Add options to disable signal handling in Player and Recorder Python API

- Also added test coverage for signals handling in Python API

Signed-off-by: Michael Orlov <[email protected]>

rosbag2_py/src/rosbag2_py/_transport.cpp

@@ -184,15 +184,32 @@ class Player
     const rosbag2_storage::StorageOptions & storage_options,
     PlayOptions & play_options)
   {
-    play_impl(storage_options, play_options, false);
+    play_impl(storage_options, play_options, false, 0, true);
+  }
+
+  void play_with_signal_option(
+    const rosbag2_storage::StorageOptions & storage_options,
+    PlayOptions & play_options,
+    bool enable_signal_handling)
+  {
+    play_impl(storage_options, play_options, false, 0, enable_signal_handling);
   }
 
   void burst(
     const rosbag2_storage::StorageOptions & storage_options,
     PlayOptions & play_options,
     size_t num_messages)
   {
-    play_impl(storage_options, play_options, true, num_messages);
+    play_impl(storage_options, play_options, true, num_messages, true);
+  }
+
+  void burst_with_signal_option(
+    const rosbag2_storage::StorageOptions & storage_options,
+    PlayOptions & play_options,
+    size_t num_messages,
+    bool enable_signal_handling)
+  {
+    play_impl(storage_options, play_options, true, num_messages, enable_signal_handling);
   }
 
 protected:
@@ -215,13 +232,10 @@ class Player
   {
     if (old_sigterm_handler_ != SIG_ERR) {
       std::signal(SIGTERM, old_sigterm_handler_);
-      old_sigterm_handler_ = SIG_ERR;
     }
     if (old_sigint_handler_ != SIG_ERR) {
       std::signal(SIGINT, old_sigint_handler_);
-      old_sigint_handler_ = SIG_ERR;
     }
-    deferred_sig_number_ = -1;
   }
 
   static void process_deferred_signal()
@@ -243,9 +257,12 @@ class Player
     const rosbag2_storage::StorageOptions & storage_options,
     PlayOptions & play_options,
     bool burst = false,
-    size_t burst_num_messages = 0)
+    size_t burst_num_messages = 0,
+    bool enable_signal_handling = true)
   {
-    install_signal_handlers();
+    if (enable_signal_handling) {
+      install_signal_handlers();
+    }
     try {
       auto reader = rosbag2_transport::ReaderWriterFactory::make_reader(storage_options);
       std::shared_ptr<KeyboardHandler> keyboard_handler;
@@ -297,25 +314,30 @@ class Player
       }
       exec.remove_node(player);
     } catch (...) {
-      process_deferred_signal();
-      uninstall_signal_handlers();
+      if (enable_signal_handling) {
+        uninstall_signal_handlers();
+        process_deferred_signal();
+      }
       throw;
     }
-    process_deferred_signal();
-    uninstall_signal_handlers();
+    if (enable_signal_handling) {
+      uninstall_signal_handlers();
+      process_deferred_signal();
+    }
   }
 
   static std::atomic_bool exit_;
+  static_assert(std::atomic_bool::is_always_lock_free);
   static std::condition_variable wait_for_exit_cv_;
   static SignalHandlerType old_sigint_handler_;
   static SignalHandlerType old_sigterm_handler_;
-  static int deferred_sig_number_;
+  static volatile std::sig_atomic_t deferred_sig_number_;
   std::mutex wait_for_exit_mutex_;
 };
 
 Player::SignalHandlerType Player::old_sigint_handler_ {SIG_ERR};
 Player::SignalHandlerType Player::old_sigterm_handler_ {SIG_ERR};
-int Player::deferred_sig_number_{-1};
+volatile std::sig_atomic_t Player::deferred_sig_number_{-1};
 std::atomic_bool Player::exit_{false};
 std::condition_variable Player::wait_for_exit_cv_{};
 
