Object doGet(Ref ref) {
if (!info.running()) throw retryex;
if (vals.containsKey(ref)) return vals.get(ref);
try {
ref.lock.readLock().lock();
if (ref.tvals == null) throw new IllegalStateException(ref.toString() + " is unbound.");
Ref.TVal ver = ref.tvals;
do {
if (ver.point <= readPoint) return ver.val;
} while ((ver = ver.prior) != ref.tvals);
} finally {
ref.lock.readLock().unlock();
}
// no version of val precedes the read point
ref.faults.incrementAndGet();
throw retryex;
}
