Fix a bug that could cause a crash on receiver stopping

If a channel event was happening after flowgraph stop and before flowgraph disconnection, it caused a crash. This was avoided by sleeping the control thread during 500 ms after disconnection and before the block destructors were called, so the event could be processed, but this was not a robust solution.

src/algorithms/acquisition/adapters/beidou_b1i_pcps_acquisition.cc

@@ -94,6 +94,7 @@ BeidouB1iPcpsAcquisition::BeidouB1iPcpsAcquisition(
 
 void BeidouB1iPcpsAcquisition::stop_acquisition()
 {
+    acquisition_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/beidou_b3i_pcps_acquisition.cc

@@ -92,6 +92,7 @@ BeidouB3iPcpsAcquisition::BeidouB3iPcpsAcquisition(
 
 void BeidouB3iPcpsAcquisition::stop_acquisition()
 {
+    acquisition_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/galileo_e1_pcps_8ms_ambiguous_acquisition.cc

@@ -121,6 +121,7 @@ GalileoE1Pcps8msAmbiguousAcquisition::GalileoE1Pcps8msAmbiguousAcquisition(
 
 void GalileoE1Pcps8msAmbiguousAcquisition::stop_acquisition()
 {
+    acquisition_cc_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/galileo_e1_pcps_ambiguous_acquisition.cc

@@ -94,6 +94,7 @@ GalileoE1PcpsAmbiguousAcquisition::GalileoE1PcpsAmbiguousAcquisition(
 
 void GalileoE1PcpsAmbiguousAcquisition::stop_acquisition()
 {
+    acquisition_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/galileo_e1_pcps_cccwsr_ambiguous_acquisition.cc

@@ -114,6 +114,8 @@ GalileoE1PcpsCccwsrAmbiguousAcquisition::GalileoE1PcpsCccwsrAmbiguousAcquisition
 
 void GalileoE1PcpsCccwsrAmbiguousAcquisition::stop_acquisition()
 {
+    acquisition_cc_->set_state(0);
+    acquisition_cc_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/galileo_e1_pcps_quicksync_ambiguous_acquisition.cc

@@ -155,6 +155,8 @@ GalileoE1PcpsQuickSyncAmbiguousAcquisition::GalileoE1PcpsQuickSyncAmbiguousAcqui
 
 void GalileoE1PcpsQuickSyncAmbiguousAcquisition::stop_acquisition()
 {
+    acquisition_cc_->set_state(0);
+    acquisition_cc_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/galileo_e1_pcps_tong_ambiguous_acquisition.cc

@@ -125,6 +125,8 @@ GalileoE1PcpsTongAmbiguousAcquisition::GalileoE1PcpsTongAmbiguousAcquisition(
 
 void GalileoE1PcpsTongAmbiguousAcquisition::stop_acquisition()
 {
+    acquisition_cc_->set_state(0);
+    acquisition_cc_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/galileo_e5a_noncoherent_iq_acquisition_caf.cc

@@ -130,6 +130,8 @@ GalileoE5aNoncoherentIQAcquisitionCaf::GalileoE5aNoncoherentIQAcquisitionCaf(
 
 void GalileoE5aNoncoherentIQAcquisitionCaf::stop_acquisition()
 {
+    acquisition_cc_->set_state(0);
+    acquisition_cc_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/galileo_e5a_pcps_acquisition.cc

@@ -93,6 +93,7 @@ GalileoE5aPcpsAcquisition::GalileoE5aPcpsAcquisition(ConfigurationInterface* con
 
 void GalileoE5aPcpsAcquisition::stop_acquisition()
 {
+    acquisition_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/glonass_l1_ca_pcps_acquisition.cc

@@ -94,6 +94,7 @@ GlonassL1CaPcpsAcquisition::GlonassL1CaPcpsAcquisition(
 
 void GlonassL1CaPcpsAcquisition::stop_acquisition()
 {
+    acquisition_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/glonass_l2_ca_pcps_acquisition.cc

@@ -93,6 +93,7 @@ GlonassL2CaPcpsAcquisition::GlonassL2CaPcpsAcquisition(
 
 void GlonassL2CaPcpsAcquisition::stop_acquisition()
 {
+    acquisition_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/gps_l1_ca_pcps_acquisition.cc

@@ -96,6 +96,7 @@ GpsL1CaPcpsAcquisition::GpsL1CaPcpsAcquisition(
 
 void GpsL1CaPcpsAcquisition::stop_acquisition()
 {
+    acquisition_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/gps_l1_ca_pcps_acquisition_fine_doppler.cc

