cmake: use shared library internally

CMakeLists.txt

@@ -5,7 +5,7 @@ set(CMAKE_CXX_STANDARD 17)
 
 option(NIX_BUILD "Is CMake called by a nix build?" OFF)
 
-add_library(tetra-decoder-library
+add_library(tetra-decoder-library SHARED
             src/decoder.cpp
             src/bit_stream_decoder.cpp
             src/iq_stream_decoder.cpp
@@ -74,6 +74,7 @@ target_link_libraries(tetra-decoder-library ZLIB::ZLIB fmt::fmt nlohmann_json::n
 target_link_libraries(tetra-decoder tetra-decoder-library)
 target_link_libraries(tetra-viterbi viterbi)
 
+install(TARGETS tetra-decoder-library DESTINATION lib)
 install(TARGETS tetra-decoder DESTINATION bin)
 install(TARGETS tetra-puncturing DESTINATION bin)
 install(TARGETS tetra-viterbi DESTINATION bin)

include/decoder.hpp

@@ -46,7 +46,8 @@ class Decoder {
             const std::shared_ptr<PrometheusExporter>& prometheus_exporter);
     ~Decoder();
 
-    void main_loop();
+    /// \returns true if we should abort
+    [[nodiscard]] auto main_loop() -> bool;
 
   private:
     /// This flag is set when the program should termiate. It is pass down to the next stage in the chain when

src/decoder.cpp

@@ -8,7 +8,6 @@
  */
 
 #include "decoder.hpp"
-#include "signal_handler.hpp"
 #include <arpa/inet.h>
 #include <cassert>
 #include <complex>
@@ -85,28 +84,25 @@ Decoder::~Decoder() {
     termination_flag_ = true;
 }
 
-void Decoder::main_loop() {
+auto Decoder::main_loop() -> bool {
     std::array<uint8_t, kRX_BUFFER_SIZE> rx_buffer{};
 
     auto bytes_read = read(input_fd_, rx_buffer.data(), sizeof(rx_buffer));
 
     if (errno == EINTR) {
-        stop = true;
-        return;
+        return true;
     }
     if (bytes_read < 0) {
         throw std::runtime_error("Read error.");
     }
     if (bytes_read == 0) {
-        stop = true;
-        return;
+        return true;
     }
 
     if (output_file_fd_.has_value()) {
         if (write(*output_file_fd_, rx_buffer.data(), bytes_read) != bytes_read) {
             throw std::runtime_error("Could not write to output file.");
-            stop = true;
-            return;
+            return true;
         }
     }
 
@@ -131,4 +127,6 @@ void Decoder::main_loop() {
             }
         }
     }
+
+    return false;
 }

src/main.cpp

@@ -1,5 +1,4 @@
 #include "decoder.hpp"
-#include "signal_handler.hpp"
 #include <csignal>
 #include <cstdlib>
 #include <cxxopts.hpp>
@@ -86,7 +85,7 @@ auto main(int argc, char** argv) -> int {
     }
 
     while (!stop) { // NOLINT handled by signal action
-        decoder->main_loop();
+        stop |= decoder->main_loop();
     }
 
     return EXIT_SUCCESS;