Method pause

smallthinker/common/log.cpp:271–293

    }

    void pause() {
        {
            std::lock_guard<std::mutex> lock(mtx);

            if (!running) {
                return;
            }

            running = false;

            // push an entry to signal the worker thread to stop
            {
                auto & entry = entries[tail];
                entry.is_end = true;

                tail = (tail + 1) % entries.size();
            }

            cv.notify_one();
        }

        thrd.join();
    }

    void set_file(const char * path) {
        pause();