Creating shared memory on Windows always fails

Development Programming & Scripting
4

Finally… a breakthrough of sorts! Here is what I did…
I changed from the default 64 bit debug game build to a 32 bit windows build. This then exposed the normal project properties I was used to seeing, rather that the very abbreviated version. I turned off all optiizations with /Od. It seems that once you have altered the default settings of project settings, you can go back to a 64 bit build, and you still can see all options.

Then I added the following includes:

#include
#include
#include
#include

to the beginning of my “myprojectPawn.cpp” c++ file

then in the initialization code for myprojectPawn object, I added:

#define BUF_SIZE 256
//TCHAR szName[] = TEXT(“Global\MyFileMappingObject”);
TCHAR szMsg[] = TEXT(“Message from first process.”);
HANDLE hMapFile;
LPCTSTR pBuf;

hMapFile = CreateFileMapping(
	INVALID_HANDLE_VALUE,    // use paging file
	NULL,                    // default security
	PAGE_READWRITE,          // read/write access
	0,                       // maximum object size (high-order DWORD)
	BUF_SIZE,                // maximum object size (low-order DWORD)
	L"mappedfilename");                 // name of mapping object

if (hMapFile == NULL)
{
	_tprintf(TEXT("Could not create file mapping object (%d).\n"),
		GetLastError());
	return;
}
pBuf = (LPTSTR)MapViewOfFile(hMapFile,   // handle to map object
	FILE_MAP_ALL_ACCESS, // read/write permission
	0,
	0,
	BUF_SIZE);

if (pBuf == NULL)
{
	_tprintf(TEXT("Could not map view of file (%d).\n"),
		GetLastError());

	CloseHandle(hMapFile);

	return;
}


CopyMemory((PVOID)pBuf, szMsg, (_tcslen(szMsg) * sizeof(TCHAR)));
_getch();

For the first time I’m now getting a valid pointer to the hMapFile.

I can’s say that shared memory is working yet, as I need to keep working, but finally getting a valid pointer back is a big step forward.

Hope this helps…