void subscribeNext() {
Observable<? extends T> t;
synchronized (guard) {
t = queue.peek();
if (t == null || active >= maxConcurrency) {
return;
}
active++;
queue.poll();
}
MergeItemSubscriber itemSub = new MergeItemSubscriber(SOURCE_INDEX.getAndIncrement(this));
subscribers.add(itemSub);
csub.add(itemSub);
WIP.incrementAndGet(this);
t.unsafeSubscribe(itemSub);
request(1);
}
int incRefCnt() {
return refcntUpdater.incrementAndGet(this);
}