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Microsoft OS/2 SDK 2.0 05-30-1990

/*==============================================================*\
 *  Vmm_init.c - routines for initialization and exit processing	*
 *	Created 1990, Microsoft, IBM Corp.        	      		*
 *--------------------------------------------------------------*
 *								*
 *  This module contains the code for application initialization*
 *  as well as the code for exit list processing		*
 *								*
 *--------------------------------------------------------------*
 *								*
 *  This source file contains the following functions:		*
 *								*
 *	Init() - initialization routines			*
 *	ExitProc(usTermCode) - exit list processing procedure	*
 *	GPFHandler(parg) - GPFault and guard page excep handler *
 *								*
\*==============================================================*/

/*--------------------------------------------------------------*\
 *  Include files, macros, defined constants, and externs	*
\*--------------------------------------------------------------*/

#define  LINT_ARGS

#define  INCL_WIN
#define  INCL_DOSPROCESS
#define  INCL_DOSSIGNALS
#define  INCL_DOSMISC
#define  INCL_DOSMEMMGR
#include <os2.h>
#include <string.h>
#include "vmm_main.h"
#include "vmm_xtrn.h"

/*--------------------------------------------------------------*\
 *  Entry point declarations					*
\*--------------------------------------------------------------*/

ULONG	GPFHandler(PXCPT parg);

/*--------------------------------------------------------------*\
 *  Global variables						*
\*--------------------------------------------------------------*/

extern	HWND	hwndMain;

EHS ehs = {0, &GPFHandler};

/****************************************************************\
 *  Initialization routine					*
 *--------------------------------------------------------------*
 *								*
 *  Name:   Init()						*
 *								*
 *  Purpose: Performs initialization functions required 	*
 *		before the main window can be created.		*
 *								*
 *  Usage:  Called once before the main window is created.	*
 *								*
 *  Method:							*
 *	    - installs the routine ExitProc into the		*
 *		DosExitList chain				*
 *	    - registers all window classes			*
 *	    - performs any command line processing		*
 *								*
 *  Returns:							*
 *	    TRUE - initialization is successful 		*
 *	    FALSE - initialization failed			*
\****************************************************************/

BOOL Init(VOID)
{
    /* Add ExitProc to the exit list to handle the exit processing */
#ifndef VER630
    if(DosExitList(EXLST_ADD, (PFNEXITLIST)ExitProc))
    {
	return FALSE;
    }
#endif

#ifdef LATER
    /* initialize the print dialog structures */
    InitPrintingDialogs();
#endif

    /* load application name from resource file */
    if(WinLoadString(hab, NULL, IDS_APPNAME, MAXAPPNAMELEN, szAppName) == 0)
    {
	return FALSE;
    }
    /* register the main client window class */
    if(WinRegisterClass(hab,
			(PSZ)szAppName,
			(PFNWP)MainWndProc,
			CS_SIZEREDRAW | CS_SYNCPAINT | CS_CLIPCHILDREN,
			0) == 0)
    {
	return FALSE;
    }

    if(DosSetExceptionHandler(&ehs) != 0)
    {
	return FALSE;
    }
    /*--------------------------------------------------*\
     *	    Add any command line processing here	*
    \*--------------------------------------------------*/

    /* Turn off hard-error popup after GP-FAULT. No return codes
       checked as it is cosmetic and if it doesn't work the only side
       effect will be to have the default hard-error popup show up. */


    DosError(FERR_DISABLEEXCEPTION | FERR_DISABLEHARDERR);

    return TRUE;

}  /* Init() */



/****************************************************************\
 *  Exit list processing procedure				*
 *--------------------------------------------------------------*
 *								*
 *  Name:   ExitProc(usTermCode)				*
 *								*
 *  Purpose: Cleans up certain resources when the application	*
 *		terminates					*
 *								*
 *  Usage:  Routine is called by DosExitList when the		*
 *	    application exits					*
 *								*
 *  Method: global resources, such as the main window and	*
 *	    message queue, are destroyed and any system 	*
 *	    resources used are freed				*
 *								*
 *  Returns:  Returns EXLST_EXIT to the DosExitList handler	*
 *								*
\****************************************************************/

