If the JobQueue is used during shutdown then those Jobs may access
Stoppables after they have already stopped. This violates the
preconditions of Stoppables and may lead to undefined behavior.
The solution taken here is to reference count all Jobs in the
JobQueue. At stop time all Jobs already in the JobQueue are
allowed to run to completion, but no further Jobs are allowed
into the JobQueue.
If a Job is rejected from the JobQueue (because we are stopping),
then JobQueue::addJob() returns false, so the caller can make any
necessary adjustments.
A new JobCounter class is introduced. The JobCounter keeps
a reference count of Jobs in flight to the JobQueue. When
NetworkOPs needs to stop, in addition to other work, it calls
JobCounter::join(), which waits until all Jobs in flight
have been destroyed before returning. This ensures that all
NetworkOPs Jobs are completed before NetworkOPs declares
itself stopped().
Also, once a JobCounter is join()ed, it refuses to produce
more counted Jobs for the JobQueue. So, once all old Jobs
in flight are done, then NetworkOPs will add no additional
Jobs to the JobQueue.
Other classes besides NetworkOPs should also be able to use
JobCounter. NetworkOPs is a first test case.
Also unneeded #includes were removed from files touched for
other reasons.
RootStoppable was using two separate flags to identify that it
was stopping. LoadManager was being notified when one flag was
set, but checking the other flag (not yet set) to see if we were
stopping. There is no strong motivation for two flags. The
timing window is closed by removing one flag and moving around
a chunk of code.
All uses of beast::Thread were previously removed from the code
base, so beast::Thread is removed. One piece of beast::Thread
needed to be preserved: the ability to set the current thread's
name. So there's now a beast::CurrentThreadName that allows the
current thread's name to be set and returned.
Thread naming is also cleaned up a bit. ThreadName.h and .cpp
are removed since beast::CurrentThreadName does a better job.
ThreadEntry is also removed, but its terminateHandler() is
preserved in TerminateHandler.cpp. The revised terminateHandler()
uses beast::CurrentThreadName to recover the name of the running
thread.
Finally, the NO_LOG_UNHANDLED_EXCEPTIONS #define is removed since
it was discovered that the MacOS debugger preserves the stack
of the original throw even if the terminateHandler() rethrows.
Validator lists from configured remote sites are fetched at a regular
interval. Fetched lists are expected to be in JSON format and contain the
following fields:
* "manifest": Base64-encoded serialization of a manifest containing the
validator publisher's master and signing public keys.
* "blob": Base64-encoded JSON string containing a "sequence",
"expiration" and "validators" field. "expiration" contains the Ripple
timestamp (seconds since January 1st, 2000 (00:00 UTC)) for when the
list expires. "validators" contains an array of objects with a
"validation_public_key" field.
* "signature": Hex-encoded signature of the blob using the publisher's
signing key.
* "version": 1
* "refreshInterval" (optional)
Instead of specifying a static list of trusted validators in the config
or validators file, the configuration can now include trusted validator
list publisher keys.
The trusted validator list and quorum are now reset each consensus
round using the latest validator lists and the list of recent
validations seen. The minimum validation quorum is now only
configurable via the command line.
* This fixes an uncommon, but annoying, spurious failure running this
test, particularly in release builds. This appears to be an issue with
Windows of the FS where quickly creating and deleting the same
directory repeatedly will eventually fail.
* RIPD-1390