@@ -100,6 +100,8 @@ GpsL1CaPcpsAcquisitionFineDoppler::GpsL1CaPcpsAcquisitionFineDoppler(
 
 void GpsL1CaPcpsAcquisitionFineDoppler::stop_acquisition()
 {
+    acquisition_cc_->set_state(0);
+    acquisition_cc_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/gps_l1_ca_pcps_assisted_acquisition.cc

@@ -92,6 +92,8 @@ GpsL1CaPcpsAssistedAcquisition::GpsL1CaPcpsAssistedAcquisition(
 
 void GpsL1CaPcpsAssistedAcquisition::stop_acquisition()
 {
+    acquisition_cc_->set_active(false);
+    acquisition_cc_->set_state(0);
 }
 
 

src/algorithms/acquisition/adapters/gps_l1_ca_pcps_opencl_acquisition.cc

@@ -119,6 +119,8 @@ GpsL1CaPcpsOpenClAcquisition::GpsL1CaPcpsOpenClAcquisition(
 
 void GpsL1CaPcpsOpenClAcquisition::stop_acquisition()
 {
+    acquisition_cc_->set_active(false);
+    acquisition_cc_->set_state(0);
 }
 
 

src/algorithms/acquisition/adapters/gps_l1_ca_pcps_quicksync_acquisition.cc

@@ -148,6 +148,8 @@ GpsL1CaPcpsQuickSyncAcquisition::GpsL1CaPcpsQuickSyncAcquisition(
 
 void GpsL1CaPcpsQuickSyncAcquisition::stop_acquisition()
 {
+    acquisition_cc_->set_state(0);
+    acquisition_cc_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/gps_l1_ca_pcps_tong_acquisition.cc

@@ -110,6 +110,8 @@ GpsL1CaPcpsTongAcquisition::GpsL1CaPcpsTongAcquisition(
 
 void GpsL1CaPcpsTongAcquisition::stop_acquisition()
 {
+    acquisition_cc_->set_state(0);
+    acquisition_cc_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/gps_l2_m_pcps_acquisition.cc

@@ -93,6 +93,7 @@ GpsL2MPcpsAcquisition::GpsL2MPcpsAcquisition(
 
 void GpsL2MPcpsAcquisition::stop_acquisition()
 {
+    acquisition_->set_active(false);
 }
 
 

src/algorithms/acquisition/adapters/gps_l5i_pcps_acquisition.cc

@@ -94,6 +94,7 @@ GpsL5iPcpsAcquisition::GpsL5iPcpsAcquisition(
 
 void GpsL5iPcpsAcquisition::stop_acquisition()
 {
+    acquisition_->set_active(false);
 }
 
 

src/algorithms/channel/adapters/channel.h

@@ -84,10 +84,10 @@ public:
     void msg_handler_events(pmt::pmt_t msg);
 
 private:
+    std::shared_ptr<ChannelFsm> channel_fsm_;
     std::shared_ptr<AcquisitionInterface> acq_;
     std::shared_ptr<TrackingInterface> trk_;
     std::shared_ptr<TelemetryDecoderInterface> nav_;
-    std::shared_ptr<ChannelFsm> channel_fsm_;
     channel_msg_receiver_cc_sptr channel_msg_rx_;
     Concurrent_Queue<pmt::pmt_t>* queue_;
     Gnss_Synchro gnss_synchro_{};

src/core/receiver/control_thread.cc

@@ -102,6 +102,7 @@ ControlThread::ControlThread(std::shared_ptr<ConfigurationInterface> configurati
 
 void ControlThread::init()
 {
+    telecommand_enabled_ = configuration_->property("GNSS-SDR.telecommand_enabled", false);
     // OPTIONAL: specify a custom year to override the system time in order to postprocess old gnss records and avoid wrong week rollover
     pre_2009_file_ = configuration_->property("GNSS-SDR.pre_2009_file", false);
     // Instantiates a control queue, a GNSS flowgraph, and a control message factory
@@ -208,15 +209,14 @@ ControlThread::~ControlThread()  // NOLINT(modernize-use-equals-default)
 
     if (cmd_interface_thread_.joinable())
         {
-            cmd_interface_thread_.detach();
+            cmd_interface_thread_.join();
         }
 }
 
 
 void ControlThread::telecommand_listener()
 {
-    bool telecommand_enabled = configuration_->property("GNSS-SDR.telecommand_enabled", false);
+    if (telecommand_enabled_)
-    if (telecommand_enabled)
         {
             int tcp_cmd_port = configuration_->property("GNSS-SDR.telecommand_tcp_port", 3333);
             cmd_interface_.run_cmd_server(tcp_cmd_port);
@@ -356,12 +356,18 @@ int ControlThread::run()
     fpga_helper_thread_.try_join_until(boost::chrono::steady_clock::now() + boost::chrono::milliseconds(1000));
 #endif
 
