rlc: call PDCP notify without holding Tx lock

move notify_info_vec as stack variable and unlock mutex
before calling PDCP notify

lib/include/srslte/upper/rlc_am_lte.h

@@ -134,7 +134,7 @@ private:
     int  build_retx_pdu(uint8_t* payload, uint32_t nof_bytes);
     int  build_segment(uint8_t* payload, uint32_t nof_bytes, rlc_amd_retx_t retx);
     int  build_data_pdu(uint8_t* payload, uint32_t nof_bytes);
-    void update_notification_ack_info(const rlc_amd_tx_pdu_t& tx_pdu);
+    void update_notification_ack_info(const rlc_amd_tx_pdu_t& tx_pdu, std::vector<uint32_t>& notify_info_vec);
 
     void debug_state();
 
@@ -191,7 +191,6 @@ private:
     // SDU info for PDCP notifications
     std::unordered_map<uint32_t, pdcp_sdu_info_t>        undelivered_sdu_info_queue;
     std::unordered_map<uint32_t, std::vector<uint32_t> > rlc_sn_to_pdcp_sn_map;
-    std::vector<uint32_t>                                notify_info_vec;
 
     // Callback function for buffer status report
     bsr_callback_t bsr_callback;

lib/src/upper/rlc_am_lte.cc

@@ -1020,7 +1020,7 @@ void rlc_am_lte::rlc_am_lte_tx::handle_control_pdu(uint8_t* payload, uint32_t no
   std::map<uint32_t, rlc_amd_tx_pdu_t>::iterator it;
   bool                                           update_vt_a = true;
   uint32_t                                       i           = vt_a;
-  notify_info_vec.clear();
+  std::vector<uint32_t>                          notify_info_vec;
 
   while (TX_MOD_BASE(i) < TX_MOD_BASE(status.ack_sn) && TX_MOD_BASE(i) < TX_MOD_BASE(vt_s)) {
     bool nack = false;
@@ -1078,7 +1078,7 @@ void rlc_am_lte::rlc_am_lte_tx::handle_control_pdu(uint8_t* payload, uint32_t no
       if (tx_window.count(i) > 0) {
         it = tx_window.find(i);
         if (it != tx_window.end()) {
-          update_notification_ack_info(it->second);
+          update_notification_ack_info(it->second, notify_info_vec);
           if (update_vt_a) {
             tx_window.erase(it);
             vt_a  = (vt_a + 1) % MOD;
@@ -1091,8 +1091,6 @@ void rlc_am_lte::rlc_am_lte_tx::handle_control_pdu(uint8_t* payload, uint32_t no
   }
 
   if (not notify_info_vec.empty()) {
-    parent->pdcp->notify_delivery(parent->lcid, notify_info_vec);
-
     // Remove all SDUs that were fully acked
     for (uint32_t acked_pdcp_sn : notify_info_vec) {
       logger.debug("Erasing SDU info: PDCP_SN=%d", acked_pdcp_sn);
@@ -1106,6 +1104,11 @@ void rlc_am_lte::rlc_am_lte_tx::handle_control_pdu(uint8_t* payload, uint32_t no
   debug_state();
 
   pthread_mutex_unlock(&mutex);
+
+  // Notify PDCP without holding Tx mutex
+  if (not notify_info_vec.empty()) {
+    parent->pdcp->notify_delivery(parent->lcid, notify_info_vec);
+  }
 }
 
 /*
@@ -1113,7 +1116,8 @@ void rlc_am_lte::rlc_am_lte_tx::handle_control_pdu(uint8_t* payload, uint32_t no
  * @tx_pdu: RLC PDU that was ack'ed.
  * @notify_info_vec: Vector which will keep track of the PDCP PDU SNs that have been fully ack'ed.
  */
-void rlc_am_lte::rlc_am_lte_tx::update_notification_ack_info(const rlc_amd_tx_pdu_t& tx_pdu)
+void rlc_am_lte::rlc_am_lte_tx::update_notification_ack_info(const rlc_amd_tx_pdu_t& tx_pdu,
+                                                             std::vector<uint32_t>&  notify_info_vec)
 {
   logger.debug("Updating ACK info: RLC SN=%d, number of notified SDU=%ld, number of undelivered SDUs=%ld",
                tx_pdu.header.sn,