In Windows using VisualStudio 10 I've created a mapped_file as

char * OpenRW(std::string filePath )

{

<<fragment >>

mfp = new boost::iostreams::mapped_file_params(filePath);

mfp->mode = boost::iostreams::mapped_file::readwrite;

mfp->new_file_size = size;

mfp->offset = 0;

mf = new boost::iostreams::mapped_file(*mfp);

return mf->data();

}

I later close the file

void Close()

{

<<fragment>>

mf->close();

delete mfp;

delete mf;

}

And then want to reopen it

{

char* fileName = filePath.c_str();

int test = _open(fileName,_O_BINARY|_O_RDWR);

}

but test is returned -1 -- note that I am able to open the file _O_RDONLY. If I close the application and restart it, then I can read the file _O_RDWR (i.e. test is returned with a valid handle)

Is this a bug or am I doing something wrong?

Thanks Mark