popping(*value);
+    }
+    pthread_cond_signal(&cv_full);
+  exit:
+    num_threads--;
+    pthread_mutex_unlock(&mutex);
+    return ret;
+  }
+
+  bool push_(const myobj& value, bool block) {
+    if (!enable) {
+      return false;
+    }
+    pthread_mutex_lock(&mutex);
+    num_threads++;
+    bool ret = false;
+    if (capacity > 0) {
+      if (block) {
+        while(q.size() >= (uint32_t) capacity && enable) {
+          pthread_cond_wait(&cv_full, &mutex);
+        }
+        if (!enable) {
+          goto exit;
+        }
+      } else if (q.size() >= (uint32_t) capacity) {
+        goto exit;
+      }
+    }
+    q.push(value);
+    ret = true;
+    if (mutexed_callback) {
+      mutexed_callback->pushing(value);
+    }
+    pthread_cond_signal(&cv_empty);
+  exit:
+    num_threads--;
+    pthread_mutex_unlock(&mutex);
+    return ret;
+  }
+
   std::queue<myobj> q; 
   pthread_mutex_t mutex;
   pthread_cond_t  cv_empty;
   pthread_cond_t  cv_full;
   call_mutexed_itf *mutexed_callback;
   int capacity;
+  bool enable;
+  uint32_t num_threads;
 };
 
 }

lib/include/srslte/interfaces/enb_interfaces.h

@@ -173,8 +173,7 @@ public:
 class rlc_interface_rrc
 {
 public:
-  virtual void reset(uint16_t rnti) = 0;
+  virtual void clear_buffer(uint16_t rnti) = 0;
-  virtual void clear_buffer(uint16_t rnti) = 0; 
   virtual void add_user(uint16_t rnti) = 0; 
   virtual void rem_user(uint16_t rnti) = 0; 
   virtual void add_bearer(uint16_t rnti, uint32_t lcid) = 0;

lib/include/srslte/upper/rlc.h

@@ -56,13 +56,15 @@ public:
             srsue::ue_interface       *ue_,
             log                       *rlc_log_,
             mac_interface_timers      *mac_timers_,
-            uint32_t                   lcid_);
+            uint32_t                   lcid_,
+            int                        buffer_size = -1); // -1 to use default buffer sizes
   void stop();
 
   void get_metrics(rlc_metrics_t &m);
 
   // PDCP interface
   void write_sdu(uint32_t lcid, byte_buffer_t *sdu);
+  void write_sdu_nb(uint32_t lcid, byte_buffer_t *sdu);
   void write_sdu_mch(uint32_t lcid, byte_buffer_t *sdu);
   bool rb_is_um(uint32_t lcid);
 
@@ -99,6 +101,7 @@ private:
   srslte::rlc_entity           rlc_array[SRSLTE_N_RADIO_BEARERS];
   srslte::rlc_um               rlc_array_mrb[SRSLTE_N_MCH_LCIDS];
   uint32_t                     default_lcid;
+  int                          buffer_size;
 
   long                ul_tput_bytes[SRSLTE_N_RADIO_BEARERS];
   long                dl_tput_bytes[SRSLTE_N_RADIO_BEARERS];

lib/include/srslte/upper/rlc_am.h

@@ -70,7 +70,7 @@ class rlc_am
     :public rlc_common
 {
 public:
-  rlc_am();
+  rlc_am(uint32_t queue_len = 16);
   ~rlc_am();
   void init(log          *rlc_entity_log_,
             uint32_t              lcid_,
@@ -78,9 +78,9 @@ public:
             srsue::rrc_interface_rlc    *rrc_,
             mac_interface_timers *mac_timers);
   void configure(srslte_rlc_config_t cnfg);
-  void reset();
   void reestablish();
   void stop();
+
   void empty_queue(); 
   
   rlc_mode_t    get_mode();
@@ -88,6 +88,7 @@ public:
 
   // PDCP interface
   void write_sdu(byte_buffer_t *sdu);
+  void write_sdu_nb(byte_buffer_t *sdu);
 
   // MAC interface
   uint32_t get_buffer_state();
@@ -122,6 +123,7 @@ private:
   // Mutexes
   pthread_mutex_t     mutex;
 
+  bool                tx_enabled;
   bool                poll_received;
   bool                do_status;
   rlc_status_pdu_t    status;

lib/include/srslte/upper/rlc_common.h

@@ -151,13 +151,13 @@ struct rlc_status_pdu_t{
 class rlc_common
 {
 public:
+  virtual ~rlc_common() {}
   virtual void init(srslte::log                       *rlc_entity_log_,
                     uint32_t                           lcid_,
                     srsue::pdcp_interface_rlc         *pdcp_,
                     srsue::rrc_interface_rlc          *rrc_,
                     srslte::mac_interface_timers      *mac_timers_) = 0;
   virtual void configure(srslte_rlc_config_t cnfg) = 0;
-  virtual void reset() = 0;
   virtual void stop() = 0;
   virtual void empty_queue() = 0; 
 
@@ -166,6 +166,7 @@ public:
 
   // PDCP interface
   virtual void write_sdu(byte_buffer_t *sdu) = 0;
+  virtual void write_sdu_nb(byte_buffer_t *sdu) = 0;
 
   // MAC interface
   virtual uint32_t get_buffer_state() = 0;

lib/include/srslte/upper/rlc_entity.h

@@ -52,10 +52,10 @@ public:
             uint32_t                    lcid_,
             srsue::pdcp_interface_rlc  *pdcp_,
             srsue::rrc_interface_rlc   *rrc_,
-            mac_interface_timers       *mac_timers_);
+            mac_interface_timers       *mac_timers_,
+            int                         buffer_size = -1); // use -1 for default buffer sizes
 
   void configure(srslte_rlc_config_t cnfg);
-  void reset();
   void reestablish();
   void stop();
   void empty_queue();
@@ -66,6 +66,7 @@ public:
 
   // PDCP interface
   void write_sdu(byte_buffer_t *sdu);
+  void write_sdu_nb(byte_buffer_t *sdu);
 
   // MAC interface
   uint32_t get_buffer_state();
@@ -75,10 +76,8 @@ public:
   
 
 private:
-  rlc_tm tm;
+  rlc_mode_t mode;
-  rlc_um um;
+  uint32_t   lcid;
-  rlc_am am;
-
   rlc_common *rlc;
 };
 

lib/include/srslte/upper/rlc_tm.h

@@ -40,14 +40,14 @@ class rlc_tm
     :public rlc_common
 {
 public:
-  rlc_tm();
+  rlc_tm(uint32_t queue_len = 16);
+  ~rlc_tm();
   void init(log                       *rlc_entity_log_,
             uint32_t                   lcid_,
             srsue::pdcp_interface_rlc *pdcp_,
             srsue::rrc_interface_rlc  *rrc_,
             mac_interface_timers      *mac_timers);
   void configure(srslte_rlc_config_t cnfg);
-  void reset();
   void stop();
   void empty_queue(); 
 
@@ -56,6 +56,7 @@ public:
 
   // PDCP interface
   void write_sdu(byte_buffer_t *sdu);
+  void write_sdu_nb(byte_buffer_t *sdu);
 
   // MAC interface
   uint32_t get_buffer_state();
@@ -71,6 +72,8 @@ private:
   srsue::pdcp_interface_rlc *pdcp;
   srsue::rrc_interface_rlc  *rrc;
 
+  bool tx_enabled;
+
   // Thread-safe queues for MAC messages
   rlc_tx_queue    ul_queue;
 };

lib/include/srslte/upper/rlc_tx_queue.h

@@ -44,7 +44,7 @@ namespace srslte {
 class rlc_tx_queue : public block_queue<byte_buffer_t*>::call_mutexed_itf
 {
 public:
-  rlc_tx_queue(uint32_t capacity = 128) : queue((int) capacity) {
+  rlc_tx_queue(int capacity = 128) : queue(capacity) {
     unread_bytes = 0;
     queue.set_mutexed_itf(this);
   }
@@ -64,6 +64,11 @@ public:
     queue.push(msg);
   }
 
+  bool try_write(byte_buffer_t *msg)
+  {
+    return queue.try_push(msg);
+  }
+
   void read(byte_buffer_t **msg)
   {
     byte_buffer_t *m = queue.wait_pop();

lib/include/srslte/upper/rlc_um.h

@@ -49,8 +49,7 @@ class rlc_um
     ,public rlc_common
 {
 public:
-  rlc_um();
+  rlc_um(uint32_t queue_len = 32);
-
   ~rlc_um();
   void init(log                       *rlc_entity_log_,
             uint32_t                   lcid_,
@@ -58,7 +57,6 @@ public:
             srsue::rrc_interface_rlc  *rrc_,
             mac_interface_timers      *mac_timers_);
   void configure(srslte_rlc_config_t cnfg);
-  void reset();
   void stop();
   void empty_queue(); 
   bool is_mrb();
@@ -68,6 +66,7 @@ public:
 
   // PDCP interface
   void write_sdu(byte_buffer_t *sdu);
+  void write_sdu_nb(byte_buffer_t *sdu);
 
   // MAC interface
   uint32_t get_buffer_state();
@@ -131,6 +130,7 @@ private:
   srslte::timers::timer *reordering_timer;
   uint32_t               reordering_timer_id;
 
+  bool     tx_enabled;
   bool     pdu_lost;
 
   int  build_data_pdu(uint8_t *payload, uint32_t nof_bytes);

lib/src/upper/rlc.cc

@@ -51,7 +51,8 @@ void rlc::init(srsue::pdcp_interface_rlc *pdcp_,
                srsue::ue_interface       *ue_,
                log                       *rlc_log_, 
                mac_interface_timers      *mac_timers_,
-               uint32_t                  lcid_)
+               uint32_t                  lcid_,
+               int                       buffer_size_)
 {
   pdcp    = pdcp_;
   rrc     = rrc_;
@@ -59,11 +60,12 @@ void rlc::init(srsue::pdcp_interface_rlc *pdcp_,
   rlc_log = rlc_log_;
   mac_timers = mac_timers_;
   default_lcid = lcid_;
+  buffer_size  = buffer_size_;
 
   gettimeofday(&metrics_time[1], NULL);
   reset_metrics(); 
 
-  rlc_array[0].init(RLC_MODE_TM, rlc_log, default_lcid, pdcp, rrc, mac_timers); // SRB0
+  rlc_array[0].init(RLC_MODE_TM, rlc_log, default_lcid, pdcp, rrc, mac_timers, buffer_size); // SRB0
 }
 
 void rlc::reset_metrics() 
@@ -75,8 +77,9 @@ void rlc::reset_metrics()
 void rlc::stop()
 {
   for(uint32_t i=0; i<SRSLTE_N_RADIO_BEARERS; i++) {
-    if(rlc_array[i].active())
+    if(rlc_array[i].active()) {
       rlc_array[i].stop();
+    }
   }
 }
 
@@ -114,6 +117,7 @@ void rlc::get_metrics(rlc_metrics_t &m)
   reset_metrics();
 }
 
+// A call to reestablish stops all lcids but does not delete the instances. The mapping lcid to rlc mode can not change
 void rlc::reestablish() {
   for(uint32_t i=0; i<SRSLTE_N_RADIO_BEARERS; i++) {
     if(rlc_array[i].active()) {
@@ -122,14 +126,16 @@ void rlc::reestablish() {
   }
 }
 
+// Resetting the RLC layer returns the object to the state after the call to init(): All lcids are stopped and
+// defaul lcid=0 is created
 void rlc::reset()
 {
   for(uint32_t i=0; i<SRSLTE_N_RADIO_BEARERS; i++) {
     if(rlc_array[i].active())
-      rlc_array[i].reset();
+      rlc_array[i].stop();
   }
 
-  rlc_array[0].init(RLC_MODE_TM, rlc_log, default_lcid, pdcp, rrc, mac_timers); // SRB0
+  rlc_array[0].init(RLC_MODE_TM, rlc_log, default_lcid, pdcp, rrc, mac_timers, buffer_size); // SRB0
 }
 
 void rlc::empty_queue()
@@ -149,6 +155,12 @@ void rlc::write_sdu(uint32_t lcid, byte_buffer_t *sdu)
     rlc_array[lcid].write_sdu(sdu);
   }
 }
+void rlc::write_sdu_nb(uint32_t lcid, byte_buffer_t *sdu)
+{
+  if(valid_lcid(lcid)) {
+    rlc_array[lcid].write_sdu_nb(sdu);
+  }
+}
 void rlc::write_sdu_mch(uint32_t lcid, byte_buffer_t *sdu)
 {
   if(valid_lcid_mrb(lcid)) {
@@ -307,16 +319,16 @@ void rlc::add_bearer(uint32_t lcid, srslte_rlc_config_t cnfg)
     switch(cnfg.rlc_mode)
     {
     case LIBLTE_RRC_RLC_MODE_AM:
-      rlc_array[lcid].init(RLC_MODE_AM, rlc_log, lcid, pdcp, rrc, mac_timers);
+      rlc_array[lcid].init(RLC_MODE_AM, rlc_log, lcid, pdcp, rrc, mac_timers, buffer_size);
       break;
     case LIBLTE_RRC_RLC_MODE_UM_BI:
-      rlc_array[lcid].init(RLC_MODE_UM, rlc_log, lcid, pdcp, rrc, mac_timers);
+      rlc_array[lcid].init(RLC_MODE_UM, rlc_log, lcid, pdcp, rrc, mac_timers, buffer_size);
       break;
     case LIBLTE_RRC_RLC_MODE_UM_UNI_DL:
-      rlc_array[lcid].init(RLC_MODE_UM, rlc_log, lcid, pdcp, rrc, mac_timers);
+      rlc_array[lcid].init(RLC_MODE_UM, rlc_log, lcid, pdcp, rrc, mac_timers, buffer_size);
       break;
     case LIBLTE_RRC_RLC_MODE_UM_UNI_UL:
-      rlc_array[lcid].init(RLC_MODE_UM, rlc_log, lcid, pdcp, rrc, mac_timers);
+      rlc_array[lcid].init(RLC_MODE_UM, rlc_log, lcid, pdcp, rrc, mac_timers, buffer_size);
       break;
     default:
       rlc_log->error("Cannot add RLC entity - invalid mode\n");

lib/src/upper/rlc_am.cc

@@ -36,7 +36,7 @@
 
 namespace srslte {
 
-rlc_am::rlc_am() : tx_sdu_queue(16)
+rlc_am::rlc_am(uint32_t queue_len) : tx_sdu_queue(queue_len)
 {
   log = NULL;
   pdcp = NULL;
@@ -68,19 +68,13 @@ rlc_am::rlc_am() : tx_sdu_queue(16)
   do_status     = false;
 }
 
+// Warning: must call stop() to properly deallocate all buffers
 rlc_am::~rlc_am()
 {
-  // reset RLC and dealloc SDUs
+  pthread_mutex_destroy(&mutex);
-  stop();
+  pool = NULL;
-
-  if(rx_sdu) {
-    pool->deallocate(rx_sdu);
-  }
-
-  if(tx_sdu) {
-    pool->deallocate(tx_sdu);
-  }
 }
+
 void rlc_am::init(srslte::log                  *log_,
                   uint32_t                      lcid_,
                   srsue::pdcp_interface_rlc    *pdcp_,
@@ -91,6 +85,7 @@ void rlc_am::init(srslte::log                  *log_,
   lcid = lcid_;
   pdcp = pdcp_;
   rrc  = rrc_;
+  tx_enabled = true;
 }
 
 void rlc_am::configure(srslte_rlc_config_t cfg_)
@@ -106,21 +101,16 @@ void rlc_am::configure(srslte_rlc_config_t cfg_)
 void rlc_am::empty_queue() {
   // Drop all messages in TX SDU queue
   byte_buffer_t *buf;
-  while(tx_sdu_queue.size() > 0) {
+  while(tx_sdu_queue.try_read(&buf)) {
-    tx_sdu_queue.read(&buf);
     pool->deallocate(buf);
   }
 }
 
 void rlc_am::stop()
 {
-  reset();
+  // Empty tx_sdu_queue before locking the mutex
-  pthread_mutex_destroy(&mutex);
+  tx_enabled = false;
-}
+  usleep(100);
-
-void rlc_am::reset()
-{
-  // Empty tx_sdu_queue before locking the mutex 
   empty_queue();
 
   pthread_mutex_lock(&mutex);
@@ -198,8 +188,34 @@ uint32_t rlc_am::get_bearer()
 
 void rlc_am::write_sdu(byte_buffer_t *sdu)
 {
-  tx_sdu_queue.write(sdu);
+  if (!tx_enabled) {
-  log->info_hex(sdu->msg, sdu->N_bytes, "%s Tx SDU (%d B, tx_sdu_queue_len=%d)", rrc->get_rb_name(lcid).c_str(), sdu->N_bytes, tx_sdu_queue.size());
+    byte_buffer_pool::get_instance()->deallocate(sdu);
+    return;
+  }
+  if (sdu) {
+    tx_sdu_queue.write(sdu);
+    log->info_hex(sdu->msg, sdu->N_bytes, "%s Tx SDU (%d B, tx_sdu_queue_len=%d)", rrc->get_rb_name(lcid).c_str(), sdu->N_bytes, tx_sdu_queue.size());
+  } else {
+    log->warning("NULL SDU pointer in write_sdu()\n");
+  }
+}
+
+void rlc_am::write_sdu_nb(byte_buffer_t *sdu)
+{
+  if (!tx_enabled) {
+    byte_buffer_pool::get_instance()->deallocate(sdu);
+    return;
+  }
+  if (sdu) {
+    if (tx_sdu_queue.try_write(sdu)) {
+      log->info_hex(sdu->msg, sdu->N_bytes, "%s Tx SDU (%d B, tx_sdu_queue_len=%d)", rrc->get_rb_name(lcid).c_str(), sdu->N_bytes, tx_sdu_queue.size());
+    } else {
+      log->warning_hex(sdu->msg, sdu->N_bytes, "[Dropped SDU] %s Tx SDU (%d B, tx_sdu_queue_len=%d)", rrc->get_rb_name(lcid).c_str(), sdu->N_bytes, tx_sdu_queue.size());
+      pool->deallocate(sdu);
+    }
+  } else {
+    log->warning("NULL SDU pointer in write_sdu()\n");
+  }
 }
 
