From a091b1806207d06e02a469487a4a9e3961c0e12b Mon Sep 17 00:00:00 2001
From: Carles Fernandez <carles.fernandez@gmail.com>
Date: Sun, 22 Nov 2020 14:08:48 +0100
Subject: [PATCH] Fix occasional segfault when exiting with enter+q if
 Acquisition_XX.blocking=false

---
 docs/changelog.md                                   |  2 ++
 .../acquisition/gnuradio_blocks/CMakeLists.txt      |  1 -
 .../acquisition/gnuradio_blocks/pcps_acquisition.cc | 13 +++----------
 .../acquisition/gnuradio_blocks/pcps_acquisition.h  |  2 --
 4 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/docs/changelog.md b/docs/changelog.md
index d0e123d5e..e0070644f 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -67,6 +67,8 @@ SPDX-FileCopyrightText: 2011-2020 Carles Fernandez-Prades <carles.fernandez@cttc
   parameters for the `DataTypeAdapter`, `InputFilter` and `Resampler` blocks are
   ignored. This was the default behavior in GNSS-SDR v0.0.12, but it changed in
   v0.0.13. This change recovers the old behavior.
+- Fixed occasional segmentation fault when exiting with `q` + `[Enter]` keys if
+  `Acquisition_XX.blocking=false`.
 - Fixed the termination of the receiver with `q` + `[Enter]` keys when using the
   `Osmosdr_Signal_Source` implementation of the `SignalSource` block.
 - The `Labsat_Signal_Source` implementation of the `SignalSource` block now can
diff --git a/src/algorithms/acquisition/gnuradio_blocks/CMakeLists.txt b/src/algorithms/acquisition/gnuradio_blocks/CMakeLists.txt
index 64ca69764..cdc89e2eb 100644
--- a/src/algorithms/acquisition/gnuradio_blocks/CMakeLists.txt
+++ b/src/algorithms/acquisition/gnuradio_blocks/CMakeLists.txt
@@ -75,7 +75,6 @@ target_link_libraries(acquisition_gr_blocks
         Armadillo::armadillo
         Gnuradio::runtime
         Gnuradio::fft
-        Threads::Threads
         Volk::volk
         Volkgnsssdr::volkgnsssdr
     PRIVATE
diff --git a/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition.cc b/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition.cc
index 759228cf6..a62e13025 100644
--- a/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition.cc
+++ b/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition.cc
@@ -659,8 +659,6 @@ void pcps_acquisition::acquisition_core(uint64_t samp_count)
                << ", doppler_step: " << d_doppler_step
                << ", use_CFAR_algorithm_flag: " << (d_use_CFAR_algorithm_flag ? "true" : "false");
 
-    lk.unlock();
-
     // Doppler frequency grid loop
     if (!d_step_two)
         {
@@ -782,7 +780,6 @@ void pcps_acquisition::acquisition_core(uint64_t samp_count)
                 }
         }
 
-    lk.lock();
     if (!d_acq_parameters.bit_transition_flag)
         {
             if (d_test_statistics > d_threshold)
@@ -872,7 +869,6 @@ void pcps_acquisition::acquisition_core(uint64_t samp_count)
                     send_negative_acquisition();
                 }
         }
-    d_worker_active = false;
 
     if ((d_num_noncoherent_integrations_counter == d_acq_parameters.max_dwells) or (d_positive_acq == 1))
         {
@@ -884,6 +880,8 @@ void pcps_acquisition::acquisition_core(uint64_t samp_count)
             d_num_noncoherent_integrations_counter = 0U;
             d_positive_acq = 0;
         }
+
+    d_worker_active = false;
 }
 
 
@@ -930,11 +928,7 @@ int pcps_acquisition::general_work(int noutput_items __attribute__((unused)),
      * 6. Declare positive or negative acquisition using a message port
      */
     gr::thread::scoped_lock lk(d_setlock);
-    if (!d_active and d_worker_active and !d_acq_parameters.blocking)
-        {
-            pthread_cancel(d_id_worker);
-            return 0;
-        }
+
     if (!d_active or d_worker_active)
         {
             if (!d_acq_parameters.blocking_on_standby)
@@ -1022,7 +1016,6 @@ int pcps_acquisition::general_work(int noutput_items __attribute__((unused)),
                 else
                     {
                         d_worker = std::thread([&] { pcps_acquisition::acquisition_core(d_sample_counter); });
-                        d_id_worker = d_worker.native_handle();
                         d_worker.detach();
                         d_worker_active = true;
                     }
diff --git a/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition.h b/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition.h
index bcdcf5332..c161cb063 100644
--- a/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition.h
+++ b/src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition.h
@@ -59,7 +59,6 @@
 #include <complex>
 #include <cstdint>
 #include <memory>
-#include <pthread.h>
 #include <queue>
 #include <string>
 #include <thread>
@@ -261,7 +260,6 @@ private:
 
     std::string d_dump_filename;
     std::thread d_worker;
-    pthread_t d_id_worker;
 
     int64_t d_dump_number;
     uint64_t d_sample_counter;