cpp

#include "mycpp/gc_iolib.h"

#include <errno.h>

namespace iolib {

SignalSafe* gSignalSafe = nullptr;

SignalSafe* InitSignalSafe() {

  gSignalSafe = Alloc<SignalSafe>();

  gHeap.RootGlobalVar(gSignalSafe);

  RegisterSignalInterest(SIGINT);  // for KeyboardInterrupt checks

  return gSignalSafe;

}

static void OurSignalHandler(int sig_num) {

  assert(gSignalSafe != nullptr);

  gSignalSafe->UpdateFromSignalHandler(sig_num);

}

void RegisterSignalInterest(int sig_num) {

  struct sigaction act = {};

  act.sa_handler = OurSignalHandler;

  if (sigaction(sig_num, &act, nullptr) != 0) {

    throw Alloc<OSError>(errno);

  }

}

// Note that the Python implementation of pyos.sigaction() calls

// signal.signal(), which calls PyOS_setsig(), which calls sigaction() #ifdef

// HAVE_SIGACTION.

void sigaction(int sig_num, void (*handler)(int)) {

  // SIGINT and SIGWINCH must be registered through SignalSafe

  DCHECK(sig_num != SIGINT);

  DCHECK(sig_num != SIGWINCH);

  struct sigaction act = {};

  act.sa_handler = handler;

  if (sigaction(sig_num, &act, nullptr) != 0) {

    throw Alloc<OSError>(errno);

  }

}

}  // namespace iolib