The function is over 10 or 20% on some of Moritz's profiles, depending
on how you could.
Since it's checking for a multi-hour timeout, this is safe to do.
Fixes bug 4518.
Completely disable stats if we aren't running as a relay. We won't
collect any anyway, so setting up the infrastructure for them and
logging about them is wrong. This also removes a confusing log
message that clients without a geoip db would have seen.
Fixes bug 4353.
When running with IOCP, we are in theory able to use userspace-
allocated buffers to avoid filling up the stingy amount of kernel
space allocated for sockets buffers.
The bufferevent_async implementation in Libevent provides this
ability, in theory. (There are likely to be remaining bugs). This
patch adds a new option that, when using IOCP bufferevents, sets
each socket's send and receive buffers to 0, so that we should use
this ability.
When all the bugs are worked out here, if we are right about bug 98,
this might solve or mitigate bug 98.
This option is experimental and will likely require lots of testing
and debugging.
This is a fancier bug4457 workaround for 0.2.3. In 0.2.2, we could
just tell Libevent "Don't enable locking!" so it wouldn't try to make
the event_base notifiable. But for IOCP, we need a notifiable base.
(Eventually, we'll want a notifiable base for other stuff, like
multithreaded crypto.) So the solution is to try a full-featured
initialization, and then retry with all the options turned off if that
fails.
Conflicts:
src/common/compat_libevent.c
Resolving conflict by not taking 7363eae13c ("Use the
EVENT_BASE_FLAG_NOLOCK flag to prevent socketpair() invocation"): in
Tor 0.2.3.x, we _do_ sometimes use notifiable event bases.
In Tor 0.2.2, we never need the event base to be notifiable, since we
don't call it from other threads. This is a workaround for bug 4457,
which is not actually a Tor bug IMO.
This thing was pretty pointless on versions of OpenSSL 0.9.8 and later,
and almost totally pointless on OpenSSL 1.0.0.
Also, favor EVP by default, since it lets us get hardware acceleration
where present. (See issue 4442)
