Program Listing for File signal_handler.hpp

            

            
/*
* SPDX-FileCopyrightText: Copyright (c) 2023 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

#ifndef HOLOSCAN_CORE_SIGNAL_HANDLER_HPP
#define HOLOSCAN_CORE_SIGNAL_HANDLER_HPP

#include <csignal>
#include <functional>
#include <memory>
#include <mutex>
#include <unordered_map>
#include <utility>

namespace holoscan {

extern void static_handle_signal(int signal);

class SignalHandler {
 public:
  using GlobalSignalHandlerMap = std::unordered_map<int, std::function<void(int)>>;
  using SignalHandlerMap = std::unordered_map<int, std::function<void(void*, int)>>;
  using ContextSignalHandlerMap = std::unordered_map<void*, SignalHandlerMap>;

  static SignalHandler& get_instance();

  static void static_handle_signal(int signal);

  static void install_signal_handler(int signal = 0);

  static void register_global_signal_handler(int signal, std::function<void(int)> handler,
                                             bool overwrite = false);

  static void register_signal_handler(void* context, int signal,
                                      std::function<void(void*, int)> handler,
                                      bool overwrite = false);

  static void unregister_global_signal_handler(int signal);

  static void unregister_signal_handler(void* context, int signal);

  static void clear_all_signal_handlers();

  static void clear_global_signal_handlers();

  static void clear_signal_handlers();

 private:
  SignalHandler();
  ~SignalHandler();

  void install_signal_handler_impl(int signal = 0);

  void register_global_signal_handler_impl(int signal, std::function<void(int)> handler,
                                           bool overwrite = false);
  void register_signal_handler_impl(void* context, int signal,
                                    std::function<void(void*, int)> handler,
                                    bool overwrite = false);

  void unregister_global_signal_handler_impl(int signal);
  void unregister_signal_handler_impl(void* context, int signal);
  void handle_signal(int signal);

  GlobalSignalHandlerMap global_signal_handlers_;
  ContextSignalHandlerMap signal_handlers_;
  std::recursive_mutex signal_handlers_mutex_;

  static struct sigaction signal_handler_;
  std::unordered_map<int, struct sigaction> old_signal_handlers_;
};

}  // namespace holoscan

#endif// HOLOSCAN_CORE_SIGNAL_HANDLER_HPP