TLS, threads, and workers

[Joel N. Weber II]

> But you can't pass sockets back and forth across processes; hence
> threads seem smart.

Is that really true?

Joel Holveck came up with working code at some point to allow you to
edit a file in emacs as a different user.  It worked by running a suid
process that opened the file, and then passing the file descriptor
back (I think over a unix domain socket) to the unprivileged process.
I believe this works on both *bsd and Linux.

(On the other hand, I suspect that passing the openssl state around,
etc, makes this not something you actually want to do anyway.)