-    std::this_thread::sleep_for(std::chrono::milliseconds(500));
     // Terminate keyboard thread
     pthread_t id = keyboard_thread_.native_handle();
     keyboard_thread_.detach();
     pthread_cancel(id);
 
+    if (telecommand_enabled_)
+        {
+            pthread_t id2 = cmd_interface_thread_.native_handle();
+            cmd_interface_thread_.detach();
+            pthread_cancel(id2);
+        }
+
     LOG(INFO) << "Flowgraph stopped";
 
     if (restart_)

src/core/receiver/control_thread.h

@@ -147,19 +147,6 @@ private:
     void keyboard_listener();
     void sysv_queue_listener();
 
-    std::shared_ptr<ConfigurationInterface> configuration_;
-    std::shared_ptr<Concurrent_Queue<pmt::pmt_t>> control_queue_;
-    std::shared_ptr<GNSSFlowgraph> flowgraph_;
-
-    std::thread cmd_interface_thread_;
-    std::thread keyboard_thread_;
-    std::thread sysv_queue_thread_;
-    std::thread gps_acq_assist_data_collector_thread_;
-
-#ifdef ENABLE_FPGA
-    boost::thread fpga_helper_thread_;
-#endif
-
     // default filename for assistance data
     const std::string eph_default_xml_filename_ = "./gps_ephemeris.xml";
     const std::string utc_default_xml_filename_ = "./gps_utc_model.xml";
@@ -176,6 +163,19 @@ private:
     const std::string gal_almanac_default_xml_filename_ = "./gal_almanac.xml";
     const std::string gps_almanac_default_xml_filename_ = "./gps_almanac.xml";
 
+    std::shared_ptr<ConfigurationInterface> configuration_;
+    std::shared_ptr<Concurrent_Queue<pmt::pmt_t>> control_queue_;
+    std::shared_ptr<GNSSFlowgraph> flowgraph_;
+
+    std::thread cmd_interface_thread_;
+    std::thread keyboard_thread_;
+    std::thread sysv_queue_thread_;
+    std::thread gps_acq_assist_data_collector_thread_;
+
+#ifdef ENABLE_FPGA
+    boost::thread fpga_helper_thread_;
+#endif
+
     TcpCmdInterface cmd_interface_;
 
     // SUPL assistance classes
@@ -196,6 +196,7 @@ private:
     bool receiver_on_standby_;
     bool stop_;
     bool restart_;
+    bool telecommand_enabled_;
     bool pre_2009_file_;  // to override the system time to postprocess old gnss records and avoid wrong week rollover
 };
 

src/core/receiver/gnss_flowgraph.cc

@@ -114,6 +114,10 @@ void GNSSFlowgraph::start()
 
 void GNSSFlowgraph::stop()
 {
+    for (auto chan : channels_)
+        {
+            chan->stop_channel();  // stop the acquisition or tracking operation
+        }
     top_block_->stop();
     running_ = false;
 }

src/tests/unit-tests/control-plane/control_thread_test.cc

@@ -135,6 +135,7 @@ TEST_F(ControlThreadTest /*unused*/, InstantiateRunControlMessages /*unused*/)
     unsigned int expected1 = 1;
     EXPECT_EQ(expected3, control_thread->processed_control_messages());
     EXPECT_EQ(expected1, control_thread->applied_actions());
+    std::this_thread::sleep_for(std::chrono::milliseconds(500));
 }
 
 
@@ -196,6 +197,7 @@ TEST_F(ControlThreadTest /*unused*/, InstantiateRunControlMessages2 /*unused*/)
     unsigned int expected1 = 1;
     EXPECT_EQ(expected5, control_thread2->processed_control_messages());
     EXPECT_EQ(expected1, control_thread2->applied_actions());
+    std::this_thread::sleep_for(std::chrono::milliseconds(500));
 }