The "nym epoch" of a stream is defined as the number of times that
NEWNYM had been called before the stream was opened. All streams
are isolated by nym epoch.
This feature should be redundant with existing signewnym stuff, but
it provides a good belt-and-suspenders way for us to avoid ever
letting any circuit type bypass signewnym.
This lets us make a lot of other stuff const, allows the compiler to
generate (slightly) better code, and will make me get slightly fewer
patches from folks who stick mutable stuff into or_options_t.
const: because not every input is an output!
This is a tweak to the bug2917 fix. Basically, if we want to simulate
a signal arriving in the controller, we shouldn't have to pretend that
we're Libevent, or depend on how Tor sets up its Libevent callbacks.
While doing so, get rid of the now unnecessary function
control_signal_act().
Fixes bug 2917, reported by Robert Ransom. Bugfix on commit
9b4aa8d2ab. This patch is loosely based on
a patch by Robert (Changelog entry).
This was originally a patch provided by pipe
(http://www.mail-archive.com/or-talk@freehaven.net/msg13085.html) to
provide a method for controllers to query the total amount of traffic
tor has handled (this is a frequently requested piece of information
by relay operators).
