Method DequeueAllSingleConsumer

util/thread/lfstack.h:182–193

    // elements are returned in order of dequeue (top to bottom; see example in unittest)
    template <typename TCollection>
    void DequeueAllSingleConsumer(TCollection* res) {
        for (TNode* head = Head.load(std::memory_order_acquire); head;) {
            if (Head.compare_exchange_weak(head, nullptr)) {
                for (TNode* x = head; x;) {
                    res->push_back(std::move(x->Value));
                    x = x->Next;
                }
                EraseList(head); // with single consumer thread ABA does not happen
                return;
            }
        }
    }
    bool IsEmpty() {
        return Head.load() == nullptr; // without lock, so result is approximate
    }