/*
 *  Portable Agile C++ Classes (PACC)
 *  Copyright (C) 2004 by Marc Parizeau
 *  http://manitou.gel.ulaval.ca/~parizeau/PACC
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *  Contact:
 *  Laboratoire de Vision et Systemes Numeriques
 *  Departement de genie electrique et de genie informatique
 *  Universite Laval, Quebec, Canada, G1K 7P4
 *  http://vision.gel.ulaval.ca
 *
 */

/*!
 * \file PACC/Util/SignalHandler.hpp
 * \brief Class definition for the portable signal handler.
 * \author Marc Dubreuil and Christian Gagne, Laboratoire de vision et systèmes numériques, Université Laval
 * $Revision: 1.5 $
 * $Date: 2005/10/05 13:38:27 $
 */

#ifndef PACC_SIGNALHANDLER_HPP
#define PACC_SIGNALHANDLER_HPP

#include <vector>
#include <signal.h>

namespace PACC {
	
	using namespace std;
	
	/*!
	*  \class SignalHandler PACC/Util/SignalHandler.hpp "PACC/Util/SignalHandler.hpp"
	 *  \brief Portable signal handling.
	 *  \author Marc Dubreuil and Christian Gagne, Laboratoire de vision et syst&egrave;mes num&eacute;riques, Universit&eacute; Laval
	 *  \ingroup Util
	 *
	 *  This class handle common signals (usually SIGINT and SIGTERM) to cleanly
	 *  end a program.  This class should be public inherited.  To specify
	 *  which method should be used when receiving a signal, see setHandler.
	 *  To ignore some kind of signal, use ignoreSignal.  When specifying
	 *  a signal (with setHandler), as long as the root process
	 *  is alive, the signals will be changed to the new value.  If it is not desired,
	 *  use restoreHandler to its old value.
	 */
	class SignalHandler {
		public:
#ifdef WIN32
		//negative numbers does not work under Windows.  Only ANSI code.
		enum SignalNumber {
			eSigHUp  = -1,      /* Hangup (POSIX).                  */
			eSigInt  = SIGINT,  /* Interrupt (ANSI).                */
			eSigQuit = -3,      /* Quit (POSIX).                    */
			eSigIll  = SIGILL,  /* Illegal instruction (ANSI).      */
			eSigTrap = -5,      /* Trace trap (POSIX).              */
			eSigAbrt = SIGABRT, /* Abort (ANSI).                    */
			eSigFPE  = SIGFPE,  /* Floating-point exception (ANSI). */
			eSigKill = -9,      /* Kill, unblockable (POSIX).       */
			eSigUsr1 = -10,     /* User-defined signal 1 (POSIX).   */
			eSigSegV = SIGSEGV, /* Segmentation violation (ANSI).   */
			eSigUsr2 = -12,     /* User-defined signal 2 (POSIX).   */
			eSigPipe = -13,     /* Broken pipe (POSIX).             */
			eSigAlrm = -14,     /* Alarm clock (POSIX).             */
			eSigTerm = SIGTERM, /* Termination (ANSI).              */
			eSigChld = -17,     /* Child status has changed (POSIX).*/
			eSigCont = -18,     /* Continue (POSIX).                */
			eSigStop = -19,     /* Stop, unblockable (POSIX).       */
			eSigTStp = -20,     /* Keyboard stop (POSIX).           */
			eSigTTin = -21,     /* Background read from tty (POSIX).*/
			eSigTTou = -22      /* Background write to tty (POSIX). */
		};
#else
		enum SignalNumber{
			eSigHUp  = SIGHUP,   /* Hangup (POSIX).                  */
			eSigInt  = SIGINT,   /* Interrupt (ANSI).                */
			eSigQuit = SIGQUIT,  /* Quit (POSIX).                    */
			eSigIll  = SIGILL,   /* Illegal instruction (ANSI).      */
			eSigTrap = SIGTRAP,  /* Trace trap (POSIX).              */
			eSigAbrt = SIGABRT,  /* Abort (ANSI).                    */
			eSigFPE  = SIGFPE,   /* Floating-point exception (ANSI). */
			eSigKill = SIGKILL,  /* Kill, unblockable (POSIX).       */
			eSigUsr1 = SIGUSR1,  /* User-defined signal 1 (POSIX).   */
			eSigSegV = SIGSEGV,  /* Segmentation violation (ANSI).   */
			eSigUsr2 = SIGUSR2,  /* User-defined signal 2 (POSIX).   */
			eSigPipe = SIGPIPE,  /* Broken pipe (POSIX).             */
			eSigAlrm = SIGALRM,  /* Alarm clock (POSIX).             */
			eSigTerm = SIGTERM,  /* Termination (ANSI).              */
			eSigChld = SIGCHLD,  /* Child status has changed (POSIX).*/
			eSigCont = SIGCONT,  /* Continue (POSIX).                */
			eSigStop = SIGSTOP,  /* Stop, unblockable (POSIX).       */
			eSigTStp = SIGTSTP,  /* Keyboard stop (POSIX).           */
			eSigTTin = SIGTTIN,  /* Background read from tty (POSIX).*/
			eSigTTou = SIGTTOU   /* Background write to tty (POSIX). */
		};
#endif
		
		//! Construct default signal handler.
		SignalHandler() {}
		//! delete signal handler.
		virtual ~SignalHandler() {}
		
		static SignalHandler* getHandler(int inSignalNumber);
		virtual void handleSignal(int inSignalNumber) = 0;
		static void ignoreSignal(int inSignalNumber);
		static bool isSignalIgnored(int inSignalNumber);
		static void reactivateSignal(int inSignalNumber);
		static SignalHandler* restoreHandler(int inSignalNumber);
		SignalHandler* setAsHandler(int inSignalNumber);
		static SignalHandler* setHandler(int inSignalNumber, SignalHandler*);
		
		protected:
			static void sighandle(int);
		
		private:
			static SignalHandler* smHandlers[32];
		
		static void* smSigAction[32]; //!< static (Old) signal action.
		static void* smOldSigIgn[32]; //!< static (Old) signal ignore.
	};
	
} // end of PACC namespace

#endif