 /****************************************************************************

lib/src/upper/rlc_entity.cc

@@ -33,34 +33,49 @@ rlc_entity::rlc_entity()
 {
 }
 
-void rlc_entity::init(rlc_mode_t                   mode,
+void rlc_entity::init(rlc_mode_t                   mode_,
                       log                         *rlc_entity_log_,
                       uint32_t                     lcid_,
                       srsue::pdcp_interface_rlc   *pdcp_,
                       srsue::rrc_interface_rlc    *rrc_,
-                      mac_interface_timers        *mac_timers_)
+                      mac_interface_timers        *mac_timers_,
+                      int                          buffer_size)
 {
-  tm.reset();
-  um.reset();
-  am.reset();
-
-  switch(mode)
-  {
-  case RLC_MODE_TM:
-    rlc = &tm;
-    break;
-  case RLC_MODE_UM:
-    rlc = &um;
-    break;
-  case RLC_MODE_AM:
-    rlc = &am;
-    break;
-  default:
-    rlc_entity_log_->error("Invalid RLC mode - defaulting to TM\n");
-    rlc = &tm;
-    break;
-  }
 
+  if (buffer_size <= 0) {
+    buffer_size = 16;
+  }
+  // Create the RLC instance the first time init() is called.
+  // If called to reestablished, the entity is stopped but not destroyed
+  // Next call to init() must use same mode
+  if (rlc == NULL) {
+    switch(mode_)
+    {
+      case RLC_MODE_TM:
+        rlc = new rlc_tm((uint32_t) buffer_size);
+        break;
+      case RLC_MODE_UM:
+        rlc = new rlc_um((uint32_t) buffer_size);
+        break;
+      case RLC_MODE_AM:
+        rlc = new rlc_am((uint32_t) buffer_size);
+        break;
+      default:
+        rlc_entity_log_->error("Invalid RLC mode - defaulting to TM\n");
+        rlc = new rlc_tm((uint32_t) buffer_size);
+        break;
+    }
+    lcid = lcid_;
+    mode = mode_;
+  } else {
+    if (lcid != lcid_) {
+      rlc_entity_log_->warning("Reestablishing RLC instance. LCID changed from %d to %d\n", lcid, lcid_);
+      lcid = lcid_;
+    }
+    if (mode != mode_) {
+      rlc_entity_log_->console("Error reestablishing RLC instance. Mode changed from %d to %d. \n", mode, mode_);
+    }
+  }
   rlc->init(rlc_entity_log_, lcid_, pdcp_, rrc_, mac_timers_);
 }
 
@@ -70,19 +85,16 @@ void rlc_entity::configure(srslte_rlc_config_t cnfg)
     rlc->configure(cnfg);
 }
 
+// Reestablishment stops the entity but does not destroy it. Mode will not change
 void rlc_entity::reestablish() {
-  rlc->reset();
+  rlc->stop();
-}
-
-void rlc_entity::reset()
-{
-  rlc->reset();
-  rlc = NULL;
 }
 
+// A call to stop() stops the entity and clears deletes the instance. Next time this entity can be used for other mode.
 void rlc_entity::stop()
 {
   rlc->stop();
+  delete rlc;
   rlc = NULL;
 }
 
@@ -119,6 +131,12 @@ void rlc_entity::write_sdu(byte_buffer_t *sdu)
     rlc->write_sdu(sdu);
 }
 
+void rlc_entity::write_sdu_nb(byte_buffer_t *sdu)
+{
+  if(rlc)
+    rlc->write_sdu_nb(sdu);
+}
+
 // MAC interface
 uint32_t rlc_entity::get_buffer_state()
 {

lib/src/upper/rlc_tm.cc

@@ -29,7 +29,7 @@
 
 namespace srslte {
 
-rlc_tm::rlc_tm() : ul_queue(16)
+rlc_tm::rlc_tm(uint32_t queue_len) : ul_queue(queue_len)
 {
   log = NULL;
   pdcp = NULL;
@@ -38,6 +38,11 @@ rlc_tm::rlc_tm() : ul_queue(16)
   pool = byte_buffer_pool::get_instance();
 }
 
+// Warning: must call stop() to properly deallocate all buffers
+rlc_tm::~rlc_tm() {
+  pool = NULL;
+}
+
 void rlc_tm::init(srslte::log               *log_,
                   uint32_t                   lcid_,
                   srsue::pdcp_interface_rlc *pdcp_,
@@ -48,6 +53,7 @@ void rlc_tm::init(srslte::log               *log_,
   lcid = lcid_;
   pdcp = pdcp_;
   rrc  = rrc_;
+  tx_enabled = true;
 }
 
 void rlc_tm::configure(srslte_rlc_config_t cnfg)
@@ -64,14 +70,10 @@ void rlc_tm::empty_queue()
   }
 }
 
-void rlc_tm::reset()
-{
-  empty_queue(); 
-}
-
 void rlc_tm::stop()
 {
-  reset();
+  tx_enabled = false;
+  empty_queue();
 }
 
 rlc_mode_t rlc_tm::get_mode()
@@ -87,11 +89,37 @@ uint32_t rlc_tm::get_bearer()
 // PDCP interface
 void rlc_tm::write_sdu(byte_buffer_t *sdu)
 {
-  log->info_hex(sdu->msg, sdu->N_bytes, "%s Tx SDU, before: queue size=%d, bytes=%d",
+  if (!tx_enabled) {
-                rrc->get_rb_name(lcid).c_str(), ul_queue.size(), ul_queue.size_bytes());
+    byte_buffer_pool::get_instance()->deallocate(sdu);
-  ul_queue.write(sdu);
+    return;
-  log->info_hex(sdu->msg, sdu->N_bytes, "%s Tx SDU, after: queue size=%d, bytes=%d",
+  }
-                rrc->get_rb_name(lcid).c_str(), ul_queue.size(), ul_queue.size_bytes());
+  if (sdu) {
+    ul_queue.write(sdu);
+    log->info_hex(sdu->msg, sdu->N_bytes, "%s Tx SDU, queue size=%d, bytes=%d",
+                  rrc->get_rb_name(lcid).c_str(), ul_queue.size(), ul_queue.size_bytes());
+  } else {
+    log->warning("NULL SDU pointer in write_sdu()\n");
+  }
+}
+
+void rlc_tm::write_sdu_nb(byte_buffer_t *sdu)
+{
+  if (!tx_enabled) {
+    byte_buffer_pool::get_instance()->deallocate(sdu);
+    return;
+  }
+  if (sdu) {
+    if (ul_queue.try_write(sdu)) {
+      log->info_hex(sdu->msg, sdu->N_bytes, "%s Tx SDU, queue size=%d, bytes=%d",
+                    rrc->get_rb_name(lcid).c_str(), ul_queue.size(), ul_queue.size_bytes());
+    } else {
+      log->warning_hex(sdu->msg, sdu->N_bytes, "[Dropped SDU] %s Tx SDU, queue size=%d, bytes=%d",
+                       rrc->get_rb_name(lcid).c_str(), ul_queue.size(), ul_queue.size_bytes());
+      pool->deallocate(sdu);
+    }
+  } else {
+    log->warning("NULL SDU pointer in write_sdu()\n");
+  }
 }
 
 // MAC interface

lib/src/upper/rlc_um.cc

@@ -33,7 +33,7 @@
 
 namespace srslte {
 
-rlc_um::rlc_um() : tx_sdu_queue(32)
+rlc_um::rlc_um(uint32_t queue_len) : tx_sdu_queue(queue_len)
 {
   log = NULL;
   pdcp = NULL;
@@ -62,10 +62,13 @@ rlc_um::rlc_um() : tx_sdu_queue(32)
   pdu_lost = false;
 }
 
+// Warning: must call stop() to properly deallocate all buffers
 rlc_um::~rlc_um()
 {
-  stop();
+  pthread_mutex_destroy(&mutex);
+  pool = NULL;
 }
+
 void rlc_um::init(srslte::log                  *log_,
                   uint32_t                      lcid_,
                   srsue::pdcp_interface_rlc    *pdcp_,
@@ -79,6 +82,7 @@ void rlc_um::init(srslte::log                  *log_,
   mac_timers            = mac_timers_;
   reordering_timer_id   = mac_timers->timer_get_unique_id();
   reordering_timer      = mac_timers->timer_get(reordering_timer_id);
+  tx_enabled = true;
 }
 
 void rlc_um::configure(srslte_rlc_config_t cnfg_)
@@ -115,8 +119,7 @@ void rlc_um::configure(srslte_rlc_config_t cnfg_)
 void rlc_um::empty_queue() {
   // Drop all messages in TX SDU queue
   byte_buffer_t *buf;
-  while(tx_sdu_queue.size() > 0) {
+  while(tx_sdu_queue.try_read(&buf)) {
-    tx_sdu_queue.read(&buf);
     pool->deallocate(buf);
   }
 }
@@ -128,16 +131,8 @@ bool rlc_um::is_mrb()
 
 void rlc_um::stop()
 {
-  reset();
+  // Empty tx_sdu_queue before locking the mutex
-  if (mac_timers && reordering_timer) {
+  tx_enabled = false;
-    mac_timers->timer_release_id(reordering_timer_id);
-    reordering_timer = NULL;
-  }
-}
-
-void rlc_um::reset()
-{
-  // Empty tx_sdu_queue before locking the mutex 
   empty_queue();
 
   pthread_mutex_lock(&mutex);
@@ -159,7 +154,7 @@ void rlc_um::reset()
   if(reordering_timer) {
     reordering_timer->stop();
   }
-  
+
   // Drop all messages in RX window
   std::map<uint32_t, rlc_umd_pdu_t>::iterator it;
   for(it = rx_window.begin(); it != rx_window.end(); it++) {
@@ -167,6 +162,11 @@ void rlc_um::reset()
   }
   rx_window.clear();
   pthread_mutex_unlock(&mutex);
+
+  if (mac_timers && reordering_timer) {
+    mac_timers->timer_release_id(reordering_timer_id);
+    reordering_timer = NULL;
+  }
 }
 
 rlc_mode_t rlc_um::get_mode()
@@ -182,11 +182,36 @@ uint32_t rlc_um::get_bearer()
 /****************************************************************************
  * PDCP interface
  ***************************************************************************/
-
 void rlc_um::write_sdu(byte_buffer_t *sdu)
 {
-  tx_sdu_queue.write(sdu);
+  if (!tx_enabled) {
-  log->info_hex(sdu->msg, sdu->N_bytes, "%s Tx SDU (%d B ,tx_sdu_queue_len=%d)", rrc->get_rb_name(lcid).c_str(), sdu->N_bytes, tx_sdu_queue.size());
+    byte_buffer_pool::get_instance()->deallocate(sdu);
+    return;
+  }
+  if (sdu) {
+    tx_sdu_queue.write(sdu);
+    log->info_hex(sdu->msg, sdu->N_bytes, "%s Tx SDU (%d B ,tx_sdu_queue_len=%d)", rrc->get_rb_name(lcid).c_str(), sdu->N_bytes, tx_sdu_queue.size());
+  } else {
+    log->warning("NULL SDU pointer in write_sdu()\n");
+  }
+}
+
+void rlc_um::write_sdu_nb(byte_buffer_t *sdu)
+{
+  if (!tx_enabled) {
+    byte_buffer_pool::get_instance()->deallocate(sdu);
+    return;
+  }
+  if (sdu) {
+    if (tx_sdu_queue.try_write(sdu)) {
+      log->info_hex(sdu->msg, sdu->N_bytes, "%s Tx SDU (%d B ,tx_sdu_queue_len=%d)", rrc->get_rb_name(lcid).c_str(), sdu->N_bytes, tx_sdu_queue.size());
+    } else {
+      log->warning_hex(sdu->msg, sdu->N_bytes, "[Dropped SDU] %s Tx SDU (%d B ,tx_sdu_queue_len=%d)", rrc->get_rb_name(lcid).c_str(), sdu->N_bytes, tx_sdu_queue.size());
+      pool->deallocate(sdu);
+    }
+  } else {
+    log->warning("NULL SDU pointer in write_sdu()\n");
+  }
 }
 
 /****************************************************************************

lib/test/upper/rlc_am_test.cc

@@ -1408,7 +1408,7 @@ void reset_test()
   pdu_bufs.N_bytes = len;
 
   // reset RLC1
-  rlc1.reset();
+  rlc1.stop();
 
   // read another PDU segment from RLC1
   len = rlc1.read_pdu(pdu_bufs.msg, 4);

srsenb/hdr/mac/mac.h

@@ -124,7 +124,8 @@ private:
   
   static const int MAC_PDU_THREAD_PRIO  = 60;
 
-  
+  // We use a rwlock in MAC to allow multiple workers to access MAC simultaneously. No conflicts will happen since access for different TTIs
+  pthread_rwlock_t rwlock;
   
   // Interaction with PHY 
   phy_interface_mac    *phy_h; 

srsenb/hdr/mac/scheduler.h

@@ -36,8 +36,15 @@
 #include <pthread.h>
 
 namespace srsenb {
-  
+
- 
+
+/* Caution: User addition (ue_cfg) and removal (ue_rem) are not thread-safe
+ * Rest of operations are thread-safe
+ *
+ * The subclass sched_ue is thread-safe so that access to shared variables like buffer states
+ * from scheduler thread and other threads is protected for each individual user.
+ */
+
 class sched : public sched_interface
 {  
   
@@ -89,7 +96,7 @@ public:
   void set_sched_cfg(sched_args_t *sched_cfg);
   int reset();
 
-  int ue_cfg(uint16_t rnti, ue_cfg_t *ue_cfg); 
+  int ue_cfg(uint16_t rnti, ue_cfg_t *ue_cfg);
   int ue_rem(uint16_t rnti);
   bool ue_exists(uint16_t rnti); 
   
@@ -216,10 +223,7 @@ private:
   uint32_t current_cfi;
   
   bool configured;
-  
+
-  pthread_mutex_t mutex, mutex2;
-  
-  
 };
 
 

srsenb/hdr/mac/scheduler_ue.h

@@ -35,6 +35,12 @@
 
 namespace srsenb {
 
+
+/** This class is designed to be thread-safe because it is called from workers through scheduler thread and from
+ * higher layers and mac threads.
+ *
+ * 1 mutex is created for every user and only access to same user variables are mutexed
+ */
 class sched_ue {
   
 public: 
@@ -56,6 +62,7 @@ public:
    * 
    ************************************************************/
   sched_ue();
+  ~sched_ue();
   void reset();
   void phy_config_enabled(uint32_t tti, bool enabled);
   void set_cfg(uint16_t rnti, sched_interface::ue_cfg_t* cfg, sched_interface::cell_cfg_t *cell_cfg, 
@@ -101,6 +108,7 @@ public:
 
   uint32_t   get_pending_dl_new_data(uint32_t tti);
   uint32_t   get_pending_ul_new_data(uint32_t tti);
+  uint32_t   get_pending_ul_old_data();
   uint32_t   get_pending_dl_new_data_total(uint32_t tti);
 
   dl_harq_proc *get_pending_dl_harq(uint32_t tti);
@@ -129,8 +137,6 @@ public:
   bool       get_pucch_sched(uint32_t current_tti, uint32_t prb_idx[2]);
   bool       pucch_sr_collision(uint32_t current_tti, uint32_t n_cce);
 
-  uint32_t   get_pending_ul_old_data();
-
 private: 
   
   typedef struct {
@@ -152,11 +158,21 @@ private:
   static bool bearer_is_ul(ue_bearer_t *lch);
   static bool bearer_is_dl(ue_bearer_t *lch);
 
+  uint32_t   get_pending_dl_new_data_unlocked(uint32_t tti);
+  uint32_t   get_pending_ul_old_data_unlocked();
+  uint32_t   get_pending_ul_new_data_unlocked(uint32_t tti);
+
+  bool       needs_cqi_unlocked(uint32_t tti, bool will_send = false);
+
+  int        generate_format2a_unlocked(dl_harq_proc *h, sched_interface::dl_sched_data_t *data, uint32_t tti, uint32_t cfi);
+
   bool is_first_dl_tx();
 
   sched_interface::ue_cfg_t cfg;
   srslte_cell_t cell; 
   srslte::log* log_h;
+
+  pthread_mutex_t mutex;
   
   /* Buffer states */
   bool sr; 

srsenb/hdr/upper/pdcp.h

@@ -103,9 +103,13 @@ private:
     user_interface_gtpu gtpu_itf;
     user_interface_rrc  rrc_itf; 
     srslte::pdcp        *pdcp; 
-  }; 
+  };
+
+  void clear_user(user_interface *ue);
   
-  std::map<uint32_t,user_interface> users; 
+  std::map<uint32_t,user_interface> users;
+
+  pthread_rwlock_t rwlock;
   
   rlc_interface_pdcp  *rlc;
   rrc_interface_pdcp  *rrc;

srsenb/hdr/upper/rlc.h

@@ -52,7 +52,6 @@ public:
   void stop(); 
   
   // rlc_interface_rrc
-  void reset(uint16_t rnti);
   void clear_buffer(uint16_t rnti);
   void add_user(uint16_t rnti); 
   void rem_user(uint16_t rnti);
@@ -91,8 +90,14 @@ private:
     srsenb::rrc_interface_rlc  *rrc;
     srslte::rlc                *rlc; 
     srsenb::rlc                *parent; 
-  }; 
+  };
-  
+
+  void clear_user(user_interface *ue);
+
+  const static int RLC_TX_QUEUE_LEN = 512;
+
+  pthread_rwlock_t rwlock;
+
   std::map<uint32_t,user_interface> users; 
   std::vector<mch_service_t> mch_services;
   

srsenb/hdr/upper/rrc.h

@@ -123,7 +123,6 @@ public:
     bzero(&cqi_sched, sizeof(cqi_sched));
     bzero(&cfg, sizeof(cfg));
     bzero(&sib2, sizeof(sib2));
-    bzero(&user_mutex, sizeof(user_mutex));
     bzero(&paging_mutex, sizeof(paging_mutex));
 
   }
@@ -350,6 +349,7 @@ private:
     srslte::byte_buffer_t*  pdu;
   }rrc_pdu;
 
+  const static uint32_t LCID_EXIT     = 0xffff0000;
   const static uint32_t LCID_REM_USER = 0xffff0001;
   const static uint32_t LCID_REL_USER = 0xffff0002;
   const static uint32_t LCID_RLF_USER = 0xffff0003;

srsenb/src/mac/mac.cc

@@ -96,96 +96,112 @@ bool mac::init(mac_args_t *args_, srslte_cell_t *cell_, phy_interface_mac *phy,
 
     reset();
 
-    started = true; 
+    pthread_rwlock_init(&rwlock, NULL);
+
+    started = true;
   }
 
