Userspace persistence libraries

Hi,

I've been going thru several userspace persistence libraries and couldn't 
find one that could support threads, or at least kernel threads. The only 
one I could find which doesn't specify if user-level threads could work is 
cpkt (or cktp), which is widely available. On the kernel-space side, there 
are some approaches based on a single kernel-module which does the job, and 
they seem to be more complete and stable solutions for what we want. (Some 
even recover open files and sockets).
Jacques Mony