This is probably slightly more efficient (as it avoids going through
uniform_int_distribution), but more importantly, won't trigger some of
Apple's new xcode buggy crap.
There's a very rare race condition where a tagged thread doesn't seem to
exist when the proxy tries syncing startup with them, and so the proxy
thread hangs in startup.
This addresses it by avoiding looking at the `proxy_thread` variable
(which probably isn't thread safe) in the worker's startup, and
signalling the you-need-to-shutdown condition via a third option for the
(formerly boolean) `tagged_go`.
MAX_SOCKETS wasn't working properly because ZMQ uses it when the context
is initialized, which happens when the first socket is constructed on
that context.
For OxenMQ, we had several sockets constructed on the context during
OxenMQ construction, which meant the context_t was being initialized
during OxenMQ construction, rather than during start(), and so setting
MAX_SOCKETS would have no effect and you'd always get the default.
This fixes it by making all the member variable zmq::socket_t's
default-constructed, then replacing them with proper zmq::socket_t's
during startup() so that we also defer zmq::context_t initialization to
the right place.
A second issue found during testing (also fixed here) is that the socket
worker threads use to communicate to the proxy could fail if the worker
socket creation would violate the zmq max sockets limit, which wound up
throwing an uncaught exception and aborting. This pre-initializes (but
doesn't connect) all potential worker threads sockets during start() so
that the lazily-initialized worker thread will have one already set up
rather than having to create a new one (which could fail).
bt_*, hex, base32z, base64 all moved to oxen-encoding a while ago; this
finishes the move by removing them from oxenmq and instead making oxenmq
depend on oxen-encoding.
Currently if the proxy thread fails to start (typically because a bind
fails) the exception happens in the proxy thread which is uncatchable by
the caller (and aborts the program).
This makes it nicer by transporting startup exceptions back to the
start() call.
inproc support is special in zmq: in particular it completely bypasses
the auth layer, which causes problems in OxenMQ because we assume that a
message will always have auth information (set during initial connection
handshake).
This adds an "always-on" inproc listener and adds a new `connect_inproc`
method for a caller to establish a connection to it.
It also throws exceptions if you try to `listen_plain` or `listen_curve`
on an inproc address, because that won't work for the reasons detailed
above.
This commit adds support for listening on new ports after startup. This
will make things easier in storage server, in particular, where we want
to delay listening on public ports until we have an established
connection and initial block status update from oxend.
Jason Rhinelander