-  return started; 
+  return started;
 }
 
 void mac::stop()
 {
+  pthread_rwlock_wrlock(&rwlock);
+
   for (uint32_t i=0;i<ue_db.size();i++) {
     delete ue_db[i];
   }
   for (int i=0;i<NOF_BCCH_DLSCH_MSG;i++) {
     srslte_softbuffer_tx_free(&bcch_softbuffer_tx[i]);
-  }  
+  }
   srslte_softbuffer_tx_free(&pcch_softbuffer_tx);
   srslte_softbuffer_tx_free(&rar_softbuffer_tx);
-  started = false;   
+  started = false;
   timers_thread.stop();
   pdu_process_thread.stop();
+
+  pthread_rwlock_unlock(&rwlock);
+  pthread_rwlock_destroy(&rwlock);
 }
 
 // Implement Section 5.9
 void mac::reset()
 {
   Info("Resetting MAC\n");
-  
+
   timers_db.stop_all();
 
-  tti = 0; 
+  tti = 0;
-  last_rnti = 70; 
+  last_rnti = 70;
-  
+
   /* Setup scheduler */
   scheduler.reset();
-  
+
 }
 
 void mac::start_pcap(srslte::mac_pcap* pcap_)
 {
-  pcap = pcap_; 
+  pcap = pcap_;
-  // Set pcap in all UEs for UL messages 
+  // Set pcap in all UEs for UL messages
   for(std::map<uint16_t, ue*>::iterator iter=ue_db.begin(); iter!=ue_db.end(); ++iter) {
     ue *u = iter->second;
     u->start_pcap(pcap);
-  }  
+  }
 }
 
 /********************************************************
  *
- * RLC interface 
+ * RLC interface
  *
  *******************************************************/
 int mac::rlc_buffer_state(uint16_t rnti, uint32_t lc_id, uint32_t tx_queue, uint32_t retx_queue)
 {
+  pthread_rwlock_rdlock(&rwlock);
+  int ret = -1;
   if (ue_db.count(rnti)) {
     if(rnti != SRSLTE_MRNTI){
-      return scheduler.dl_rlc_buffer_state(rnti, lc_id, tx_queue, retx_queue);
+      ret = scheduler.dl_rlc_buffer_state(rnti, lc_id, tx_queue, retx_queue);
     } else {
       for(uint32_t i = 0; i < mch.num_mtch_sched; i++){
         if(lc_id == mch.mtch_sched[i].lcid){
           mch.mtch_sched[i].lcid_buffer_size = tx_queue;
         }
       }
-      return 0;
+      ret = 0;
     }
   } else {
     Error("User rnti=0x%x not found\n", rnti);
-    return -1;
   }
+  pthread_rwlock_unlock(&rwlock);
+  return ret;
 }
 
 int mac::bearer_ue_cfg(uint16_t rnti, uint32_t lc_id, sched_interface::ue_bearer_cfg_t* cfg)
 {
+  int ret = -1;
+  pthread_rwlock_rdlock(&rwlock);
   if (ue_db.count(rnti)) {
     // configure BSR group in UE
     ue_db[rnti]->set_lcg(lc_id, (uint32_t) cfg->group);
-    return scheduler.bearer_ue_cfg(rnti, lc_id, cfg);      
+    ret = scheduler.bearer_ue_cfg(rnti, lc_id, cfg);
   } else {
     Error("User rnti=0x%x not found\n", rnti);
-    return -1;
   }
+  pthread_rwlock_unlock(&rwlock);
+  return ret;
 }
 
 int mac::bearer_ue_rem(uint16_t rnti, uint32_t lc_id)
 {
-  if (ue_db.count(rnti)) {   
+  pthread_rwlock_rdlock(&rwlock);
-    return scheduler.bearer_ue_rem(rnti, lc_id);
+  int ret = -1;
+  if (ue_db.count(rnti)) {
+    ret = scheduler.bearer_ue_rem(rnti, lc_id);
   } else {
     Error("User rnti=0x%x not found\n", rnti);
-    return -1;
   }
+  pthread_rwlock_unlock(&rwlock);
+  return ret;
 }
 
 void mac::phy_config_enabled(uint16_t rnti, bool enabled)
@@ -193,58 +209,74 @@ void mac::phy_config_enabled(uint16_t rnti, bool enabled)
   scheduler.phy_config_enabled(rnti, enabled);
 }
 
-// Update UE configuration 
+// Update UE configuration
 int mac::ue_cfg(uint16_t rnti, sched_interface::ue_cfg_t* cfg)
 {
-  if (ue_db.count(rnti)) {         
+  int ret = -1;
-    
+  pthread_rwlock_rdlock(&rwlock);
+  if (ue_db.count(rnti)) {
+
     // Add RNTI to the PHY (pregerate signals) now instead of after PRACH
     if (!ue_db[rnti]->is_phy_added) {
-      ue_db[rnti]->is_phy_added = true; 
+      ue_db[rnti]->is_phy_added = true;
       Info("Registering rnti=0x%x to PHY...\n", rnti);
       // Register new user in PHY
       if (phy_h->add_rnti(rnti)) {
-        Error("Registering new ue rnti=0x%x to PHY\n", rnti);       
+        Error("Registering new ue rnti=0x%x to PHY\n", rnti);
       }
       Info("Done registering rnti=0x%x to PHY...\n", rnti);
     }
-    
+
-    // Update Scheduler configuration 
+    // Update Scheduler configuration
     if (scheduler.ue_cfg(rnti, cfg)) {
       Error("Registering new UE rnti=0x%x to SCHED\n", rnti);
-      return -1;
+    } else {
-    }     
+      ret = 0;
-    return 0;
+    }
   } else {
     Error("User rnti=0x%x not found\n", rnti);
-    return -1;
   }
+  pthread_rwlock_unlock(&rwlock);
+  return ret;
 }
 
 // Removes UE from DB
 int mac::ue_rem(uint16_t rnti)
 {
-  if (ue_db.count(rnti)) {         
+  int ret = -1;
+  pthread_rwlock_rdlock(&rwlock);
+  if (ue_db.count(rnti)) {
     scheduler.ue_rem(rnti);
     phy_h->rem_rnti(rnti);
-    delete ue_db[rnti]; 
+    ret = 0;
+  } else {
+    Error("User rnti=0x%x not found\n", rnti);
+  }
+  pthread_rwlock_unlock(&rwlock);
+  if (ret) {
+    return ret;
+  }
+  pthread_rwlock_wrlock(&rwlock);
+  if (ue_db.count(rnti)) {
+    delete ue_db[rnti];
     ue_db.erase(rnti);
     Info("User rnti=0x%x removed from MAC/PHY\n", rnti);
-    return 0; 
   } else {
-    Error("User rnti=0x%x not found\n", rnti);
+    Error("User rnti=0x%x already removed\n", rnti);
-    return -1;
   }
+  pthread_rwlock_unlock(&rwlock);
+  return 0;
 }
 
 int mac::cell_cfg(sched_interface::cell_cfg_t* cell_cfg)
 {
   memcpy(&this->cell_config, cell_cfg, sizeof(sched_interface::cell_cfg_t));
-  return scheduler.cell_cfg(cell_cfg);  
+  return scheduler.cell_cfg(cell_cfg);
 }
 
 void mac::get_metrics(mac_metrics_t metrics[ENB_METRICS_MAX_USERS])
 {
+  pthread_rwlock_rdlock(&rwlock);
   int cnt=0;
   for(std::map<uint16_t, ue*>::iterator iter=ue_db.begin(); iter!=ue_db.end(); ++iter) {
     ue *u = iter->second;
@@ -252,21 +284,23 @@ void mac::get_metrics(mac_metrics_t metrics[ENB_METRICS_MAX_USERS])
       u->metrics_read(&metrics[cnt]);
       cnt++;
     }
-  } 
+  }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 
 /********************************************************
  *
- * PHY interface 
+ * PHY interface
  *
  *******************************************************/
 
 void mac::rl_failure(uint16_t rnti)
 {
-  if (ue_db.count(rnti)) {         
+  pthread_rwlock_rdlock(&rwlock);
-    uint32_t nof_fails = ue_db[rnti]->rl_failure();  
+  if (ue_db.count(rnti)) {
-    if (nof_fails >= (uint32_t) args.link_failure_nof_err && args.link_failure_nof_err > 0) {    
+    uint32_t nof_fails = ue_db[rnti]->rl_failure();
+    if (nof_fails >= (uint32_t) args.link_failure_nof_err && args.link_failure_nof_err > 0) {
       Info("Detected Uplink failure for rnti=0x%x\n", rnti);
       rrc_h->rl_failure(rnti);
       ue_db[rnti]->rl_failure_reset();
@@ -274,141 +308,166 @@ void mac::rl_failure(uint16_t rnti)
   } else {
     Error("User rnti=0x%x not found\n", rnti);
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 void mac::rl_ok(uint16_t rnti)
 {
-  if (ue_db.count(rnti)) {         
+  pthread_rwlock_rdlock(&rwlock);
-    ue_db[rnti]->rl_failure_reset();  
+  if (ue_db.count(rnti)) {
+    ue_db[rnti]->rl_failure_reset();
   } else {
     Error("User rnti=0x%x not found\n", rnti);
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 int mac::ack_info(uint32_t tti, uint16_t rnti, uint32_t tb_idx, bool ack)
 {
+  pthread_rwlock_rdlock(&rwlock);
   log_h->step(tti);
   uint32_t nof_bytes = scheduler.dl_ack_info(tti, rnti, tb_idx, ack);
   ue_db[rnti]->metrics_tx(ack, nof_bytes);
-  
+
   if (ack) {
     if (nof_bytes > 64) { // do not count RLC status messages only
-      rrc_h->set_activity_user(rnti); 
+      rrc_h->set_activity_user(rnti);
       log_h->info("DL activity rnti=0x%x, n_bytes=%d\n", rnti, nof_bytes);
     }
   }
-  return 0; 
+  pthread_rwlock_unlock(&rwlock);
+  return 0;
 }
 
 int mac::crc_info(uint32_t tti, uint16_t rnti, uint32_t nof_bytes, bool crc)
 {
   log_h->step(tti);
-
+  int ret = -1;
-  if (ue_db.count(rnti)) {         
+  pthread_rwlock_rdlock(&rwlock);
+  if (ue_db.count(rnti)) {
     ue_db[rnti]->set_tti(tti);
-    
+
     ue_db[rnti]->metrics_rx(crc, nof_bytes);
-    
+
     // push the pdu through the queue if received correctly
     if (crc) {
       ue_db[rnti]->push_pdu(tti, nof_bytes);
-      pdu_process_thread.notify();      
+      pdu_process_thread.notify();
     } else {
       ue_db[rnti]->deallocate_pdu(tti);
     }
-    
+
-    return scheduler.ul_crc_info(tti, rnti, crc);  
+    ret = scheduler.ul_crc_info(tti, rnti, crc);
   } else {
     Error("User rnti=0x%x not found\n", rnti);
-    return -1;
   }
+  pthread_rwlock_unlock(&rwlock);
+  return ret;
 }
 
 int mac::set_dl_ant_info(uint16_t rnti, LIBLTE_RRC_ANTENNA_INFO_DEDICATED_STRUCT *dl_ant_info) {
   log_h->step(tti);
 
+  int ret = -1;
+  pthread_rwlock_rdlock(&rwlock);
   if (ue_db.count(rnti)) {
     scheduler.dl_ant_info(rnti, dl_ant_info);
+    ret = 0;
   } else {
     Error("User rnti=0x%x not found\n", rnti);
-    return -1;
   }
-  return 0;
+  pthread_rwlock_unlock(&rwlock);
+  return ret;
 }
 
 int mac::ri_info(uint32_t tti, uint16_t rnti, uint32_t ri_value)
 {
   log_h->step(tti);
-
+  int ret = -1;
-  if (ue_db.count(rnti)) {         
+  pthread_rwlock_rdlock(&rwlock);
+  if (ue_db.count(rnti)) {
     scheduler.dl_ri_info(tti, rnti, ri_value);
     ue_db[rnti]->metrics_dl_ri(ri_value);
+    ret = 0;
   } else {
     Error("User rnti=0x%x not found\n", rnti);
-    return -1;
   }
-  return 0; 
+  pthread_rwlock_unlock(&rwlock);
+  return ret;
 }
 
 int mac::pmi_info(uint32_t tti, uint16_t rnti, uint32_t pmi_value)
 {
   log_h->step(tti);
-
+  pthread_rwlock_rdlock(&rwlock);
+  int ret = -1;
   if (ue_db.count(rnti)) {
     scheduler.dl_pmi_info(tti, rnti, pmi_value);
     ue_db[rnti]->metrics_dl_pmi(pmi_value);
+    ret = 0;
   } else {
     Error("User rnti=0x%x not found\n", rnti);
-    return -1;
   }
-  return 0;
+  pthread_rwlock_unlock(&rwlock);
+  return ret;
 }
 
 int mac::cqi_info(uint32_t tti, uint16_t rnti, uint32_t cqi_value)
 {
   log_h->step(tti);
+  int ret = -1;
 
+  pthread_rwlock_rdlock(&rwlock);
   if (ue_db.count(rnti)) {
     scheduler.dl_cqi_info(tti, rnti, cqi_value);
     ue_db[rnti]->metrics_dl_cqi(cqi_value);
+    ret = 0;
   } else {
     Error("User rnti=0x%x not found\n", rnti);
-    return -1;
   }
-  return 0; 
+  pthread_rwlock_unlock(&rwlock);
+  return ret;
 }
 
 int mac::snr_info(uint32_t tti, uint16_t rnti, float snr)
 {
   log_h->step(tti);
-
+  int ret = -1;
-  if (ue_db.count(rnti)) {         
+  pthread_rwlock_rdlock(&rwlock);
-    uint32_t cqi = srslte_cqi_from_snr(snr); 
+  if (ue_db.count(rnti)) {
+    uint32_t cqi = srslte_cqi_from_snr(snr);
     scheduler.ul_cqi_info(tti, rnti, cqi, 0);
+    ret = 0;
   } else {
     Error("User rnti=0x%x not found\n", rnti);
-    return -1;
   }
-  return 0; 
+  pthread_rwlock_unlock(&rwlock);
+  return ret;
 }
 
 int mac::sr_detected(uint32_t tti, uint16_t rnti)
 {
   log_h->step(tti);
-
+  int ret = -1;
-  if (ue_db.count(rnti)) {         
+  pthread_rwlock_rdlock(&rwlock);
-    scheduler.ul_sr_info(tti, rnti);    
+  if (ue_db.count(rnti)) {
+    scheduler.ul_sr_info(tti, rnti);
+    ret = 0;
   } else {
     Error("User rnti=0x%x not found\n", rnti);
-    return -1;
   }
-  return 0; 
+  pthread_rwlock_unlock(&rwlock);
+  return ret;
 }
 
 int mac::rach_detected(uint32_t tti, uint32_t preamble_idx, uint32_t time_adv)
 {
   log_h->step(tti);
 
+  int ret = -1;
+
+  pthread_rwlock_rdlock(&rwlock);
+
   // Find empty slot for pending rars
   uint32_t ra_id=0;
   while(pending_rars[ra_id].temp_crnti && ra_id<MAX_PENDING_RARS-1) {
@@ -416,49 +475,53 @@ int mac::rach_detected(uint32_t tti, uint32_t preamble_idx, uint32_t time_adv)
   }
   if (ra_id == MAX_PENDING_RARS) {
     Error("Maximum number of pending RARs exceeded (%d)\n", MAX_PENDING_RARS);
-    return -1; 
+    goto unlock;
   }
-  
+
-  // Create new UE 
+  // Create new UE
-  ue_db[last_rnti] = new ue; 
+  ue_db[last_rnti] = new ue;
   ue_db[last_rnti]->config(last_rnti, cell.nof_prb, &scheduler, rrc_h, rlc_h, log_h);
-  
+
-  // Set PCAP if available 
+  // Set PCAP if available
   if (pcap) {
     ue_db[last_rnti]->start_pcap(pcap);
   }
   // Save RA info
-  pending_rars[ra_id].preamble_idx = preamble_idx; 
+  pending_rars[ra_id].preamble_idx = preamble_idx;
   pending_rars[ra_id].ta_cmd       = 2*time_adv;
-  pending_rars[ra_id].temp_crnti   = last_rnti;   
+  pending_rars[ra_id].temp_crnti   = last_rnti;
-  
+
   // Add new user to the scheduler so that it can RX/TX SRB0
-  sched_interface::ue_cfg_t uecfg; 
+  sched_interface::ue_cfg_t uecfg;
   bzero(&uecfg, sizeof(sched_interface::ue_cfg_t));
-  uecfg.ue_bearers[0].direction = srsenb::sched_interface::ue_bearer_cfg_t::BOTH; 
+  uecfg.ue_bearers[0].direction = srsenb::sched_interface::ue_bearer_cfg_t::BOTH;
   if (scheduler.ue_cfg(last_rnti, &uecfg)) {
     // Release pending RAR
     bzero(&pending_rars[ra_id], sizeof(pending_rar_t));
     Error("Registering new user rnti=0x%x to SCHED\n", last_rnti);
-    return -1;
+    goto unlock;
   }
 
