Timer removes itself from the map upon expiration

lib/include/srslte/upper/pdcp_entity_nr.h

@@ -53,9 +53,6 @@ public:
   // RRC interface
   void write_sdu(unique_byte_buffer_t sdu, bool blocking);
 
-  uint32_t get_dl_count();
-  uint32_t get_ul_count();
-
   // RLC interface
   void write_pdu(unique_byte_buffer_t pdu);
 
@@ -65,6 +62,9 @@ public:
   void set_rx_deliv(uint32_t rx_deliv_) { rx_deliv = rx_deliv_; }
   void set_rx_reord(uint32_t rx_reord_) { rx_reord = rx_reord_; }
 
+  // State variable getters (useful for testing)
+  uint32_t nof_discard_timers() { return discard_timers_map.size(); }
+
 private:
   bool initialized = false;
 

lib/src/upper/pdcp_entity_nr.cc

@@ -373,6 +373,10 @@ void pdcp_entity_nr::discard_callback::operator()(uint32_t timer_id)
 
   // Notify the RLC of the discard. It's the RLC to actually discard, if no segment was transmitted yet.
   parent->rlc->discard_sdu(parent->lcid, discard_sn);
+
+  // Remove timer from map 
+  // NOTE: this will delete the callback. It *must* be the last instruction.
+  parent->discard_timers_map.erase(discard_sn);
   return;
 }
 

lib/test/upper/pdcp_nr_test.h

@@ -144,7 +144,7 @@ public:
   {
     log->info("Notifing RLC to discard SDU (SN=%" PRIu32 ")\n", discard_sn);
     discard_count++;
-    log->info("Discard_count=%" PRIu64 ")\n", discard_count);
+    log->info("Discard_count=%" PRIu64 "\n", discard_count);
   }
 
   uint64_t rx_count      = 0;

lib/test/upper/pdcp_nr_test_discard_sdu.cc

@@ -54,12 +54,27 @@ int test_tx_sdu_discard(const pdcp_initial_state&    init_state,
     timers->step_all();
   }
   TESTASSERT(rlc->discard_count == 0);
+
+  // Check if timers were started
+  if (imediate_notify) {
+    TESTASSERT(pdcp->nof_discard_timers() == 0); // RLC notified PDCP already, timer should have been disarmed
+  } else {
+    TESTASSERT(pdcp->nof_discard_timers() == 1); // One timer should be running
+  }
+
+  // Last timer step
   timers->step_all();
+
+  // Check if RLC was notified of SDU discard
   if (imediate_notify) {
     TESTASSERT(rlc->discard_count == 0); // RLC imediatly notified the PDCP of tx, there should be no timeouts
   } else {
     TESTASSERT(rlc->discard_count == 1); // RLC does not notify the the PDCP of tx, there should be a timeout
   }
+
+  // Make sure there are no timers still left on the map
+  TESTASSERT(pdcp->nof_discard_timers() == 0);
+
   return 0;
 }
 
@@ -75,6 +90,12 @@ int test_tx_discard_all(srslte::byte_buffer_pool* pool, srslte::log* log)
    * Test TX PDU discard.
    */
   TESTASSERT(test_tx_sdu_discard(normal_init_state, srslte::pdcp_discard_timer_t::ms50, false, pool, log) == 0);
+
+  /*
+   * TX Test 2: PDCP Entity with SN LEN = 12
+   * Test TX PDU discard.
+   */
+  //TESTASSERT(test_tx_sdu_discard(normal_init_state, srslte::pdcp_discard_timer_t::ms50, true, pool, log) == 0);
   return 0;
 }