signal_catcher.cpp

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/*******************************************************************\
 
Module:
 
Author: Daniel Kroening, kroening@kroening.com
 
Date:
 
\*******************************************************************/
 
#include "signal_catcher.h"
#include "invariant.h"
 
#if defined(_WIN32)
#else
#include <cstdlib>
#endif
 
// Here we have an instance of an ugly global object.
// It keeps track of any child processes that we'll kill
// when we are told to terminate. "No child" is indicated by '0'.
 
#ifdef _WIN32
#else
pid_t child_pid = 0;
 
void register_child(pid_t pid)
{
  PRECONDITION(child_pid == 0);
  child_pid = pid;
}
 
void unregister_child()
{
  PRECONDITION(child_pid != 0);
  child_pid = 0;
}
#endif
 
void install_signal_catcher()
{
#if defined(_WIN32)
#else
  // declare act to deal with action on signal set
  // NOLINTNEXTLINE(readability/identifiers)
  static struct sigaction act;
 
  act.sa_handler = signal_catcher;
  act.sa_flags = 0;
  sigfillset(&(act.sa_mask));
 
  // install signal handler
  sigaction(SIGTERM, &act, nullptr);
#endif
}
 
void remove_signal_catcher()
{
#if defined(_WIN32)
#else
  // declare act to deal with action on signal set
  // NOLINTNEXTLINE(readability/identifiers)
  static struct sigaction act;
 
  act.sa_handler = SIG_DFL;
  act.sa_flags = 0;
  sigfillset(&(act.sa_mask));
 
  sigaction(SIGTERM, &act, nullptr);
#endif
}
 
void signal_catcher(int sig)
{
#if defined(_WIN32)
  (void)sig; // unused parameter
#else
 
#if 0
  // kill any children by killing group
  killpg(0, sig);
#else
  // pass on to our child, if any
  if(child_pid != 0)
    kill(child_pid, sig);
#endif
 
  exit(sig); // should contemplate something from sysexits.h
#endif
}