pjs/mailnews/mapi/mapi32/smem.cpp

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C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
//
// smem.cpp - This deals with all shared memory functions needed for
// the MAPI component of Communicator
// Written by: Rich Pizzarro (rhp@netscape.com)
// November 1997
//
#include <windows.h>
#include <windowsx.h>
#include "mapismem.h"
#ifndef ZeroMemory
#include <memory.h>
#define ZeroMemory(PTR, SIZE) memset(PTR, 0, SIZE)
#endif // ZeroMemory
//
// *create new* shared memory chunk
// once this is created, use the pointer
// to the segment to to store data
// e.g.:
// lpString = "string for communicator";
// lstrcpy((LPSTR)pData->m_buf[0], lpString);
//
CSharedMem *
NSCreateSharedMemory(DWORD memSize, LPCTSTR memName, HANDLE *hSharedMemory)
{
#ifdef WIN32
BOOL bExistedBefore;
CSharedMem *pData;
LPCTSTR szObjectName = memName;
DWORD dwSize = sizeof(CSharedMem) + memSize;
*hSharedMemory = CreateFileMapping(
(HANDLE)0xFFFFFFFF,0,PAGE_READWRITE,0,dwSize,szObjectName);
if(*hSharedMemory == 0)
{
return NULL;
}
bExistedBefore = (GetLastError() == ERROR_ALREADY_EXISTS);
if(bExistedBefore)
{
return NULL;
}
pData = (CSharedMem *)MapViewOfFile(
*hSharedMemory, FILE_MAP_ALL_ACCESS, 0, 0, 0);
if(pData == NULL)
{
return NULL;
}
ZeroMemory(pData, dwSize);
pData->m_dwSize = memSize;
return pData;
#else
CSharedMem *sMemChunk = NULL;
DWORD dwSize = memSize = (sizeof(CSharedMem) + memSize);
if (sMemChunk != NULL)
return(sMemChunk);
sMemChunk = (CSharedMem *) GlobalAllocPtr(GMEM_MOVEABLE, dwSize);
ZeroMemory(sMemChunk, (size_t) dwSize);
sMemChunk->m_dwSize = dwSize; // Missing in Communicator code!
return(sMemChunk);
#endif // WIN32
}
//
// *open existing* shared memory chunk
// once you have the pointer to the new segment
// use this pointer to access data, e.g.:
//
CSharedMem *
NSOpenExistingSharedMemory(LPCTSTR memName, HANDLE *hSharedMemory)
{
#ifdef WIN32
CSharedMem *pData;
DWORD dwSize;
LPCTSTR szObjectName = memName;
*hSharedMemory = OpenFileMapping(
PAGE_READWRITE,FALSE,szObjectName);
if(*hSharedMemory == 0)
{
return NULL;
}
pData = (CSharedMem *)MapViewOfFile(
*hSharedMemory,FILE_MAP_ALL_ACCESS,0,0,0);
if(pData == NULL)
{
return NULL;
}
dwSize = pData->m_dwSize;
return pData;
#else
return(NULL); // In Win16, this is really meaningless...
#endif
}
//
// to close shared memory segment
//
void
NSCloseSharedMemory(CSharedMem *pData, HANDLE hSharedMemory)
{
#ifdef WIN32
if(pData != 0)
{
UnmapViewOfFile(pData);
pData = 0;
}
if(hSharedMemory != 0)
{
CloseHandle(hSharedMemory);
hSharedMemory = 0;
}
#else
if (pData != NULL)
{
GlobalFreePtr(pData);
pData = NULL;
}
#endif // WIN32
}