Sigaction and porting Linux code to Windows

Question

I am trying to port caffe (developed for Linux) source code to Windows environment. The problem is at sigaction structure at signal_handler.cpp and

Answer 1

Based on @nneonneo:

void handle_signal(int signal) {
    switch (signal) {
#ifdef _WIN32
    case SIGTERM:
    case SIGABRT:
    case SIGBREAK:
#else
    case SIGHUP:
#endif
      got_sighup = true;
      break;
    case SIGINT:
      got_sigint = true;
      break;
    }
  }
void HookupHandler() {
    if (already_hooked_up) {
      LOG(FATAL) << "Tried to hookup signal handlers more than once.";
    }
    already_hooked_up = true;
#ifdef _WIN32
    signal(SIGINT, handle_signal);
    signal(SIGTERM, handle_signal);
    signal(SIGABRT, handle_signal);
#else
    struct sigaction sa;
    // Setup the handler
    sa.sa_handler = &handle_signal;
    // Restart the system call, if at all possible
    sa.sa_flags = SA_RESTART;
    // Block every signal during the handler
    sigfillset(&sa.sa_mask);
    // Intercept SIGHUP and SIGINT
    if (sigaction(SIGHUP, &sa, NULL) == -1) {
      LOG(FATAL) << "Cannot install SIGHUP handler.";
    }
    if (sigaction(SIGINT, &sa, NULL) == -1) {
      LOG(FATAL) << "Cannot install SIGINT handler.";
    }
#endif
  }
 void UnhookHandler() {
    if (already_hooked_up) {
#ifdef _WIN32
        signal(SIGINT, SIG_DFL);
        signal(SIGTERM, SIG_DFL);
        signal(SIGABRT, SIG_DFL);
#else
      struct sigaction sa;
      // Setup the sighub handler
      sa.sa_handler = SIG_DFL;
      // Restart the system call, if at all possible
      sa.sa_flags = SA_RESTART;
      // Block every signal during the handler
      sigfillset(&sa.sa_mask);
      // Intercept SIGHUP and SIGINT
      if (sigaction(SIGHUP, &sa, NULL) == -1) {
        LOG(FATAL) << "Cannot uninstall SIGHUP handler.";
      }
      if (sigaction(SIGINT, &sa, NULL) == -1) {
        LOG(FATAL) << "Cannot uninstall SIGINT handler.";
      }
#endif

      already_hooked_up = false;
    }
  }

Answer 2

sigaction is part of the UNIX signals API. Windows provides only signal, which doesn't support SIGHUP or any flags (such as SA_RESTART). However, the very basic support is still there, so the code should still work reasonably correctly if you use just signal (and not sigaction).