VOID PASCAL FAR ExitProc(usTermCode)
USHORT usTermCode;	/* code for the reason for termination */
{

    WinDestroyWindow(hwndMainFrame);

    /*--------------------------------------------------*\
     *	    Any other system resources used		*
     *	    (e.g. memory or files) should be freed here *
    \*--------------------------------------------------*/

    WinDestroyMsgQueue(hmq);

    WinTerminate(hab);

    DosUnsetExceptionHandler(&ehs);

    DosExitList(EXLST_EXIT, 0L);    /* termination complete */

    /* This routine currently doesn't use the usTermCode parameter so *\
     *	it is referenced here to prevent an 'Unreferenced Parameter'  *
    \*	warning at compile time 				      */

    usTermCode;

}   /* ExitProc() */

/****************************************************************\
 *  Do nothing Guard Page Exception Handler			*
 *--------------------------------------------------------------*
 *								*
 *  Name:   GPFHandler(PXCPT)					*
 *								*
 *  Purpose: To notify user when a guard page entered exception *
 *	     occurs						*
 *								*
 *  Usage:  Routine is called when a guard page is accessed	*
 *								*
 *  Method: Whenever a guard page is accessed, a message	*
 *	    box is put on the screen indicating this		*
 *								*
 *  Returns:  Returns HANDLED if guard page exception,		*
 *	      otherwise, returns NOT_HANDLED			*
\****************************************************************/

ULONG	GPFHandler(parg)
PXCPT	parg;

{
    ULONG   flMemAttrs;
    ULONG   ulMemSize;

    /* Notify the user when they have accessed a guard page, and let
       the system default guard page handler handle the exception. */

    if(parg->ExceptionNum == XCPT_GPF)
    {
	WinMessageBox(HWND_DESKTOP,
			hwndMain,
			"Guard Page Accessed.\n\n"
			"Calling Default Handler.\n",
			szAppName,
			13,
			MB_OK | MB_ICONASTERISK);

	WinInvalidateRect(hwndMain,NULL,TRUE);

	return(NOT_HANDLED);
    }

    if(parg->ExceptionNum == XCPT_GP)
    {
	if (parg->ExceptionInfo[0] & XCPTF_PF)
	{

	    ulMemSize = 1L;
	    DosQueryMem((PVOID)(parg->pExceptionContext->EC_cr2),
			&ulMemSize,&flMemAttrs);

	    /* If the exception is due to accessing a page that has
	       been allocated but not committed, then commit the page.
	       Otherwise, GP Fault. */

	    if (((flMemAttrs & PAG_FREE) || (flMemAttrs & PAG_COMMIT)) == 0)
	    {

		WinMessageBox(HWND_DESKTOP,
				hwndMain,
				"The memory to be written to has not been"
				" committed. \n\rAttempting to committ memory"
				" before write.",
				szAppName,
				13,
				MB_OK | MB_ICONASTERISK);

		 if (DosSetMem((PVOID)(parg->pExceptionContext->EC_cr2),
			   1L,PAG_DEFAULT | PAG_COMMIT) != 0L)
		    return(NOT_HANDLED);
		 else
		    return(HANDLED);
	     }
	}

		/* At this point, we have a GP Fault. We cannot
		   recover, so raise the terminate process exception and
		   return (GP Fault) exception handled. */

		WinMessageBox(HWND_DESKTOP,
				hwndMain,
				"A non-recoverable General Protection Error "
				"has occured.\n\rProgram Terminating.",
				szAppName,
				13,
				MB_OK | MB_ICONHAND);

		return(NOT_HANDLED);
    }

    /* The exception is not one that we handle, so pass it on as
       NOT_HANDLED. */

    return(NOT_HANDLED);
}

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