From 9058ee9a5bd758962ab7a67b641d87f1fd7d3453 Mon Sep 17 00:00:00 2001
From: faluco <borja.ferrer@softwareradiosystems.com>
Date: Tue, 5 Oct 2021 14:19:49 +0200
Subject: [PATCH] Move gNB metrics processing to the stack thread avoiding
 concurrency issues in MAC and RRC.

---
 srsenb/hdr/stack/gnb_stack_nr.h  |  5 ++++-
 srsenb/src/stack/gnb_stack_nr.cc | 33 ++++++++++++++++++++++----------
 2 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/srsenb/hdr/stack/gnb_stack_nr.h b/srsenb/hdr/stack/gnb_stack_nr.h
index cb0af14e9..0a48d1201 100644
--- a/srsenb/hdr/stack/gnb_stack_nr.h
+++ b/srsenb/hdr/stack/gnb_stack_nr.h
@@ -120,7 +120,10 @@ private:
   // task scheduling
   static const int                      STACK_MAIN_THREAD_PRIO = 4;
   srsran::task_scheduler                task_sched;
-  srsran::task_multiqueue::queue_handle sync_task_queue, ue_task_queue, gtpu_task_queue, mac_task_queue;
+  srsran::task_multiqueue::queue_handle sync_task_queue, ue_task_queue, gtpu_task_queue, mac_task_queue,
+      metrics_task_queue;
+
+  srsran::dyn_blocking_queue<stack_metrics_t> pending_stack_metrics;
 
   // derived
   srsenb::mac_nr mac;
diff --git a/srsenb/src/stack/gnb_stack_nr.cc b/srsenb/src/stack/gnb_stack_nr.cc
index ed973f3ba..62016bd32 100644
--- a/srsenb/src/stack/gnb_stack_nr.cc
+++ b/srsenb/src/stack/gnb_stack_nr.cc
@@ -25,15 +25,17 @@ gnb_stack_nr::gnb_stack_nr(srslog::sink& log_sink) :
   pdcp_logger(srslog::fetch_basic_logger("PDCP-NR", log_sink, false)),
   rrc_logger(srslog::fetch_basic_logger("RRC-NR", log_sink, false)),
   stack_logger(srslog::fetch_basic_logger("STCK-NR", log_sink, false)),
+  pending_stack_metrics(64),
   mac(&task_sched),
   rrc(&task_sched),
   pdcp(&task_sched, pdcp_logger),
   rlc(rlc_logger)
 {
-  ue_task_queue   = task_sched.make_task_queue();
-  sync_task_queue = task_sched.make_task_queue();
-  gtpu_task_queue = task_sched.make_task_queue();
-  mac_task_queue  = task_sched.make_task_queue();
+  ue_task_queue      = task_sched.make_task_queue();
+  sync_task_queue    = task_sched.make_task_queue();
+  gtpu_task_queue    = task_sched.make_task_queue();
+  mac_task_queue     = task_sched.make_task_queue();
+  metrics_task_queue = task_sched.make_task_queue();
 }
 
 gnb_stack_nr::~gnb_stack_nr()
@@ -129,9 +131,7 @@ void gnb_stack_nr::tti_clock_impl()
   task_sched.tic();
 }
 
-void gnb_stack_nr::process_pdus()
-{
-}
+void gnb_stack_nr::process_pdus() {}
 
 /********************************************************
  *
@@ -141,9 +141,22 @@ void gnb_stack_nr::process_pdus()
 
 bool gnb_stack_nr::get_metrics(srsenb::stack_metrics_t* metrics)
 {
-  mac.get_metrics(metrics->mac);
-  rrc.get_metrics(metrics->rrc);
-  return true;
+  // use stack thread to query metrics
+  auto ret = metrics_task_queue.try_push([this]() {
+    srsenb::stack_metrics_t metrics{};
+    mac.get_metrics(metrics.mac);
+    rrc.get_metrics(metrics.rrc);
+    if (not pending_stack_metrics.try_push(std::move(metrics))) {
+      stack_logger.error("Unable to push metrics to queue");
+    }
+  });
+
+  if (ret.has_value()) {
+    // wait for result
+    *metrics = pending_stack_metrics.pop_blocking();
+    return true;
+  }
+  return false;
 }
 
 // Temporary GW interface