shutdown.cxx

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/******************************************************************************
** Copyright (C) 2006-2008 Unified Automation GmbH. All Rights Reserved.
** Web: http://www.unifiedautomation.com
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
** 
** Project: Utility functions.
** Description: Portable shutdown flag using CTRL-C (SIGINT)
** Notes: Visual Studio catches CTRL-C when it's thrown by default,
**        which is not wanted normally. You can disable this by opening the
          exceptions dialog via the menu Debug->Exceptions. Then deactivate
          the "CTRL-C" exception in the "Win32 Exceptions" category.
******************************************************************************/
#include "shutdown.h"

/* shutdown flag */
static volatile unsigned int g_ShutDown = 0;

#ifdef _WIN32_WCE
#  include <windows.h>
#elif defined(_WIN32) && !defined(USE_CTRLC_ON_WINDOWS)
#  include <conio.h> /* DOS header for _kbhit() and _getch() */
#endif

/* Return shutdown flag. */
unsigned int ShutDownFlag()
{
#if defined(_WIN32) && !defined(USE_CTRLC_ON_WINDOWS)
  #ifndef _WIN32_WCE
    if (_kbhit() && _getch() == 'x') return 1;
    else return 0;
  #else
    if (GetAsyncKeyState(VK_ESCAPE)) return 1;
    else return 0;
  #endif
#else
    return g_ShutDown;
#endif
}

/****************************************
 * Linux SIGINT Handler implementation. *
 ****************************************/
#ifdef __linux__
#include <signal.h>

void sig_int(int signo)
{
    SHUTDOWN_TRACE("Received SIG_INT(%i) signal.\n", signo);
    g_ShutDown = 1;
}

void RegisterSignalHandler()
{
    struct sigaction new_action, old_action;
    /* Set up the structure to specify the new action. */
    new_action.sa_handler = sig_int;
    sigemptyset (&new_action.sa_mask);
    new_action.sa_flags = 0;
    /* install new signal handler */
    sigaction(SIGINT, NULL, &old_action);
    if (old_action.sa_handler != SIG_IGN)
    {
        sigaction(SIGINT, &new_action, NULL);
    }
}
#elif defined(_WIN32)
/******************************************
 * Windows CTRL-C Handler implementation. *
 ******************************************/
# ifdef USE_CTRLC_ON_WINDOWS
#  include <windows.h>
#  include <conio.h>
BOOL CtrlHandler(DWORD fdwCtrlType) 
{
    switch( fdwCtrlType ) 
    { 
    // Handle the CTRL-C signal. 
    case CTRL_C_EVENT: 
        SHUTDOWN_TRACE("Received CTRL-C signal.\n");
        g_ShutDown = 1;
        return( TRUE );
    default:
        break;
    }
    return FALSE;
}
void RegisterSignalHandler()
{
    SetConsoleCtrlHandler( (PHANDLER_ROUTINE) CtrlHandler, TRUE );
}
# else /* USE_CTRLC_ON_WINDOWS */
void RegisterSignalHandler()
{

}
# endif /* USE_CTRLC_ON_WINDOWS */ 
#else /* __linux__ */
/********************************************************************
 * Dummy implementation for embedded systems. They never shut down. *
 ********************************************************************/
void RegisterSignalHandler()
{
}
#endif