@@ -339,7 +361,18 @@ class Recorder
     RecordOptions & record_options,
     std::string & node_name)
   {
-    install_signal_handlers();
+    record_with_signal_option(storage_options, record_options, node_name, true);
+  }
+
+  void record_with_signal_option(
+    const rosbag2_storage::StorageOptions & storage_options,
+    RecordOptions & record_options,
+    std::string & node_name,
+    bool enable_signal_handling)
+  {
+    if (enable_signal_handling) {
+      install_signal_handlers();
+    }
     try {
       exit_ = false;
       auto exec = std::make_unique<rclcpp::executors::SingleThreadedExecutor>();
@@ -385,12 +418,16 @@ class Recorder
       }
       exec->remove_node(recorder);
     } catch (...) {
-      process_deferred_signal();
-      uninstall_signal_handlers();
+      if (enable_signal_handling) {
+        uninstall_signal_handlers();
+        process_deferred_signal();
+      }
       throw;
     }
-    process_deferred_signal();
-    uninstall_signal_handlers();
+    if (enable_signal_handling) {
+      uninstall_signal_handlers();
+      process_deferred_signal();
+    }
   }
 
   static void cancel()
@@ -419,13 +456,10 @@ class Recorder
   {
     if (old_sigterm_handler_ != SIG_ERR) {
       std::signal(SIGTERM, old_sigterm_handler_);
-      old_sigterm_handler_ = SIG_ERR;
     }
     if (old_sigint_handler_ != SIG_ERR) {
       std::signal(SIGINT, old_sigint_handler_);
-      old_sigint_handler_ = SIG_ERR;
     }
-    deferred_sig_number_ = -1;
   }
 
   static void process_deferred_signal()
@@ -444,16 +478,17 @@ class Recorder
   }
 
   static std::atomic_bool exit_;
+  static_assert(std::atomic_bool::is_always_lock_free);
   static std::condition_variable wait_for_exit_cv_;
   static SignalHandlerType old_sigint_handler_;
   static SignalHandlerType old_sigterm_handler_;
-  static int deferred_sig_number_;
+  static volatile std::sig_atomic_t deferred_sig_number_;
   std::mutex wait_for_exit_mutex_;
 };
 
 Recorder::SignalHandlerType Recorder::old_sigint_handler_ {SIG_ERR};
 Recorder::SignalHandlerType Recorder::old_sigterm_handler_ {SIG_ERR};
-int Recorder::deferred_sig_number_{-1};
+volatile std::sig_atomic_t Recorder::deferred_sig_number_{-1};
 std::atomic_bool Recorder::exit_{false};
 std::condition_variable Recorder::wait_for_exit_cv_{};
 
@@ -591,18 +626,22 @@ PYBIND11_MODULE(_transport, m) {
   .def(py::init<>())
   .def(py::init<const std::string &>())
   .def("play", &rosbag2_py::Player::play, py::arg("storage_options"), py::arg("play_options"))
-  .def(
-    "burst", &rosbag2_py::Player::burst, py::arg("storage_options"), py::arg("play_options"),
+  .def("play", &rosbag2_py::Player::play_with_signal_option, py::arg("storage_options"),
+       py::arg("play_options"), py::arg("enable_signal_handling"))
+  .def("burst", &rosbag2_py::Player::burst, py::arg("storage_options"), py::arg("play_options"),
     py::arg("num_messages"))
+  .def("burst", &rosbag2_py::Player::burst_with_signal_option, py::arg("storage_options"),
+       py::arg("play_options"), py::arg("num_messages"), py::arg("enable_signal_handling"))
   .def_static("cancel", &rosbag2_py::Player::cancel)
   ;
 
   py::class_<rosbag2_py::Recorder>(m, "Recorder")
   .def(py::init<>())
   .def(py::init<const std::string &>())
-  .def(
-    "record", &rosbag2_py::Recorder::record, py::arg("storage_options"), py::arg("record_options"),
-    py::arg("node_name") = "rosbag2_recorder")
+  .def("record", &rosbag2_py::Recorder::record, py::arg("storage_options"),
+    py::arg("record_options"), py::arg("node_name") = "rosbag2_recorder")
+  .def("record", &rosbag2_py::Recorder::record_with_signal_option, py::arg("storage_options"),
+    py::arg("record_options"), py::arg("node_name"), py::arg("enable_signal_handling"))
   .def_static("cancel", &rosbag2_py::Recorder::cancel)
   ;