}
if (state == INVALID) {
nmgr.logEvent("Got Invalid Node: " + this);
Thread.dumpStack();
throw new ConcurrencyException("Node " + this +
" was invalidated by another thread.");
}
if ((lock != null) && (lock != tx) && lock.isAlive() && lock.isActive()) {
// nmgr.logEvent("Concurrency conflict for " + this + ", lock held by " + lock);
throw new ConcurrencyException("Tried to modify " + this +
" from two threads at the same time.");
}
tx.visitDirtyNode(this);
lock = tx;