-  // Register new user in RRC 
+  // Register new user in RRC
   rrc_h->add_user(last_rnti);
-  // Trigger scheduler RACH 
+  // Trigger scheduler RACH
-  scheduler.dl_rach_info(tti, ra_id, last_rnti, 7);    
+  scheduler.dl_rach_info(tti, ra_id, last_rnti, 7);
-    
+
-  log_h->info("RACH:  tti=%d, preamble=%d, offset=%d, temp_crnti=0x%x\n", 
+  log_h->info("RACH:  tti=%d, preamble=%d, offset=%d, temp_crnti=0x%x\n",
-                 tti, preamble_idx, time_adv, last_rnti);  
+                 tti, preamble_idx, time_adv, last_rnti);
-  log_h->console("RACH:  tti=%d, preamble=%d, offset=%d, temp_crnti=0x%x\n", 
+  log_h->console("RACH:  tti=%d, preamble=%d, offset=%d, temp_crnti=0x%x\n",
-                 tti, preamble_idx, time_adv, last_rnti);  
+                 tti, preamble_idx, time_adv, last_rnti);
-  
+
-  // Increae RNTI counter 
+  // Increae RNTI counter
   last_rnti++;
   if (last_rnti >= 60000) {
-    last_rnti = 70; 
+    last_rnti = 70;
   }
-  return 0; 
+  ret = 0;
+
+unlock:
+  pthread_rwlock_unlock(&rwlock);
+  return ret;
 }
 
 int mac::get_dl_sched(uint32_t tti, dl_sched_t *dl_sched_res)
@@ -468,76 +531,85 @@ int mac::get_dl_sched(uint32_t tti, dl_sched_t *dl_sched_res)
   if (!started) {
     return 0;
   }
-  
+
   if (!dl_sched_res) {
-    return SRSLTE_ERROR_INVALID_INPUTS;  
+    return SRSLTE_ERROR_INVALID_INPUTS;
   }
-  
+
-  // Run scheduler with current info 
+  // Run scheduler with current info
-  sched_interface::dl_sched_res_t sched_result; 
+  sched_interface::dl_sched_res_t sched_result;
   bzero(&sched_result, sizeof(sched_interface::dl_sched_res_t));
   if (scheduler.dl_sched(tti, &sched_result) < 0) {
     Error("Running scheduler\n");
     return SRSLTE_ERROR;
   }
-  
+
-  int n = 0; 
+  int n = 0;
-  
+
-  // Copy data grants 
+  pthread_rwlock_rdlock(&rwlock);
+
+  // Copy data grants
   for (uint32_t i=0;i<sched_result.nof_data_elems;i++) {
-    
+
-    // Get UE 
+    // Get UE
     uint16_t rnti = sched_result.data[i].rnti;
-    
-    // Copy grant info 
-    dl_sched_res->sched_grants[n].rnti = rnti; 
-    dl_sched_res->sched_grants[n].dci_format = sched_result.data[i].dci_format;
-    memcpy(&dl_sched_res->sched_grants[n].grant,    &sched_result.data[i].dci,          sizeof(srslte_ra_dl_dci_t));
-    memcpy(&dl_sched_res->sched_grants[n].location, &sched_result.data[i].dci_location, sizeof(srslte_dci_location_t));    
-
-    for (uint32_t tb = 0; tb < SRSLTE_MAX_TB; tb++) {
-      dl_sched_res->sched_grants[n].softbuffers[tb] =
-          ue_db[rnti]->get_tx_softbuffer(sched_result.data[i].dci.harq_process, tb);
-
-      if (sched_result.data[i].nof_pdu_elems[tb] > 0) {
-        /* Get PDU if it's a new transmission */
-        dl_sched_res->sched_grants[n].data[tb] = ue_db[rnti]->generate_pdu(tb,
-                                                                           sched_result.data[i].pdu[tb],
-                                                                           sched_result.data[i].nof_pdu_elems[tb],
-                                                                           sched_result.data[i].tbs[tb]);
-
-        if (!dl_sched_res->sched_grants[n].data[tb]) {
-          Error("Error! PDU was not generated (rnti=0x%04x, tb=%d)\n", rnti, tb);
-          sched_result.data[i].dci.tb_en[tb] = false;
-        }
 
-        if (pcap) {
+    if (ue_db.count(rnti)) {
-          pcap->write_dl_crnti(dl_sched_res->sched_grants[n].data[tb], sched_result.data[i].tbs[tb], rnti, true, tti);
+      // Copy grant info
+      dl_sched_res->sched_grants[n].rnti = rnti;
+      dl_sched_res->sched_grants[n].dci_format = sched_result.data[i].dci_format;
+      memcpy(&dl_sched_res->sched_grants[n].grant,    &sched_result.data[i].dci,          sizeof(srslte_ra_dl_dci_t));
+      memcpy(&dl_sched_res->sched_grants[n].location, &sched_result.data[i].dci_location, sizeof(srslte_dci_location_t));
+
+      for (uint32_t tb = 0; tb < SRSLTE_MAX_TB; tb++) {
+        dl_sched_res->sched_grants[n].softbuffers[tb] =
+            ue_db[rnti]->get_tx_softbuffer(sched_result.data[i].dci.harq_process, tb);
+
+        if (sched_result.data[i].nof_pdu_elems[tb] > 0) {
+          /* Get PDU if it's a new transmission */
+          dl_sched_res->sched_grants[n].data[tb] = ue_db[rnti]->generate_pdu(tb,
+                                                                             sched_result.data[i].pdu[tb],
+                                                                             sched_result.data[i].nof_pdu_elems[tb],
+                                                                             sched_result.data[i].tbs[tb]);
+
+          if (!dl_sched_res->sched_grants[n].data[tb]) {
+            Error("Error! PDU was not generated (rnti=0x%04x, tb=%d)\n", rnti, tb);
+            sched_result.data[i].dci.tb_en[tb] = false;
+          }
+
+          if (pcap) {
+            pcap->write_dl_crnti(dl_sched_res->sched_grants[n].data[tb], sched_result.data[i].tbs[tb], rnti, true, tti);
+          }
+
+        } else {
+          /* TB not enabled OR no data to send: set pointers to NULL  */
+          dl_sched_res->sched_grants[n].data[tb] = NULL;
         }
-
-      } else {
-        /* TB not enabled OR no data to send: set pointers to NULL  */
-        dl_sched_res->sched_grants[n].data[tb] = NULL;
       }
+      n++;
+    } else {
+      Warning("Invalid DL scheduling result. User 0x%x does not exist\n", rnti);
     }
-    n++;
   }
 
-  // Copy RAR grants 
+  // No more uses of shared ue_db beyond here
+  pthread_rwlock_unlock(&rwlock);
+
+  // Copy RAR grants
   for (uint32_t i=0;i<sched_result.nof_rar_elems;i++) {
-    // Copy grant info 
+    // Copy grant info
     dl_sched_res->sched_grants[n].rnti = sched_result.rar[i].rarnti;
     dl_sched_res->sched_grants[n].dci_format = SRSLTE_DCI_FORMAT1A; // Force Format 1A
     memcpy(&dl_sched_res->sched_grants[n].grant,    &sched_result.rar[i].dci,          sizeof(srslte_ra_dl_dci_t));
-    memcpy(&dl_sched_res->sched_grants[n].location, &sched_result.rar[i].dci_location, sizeof(srslte_dci_location_t));    
+    memcpy(&dl_sched_res->sched_grants[n].location, &sched_result.rar[i].dci_location, sizeof(srslte_dci_location_t));
 
     // Set softbuffer (there are no retx in RAR but a softbuffer is required)
     dl_sched_res->sched_grants[n].softbuffers[0] = &rar_softbuffer_tx;
 
-    // Assemble PDU 
+    // Assemble PDU
     dl_sched_res->sched_grants[n].data[0] = assemble_rar(sched_result.rar[i].grants, sched_result.rar[i].nof_grants, i, sched_result.rar[i].tbs);
 
-    
+
     if (pcap) {
       pcap->write_dl_ranti(dl_sched_res->sched_grants[n].data[0], sched_result.rar[i].tbs, dl_sched_res->sched_grants[n].rnti, true, tti);
     }
@@ -545,15 +617,15 @@ int mac::get_dl_sched(uint32_t tti, dl_sched_t *dl_sched_res)
     n++;
   }
 
-  // Copy SI and Paging grants   
+  // Copy SI and Paging grants
   for (uint32_t i=0;i<sched_result.nof_bc_elems;i++) {
-    // Copy grant info 
+    // Copy grant info
     dl_sched_res->sched_grants[n].rnti = (sched_result.bc[i].type == sched_interface::dl_sched_bc_t::BCCH ) ? SRSLTE_SIRNTI : SRSLTE_PRNTI;
     dl_sched_res->sched_grants[n].dci_format = SRSLTE_DCI_FORMAT1A; // Force Format 1A
     memcpy(&dl_sched_res->sched_grants[n].grant,    &sched_result.bc[i].dci,          sizeof(srslte_ra_dl_dci_t));
-    memcpy(&dl_sched_res->sched_grants[n].location, &sched_result.bc[i].dci_location, sizeof(srslte_dci_location_t));    
+    memcpy(&dl_sched_res->sched_grants[n].location, &sched_result.bc[i].dci_location, sizeof(srslte_dci_location_t));
-    
+
-    // Set softbuffer    
+    // Set softbuffer
     if (sched_result.bc[i].type == sched_interface::dl_sched_bc_t::BCCH) {
       dl_sched_res->sched_grants[n].softbuffers[0] = &bcch_softbuffer_tx[sched_result.bc[i].index];
       dl_sched_res->sched_grants[n].data[0] = assemble_si(sched_result.bc[i].index);
@@ -566,20 +638,20 @@ int mac::get_dl_sched(uint32_t tti, dl_sched_t *dl_sched_res)
       dl_sched_res->sched_grants[n].softbuffers[0] = &pcch_softbuffer_tx;
       dl_sched_res->sched_grants[n].data[0] = pcch_payload_buffer;
       rlc_h->read_pdu_pcch(pcch_payload_buffer, pcch_payload_buffer_len);
-      
+
       if (pcap) {
         pcap->write_dl_pch(dl_sched_res->sched_grants[n].data[0], sched_result.bc[i].tbs, true, tti);
       }
     }
-    
+
     n++;
   }
-  
+
-  dl_sched_res->nof_grants = n; 
+  dl_sched_res->nof_grants = n;
-  
+
-  // Number of CCH symbols 
+  // Number of CCH symbols
-  dl_sched_res->cfi = sched_result.cfi; 
+  dl_sched_res->cfi = sched_result.cfi;
-    
+
   return SRSLTE_SUCCESS;
 }
 
@@ -587,12 +659,12 @@ void mac::build_mch_sched(uint32_t tbs)
 {
   int sfs_per_sched_period = mcch.pmch_infolist_r9[0].pmch_config_r9.sf_alloc_end_r9;
   int bytes_per_sf = tbs/8 - 6;// leave 6 bytes for header
-  
+
   int total_space_avail_bytes =  sfs_per_sched_period*bytes_per_sf;
-  
+
-  int total_bytes_to_tx = 0; 
+  int total_bytes_to_tx = 0;
-  
+
-  
+
   // calculate total bytes to be scheduled
   for (uint32_t i = 0; i < mch.num_mtch_sched; i++) {
     total_bytes_to_tx += mch.mtch_sched[i].lcid_buffer_size;
@@ -600,34 +672,34 @@ void mac::build_mch_sched(uint32_t tbs)
   }
 
   int last_mtch_stop = 0;
-  
+
   if(total_bytes_to_tx >= total_space_avail_bytes){
     for(uint32_t i = 0; i < mch.num_mtch_sched;i++){
        double ratio =  mch.mtch_sched[i].lcid_buffer_size/total_bytes_to_tx;
        float assigned_sfs = floor(sfs_per_sched_period*ratio);
        mch.mtch_sched[i].stop = last_mtch_stop + (uint32_t)assigned_sfs;
        last_mtch_stop = mch.mtch_sched[i].stop;
-    } 
+    }
   }else {
     for(uint32_t i = 0; i < mch.num_mtch_sched;i++){
       float assigned_sfs =  ceil(((float)mch.mtch_sched[i].lcid_buffer_size)/((float)bytes_per_sf));
       mch.mtch_sched[i].stop = last_mtch_stop + (uint32_t)assigned_sfs;
-      last_mtch_stop = mch.mtch_sched[i].stop; 
+      last_mtch_stop = mch.mtch_sched[i].stop;
     }
   }
 }
 
 int mac::get_mch_sched(bool is_mcch, dl_sched_t *dl_sched_res)
 {
-  
+
   srslte_ra_mcs_t mcs;
   srslte_ra_mcs_t mcs_data;
   mcs.idx = this->sib13.mbsfn_area_info_list_r9[0].signalling_mcs_r9;
   mcs_data.idx = this->mcch.pmch_infolist_r9[0].pmch_config_r9.datamcs_r9;
   srslte_dl_fill_ra_mcs(&mcs, this->cell_config.cell.nof_prb);
   srslte_dl_fill_ra_mcs(&mcs_data, this->cell_config.cell.nof_prb);
-  if(is_mcch){ 
+  if(is_mcch){
-    
+
     build_mch_sched(mcs_data.tbs);
     mch.mcch_payload = mcch_payload_buffer;
     mch.current_sf_allocation_num = 1;
@@ -636,17 +708,17 @@ int mac::get_mch_sched(bool is_mcch, dl_sched_t *dl_sched_res)
       mch.pdu[i].lcid = srslte::sch_subh::MCH_SCHED_INFO;
      // mch.mtch_sched[i].lcid = 1+i;
     }
-    
+
     mch.pdu[mch.num_mtch_sched].lcid = 0;
     mch.pdu[mch.num_mtch_sched].nbytes =  current_mcch_length;
     dl_sched_res->sched_grants[0].rnti = SRSLTE_MRNTI;
     dl_sched_res->sched_grants[0].data[0] = ue_db[SRSLTE_MRNTI]->generate_mch_pdu(mch, mch.num_mtch_sched + 1, mcs.tbs/8);
-    
+
   } else {
     uint32_t current_lcid = 1;
     uint32_t mtch_index = 0;
     uint32_t mtch_stop = mch.mtch_sched[mch.num_mtch_sched -1].stop;
-    
+
     for(uint32_t i = 0;i < mch.num_mtch_sched;i++) {
       if(mch.current_sf_allocation_num <= mch.mtch_sched[i].stop){
         current_lcid = mch.mtch_sched[i].lcid;
@@ -669,9 +741,9 @@ int mac::get_mch_sched(bool is_mcch, dl_sched_t *dl_sched_res)
     }
     mch.current_sf_allocation_num++;
   }
-     
+
  return SRSLTE_SUCCESS;
-}  
+}
 
 uint8_t* mac::assemble_rar(sched_interface::dl_sched_rar_grant_t* grants, uint32_t nof_grants, int rar_idx, uint32_t pdu_len)
 {
@@ -684,10 +756,10 @@ uint8_t* mac::assemble_rar(sched_interface::dl_sched_rar_grant_t* grants, uint32
       if (pdu->new_subh()) {
         /* Search pending RAR */
         int idx = grants[i].ra_id;
-        pdu->get()->set_rapid(pending_rars[idx].preamble_idx); 
+        pdu->get()->set_rapid(pending_rars[idx].preamble_idx);
         pdu->get()->set_ta_cmd(pending_rars[idx].ta_cmd);
-        pdu->get()->set_temp_crnti(pending_rars[idx].temp_crnti);          
+        pdu->get()->set_temp_crnti(pending_rars[idx].temp_crnti);
-        pdu->get()->set_sched_grant(grant_buffer);                 
+        pdu->get()->set_sched_grant(grant_buffer);
         bzero(&pending_rars[idx], sizeof(pending_rar_t));
       }
     }
@@ -695,76 +767,85 @@ uint8_t* mac::assemble_rar(sched_interface::dl_sched_rar_grant_t* grants, uint32
     return rar_payload[rar_idx];
   } else {
     Error("Assembling RAR: pdu_len > rar_payload_len (%d>%d)\n", pdu_len, rar_payload_len);
-    return NULL; 
+    return NULL;
   }
 }
 
 uint8_t* mac::assemble_si(uint32_t index)
-{ 
+{
   rlc_h->read_pdu_bcch_dlsch(index, bcch_dlsch_payload);
   return bcch_dlsch_payload;
 }
 
-int mac::get_ul_sched(uint32_t tti, ul_sched_t *ul_sched_res) 
+int mac::get_ul_sched(uint32_t tti, ul_sched_t *ul_sched_res)
 {
 
   log_h->step(tti);
-  
+
   if (!started) {
-    return 0; 
+    return 0;
   }
-  
+
   if (!ul_sched_res) {
-    return SRSLTE_ERROR_INVALID_INPUTS; 
+    return SRSLTE_ERROR_INVALID_INPUTS;
   }
-  
+
-  // Run scheduler with current info 
+  // Run scheduler with current info
-  sched_interface::ul_sched_res_t sched_result; 
+  sched_interface::ul_sched_res_t sched_result;
   bzero(&sched_result, sizeof(sched_interface::ul_sched_res_t));
   if (scheduler.ul_sched(tti, &sched_result)<0) {
     Error("Running scheduler\n");
-    return SRSLTE_ERROR; 
+    return SRSLTE_ERROR;
   }
 
-  // Copy DCI grants 
+  pthread_rwlock_rdlock(&rwlock);
-  ul_sched_res->nof_grants = 0; 
+
-  int n = 0; 
+  // Copy DCI grants
+  ul_sched_res->nof_grants = 0;
+  int n = 0;
   for (uint32_t i=0;i<sched_result.nof_dci_elems;i++) {
-    
+
     if (sched_result.pusch[i].tbs > 0) {
-      // Get UE 
+      // Get UE
       uint16_t rnti = sched_result.pusch[i].rnti;
-            
+
-      // Copy grant info 
+      if (ue_db.count(rnti)) {
-      ul_sched_res->sched_grants[n].rnti             = rnti; 
+        // Copy grant info
-      ul_sched_res->sched_grants[n].current_tx_nb    = sched_result.pusch[i].current_tx_nb; 
+        ul_sched_res->sched_grants[n].rnti             = rnti;
-      ul_sched_res->sched_grants[n].needs_pdcch      = sched_result.pusch[i].needs_pdcch; 
+        ul_sched_res->sched_grants[n].current_tx_nb    = sched_result.pusch[i].current_tx_nb;
-      memcpy(&ul_sched_res->sched_grants[n].grant,    &sched_result.pusch[i].dci,          sizeof(srslte_ra_ul_dci_t));
+        ul_sched_res->sched_grants[n].needs_pdcch      = sched_result.pusch[i].needs_pdcch;
-      memcpy(&ul_sched_res->sched_grants[n].location, &sched_result.pusch[i].dci_location, sizeof(srslte_dci_location_t));    
+        memcpy(&ul_sched_res->sched_grants[n].grant,    &sched_result.pusch[i].dci,          sizeof(srslte_ra_ul_dci_t));
-      
+        memcpy(&ul_sched_res->sched_grants[n].location, &sched_result.pusch[i].dci_location, sizeof(srslte_dci_location_t));
-      ul_sched_res->sched_grants[n].softbuffer = ue_db[rnti]->get_rx_softbuffer(tti);        
+
-      
+        ul_sched_res->sched_grants[n].softbuffer = ue_db[rnti]->get_rx_softbuffer(tti);
-      if (sched_result.pusch[n].current_tx_nb == 0) {
+
-        srslte_softbuffer_rx_reset_tbs(ul_sched_res->sched_grants[n].softbuffer, sched_result.pusch[i].tbs*8);      
+        if (sched_result.pusch[n].current_tx_nb == 0) {
+          srslte_softbuffer_rx_reset_tbs(ul_sched_res->sched_grants[n].softbuffer, sched_result.pusch[i].tbs*8);
+        }
+        ul_sched_res->sched_grants[n].data = ue_db[rnti]->request_buffer(tti, sched_result.pusch[i].tbs);
+        ul_sched_res->nof_grants++;
+        n++;
+      } else {
+        Warning("Invalid DL scheduling result. User 0x%x does not exist\n", rnti);
       }
-      ul_sched_res->sched_grants[n].data = ue_db[rnti]->request_buffer(tti, sched_result.pusch[i].tbs);
+
-      ul_sched_res->nof_grants++;
-      n++; 
-      
     } else {
       Warning("Grant %d for rnti=0x%x has zero TBS\n", i, sched_result.pusch[i].rnti);
     }
   }
 
