NMMEMSRV.C

/******************************************************************************\ 
*       This is a part of the Microsoft Source Code Samples. 
*       Copyright 1993 - 1998 Microsoft Corporation. 
*       All rights reserved. 
*       This source code is only intended as a supplement to 
*       Microsoft Development Tools and/or WinHelp documentation. 
*       See these sources for detailed information regarding the 
*       Microsoft samples programs. 
\******************************************************************************/ 
 
 
#include <windows.h> 
#include "memory.h" 
 
 
/************************************************************************** 
 * HANDLE CreateMapFile(char *MapFileName) 
 * 
 * Purpose: Create a Map file to map named share memory 
 * 
 * Inputs:  none 
 * 
 * Returns: MapFileHandle - a handle to the file 
 *                        or NULL if failure 
 * 
 * Calls:   CreateFile, ErrorOut 
 * 
\**************************************************************************/ 
HANDLE CreateMapFile(char *MapFileName) 
{ 
   HANDLE MapFileHandle; 
 
   MapFileHandle= CreateFile(MapFileName, 
                             GENERIC_READ | GENERIC_WRITE, 
                             FILE_SHARE_READ | FILE_SHARE_WRITE, 
                             NULL, 
                             CREATE_ALWAYS, 
                             FILE_ATTRIBUTE_NORMAL, 
                             NULL); 
 
   if (MapFileHandle == INVALID_HANDLE_VALUE) 
   { 
      ErrorOut("CreateFile"); 
      return(NULL); 
   } 
   else 
      return(MapFileHandle); 
 
} 
 
/************************************************************************** 
 * HANDLE CreateMap(HANDLE FileToBeMapped, char *MapName ) 
 * 
 * Purpose: Create File Mapping object using the open file handle 
 * 
 * Inputs:  FileToBeMapped - handle to the file 
 * 
 * Returns: MapHandle - handle to the file mapping object 
 *                    or NULL if failure 
 * 
 * Calls:   CreateFileMapping, ErrorOut 
\**************************************************************************/ 
 
HANDLE CreateMap(HANDLE FileToBeMapped, LPSTR MapName) 
{ 
   HANDLE MapHandle; 
 
   MapHandle= CreateFileMapping(FileToBeMapped, 
                                NULL, 
                                PAGE_READWRITE, 
                                0, 
                                4096, 
                                MapName); 
 
   if (MapHandle == NULL) 
   { 
      ErrorOut("CreateFileMapping"); 
      return(NULL); 
   } 
   else 
      return(MapHandle); 
} 
 
 
/************************************************************************** 
 * LPVOID MapView(HANDLE hMap) 
 * 
 * Purpose: Map the file mapping object into address space 
 * 
 * Inputs:  hMap - handle to the mapping object 
 * 
 * Returns: MappedPointer - pointer to the address space that the 
 *                        object is mapped into 
 *                        or NULL if failure 
 * 
 * Calls:   MapViewOfFile, ErrorOut 
 * 
\**************************************************************************/ 
 
LPVOID MapView(HANDLE hMap) 
{ 
   LPVOID MappedPointer; 
 
   MappedPointer= MapViewOfFile(hMap, 
                                FILE_MAP_WRITE | FILE_MAP_READ, 
                                0, 0, 4096); 
   if (MappedPointer == NULL) 
   { 
      ErrorOut("MapViewOfFile"); 
      return(NULL); 
   } 
   else 
      return(MappedPointer); 
}