MS VirtualFree(), VirtualAlloc()

[BLS]

Hi, for reasons I don't completely understand I would like to implement 
a BIP Buffer in D2.  ;) well async IO is the use case .. I think.

How can I allocate/free buffer-space from virtual memory ?
What I am looking for is a way to do platform independent allocating of 
memory from the virtual address space.  Like - VirtualAlloc/Free() in MS 
Win.

Thanks in advance,
Bjoern