+  // No more uses of ue_db beyond here
+  pthread_rwlock_unlock(&rwlock);
+
   // Copy PHICH actions
   for (uint32_t i=0;i<sched_result.nof_phich_elems;i++) {
     ul_sched_res->phich[i].ack  = sched_result.phich[i].phich == sched_interface::ul_sched_phich_t::ACK;
-    ul_sched_res->phich[i].rnti = sched_result.phich[i].rnti; 
+    ul_sched_res->phich[i].rnti = sched_result.phich[i].rnti;
   }
   ul_sched_res->nof_phich = sched_result.nof_phich_elems;
-  return SRSLTE_SUCCESS; 
+  return SRSLTE_SUCCESS;
 }
-  
+
 void mac::tti_clock()
 {
   timers_thread.tti_clock();
@@ -799,7 +880,7 @@ srslte::timers::timer* mac::timer_get(uint32_t timer_id)
  *******************************************************/
 void mac::timer_thread::run_thread()
 {
-  running=true; 
+  running=true;
   ttisync.set_producer_cntr(0);
   ttisync.resync();
   while(running) {
@@ -829,34 +910,34 @@ void mac::timer_thread::tti_clock()
  *
  *******************************************************/
 mac::pdu_process::pdu_process(pdu_process_handler *h) : running(false) {
-  handler = h; 
+  handler = h;
   pthread_mutex_init(&mutex, NULL);
   pthread_cond_init(&cvar, NULL);
-  have_data = false; 
+  have_data = false;
-  start(MAC_PDU_THREAD_PRIO);  
+  start(MAC_PDU_THREAD_PRIO);
 }
 
 void mac::pdu_process::stop()
 {
   pthread_mutex_lock(&mutex);
-  running = false; 
+  running = false;
   pthread_cond_signal(&cvar);
   pthread_mutex_unlock(&mutex);
-  
+
   wait_thread_finish();
 }
 
 void mac::pdu_process::notify()
 {
   pthread_mutex_lock(&mutex);
-  have_data = true; 
+  have_data = true;
   pthread_cond_signal(&cvar);
   pthread_mutex_unlock(&mutex);
 }
 
 void mac::pdu_process::run_thread()
 {
-  running = true; 
+  running = true;
   while(running) {
     have_data = handler->process_pdus();
     if (!have_data) {
@@ -871,13 +952,15 @@ void mac::pdu_process::run_thread()
 
 bool mac::process_pdus()
 {
-  bool ret = false; 
+  pthread_rwlock_rdlock(&rwlock);
+  bool ret = false;
   for(std::map<uint16_t, ue*>::iterator iter=ue_db.begin(); iter!=ue_db.end(); ++iter) {
-    ue *u         = iter->second; 
+    ue *u         = iter->second;
-    uint16_t rnti = iter->first; 
+    uint16_t rnti = iter->first;
     ret = ret | u->process_pdus();
   }
-  return ret; 
+  pthread_rwlock_unlock(&rwlock);
+  return ret;
 }
 
 

srsenb/src/mac/scheduler.cc

@@ -57,22 +57,16 @@ sched::sched() : bc_aggr_level(0), rar_aggr_level(0), avail_rbg(0), P(0), start_
   bzero(&sched_cfg, sizeof(sched_cfg));
   bzero(&common_locations, sizeof(common_locations));
   bzero(&pdsch_re, sizeof(pdsch_re));
-  bzero(&mutex, sizeof(mutex));
 
   for (int i = 0; i < 3; i++) {
     bzero(rar_locations[i], sizeof(sched_ue::sched_dci_cce_t) * 10);
   }
-
-  pthread_mutex_init(&mutex, NULL);
-  pthread_mutex_init(&mutex2, NULL);
   reset();
 }
 
 sched::~sched()
 {
   srslte_regs_free(&regs);
-  pthread_mutex_destroy(&mutex);
-  pthread_mutex_destroy(&mutex2);
 }
 
 void sched::init(rrc_interface_mac *rrc_, srslte::log* log)
@@ -118,8 +112,6 @@ int sched::cell_cfg(sched_interface::cell_cfg_t* cell_cfg)
     return -1;
   }
 
-  pthread_mutex_lock(&mutex);
-  
   memcpy(&cfg, cell_cfg, sizeof(sched_interface::cell_cfg_t));
     
   // Get DCI locations 
@@ -147,9 +139,7 @@ int sched::cell_cfg(sched_interface::cell_cfg_t* cell_cfg)
   }  
   configured = true;
   
-  pthread_mutex_unlock(&mutex);
+  return 0;
-  
-  return 0; 
 }
 
 
@@ -161,31 +151,24 @@ int sched::cell_cfg(sched_interface::cell_cfg_t* cell_cfg)
 
 int sched::ue_cfg(uint16_t rnti, sched_interface::ue_cfg_t *ue_cfg)
 {
-  pthread_mutex_lock(&mutex);
+   // Add or config user
-  
-   // Add or config user 
   ue_db[rnti].set_cfg(rnti, ue_cfg, &cfg, &regs, log_h);   
   ue_db[rnti].set_max_mcs(sched_cfg.pusch_max_mcs, sched_cfg.pdsch_max_mcs);
   ue_db[rnti].set_fixed_mcs(sched_cfg.pusch_mcs, sched_cfg.pdsch_mcs);
 
-  pthread_mutex_unlock(&mutex);
+  return 0;
-  return 0; 
 }
 
 int sched::ue_rem(uint16_t rnti)
 {
-  pthread_mutex_lock(&mutex);
-  pthread_mutex_lock(&mutex2);
   int ret = 0;
-  if (ue_db.count(rnti)) {         
+  if (ue_db.count(rnti)) {
     ue_db.erase(rnti);
   } else {
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex2);
+  return ret;
-  pthread_mutex_unlock(&mutex);
-  return ret; 
 }
 
 bool sched::ue_exists(uint16_t rnti) 
@@ -195,33 +178,27 @@ bool sched::ue_exists(uint16_t rnti)
 
 void sched::phy_config_enabled(uint16_t rnti, bool enabled)
 {
-  pthread_mutex_lock(&mutex);
+  if (ue_db.count(rnti)) {
-  if (ue_db.count(rnti)) {         
     ue_db[rnti].phy_config_enabled(current_tti, enabled);
   } else {
     Error("User rnti=0x%x not found\n", rnti);
   }
-  pthread_mutex_unlock(&mutex);
 }
 
 int sched::bearer_ue_cfg(uint16_t rnti, uint32_t lc_id, sched_interface::ue_bearer_cfg_t *cfg)
 {
-  pthread_mutex_lock(&mutex);
+  int ret = 0;
-  int ret = 0; 
   if (ue_db.count(rnti)) {         
     ue_db[rnti].set_bearer_cfg(lc_id, cfg);
   } else {
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex);
   return ret;
 }
 
 int sched::bearer_ue_rem(uint16_t rnti, uint32_t lc_id)
 {
-  pthread_mutex_lock(&mutex);
-  pthread_mutex_lock(&mutex2);
   int ret = 0;
   if (ue_db.count(rnti)) {         
     ue_db[rnti].rem_bearer(lc_id);
@@ -229,49 +206,33 @@ int sched::bearer_ue_rem(uint16_t rnti, uint32_t lc_id)
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex2);
+  return ret;
-  pthread_mutex_unlock(&mutex);
-  return ret; 
 }
 
 uint32_t sched::get_dl_buffer(uint16_t rnti)
 {
-  pthread_mutex_lock(&mutex);
+  uint32_t ret = 0;
-  uint32_t ret = 0; 
   if (ue_db.count(rnti)) {         
     ret = ue_db[rnti].get_pending_dl_new_data(current_tti);
   } else {
     Error("User rnti=0x%x not found\n", rnti);
   }
-  pthread_mutex_unlock(&mutex);
+  return ret;
-  return ret; 
 }
 
 uint32_t sched::get_ul_buffer(uint16_t rnti)
 {
-  pthread_mutex_lock(&mutex);
+  uint32_t ret = 0;
-  uint32_t ret = 0; 
   if (ue_db.count(rnti)) {         
     ret = ue_db[rnti].get_pending_ul_new_data(current_tti);
   } else {
     Error("User rnti=0x%x not found\n", rnti);
   }
-  pthread_mutex_unlock(&mutex);
+  return ret;
-  return ret; 
 }
 
-/* \Warning: This function is not mutexed because it can produce late changes on the buffer state while
- * the scheduler is already allocating data, resulting in empty grants.
- * Ideally we would like the scheduler to query the RLC for buffer states in order to get the most updated
- * buffer state with the minimum overhead. However, the current architecture is designed to be compliant
- * with the FAPI interface
- *
- * We add a new mutex used only in ue_rem to avoid the UE being removed in between the access to
- * ue_db.count() and the access to the std::map.
- */
 int sched::dl_rlc_buffer_state(uint16_t rnti, uint32_t lc_id, uint32_t tx_queue, uint32_t retx_queue)
 {
-  pthread_mutex_lock(&mutex2);
   int ret = 0;
   if (ue_db.count(rnti)) {
     ue_db[rnti].dl_buffer_state(lc_id, tx_queue, retx_queue);
@@ -279,14 +240,11 @@ int sched::dl_rlc_buffer_state(uint16_t rnti, uint32_t lc_id, uint32_t tx_queue,
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex2);
   return ret;
 }
 
-/* \Warning Read comment in dl_rlc_buffer_state() */
 int sched::dl_mac_buffer_state(uint16_t rnti, uint32_t ce_code)
 {
-  pthread_mutex_lock(&mutex2);
   int ret = 0;
   if (ue_db.count(rnti)) {         
     ue_db[rnti].mac_buffer_state(ce_code);
@@ -294,12 +252,10 @@ int sched::dl_mac_buffer_state(uint16_t rnti, uint32_t ce_code)
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex2);
   return ret;
 }
 
 int sched::dl_ant_info(uint16_t rnti, LIBLTE_RRC_ANTENNA_INFO_DEDICATED_STRUCT *dl_ant_info) {
-  pthread_mutex_lock(&mutex);
   int ret = 0;
   if (ue_db.count(rnti)) {
     ue_db[rnti].set_dl_ant_info(dl_ant_info);
@@ -307,55 +263,47 @@ int sched::dl_ant_info(uint16_t rnti, LIBLTE_RRC_ANTENNA_INFO_DEDICATED_STRUCT *
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex);
   return ret;
 }
 
 int sched::dl_ack_info(uint32_t tti, uint16_t rnti, uint32_t tb_idx, bool ack)
 {
-  pthread_mutex_lock(&mutex);
+  int ret = 0;
-  int ret = 0; 
   if (ue_db.count(rnti)) {         
     ret = ue_db[rnti].set_ack_info(tti, tb_idx, ack);
   } else {
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex);
+  return ret;
-  return ret; 
 }
 
 int sched::ul_crc_info(uint32_t tti, uint16_t rnti, bool crc)
 {
-  pthread_mutex_lock(&mutex);
+  int ret = 0;
-  int ret = 0; 
   if (ue_db.count(rnti)) {         
     ue_db[rnti].set_ul_crc(tti, crc);
   } else {
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex);
+  return ret;
-  return ret; 
 }
 
 int sched::dl_ri_info(uint32_t tti, uint16_t rnti, uint32_t cqi_value)
 {
-  pthread_mutex_lock(&mutex);
+  int ret = 0;
-  int ret = 0; 
   if (ue_db.count(rnti)) {         
     ue_db[rnti].set_dl_ri(tti, cqi_value);
   } else {
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex);
+  return ret;
-  return ret; 
 }
 
 int sched::dl_pmi_info(uint32_t tti, uint16_t rnti, uint32_t pmi_value)
 {
-  pthread_mutex_lock(&mutex);
   int ret = 0;
   if (ue_db.count(rnti)) {
     ue_db[rnti].set_dl_pmi(tti, pmi_value);
@@ -363,13 +311,11 @@ int sched::dl_pmi_info(uint32_t tti, uint16_t rnti, uint32_t pmi_value)
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex);
   return ret;
 }
 
 int sched::dl_cqi_info(uint32_t tti, uint16_t rnti, uint32_t cqi_value)
 {
-  pthread_mutex_lock(&mutex);
   int ret = 0;
   if (ue_db.count(rnti)) {
     ue_db[rnti].set_dl_cqi(tti, cqi_value);
@@ -377,7 +323,6 @@ int sched::dl_cqi_info(uint32_t tti, uint16_t rnti, uint32_t cqi_value)
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex);
   return ret;
 }
 
@@ -399,72 +344,62 @@ int sched::dl_rach_info(uint32_t tti, uint32_t ra_id, uint16_t rnti, uint32_t es
 
 int sched::ul_cqi_info(uint32_t tti, uint16_t rnti, uint32_t cqi, uint32_t ul_ch_code)
 {
-  pthread_mutex_lock(&mutex);
+  int ret = 0;
-  int ret = 0; 
   if (ue_db.count(rnti)) {         
     ue_db[rnti].set_ul_cqi(tti, cqi, ul_ch_code);
   } else {
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex);
+  return ret;
-  return ret; 
 }
 
 int sched::ul_bsr(uint16_t rnti, uint32_t lcid, uint32_t bsr, bool set_value)
 {
-  pthread_mutex_lock(&mutex);
+  int ret = 0;
-  int ret = 0; 
   if (ue_db.count(rnti)) {         
     ue_db[rnti].ul_buffer_state(lcid, bsr, set_value);
   } else {
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex);
+  return ret;
-  return ret; 
 }
 
 int sched::ul_recv_len(uint16_t rnti, uint32_t lcid, uint32_t len)
 {
-  pthread_mutex_lock(&mutex);
+  int ret = 0;
-  int ret = 0; 
   if (ue_db.count(rnti)) {         
     ue_db[rnti].ul_recv_len(lcid, len);
   } else {
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex);
+  return ret;
-  return ret; 
 }
 
 int sched::ul_phr(uint16_t rnti, int phr)
 {
-  pthread_mutex_lock(&mutex);
+  int ret = 0;
-  int ret = 0; 
   if (ue_db.count(rnti)) {         
     ue_db[rnti].ul_phr(phr);
   } else {
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex);
+  return ret;
-  return ret; 
 }
 
 int sched::ul_sr_info(uint32_t tti, uint16_t rnti)
 {
-  pthread_mutex_lock(&mutex);
+  int ret = 0;
-  int ret = 0; 
   if (ue_db.count(rnti)) {         
     ue_db[rnti].set_sr();;
   } else {
     Error("User rnti=0x%x not found\n", rnti);
     ret = -1;
   }
-  pthread_mutex_unlock(&mutex);
+  return ret;
-  return ret; 
 }
 
 void sched::tpc_inc(uint16_t rnti)
@@ -756,7 +691,6 @@ int sched::dl_sched(uint32_t tti, sched_interface::dl_sched_res_t* sched_result)
   if (!configured) {
     return 0; 
   }
-  pthread_mutex_lock(&mutex);
 
   /* If ul_sched() not yet called this tti, reset CCE state */
   if (current_tti != tti) {
@@ -786,8 +720,7 @@ int sched::dl_sched(uint32_t tti, sched_interface::dl_sched_res_t* sched_result)
   /* Set CFI */
   sched_result->cfi = current_cfi; 
   
-  pthread_mutex_unlock(&mutex);
+  return 0;
-  return 0; 
 }
 
 // Uplink sched 
@@ -798,8 +731,6 @@ int sched::ul_sched(uint32_t tti, srsenb::sched_interface::ul_sched_res_t* sched
     return 0; 
   }
 
-  pthread_mutex_lock(&mutex);
-
   /* If dl_sched() not yet called this tti (this tti is +4ms advanced), reset CCE state */
   if (TTI_TX(current_tti) != tti) {
     bzero(used_cce, MAX_CCE*sizeof(bool));    
@@ -858,14 +789,8 @@ int sched::ul_sched(uint32_t tti, srsenb::sched_interface::ul_sched_res_t* sched
     pucch.L        = (uint32_t) cfg.nrb_pucch;
     if(!ul_metric->update_allocation(pucch)) {
       log_h->warning("SCHED: Failed to allocate PUCCH\n");
-    }
+    } else {
-    for(it_t iter=ue_db.begin(); iter!=ue_db.end(); ++iter) {
+      log_h->debug("Allocating PUCCH (%d,%d)\n", pucch.RB_start, pucch.RB_start+pucch.L);
-      sched_ue *user = (sched_ue *) &iter->second;
-      uint16_t rnti = (uint16_t) iter->first;
-      uint32_t prb_idx[2] = {0, 0};
-      if(user->get_pucch_sched(current_tti, prb_idx)) {
-        user->has_pucch = true;
-      }
     }
   } else {
     for(it_t iter=ue_db.begin(); iter!=ue_db.end(); ++iter) {
@@ -888,6 +813,10 @@ int sched::ul_sched(uint32_t tti, srsenb::sched_interface::ul_sched_res_t* sched
     ul_harq_proc::ul_alloc_t prach = {cfg.prach_freq_offset, 6};
     if(!ul_metric->update_allocation(prach)) {
       log_h->warning("SCHED: Failed to allocate PRACH RBs within (%d,%d)\n", prach.RB_start, prach.RB_start + prach.L);
+      if (prach.RB_start + prach.L > cfg.cell.nof_prb) {
+        fprintf(stderr, "Invalid PRACH configuration: frequency offset=%d outside bandwidth limits\n", cfg.prach_freq_offset);
+        return -1;
+      }
     }
     else {
       log_h->debug("SCHED: Allocated PRACH RBs within (%d,%d)\n", prach.RB_start, prach.RB_start + prach.L);
@@ -999,8 +928,6 @@ int sched::ul_sched(uint32_t tti, srsenb::sched_interface::ul_sched_res_t* sched
   sched_result->nof_dci_elems   = nof_dci_elems;
   sched_result->nof_phich_elems = nof_phich_elems;
 
