cu-cp: stop() cu-cp from within cu-cp executor

Author: frankist

apps/gnb/gnb.cpp

@@ -549,6 +549,9 @@ int main(int argc, char** argv)
   // Stop CU-UP activity.
   cu_up_obj->stop();
 
+  // Stop CU-CP activity.
+  cu_cp_obj->stop();
+
   if (not gnb_cfg.amf_cfg.no_core) {
     gnb_logger.info("Closing network connections...");
     ngap_adapter->disconnect_gateway();

include/srsran/cu_cp/cu_cp.h

@@ -80,6 +80,7 @@ class cu_cp_interface : public cu_cp_ngap_connection_interface,
   virtual cu_cp_cu_up_connection_interface& get_cu_cp_cu_up_connection_interface() = 0;
 
   virtual void start() = 0;
+  virtual void stop()  = 0;
 };
 
 } // namespace srs_cu_cp

lib/cu_cp/cu_cp_impl.cpp

@@ -112,7 +112,30 @@ void cu_cp_impl::start()
   }
 }
 
-void cu_cp_impl::stop() {}
+void cu_cp_impl::stop()
+{
+  logger.info("Stopping CU-CP...");
+  std::promise<void> p;
+  std::future<void>  fut = p.get_future();
+
+  // Shut down components from within CU-CP executor.
+  while (not cfg.cu_cp_executor->execute([this, &p]() {
+    statistics_report_timer.stop();
+
+    routine_mng.reset();
+
+    // Signal back that CU-CP is stopped.
+    p.set_value();
+  })) {
+    // Keep dispatching until the task is accepted.
+    std::this_thread::sleep_for(std::chrono::milliseconds(100));
+  }
+
+  // Block waiting for CU-CP stop to complete.
+  fut.wait();
+
+  logger.info("CU-CP stopped successfully.");
+}
 
 size_t cu_cp_impl::get_nof_cu_ups() const
 {

lib/cu_cp/cu_cp_impl.h

@@ -39,10 +39,10 @@ class cu_cp_impl final : public cu_cp_interface, public cu_cp_impl_interface
 {
 public:
   explicit cu_cp_impl(const cu_cp_configuration& config_);
-  ~cu_cp_impl();
+  ~cu_cp_impl() override;
 
   void start() override;
-  void stop();
+  void stop() override;
 
   // CU-CP CU-UP interface
   size_t                get_nof_cu_ups() const override;