Method close_write

tools/server/server-models.cpp:1068–1071

    std::atomic<bool> writer_closed{false};
    std::atomic<bool> reader_closed{false};
    void close_write() {
        writer_closed.store(true, std::memory_order_relaxed);
        cv.notify_all();
    }
    void close_read() {
        reader_closed.store(true, std::memory_order_relaxed);
        cv.notify_all();