-  pthread_mutex_unlock(&mutex);
-
   return SRSLTE_SUCCESS;
 }
 

srsenb/src/mac/scheduler_ue.cc

@@ -60,15 +60,24 @@ sched_ue::sched_ue() : dl_next_alloc(NULL), ul_next_alloc(NULL), has_pucch(false
   bzero(&dl_harq, sizeof(dl_harq));
   bzero(&ul_harq, sizeof(ul_harq));
   bzero(&dl_ant_info, sizeof(dl_ant_info));
+
+  pthread_mutex_init(&mutex, NULL);
   reset();
 }
 
+sched_ue::~sched_ue() {
+  pthread_mutex_lock(&mutex);
+  pthread_mutex_unlock(&mutex);
+  pthread_mutex_destroy(&mutex);
+}
+
 void sched_ue::set_cfg(uint16_t rnti_, sched_interface::ue_cfg_t *cfg_, sched_interface::cell_cfg_t *cell_cfg, 
                             srslte_regs_t *regs, srslte::log *log_h_) 
 {
   reset();
-  
+
-  rnti  = rnti_; 
+  pthread_mutex_lock(&mutex);
+  rnti  = rnti_;
   log_h = log_h_; 
   memcpy(&cell, &cell_cfg->cell, sizeof(srslte_cell_t));
   P = srslte_ra_type0_P(cell.nof_prb);
@@ -81,11 +90,7 @@ void sched_ue::set_cfg(uint16_t rnti_, sched_interface::ue_cfg_t *cfg_, sched_in
   }  
   
   Info("SCHED: Added user rnti=0x%x\n", rnti);
-  for (int i=0;i<sched_interface::MAX_LC;i++) {
+  // Config HARQ processes
-    set_bearer_cfg(i, &cfg.ue_bearers[i]);    
-  }
-
-  // Config HARQ processes 
   for (int i=0;i<SCHED_MAX_HARQ_PROC;i++) {
     dl_harq[i].config(i, cfg.maxharq_tx, log_h); 
     ul_harq[i].config(i, cfg.maxharq_tx, log_h);
@@ -96,11 +101,18 @@ void sched_ue::set_cfg(uint16_t rnti_, sched_interface::ue_cfg_t *cfg_, sched_in
     for (int sf_idx=0;sf_idx<10;sf_idx++) {
       sched::generate_cce_location(regs, &dci_locations[cfi][sf_idx], cfi+1, sf_idx, rnti);
     }
-  }    
+  }
+  pthread_mutex_unlock(&mutex);
+
+  for (int i=0;i<sched_interface::MAX_LC;i++) {
+    set_bearer_cfg(i, &cfg.ue_bearers[i]);
+  }
+
 }
 
 void sched_ue::reset()
 {
+  pthread_mutex_lock(&mutex);
   bzero(&cfg, sizeof(sched_interface::ue_cfg_t));
   sr = false;
   next_tpc_pusch = 1;
@@ -123,17 +135,22 @@ void sched_ue::reset()
       ul_harq[i].reset(tb);
     }
   }
+  pthread_mutex_unlock(&mutex);
+
   for (int i=0;i<sched_interface::MAX_LC; i++) {
     rem_bearer(i);
   }
 }
 
 void sched_ue::set_fixed_mcs(int mcs_ul, int mcs_dl) {
-  fixed_mcs_ul = mcs_ul; 
+  pthread_mutex_lock(&mutex);
-  fixed_mcs_dl = mcs_dl; 
+  fixed_mcs_ul = mcs_ul;
+  fixed_mcs_dl = mcs_dl;
+  pthread_mutex_unlock(&mutex);
 }
 
 void sched_ue::set_max_mcs(int mcs_ul, int mcs_dl) {
+  pthread_mutex_lock(&mutex);
   if (mcs_ul < 0) {
     max_mcs_ul = 28;     
   } else {
@@ -144,6 +161,7 @@ void sched_ue::set_max_mcs(int mcs_ul, int mcs_dl) {
   } else {
     max_mcs_dl = mcs_dl;     
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 
@@ -155,6 +173,7 @@ void sched_ue::set_max_mcs(int mcs_ul, int mcs_dl) {
 
 void sched_ue::set_bearer_cfg(uint32_t lc_id, sched_interface::ue_bearer_cfg_t* cfg)
 {
+  pthread_mutex_lock(&mutex);
   if (lc_id < sched_interface::MAX_LC) {
     memcpy(&lch[lc_id].cfg, cfg, sizeof(sched_interface::ue_bearer_cfg_t));
     lch[lc_id].buf_tx = 0; 
@@ -163,13 +182,16 @@ void sched_ue::set_bearer_cfg(uint32_t lc_id, sched_interface::ue_bearer_cfg_t*
       Info("SCHED: Set bearer config lc_id=%d, direction=%d\n", lc_id, (int) lch[lc_id].cfg.direction);
     }
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void sched_ue::rem_bearer(uint32_t lc_id)
 {
+  pthread_mutex_lock(&mutex);
   if (lc_id < sched_interface::MAX_LC) {
     bzero(&lch[lc_id], sizeof(ue_bearer_t));
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void sched_ue::phy_config_enabled(uint32_t tti, bool enabled)
@@ -180,6 +202,7 @@ void sched_ue::phy_config_enabled(uint32_t tti, bool enabled)
 
 void sched_ue::ul_buffer_state(uint8_t lc_id, uint32_t bsr, bool set_value)
 {
+  pthread_mutex_lock(&mutex);
   if (lc_id < sched_interface::MAX_LC) {
     if (set_value) {
       lch[lc_id].bsr = bsr;
@@ -189,25 +212,30 @@ void sched_ue::ul_buffer_state(uint8_t lc_id, uint32_t bsr, bool set_value)
   }
   Debug("SCHED: bsr=%d, lcid=%d, bsr={%d,%d,%d,%d}\n", bsr, lc_id,
        lch[0].bsr, lch[1].bsr, lch[2].bsr, lch[3].bsr);
+  pthread_mutex_unlock(&mutex);
 }
 
 void sched_ue::ul_phr(int phr)
 { 
-  power_headroom= phr; 
+  power_headroom = phr;
 }
 
 void sched_ue::dl_buffer_state(uint8_t lc_id, uint32_t tx_queue, uint32_t retx_queue)
 {
+  pthread_mutex_lock(&mutex);
   if (lc_id < sched_interface::MAX_LC) {
     lch[lc_id].buf_retx = retx_queue;
     lch[lc_id].buf_tx   = tx_queue;
     Debug("SCHED: DL lcid=%d buffer_state=%d,%d\n", lc_id, tx_queue, retx_queue);
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void sched_ue::mac_buffer_state(uint32_t ce_code)
 {
-  buf_mac++; 
+  pthread_mutex_lock(&mutex);
+  buf_mac++;
+  pthread_mutex_unlock(&mutex);
 }
 
 void sched_ue::set_sr()
@@ -222,42 +250,59 @@ void sched_ue::unset_sr()
 
 bool sched_ue::pucch_sr_collision(uint32_t current_tti, uint32_t n_cce)
 {
+  bool ret = false;
+  pthread_mutex_lock(&mutex);
+
+  uint32_t n_pucch_sr, n_pucch_nosr;
+  srslte_pucch_sched_t pucch_sched;
+  bool has_sr;
+
   if (!phy_config_dedicated_enabled) {
-    return false; 
+    goto unlock;
   }
-  srslte_pucch_sched_t pucch_sched; 
   pucch_sched.sps_enabled = false;
   pucch_sched.n_pucch_sr = cfg.sr_N_pucch;
   pucch_sched.n_pucch_2  = cfg.n_pucch_cqi;
   pucch_sched.N_pucch_1  = cfg.pucch_cfg.n1_pucch_an; 
 
-  bool has_sr = cfg.sr_enabled && srslte_ue_ul_sr_send_tti(cfg.sr_I, current_tti);    
+  has_sr = cfg.sr_enabled && srslte_ue_ul_sr_send_tti(cfg.sr_I, current_tti);
   if (!has_sr) {
-    return false; 
+    goto unlock;
   }
-  uint32_t n_pucch_sr = srslte_pucch_get_npucch(n_cce, SRSLTE_PUCCH_FORMAT_1A, true, &pucch_sched);
+  n_pucch_sr = srslte_pucch_get_npucch(n_cce, SRSLTE_PUCCH_FORMAT_1A, true, &pucch_sched);
-  uint32_t n_pucch_nosr = srslte_pucch_get_npucch(n_cce, SRSLTE_PUCCH_FORMAT_1A, false, &pucch_sched);
+  n_pucch_nosr = srslte_pucch_get_npucch(n_cce, SRSLTE_PUCCH_FORMAT_1A, false, &pucch_sched);
+
   if (srslte_pucch_n_prb(&cfg.pucch_cfg, SRSLTE_PUCCH_FORMAT_1A, n_pucch_sr, cell.nof_prb, cell.cp, 0) == 
       srslte_pucch_n_prb(&cfg.pucch_cfg, SRSLTE_PUCCH_FORMAT_1A, n_pucch_nosr, cell.nof_prb, cell.cp, 0)) 
   {
-    return true;       
+    ret = true;
   } else {
-    return false; 
+    ret = false;
   }
+
+unlock:
+  pthread_mutex_unlock(&mutex);
+  return ret;
 }
 
 bool sched_ue::get_pucch_sched(uint32_t current_tti, uint32_t prb_idx[2])
 {
+  bool ret = false;
+  bool has_sr;
+
+  pthread_mutex_lock(&mutex);
+
   if (!phy_config_dedicated_enabled) {
-    return false; 
+    goto unlock;
   }
+
   srslte_pucch_sched_t pucch_sched;
   pucch_sched.sps_enabled = false;
   pucch_sched.n_pucch_sr = cfg.sr_N_pucch;
   pucch_sched.n_pucch_2  = cfg.n_pucch_cqi;
   pucch_sched.N_pucch_1  = cfg.pucch_cfg.n1_pucch_an;
   
-  bool has_sr = cfg.sr_enabled && srslte_ue_ul_sr_send_tti(cfg.sr_I, current_tti);    
+  has_sr = cfg.sr_enabled && srslte_ue_ul_sr_send_tti(cfg.sr_I, current_tti);
   
   // First check if it has pending ACKs 
   for (int i=0;i<SCHED_MAX_HARQ_PROC;i++) {
@@ -270,7 +315,8 @@ bool sched_ue::get_pucch_sched(uint32_t current_tti, uint32_t prb_idx[2])
         Debug("SCHED: Reserved Format1A PUCCH for rnti=0x%x, n_prb=%d,%d, n_pucch=%d, ncce=%d, has_sr=%d, n_pucch_1=%d\n",
               rnti, prb_idx[0], prb_idx[1], n_pucch, dl_harq[i].get_n_cce(), has_sr, pucch_sched.N_pucch_1);
       }
-      return true;
+      ret = true;
+      goto unlock;
     }
   }
   // If there is no Format1A/B, then check if it's expecting Format1
@@ -281,7 +327,8 @@ bool sched_ue::get_pucch_sched(uint32_t current_tti, uint32_t prb_idx[2])
       }
     }
     Debug("SCHED: Reserved Format1 PUCCH for rnti=0x%x, n_prb=%d,%d, n_pucch=%d\n", rnti, prb_idx[0], prb_idx[1], cfg.sr_N_pucch);
-    return true; 
+    ret = true;
+    goto unlock;
   }
   // Finally check Format2 (periodic CQI)
   if (cfg.cqi_enabled && srslte_cqi_send(cfg.cqi_idx, current_tti)) {
@@ -292,27 +339,41 @@ bool sched_ue::get_pucch_sched(uint32_t current_tti, uint32_t prb_idx[2])
       Debug("SCHED: Reserved Format2 PUCCH for rnti=0x%x, n_prb=%d,%d, n_pucch=%d, pmi_idx=%d\n",
             rnti, prb_idx[0], prb_idx[1], cfg.cqi_pucch, cfg.cqi_idx);
     }
-    return true;
+    ret = true;
+    goto unlock;
   }
 
-  return false; 
+  ret = false;
+unlock:
+  pthread_mutex_unlock(&mutex);
+  return ret;
 }
 
 int sched_ue::set_ack_info(uint32_t tti, uint32_t tb_idx, bool ack)
 {
+  pthread_mutex_lock(&mutex);
+  int ret = -1;
   for (int i=0;i<SCHED_MAX_HARQ_PROC;i++) {
     if (TTI_TX(dl_harq[i].get_tti()) == tti) {
       Debug("SCHED: Set ACK=%d for rnti=0x%x, pid=%d.%d, tti=%d\n", ack, rnti, i, tb_idx, tti);
       dl_harq[i].set_ack(tb_idx, ack);
-      return dl_harq[i].get_tbs(tb_idx);
+      ret = dl_harq[i].get_tbs(tb_idx);
+      goto unlock;
     }
   }
+
   Warning("SCHED: Received ACK info for unknown TTI=%d\n", tti);
-  return -1;
+  ret = -1;
+
+unlock:
+  pthread_mutex_unlock(&mutex);
+  return ret;
 }
 
 void sched_ue::ul_recv_len(uint32_t lcid, uint32_t len)
 {
+  pthread_mutex_lock(&mutex);
+
   // Remove PDCP header??
   if (len > 4) {
     len -= 4; 
@@ -328,54 +389,72 @@ void sched_ue::ul_recv_len(uint32_t lcid, uint32_t len)
   }
   Debug("SCHED: recv_len=%d, lcid=%d, bsr={%d,%d,%d,%d}\n", len, lcid,
        lch[0].bsr, lch[1].bsr, lch[2].bsr, lch[3].bsr);
+
+  pthread_mutex_unlock(&mutex);
 }
 
 void sched_ue::set_ul_crc(uint32_t tti, bool crc_res)
 {
+  pthread_mutex_lock(&mutex);
   get_ul_harq(tti)->set_ack(0, crc_res);
+  pthread_mutex_unlock(&mutex);
 }
 
 void sched_ue::set_dl_ri(uint32_t tti, uint32_t ri)
 {
+  pthread_mutex_lock(&mutex);
   dl_ri     = ri;
   dl_ri_tti = tti;
+  pthread_mutex_unlock(&mutex);
 }
 
 void sched_ue::set_dl_pmi(uint32_t tti, uint32_t pmi)
 {
+  pthread_mutex_lock(&mutex);
   dl_pmi     = pmi;
   dl_pmi_tti = tti;
+  pthread_mutex_unlock(&mutex);
 }
 
 void sched_ue::set_dl_cqi(uint32_t tti, uint32_t cqi)
 {
+  pthread_mutex_lock(&mutex);
   dl_cqi     = cqi;
   dl_cqi_tti = tti;
+  pthread_mutex_unlock(&mutex);
 }
 
 void sched_ue::set_dl_ant_info(LIBLTE_RRC_ANTENNA_INFO_DEDICATED_STRUCT *d)
 {
+  pthread_mutex_lock(&mutex);
   memcpy(&dl_ant_info, d, sizeof(LIBLTE_RRC_ANTENNA_INFO_DEDICATED_STRUCT));
+  pthread_mutex_unlock(&mutex);
 }
 
 void sched_ue::set_ul_cqi(uint32_t tti, uint32_t cqi, uint32_t ul_ch_code)
 {
-  ul_cqi     = cqi; 
+  pthread_mutex_lock(&mutex);
-  ul_cqi_tti = tti; 
+  ul_cqi     = cqi;
+  ul_cqi_tti = tti;
+  pthread_mutex_unlock(&mutex);
 }
 
 void sched_ue::tpc_inc() {
+  pthread_mutex_lock(&mutex);
   if (power_headroom > 0) {
     next_tpc_pusch = 3;
     next_tpc_pucch = 3;    
   }
   log_h->info("SCHED: Set TCP=%d for rnti=0x%x\n", next_tpc_pucch, rnti);
+  pthread_mutex_unlock(&mutex);
 }
 
 void sched_ue::tpc_dec() {
+  pthread_mutex_lock(&mutex);
   next_tpc_pusch = 0;
   next_tpc_pucch = 0;
   log_h->info("SCHED: Set TCP=%d for rnti=0x%x\n", next_tpc_pucch, rnti);
+  pthread_mutex_unlock(&mutex);
 }
 
 /*******************************************************
@@ -391,6 +470,8 @@ int sched_ue::generate_format1(dl_harq_proc *h,
                          uint32_t tti,
                          uint32_t cfi)
 {
+  pthread_mutex_lock(&mutex);
+
   srslte_ra_dl_dci_t *dci = &data->dci;
   bzero(dci, sizeof(srslte_ra_dl_dci_t));
   
@@ -410,7 +491,7 @@ int sched_ue::generate_format1(dl_harq_proc *h,
   }
   if (h->is_empty(0)) {
 
-    uint32_t req_bytes = get_pending_dl_new_data(tti); 
+    uint32_t req_bytes = get_pending_dl_new_data_unlocked(tti);
     
     uint32_t nof_prb = format1_count_prb(h->get_rbgmask(), cell.nof_prb);  
     srslte_ra_dl_grant_t grant; 
@@ -462,8 +543,9 @@ int sched_ue::generate_format1(dl_harq_proc *h,
     data->tbs[1]      = 0;
     dci->tb_en[0]     = true;
     dci->tb_en[1]     = false; 
-  }  
+  }
-  return tbs; 
+  pthread_mutex_unlock(&mutex);
+  return tbs;
 }
 
 // Generates a Format2a grant
@@ -471,8 +553,21 @@ int sched_ue::generate_format2a(dl_harq_proc *h,
                          sched_interface::dl_sched_data_t *data,
                          uint32_t tti,
                          uint32_t cfi)
+{
+  pthread_mutex_lock(&mutex);
+  int ret = generate_format2a_unlocked(h, data, tti, cfi);
+  pthread_mutex_unlock(&mutex);
+  return ret;
+}
+
+// Generates a Format2a grant
+int sched_ue::generate_format2a_unlocked(dl_harq_proc *h,
+                                       sched_interface::dl_sched_data_t *data,
+                                       uint32_t tti,
+                                       uint32_t cfi)
 {
   bool tb_en[SRSLTE_MAX_TB] = {false};
+
   srslte_ra_dl_dci_t *dci = &data->dci;
   bzero(dci, sizeof(srslte_ra_dl_dci_t));
 
