Re: [boost] [Review] Shmem Library

From: Andrew J Bromage (ajb_at_[hidden])
Date: 2006-02-07 01:17:39

G'day everyone.

Just in case I don't get a chance to do a formal review before the 16th,
I have one brief comment.

The mmaped_file class merges "a file which has some of its space mapped"
with "a mapped portion of a file".  While I realise that this is a shared
memory library, not a general memory mapped file library, it might be
useful to separate the two.

The problem is that under the current design, mapping two separate parts
of one file (a common task when trying to be clever with page-structured
files) requires two file descriptors and two filename lookups.  The other
option is mapping a region which includes both parts, which wastes address
space (occasionally to the point of it being impossible; consider mapping a
4Gb file on a 32-bit architecture).

Cheers,
Andrew Bromage