breakdetector.cc

/*
 *  $Id$
 *
 * SocketAPI implementation for the sctplib.
 * Copyright (C) 2005-2026 by Thomas Dreibholz
 *
 * Realized in co-operation between
 * - Siemens AG
 * - University of Duisburg-Essen, Institute for Experimental Mathematics
 * - Münster University of Applied Sciences, Burgsteinfurt
 *
 * Acknowledgement
 * This work was partially funded by the Bundesministerium fuer Bildung und
 * Forschung (BMBF) of the Federal Republic of Germany (Foerderkennzeichen 01AK045).
 * The authors alone are responsible for the contents.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Contact: discussion@sctp.de
 *          thomas.dreibholz@gmail.com
 *          tuexen@fh-muenster.de
 *
 * Purpose:    Break Detector
 *
 */

#include "tdsystem.h"
#include "breakdetector.h"
#include "tools.h"


#include <signal.h>



// Kill after timeout: Send kill signal, if Ctrl-C is pressed again
// after more than KILL_TIMEOUT microseconds,
#define KILL_AFTER_TIMEOUT
#define KILL_TIMEOUT 2000000



// ###### Global variables ##################################################
static bool   DetectedBreak = false;
static bool   PrintedBreak  = false;
static bool   Quiet         = false;
static pid_t  MainThreadPID = getpid();
#ifdef KILL_AFTER_TIMEOUT
static bool   PrintedKill   = false;
static card64 LastDetection = (card64)-1;
#endif


// ###### Handler for SIGINT ################################################
void breakDetector(int signum)
{
   DetectedBreak = true;

#ifdef KILL_AFTER_TIMEOUT
   if(!PrintedKill) {
      const card64 now = getMicroTime();
      if(LastDetection == (card64)-1) {
         LastDetection = now;
      }
      else if(now - LastDetection >= 2000000) {
         PrintedKill = true;
         std::cerr << std::endl << "*** Kill ***" << std::endl << std::endl;
         kill(MainThreadPID,SIGKILL);
      }
   }
#endif
}


// ###### Install break detector ############################################
void installBreakDetector()
{
   DetectedBreak = false;
   PrintedBreak  = false;
   Quiet         = false;
#ifdef KILL_AFTER_TIMEOUT
   PrintedKill   = false;
   LastDetection = (card64)-1;
#endif
   signal(SIGINT,&breakDetector);
}


// ###### Unnstall break detector ###########################################
void uninstallBreakDetector()
{
   signal(SIGINT,SIG_DFL);
#ifdef KILL_AFTER_TIMEOUT
   PrintedKill   = false;
   LastDetection = (card64)-1;
#endif
   DetectedBreak = false;
   PrintedBreak  = false;
   Quiet         = false;
}


// ###### Check, if break has been detected #################################
bool breakDetected()
{
   if((DetectedBreak) && (!PrintedBreak)) {
      if(!Quiet) {
         std::cerr << std::endl << "*** Break ***    Signal #" << SIGINT << std::endl << std::endl;
      }
      PrintedBreak = getMicroTime();
   }
   return(DetectedBreak);
}


// ###### Send break to main thread #########################################
void sendBreak(const bool quiet)
{
   Quiet = quiet;
   kill(MainThreadPID,SIGINT);
}