@@ -512,7 +607,7 @@ int sched_ue::generate_format2a(dl_harq_proc *h,
   }
 
   for (uint32_t tb = 0; tb < SRSLTE_MAX_TB; tb++) {
-    uint32_t req_bytes = get_pending_dl_new_data(tti);
+    uint32_t req_bytes = get_pending_dl_new_data_unlocked(tti);
     int mcs = 0;
     int tbs = 0;
 
@@ -566,17 +661,22 @@ int sched_ue::generate_format2a(dl_harq_proc *h,
   dci->tpc_pucch = (uint8_t) next_tpc_pucch;
   next_tpc_pucch = 1;
 
-  return data->tbs[0] + data->tbs[1];
+  int ret = data->tbs[0] + data->tbs[1];
+  return ret;
 }
 
+
 // Generates a Format2 grant
 int sched_ue::generate_format2(dl_harq_proc *h,
                          sched_interface::dl_sched_data_t *data,
                          uint32_t tti,
                          uint32_t cfi)
 {
+
+  pthread_mutex_lock(&mutex);
+
   /* Call Format 2a (common) */
-  int ret = generate_format2a(h, data, tti, cfi);
+  int ret = generate_format2a_unlocked(h, data, tti, cfi);
 
   /* Compute precoding information */
   if (SRSLTE_RA_DL_GRANT_NOF_TB(&data->dci) == 1) {
@@ -585,6 +685,8 @@ int sched_ue::generate_format2(dl_harq_proc *h,
     data->dci.pinfo = (uint8_t) (dl_pmi & 1);
   }
 
+  pthread_mutex_unlock(&mutex);
+
   return ret;
 }
 
@@ -594,7 +696,9 @@ int sched_ue::generate_format0(ul_harq_proc *h,
                          uint32_t tti,
                          bool cqi_request) 
 {
-  srslte_ra_ul_dci_t *dci = &data->dci; 
+  pthread_mutex_lock(&mutex);
+
+  srslte_ra_ul_dci_t *dci = &data->dci;
   bzero(dci, sizeof(srslte_ra_ul_dci_t));
   
   int mcs = 0;   
@@ -608,7 +712,7 @@ int sched_ue::generate_format0(ul_harq_proc *h,
     h->new_tx(tti, mcs, tbs); 
   } else if (h->is_empty(0)) {
     
-    uint32_t req_bytes = get_pending_ul_new_data(tti); 
+    uint32_t req_bytes = get_pending_ul_new_data_unlocked(tti);
     
     uint32_t N_srs = 0; 
     uint32_t nof_re = (2*(SRSLTE_CP_NSYMB(cell.cp)-1) - N_srs)*allocation.L*SRSLTE_NRE;
@@ -645,8 +749,10 @@ int sched_ue::generate_format0(ul_harq_proc *h,
     dci->tpc_pusch   = next_tpc_pusch; 
     next_tpc_pusch   = 1; 
   }
-  
+
-  return tbs; 
+  pthread_mutex_unlock(&mutex);
+
+  return tbs;
 }
 
 /*******************************************************
@@ -678,37 +784,43 @@ bool sched_ue::is_first_dl_tx()
 }
 
 bool sched_ue::needs_cqi(uint32_t tti, bool will_be_sent)
-{  
+{
-  bool ret = false; 
+  pthread_mutex_lock(&mutex);
-  if (phy_config_dedicated_enabled && 
+  bool ret = needs_cqi_unlocked(tti, will_be_sent);
-      cfg.aperiodic_cqi_period     && 
+  pthread_mutex_unlock(&mutex);
-      get_pending_dl_new_data(tti) > 0) 
+  return ret;
+}
+
+// Private lock-free implemenentation
+bool sched_ue::needs_cqi_unlocked(uint32_t tti, bool will_be_sent)
+{
+  bool ret = false;
+  if (phy_config_dedicated_enabled &&
+      cfg.aperiodic_cqi_period     &&
+      get_pending_dl_new_data_unlocked(tti) > 0)
   {
-    uint32_t interval = srslte_tti_interval(tti, dl_cqi_tti); 
+    uint32_t interval = srslte_tti_interval(tti, dl_cqi_tti);
     bool needscqi = interval >= cfg.aperiodic_cqi_period;
-    if (needscqi) {    
+    if (needscqi) {
-      uint32_t interval_sent = srslte_tti_interval(tti, cqi_request_tti); 
+      uint32_t interval_sent = srslte_tti_interval(tti, cqi_request_tti);
       if (interval_sent >= 16) {
         if (will_be_sent) {
-          cqi_request_tti = tti; 
+          cqi_request_tti = tti;
         }
         Debug("SCHED: Needs_cqi, last_sent=%d, will_be_sent=%d\n", cqi_request_tti, will_be_sent);
-        ret = true; 
+        ret = true;
-      } 
+      }
     }
   }
-  return ret; 
+  return ret;
 }
 
 uint32_t sched_ue::get_pending_dl_new_data(uint32_t tti)
 {
-  uint32_t pending_data = 0; 
+  pthread_mutex_lock(&mutex);
-  for (int i=0;i<sched_interface::MAX_LC;i++) {
+  uint32_t pending_data = get_pending_dl_new_data_unlocked(tti);
-    if (bearer_is_dl(&lch[i])) {
+  pthread_mutex_unlock(&mutex);
-      pending_data += lch[i].buf_retx + lch[i].buf_tx;
+  return pending_data;
-    }
-  }
-  return pending_data; 
 }
 
 /// Use this function in the dl-metric to get the bytes to be scheduled. It accounts for the UE data,
@@ -717,46 +829,78 @@ uint32_t sched_ue::get_pending_dl_new_data(uint32_t tti)
 /// \return number of bytes to be allocated
 uint32_t sched_ue::get_pending_dl_new_data_total(uint32_t tti)
 {
-  uint32_t req_bytes = get_pending_dl_new_data(tti);
+  pthread_mutex_lock(&mutex);
+  uint32_t req_bytes = get_pending_dl_new_data_unlocked(tti);
   if(req_bytes>0) {
     req_bytes += (req_bytes < 128) ? 2 : 3; // consider the header
     if(is_first_dl_tx()) {
       req_bytes += 6; // count for RAR
     }
   }
+  pthread_mutex_unlock(&mutex);
   return req_bytes;
 }
 
+// Private lock-free implementation
+uint32_t sched_ue::get_pending_dl_new_data_unlocked(uint32_t tti)
+{
+  uint32_t pending_data = 0;
+  for (int i=0;i<sched_interface::MAX_LC;i++) {
+    if (bearer_is_dl(&lch[i])) {
+      pending_data += lch[i].buf_retx + lch[i].buf_tx;
+    }
+  }
+  return pending_data;
+}
+
 uint32_t sched_ue::get_pending_ul_new_data(uint32_t tti)
 {
-  uint32_t pending_data = 0; 
+  pthread_mutex_lock(&mutex);
+  uint32_t pending_data = get_pending_ul_new_data_unlocked(tti);
+  pthread_mutex_unlock(&mutex);
+  return pending_data;
+}
+
+uint32_t sched_ue::get_pending_ul_old_data()
+{
+  pthread_mutex_lock(&mutex);
+  uint32_t pending_data = get_pending_ul_old_data_unlocked();
+  pthread_mutex_unlock(&mutex);
+  return pending_data;
+}
+
+// Private lock-free implementation
+uint32_t sched_ue::get_pending_ul_new_data_unlocked(uint32_t tti)
+{
+  uint32_t pending_data = 0;
   for (int i=0;i<sched_interface::MAX_LC;i++) {
     if (bearer_is_ul(&lch[i])) {
       pending_data += lch[i].bsr;
     }
   }
   if (!pending_data && is_sr_triggered()) {
-    return 512; 
+    return 512;
   }
-  if (!pending_data && needs_cqi(tti)) {
+  if (!pending_data && needs_cqi_unlocked(tti)) {
-    return 128; 
+    return 128;
   }
-  uint32_t pending_ul_data = get_pending_ul_old_data(); 
+  uint32_t pending_ul_data = get_pending_ul_old_data_unlocked();
   if (pending_data > pending_ul_data) {
-    pending_data -= pending_ul_data; 
+    pending_data -= pending_ul_data;
   } else {
-    pending_data = 0; 
+    pending_data = 0;
   }
   if (pending_data) {
     Debug("SCHED: pending_data=%d, pending_ul_data=%d, bsr={%d,%d,%d,%d}\n", pending_data,pending_ul_data,
-         lch[0].bsr, lch[1].bsr, lch[2].bsr, lch[3].bsr);
+          lch[0].bsr, lch[1].bsr, lch[2].bsr, lch[3].bsr);
   }
-  return pending_data; 
+  return pending_data;
 }
 
-uint32_t sched_ue::get_pending_ul_old_data()
+// Private lock-free implementation
+uint32_t sched_ue::get_pending_ul_old_data_unlocked()
 {
-  uint32_t pending_data = 0; 
+  uint32_t pending_data = 0;
   for (int i=0;i<SCHED_MAX_HARQ_PROC;i++) {
     pending_data += ul_harq[i].get_pending_data();
   }
@@ -775,6 +919,8 @@ uint32_t sched_ue::rgb_to_prb(uint32_t nof_rbg)
 
 uint32_t sched_ue::get_required_prb_dl(uint32_t req_bytes, uint32_t nof_ctrl_symbols)
 {
+  pthread_mutex_lock(&mutex);
+
   int mcs = 0;
   uint32_t nof_re = 0;
   int tbs = 0;
@@ -791,10 +937,12 @@ uint32_t sched_ue::get_required_prb_dl(uint32_t req_bytes, uint32_t nof_ctrl_sym
     if (tbs > 0) {
       nbytes = tbs;
     } else if (tbs < 0) {
+      pthread_mutex_unlock(&mutex);
       return 0;
     }
   }
 
+  pthread_mutex_unlock(&mutex);
   return n;
 }
 
@@ -803,13 +951,15 @@ uint32_t sched_ue::get_required_prb_ul(uint32_t req_bytes)
   int mcs = 0; 
   int tbs = 0; 
   uint32_t nbytes = 0; 
-  uint32_t N_srs = 0; 
+  uint32_t N_srs = 0;
-  
+
-  uint32_t n = 0; 
+  uint32_t n = 0;
   if (req_bytes == 0) {
     return 0; 
   }
-  
+
+  pthread_mutex_lock(&mutex);
+
   for (n=1;n<cell.nof_prb && nbytes < req_bytes + 4;n++) {
     uint32_t nof_re = (2*(SRSLTE_CP_NSYMB(cell.cp)-1) - N_srs)*n*SRSLTE_NRE;
     int tbs = 0; 
@@ -826,7 +976,9 @@ uint32_t sched_ue::get_required_prb_ul(uint32_t req_bytes)
   while (!srslte_dft_precoding_valid_prb(n) && n<=cell.nof_prb) {
     n++;
   }
-  
+
+  pthread_mutex_unlock(&mutex);
+
   return n; 
 }
 
@@ -839,7 +991,10 @@ bool sched_ue::is_sr_triggered()
 dl_harq_proc* sched_ue::get_pending_dl_harq(uint32_t tti)
 {
 #if ASYNC_DL_SCHED
-  int oldest_idx=-1; 
+
+  pthread_mutex_lock(&mutex);
+
+  int oldest_idx=-1;
   uint32_t oldest_tti = 0; 
   for (int i=0;i<SCHED_MAX_HARQ_PROC;i++) {
     if (dl_harq[i].has_pending_retx(0, tti) || dl_harq[i].has_pending_retx(1, tti)) {
@@ -850,11 +1005,15 @@ dl_harq_proc* sched_ue::get_pending_dl_harq(uint32_t tti)
       }
     }
   }
+  dl_harq_proc *h = NULL;
   if (oldest_idx >= 0) {
-    return &dl_harq[oldest_idx]; 
+    h = &dl_harq[oldest_idx];
-  } else {
-    return NULL; 
   }
+
+  pthread_mutex_unlock(&mutex);
+
+  return h;
+
 #else
   return &dl_harq[tti%SCHED_MAX_HARQ_PROC];
 #endif
@@ -862,12 +1021,16 @@ dl_harq_proc* sched_ue::get_pending_dl_harq(uint32_t tti)
 
 dl_harq_proc* sched_ue::get_empty_dl_harq()
 {
-  for (int i=0;i<SCHED_MAX_HARQ_PROC;i++) {
+  pthread_mutex_lock(&mutex);
+
+  dl_harq_proc *h = NULL;
+  for (int i=0;i<SCHED_MAX_HARQ_PROC && !h;i++) {
     if (dl_harq[i].is_empty(0) && dl_harq[i].is_empty(1)) {
-      return &dl_harq[i]; 
+      h = &dl_harq[i];
     }
   }
-  return NULL;
+  pthread_mutex_unlock(&mutex);
+  return h;
 }
 
 ul_harq_proc* sched_ue::get_ul_harq(uint32_t tti)
@@ -908,6 +1071,7 @@ srslte_dci_format_t sched_ue::get_dci_format() {
 /* Find lowest DCI aggregation level supported by the UE spectral efficiency */
 uint32_t sched_ue::get_aggr_level(uint32_t nof_bits)
 {
+  pthread_mutex_lock(&mutex);
   uint32_t l=0;
   float max_coderate = srslte_cqi_to_coderate(dl_cqi);
   float coderate = 99;
@@ -922,7 +1086,8 @@ uint32_t sched_ue::get_aggr_level(uint32_t nof_bits)
     l++;
   } while(l<l_max && factor*coderate > max_coderate);
   Debug("SCHED: CQI=%d, l=%d, nof_bits=%d, coderate=%.2f, max_coderate=%.2f\n", dl_cqi, l, nof_bits, coderate, max_coderate);
-  return l; 
+  pthread_mutex_unlock(&mutex);
+  return l;
 }
 
 sched_ue::sched_dci_cce_t* sched_ue::get_locations(uint32_t cfi, uint32_t sf_idx)
@@ -955,7 +1120,7 @@ int sched_ue::alloc_pdu(int tbs_bytes, sched_interface::dl_sched_pdu_t* pdu)
     pdu->nbytes = x;  
     Debug("SCHED: Allocated lcid=%d, nbytes=%d, tbs_bytes=%d\n", pdu->lcid, pdu->nbytes, tbs_bytes);
   }
-  return x; 
+  return x;
 }
 
 uint32_t sched_ue::format1_count_prb(uint32_t bitmask, uint32_t cell_nof_prb) {
@@ -1029,18 +1194,15 @@ int sched_ue::alloc_tbs(uint32_t nof_prb,
   uint32_t max_Qm  = is_ul?4:6; // Allow 16-QAM in PUSCH Only
 
   // TODO: Compute real spectral efficiency based on PUSCH-UCI configuration
-  if (has_pucch && is_ul) {
-    cqi-=3;
-  }
 
   int tbs = cqi_to_tbs(cqi, nof_prb, nof_re, max_mcs, max_Qm, &sel_mcs)/8;
-  
+
   /* If less bytes are requested, lower the MCS */
   if (tbs > (int) req_bytes && req_bytes > 0) {
     uint32_t req_tbs_idx = srslte_ra_tbs_to_table_idx(req_bytes*8, nof_prb); 
     uint32_t req_mcs = srslte_ra_mcs_from_tbs_idx(req_tbs_idx);
     if (req_mcs < sel_mcs) {
-      sel_mcs = req_mcs; 
+      sel_mcs = req_mcs;
       tbs = srslte_ra_tbs_from_idx(req_tbs_idx, nof_prb)/8;
     }
   }

srsenb/src/mac/ue.cc

@@ -115,8 +115,7 @@ srslte_softbuffer_tx_t* ue::get_tx_softbuffer(uint32_t harq_process, uint32_t tb
 uint8_t* ue::request_buffer(uint32_t tti, uint32_t len)
 {
   uint8_t *ret = NULL; 
-  pthread_mutex_lock(&mutex);
+  if (len > 0) {
-  if (len > 0) {   
     if (!pending_buffers[tti%NOF_HARQ_PROCESSES]) {
       ret = pdus.request(len);   
       pending_buffers[tti%NOF_HARQ_PROCESSES] = ret; 
@@ -127,8 +126,7 @@ uint8_t* ue::request_buffer(uint32_t tti, uint32_t len)
   } else {
     log_h->warning("Requesting buffer for zero bytes\n");
   }
-  pthread_mutex_unlock(&mutex);
+  return ret;
-  return ret; 
 }
 
 bool ue::process_pdus()

srsenb/src/metrics_stdout.cc

@@ -41,6 +41,8 @@ using namespace std;
 
 namespace srsenb{
 
+#define MAX(a,b) (a>b?a:b)
+
 char const * const prefixes[2][9] =
 {
   {   "",   "m",   "u",   "n",    "p",    "f",    "a",    "z",    "y", },
@@ -125,25 +127,41 @@ void metrics_stdout::print_metrics()
       }
     
       cout << std::hex << metrics.mac[i].rnti << " ";
-      cout << float_to_string(metrics.mac[i].dl_cqi, 2);
+      cout << float_to_string(MAX(0.1,metrics.mac[i].dl_cqi), 2);
       cout << float_to_string(metrics.mac[i].dl_ri, 1);
-      cout << float_to_string(metrics.phy[i].dl.mcs, 2);
+      if(not isnan(metrics.phy[i].dl.mcs)) {
-      cout << float_to_eng_string((float) metrics.mac[i].tx_brate/metrics_report_period, 2);
+        cout << float_to_string(MAX(0.1,metrics.phy[i].dl.mcs), 2);
+      } else {
+        cout << float_to_string(0,2);
+      }
+      if (metrics.mac[i].tx_brate > 0 && metrics_report_period) {
+        cout << float_to_eng_string(MAX(0.1,(float) metrics.mac[i].tx_brate/metrics_report_period), 2);
+      } else {
+        cout << float_to_string(0, 2) << "";
+      }
       if (metrics.mac[i].tx_pkts > 0 && metrics.mac[i].tx_errors) {
-        cout << float_to_string((float) 100*metrics.mac[i].tx_errors/metrics.mac[i].tx_pkts, 1) << "%";
+        cout << float_to_string(MAX(0.1,(float) 100*metrics.mac[i].tx_errors/metrics.mac[i].tx_pkts), 1) << "%";
       } else {
         cout << float_to_string(0, 1) << "%";
       }
-      cout << float_to_string(metrics.phy[i].ul.sinr, 2);
+      if(not isnan(metrics.phy[i].ul.sinr)) {
+        cout << float_to_string(MAX(0.1,metrics.phy[i].ul.sinr), 2);
+      } else {
+        cout << float_to_string(0,2);
+      }
       cout << float_to_string(metrics.mac[i].phr, 2);
-      cout << float_to_string(metrics.phy[i].ul.mcs, 2);
+      if(not isnan(metrics.phy[i].ul.mcs)) {
+        cout << float_to_string(MAX(0.1,metrics.phy[i].ul.mcs), 2);
+      } else {
+        cout << float_to_string(0,2);
+      }
       if (metrics.mac[i].rx_brate > 0 && metrics_report_period) {
-        cout << float_to_eng_string((float) metrics.mac[i].rx_brate/metrics_report_period, 2);
+        cout << float_to_eng_string(MAX(0.1,(float) metrics.mac[i].rx_brate/metrics_report_period), 2);
       } else {        
-        cout << " " << float_to_string(0, 2);
+        cout << float_to_string(0, 2) << "";
       }
       if (metrics.mac[i].rx_pkts > 0 && metrics.mac[i].rx_errors > 0) {
-        cout << float_to_string((float) 100*metrics.mac[i].rx_errors/metrics.mac[i].rx_pkts, 1) << "%";
+        cout << float_to_string(MAX(0.1,(float) 100*metrics.mac[i].rx_errors/metrics.mac[i].rx_pkts), 1) << "%";
       } else {
         cout << float_to_string(0, 1) << "%";
       }

srsenb/src/phy/phch_worker.cc

@@ -39,10 +39,10 @@
 using namespace std; 
 
