main.cpp

#include <iostream>

#include <signal.h>

#include "signal_guard.hpp"

int main()
{
  signal_guard sg(SIGINT);

  while (!sg.timed_wait(std::chrono::milliseconds(500)))
    std::cout << '.' << std::flush;

  std::cout << "\nSignal received\n";

  return 0;
}

signal_guard.cpp

#ifndef SIGNAL_GUARD_HPP
#define SIGNAL_GUARD_HPP

#include <chrono>
#include <system_error>

#include <errno.h>
#include <signal.h>

class signal_guard
{
public:
  explicit signal_guard(int sig_num)
  {
    sigemptyset(&current_mask);
    if (sigaddset(&current_mask, sig_num) < 0)
      throw_system_error();

    if (sigprocmask(SIG_SETMASK, &current_mask, &old_mask) < 0)
      throw_system_error();
  }

  ~signal_guard()
  {
    sigprocmask(SIG_SETMASK, &old_mask, nullptr);
  }

  bool timed_wait(std::chrono::nanoseconds duration)
  {
    const struct timespec ts = { 0, duration.count() };
    if (sigtimedwait(&current_mask, nullptr, &ts) >= 0)
      return true;

    if (errno == EAGAIN)
      return false;

    throw_system_error();
  }

private:
  static [[noreturn]] void throw_system_error() const
  {
    throw std::system_error(errno, std::system_category());
  }

  sigset_t current_mask;
  sigset_t old_mask;
};

#endif // SIGNAL_GUARD_HPP