 // Enable this to log SI
-#define LOG_THIS(a) 1
+//#define LOG_THIS(a) 1
 
 // Enable this one to skip SI-RNTI
-//#define LOG_THIS(rnti) (rnti != 0xFFFF)
+#define LOG_THIS(rnti) (rnti != 0xFFFF)
 
 
 /* Define GUI-related things */
@@ -185,11 +185,11 @@ void phch_worker::stop()
         free(signal_buffer_tx[p]);
       }
     }
-    pthread_mutex_unlock(&mutex);
-    pthread_mutex_destroy(&mutex);
   } else {
     printf("Warning could not stop properly PHY\n");
   }
+  pthread_mutex_unlock(&mutex);
+  pthread_mutex_destroy(&mutex);
 }
 void phch_worker::reset() 
 {
@@ -372,9 +372,10 @@ void phch_worker::work_imp()
 
   subframe_cfg_t sf_cfg;
   phy->get_sf_config(&sf_cfg, tti_tx_dl);// TODO difference between  tti_tx_dl and t_tx_dl
+
   pthread_mutex_lock(&mutex);
   is_worker_running = true;
-  
+
   mac_interface_phy::ul_sched_t *ul_grants = phy->ul_grants;
   mac_interface_phy::dl_sched_t *dl_grants = phy->dl_grants;
   mac_interface_phy *mac = phy->mac;
@@ -398,7 +399,7 @@ void phch_worker::work_imp()
   decode_pucch();
 
   // Get DL scheduling for the TX TTI from MAC
-  
+
   if(sf_cfg.sf_type == SUBFRAME_TYPE_REGULAR) {
     if (mac->get_dl_sched(tti_tx_dl, &dl_grants[t_tx_dl]) < 0) {
       Error("Getting DL scheduling from MAC\n");

srsenb/src/upper/pdcp.cc

@@ -37,18 +37,24 @@ void pdcp::init(rlc_interface_pdcp* rlc_, rrc_interface_pdcp* rrc_, gtpu_interfa
   log_h = pdcp_log_;
   
   pool = srslte::byte_buffer_pool::get_instance();
+
+  pthread_rwlock_init(&rwlock, NULL);
 }
 
 void pdcp::stop()
 {
+  pthread_rwlock_wrlock(&rwlock);
   for(std::map<uint32_t, user_interface>::iterator iter=users.begin(); iter!=users.end(); ++iter) {
-    rem_user((uint32_t) iter->first);
+    clear_user(&iter->second);
   }
   users.clear();
+  pthread_rwlock_unlock(&rwlock);
+  pthread_rwlock_destroy(&rwlock);
 }
 
 void pdcp::add_user(uint16_t rnti)
 {
+  pthread_rwlock_rdlock(&rwlock);
   if (users.count(rnti) == 0) {
     srslte::pdcp *obj = new srslte::pdcp;     
     obj->init(&users[rnti].rlc_itf, &users[rnti].rrc_itf, &users[rnti].gtpu_itf, log_h, RB_ID_SRB0, SECURITY_DIRECTION_DOWNLINK);
@@ -61,20 +67,30 @@ void pdcp::add_user(uint16_t rnti)
     users[rnti].gtpu_itf.gtpu = gtpu;
     users[rnti].pdcp = obj;
   }
+  pthread_rwlock_unlock(&rwlock);
+}
+
+// Private unlocked deallocation of user
+void pdcp::clear_user(user_interface *ue)
+{
+  ue->pdcp->stop();
+  delete ue->pdcp;
+  ue->pdcp = NULL;
 }
 
 void pdcp::rem_user(uint16_t rnti)
 {
+  pthread_rwlock_wrlock(&rwlock);
   if (users.count(rnti)) {
-    users[rnti].pdcp->stop();
+    clear_user(&users[rnti]);
-    delete users[rnti].pdcp; 
-    users[rnti].pdcp = NULL;
     users.erase(rnti);
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 void pdcp::add_bearer(uint16_t rnti, uint32_t lcid, srslte::srslte_pdcp_config_t cfg)
 {
+  pthread_rwlock_rdlock(&rwlock);
   if (users.count(rnti)) {
     if(rnti != SRSLTE_MRNTI){
       users[rnti].pdcp->add_bearer(lcid, cfg);
@@ -82,37 +98,45 @@ void pdcp::add_bearer(uint16_t rnti, uint32_t lcid, srslte::srslte_pdcp_config_t
       users[rnti].pdcp->add_bearer_mrb(lcid, cfg);
     }
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 void pdcp::reset(uint16_t rnti)
 {
+  pthread_rwlock_rdlock(&rwlock);
   if (users.count(rnti)) {
     users[rnti].pdcp->reset();
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 void pdcp::config_security(uint16_t rnti, uint32_t lcid, uint8_t* k_rrc_enc_, uint8_t* k_rrc_int_, 
                            srslte::CIPHERING_ALGORITHM_ID_ENUM cipher_algo_, 
                            srslte::INTEGRITY_ALGORITHM_ID_ENUM integ_algo_)
 {
+  pthread_rwlock_rdlock(&rwlock);
   if (users.count(rnti)) {
     users[rnti].pdcp->config_security(lcid, k_rrc_enc_, k_rrc_int_, cipher_algo_, integ_algo_);
     users[rnti].pdcp->enable_integrity(lcid);
     users[rnti].pdcp->enable_encryption(lcid);
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 void pdcp::write_pdu(uint16_t rnti, uint32_t lcid, srslte::byte_buffer_t* sdu)
 {
+  pthread_rwlock_rdlock(&rwlock);
   if (users.count(rnti)) {
     users[rnti].pdcp->write_pdu(lcid, sdu);
   } else {
     pool->deallocate(sdu);
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 void pdcp::write_sdu(uint16_t rnti, uint32_t lcid, srslte::byte_buffer_t* sdu)
 {
+  pthread_rwlock_rdlock(&rwlock);
   if (users.count(rnti)) {
     if(rnti != SRSLTE_MRNTI){
       users[rnti].pdcp->write_sdu(lcid, sdu);
@@ -122,6 +146,7 @@ void pdcp::write_sdu(uint16_t rnti, uint32_t lcid, srslte::byte_buffer_t* sdu)
   } else {
     pool->deallocate(sdu);
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 void pdcp::user_interface_gtpu::write_pdu(uint32_t lcid, srslte::byte_buffer_t *pdu)

srsenb/src/upper/rlc.cc

@@ -40,48 +40,57 @@ void rlc::init(pdcp_interface_rlc* pdcp_, rrc_interface_rlc* rrc_, mac_interface
 
   pool       = srslte::byte_buffer_pool::get_instance();
 
+  pthread_rwlock_init(&rwlock, NULL);
 }
 
 void rlc::stop()
 {
+  pthread_rwlock_wrlock(&rwlock);
   for(std::map<uint32_t, user_interface>::iterator iter=users.begin(); iter!=users.end(); ++iter) {
-    rem_user((uint32_t) iter->first);
+    clear_user(&iter->second);
   }
   users.clear();
+  pthread_rwlock_unlock(&rwlock);
+  pthread_rwlock_destroy(&rwlock);
 }
 
 void rlc::add_user(uint16_t rnti)
 {
+  pthread_rwlock_rdlock(&rwlock);
   if (users.count(rnti) == 0) {    
     srslte::rlc *obj = new srslte::rlc;     
-    obj->init(&users[rnti], &users[rnti], &users[rnti], log_h, mac_timers, RB_ID_SRB0);
+    obj->init(&users[rnti], &users[rnti], &users[rnti], log_h, mac_timers, RB_ID_SRB0, RLC_TX_QUEUE_LEN);
     users[rnti].rnti   = rnti; 
     users[rnti].pdcp   = pdcp; 
     users[rnti].rrc    = rrc; 
     users[rnti].rlc    = obj;
     users[rnti].parent = this; 
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
-void rlc::rem_user(uint16_t rnti)
+// Private unlocked deallocation of user
+void rlc::clear_user(user_interface *ue)
 {
-  if (users.count(rnti)) {
+  ue->rlc->stop();
-    users[rnti].rlc->stop();
+  delete ue->rlc;
-    delete users[rnti].rlc; 
+  ue->rlc = NULL;
-    users[rnti].rlc = NULL;
-    users.erase(rnti);
-  }
 }
-
+void rlc::rem_user(uint16_t rnti)
-void rlc::reset(uint16_t rnti)
 {
+  pthread_rwlock_wrlock(&rwlock);
   if (users.count(rnti)) {
-    users[rnti].rlc->reset();
+    clear_user(&users[rnti]);
+    users.erase(rnti);
+  } else {
+    log_h->error("Removing rnti=0x%x. Already removed\n", rnti);
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 void rlc::clear_buffer(uint16_t rnti)
 {
+  pthread_rwlock_rdlock(&rwlock);
   if (users.count(rnti)) {
     users[rnti].rlc->empty_queue();
     for (int i=0;i<SRSLTE_N_RADIO_BEARERS;i++) {
@@ -89,27 +98,34 @@ void rlc::clear_buffer(uint16_t rnti)
     }
     log_h->info("Cleared buffer rnti=0x%x\n", rnti);
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 void rlc::add_bearer(uint16_t rnti, uint32_t lcid)
 {
+  pthread_rwlock_rdlock(&rwlock);
   if (users.count(rnti)) {
     users[rnti].rlc->add_bearer(lcid);
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 void rlc::add_bearer(uint16_t rnti, uint32_t lcid, srslte::srslte_rlc_config_t cnfg)
 {
+  pthread_rwlock_rdlock(&rwlock);
   if (users.count(rnti)) {
     users[rnti].rlc->add_bearer(lcid, cnfg);
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 void rlc::add_bearer_mrb(uint16_t rnti, uint32_t lcid)
 {
+  pthread_rwlock_rdlock(&rwlock);
   if (users.count(rnti)) {
     users[rnti].rlc->add_bearer_mrb_enb(lcid);
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 void rlc::read_pdu_pcch(uint8_t* payload, uint32_t buffer_size)
@@ -121,11 +137,13 @@ int rlc::read_pdu(uint16_t rnti, uint32_t lcid, uint8_t* payload, uint32_t nof_b
 {
   int ret;
   uint32_t tx_queue;
-  if(users.count(rnti)){
+
-    if(rnti != SRSLTE_MRNTI){
+  pthread_rwlock_rdlock(&rwlock);
+  if(users.count(rnti)) {
+    if(rnti != SRSLTE_MRNTI) {
       ret = users[rnti].rlc->read_pdu(lcid, payload, nof_bytes);
       tx_queue = users[rnti].rlc->get_total_buffer_state(lcid);
-    }else{
+    } else {
       ret = users[rnti].rlc->read_pdu_mch(lcid, payload, nof_bytes);
       tx_queue = users[rnti].rlc->get_total_mch_buffer_state(lcid);
     }
@@ -135,15 +153,16 @@ int rlc::read_pdu(uint16_t rnti, uint32_t lcid, uint8_t* payload, uint32_t nof_b
     uint32_t retx_queue = 0;
     log_h->debug("Buffer state PDCP: rnti=0x%x, lcid=%d, tx_queue=%d\n", rnti, lcid, tx_queue);
     mac->rlc_buffer_state(rnti, lcid, tx_queue, retx_queue);
-    return ret;
-    
   }else{
-    return SRSLTE_ERROR;
+    ret = SRSLTE_ERROR;
   }
+  pthread_rwlock_unlock(&rwlock);
+  return ret;
 }
 
 void rlc::write_pdu(uint16_t rnti, uint32_t lcid, uint8_t* payload, uint32_t nof_bytes)
 {
+  pthread_rwlock_rdlock(&rwlock);
   if (users.count(rnti)) {
     users[rnti].rlc->write_pdu(lcid, payload, nof_bytes);
     
@@ -154,6 +173,7 @@ void rlc::write_pdu(uint16_t rnti, uint32_t lcid, uint8_t* payload, uint32_t nof
     log_h->debug("Buffer state PDCP: rnti=0x%x, lcid=%d, tx_queue=%d\n", rnti, lcid, tx_queue);
     mac->rlc_buffer_state(rnti, lcid, tx_queue, retx_queue);
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 void rlc::read_pdu_bcch_dlsch(uint32_t sib_index, uint8_t *payload)
@@ -166,9 +186,11 @@ void rlc::write_sdu(uint16_t rnti, uint32_t lcid, srslte::byte_buffer_t* sdu)
 {
   
   uint32_t tx_queue;
+
+  pthread_rwlock_rdlock(&rwlock);
   if (users.count(rnti)) {
     if(rnti != SRSLTE_MRNTI){
-      users[rnti].rlc->write_sdu(lcid, sdu);
+      users[rnti].rlc->write_sdu_nb(lcid, sdu);
       tx_queue   = users[rnti].rlc->get_total_buffer_state(lcid);
     }else {
       users[rnti].rlc->write_sdu_mch(lcid, sdu);
@@ -183,14 +205,17 @@ void rlc::write_sdu(uint16_t rnti, uint32_t lcid, srslte::byte_buffer_t* sdu)
   } else {
     pool->deallocate(sdu);
   }
+  pthread_rwlock_unlock(&rwlock);
 }
 
 bool rlc::rb_is_um(uint16_t rnti, uint32_t lcid) {
+  bool ret = false;
+  pthread_rwlock_rdlock(&rwlock);
   if (users.count(rnti)) {
-    return users[rnti].rlc->rb_is_um(lcid);
+    ret = users[rnti].rlc->rb_is_um(lcid);
-  } else {
-    return false;
   }
+  pthread_rwlock_unlock(&rwlock);
+  return ret;
 }
 
 void rlc::user_interface::max_retx_attempted()

srsenb/src/upper/rrc.cc

@@ -84,7 +84,8 @@ void rrc::stop()
 {
   if(running) {
     running = false;
-    thread_cancel();
+    rrc_pdu p = {0, LCID_EXIT, NULL};
+    rx_pdu_queue.push(p);
     wait_thread_finish();
   }
   act_monitor.stop();
@@ -585,8 +586,7 @@ void rrc::process_release_complete(uint16_t rnti)
       // There is no RRCReleaseComplete message from UE thus wait ~50 subframes for tx
       usleep(50000);
     }
-    // Save to call rem_user() directly without thread, because calling from private function
+    rem_user_thread(rnti);
-    rem_user(rnti);
   } else {
     rrc_log->error("Received ReleaseComplete for unknown rnti=0x%x\n", rnti);
   }
@@ -594,6 +594,7 @@ void rrc::process_release_complete(uint16_t rnti)
 
 void rrc::rem_user(uint16_t rnti)
 {
+  pthread_mutex_lock(&user_mutex);
   if (users.count(rnti) == 1) {
     rrc_log->console("Disconnecting rnti=0x%x.\n", rnti);
     rrc_log->info("Disconnecting rnti=0x%x.\n", rnti);
@@ -603,11 +604,6 @@ void rrc::rem_user(uint16_t rnti)
     mac->ue_rem(rnti);  // MAC handles PHY
     gtpu->rem_user(rnti);
 
-    // Wait enough time
-    pthread_mutex_unlock(&user_mutex);
-    usleep(50000);
-    pthread_mutex_lock(&user_mutex);
-
     // Now remove RLC and PDCP
     rlc->rem_user(rnti);
     pdcp->rem_user(rnti);
@@ -615,11 +611,13 @@ void rrc::rem_user(uint16_t rnti)
     // And deallocate resources from RRC
     users[rnti].sr_free();
     users[rnti].cqi_free();
+
     users.erase(rnti);
     rrc_log->info("Removed user rnti=0x%x\n", rnti);
   } else {
     rrc_log->error("Removing user rnti=0x%x (does not exist)\n", rnti);
   }
+  pthread_mutex_unlock(&user_mutex);
 }
 
 void rrc::config_mac()
@@ -778,7 +776,6 @@ void rrc::run_thread()
     }
 
     // Mutex these calls even though it's a private function
-    pthread_mutex_lock(&user_mutex);
     if (users.count(p.rnti) == 1) {
       switch(p.lcid)
       {
@@ -803,6 +800,9 @@ void rrc::run_thread()
             users[p.rnti].set_activity();
           }
           break;
+        case LCID_EXIT:
+          rrc_log->info("Exiting thread\n");
+          break;
         default:
           rrc_log->error("Rx PDU with invalid bearer id: %d", p.lcid);
           break;
@@ -810,7 +810,6 @@ void rrc::run_thread()
     } else {
       rrc_log->warning("Discarding PDU for removed rnti=0x%x\n", p.rnti);
     }
-    pthread_mutex_unlock(&user_mutex);
   }
 }
 
@@ -863,7 +862,7 @@ void rrc::activity_monitor::run_thread()
         parent->s1ap->user_release(rem_rnti, LIBLTE_S1AP_CAUSERADIONETWORK_USER_INACTIVITY);
       } else {
         if(rem_rnti != SRSLTE_MRNTI)
-          parent->rem_user(rem_rnti);
+          parent->rem_user_thread(rem_rnti);
       }
     }
     pthread_mutex_unlock(&parent->user_mutex);