Function StartIndexingIfNeeded

src/brpc/span.cpp:570–575

}

static int StartIndexingIfNeeded() {
    if (pthread_once(&start_span_indexing_once, StartSpanIndexing) != 0) {
        return -1;
    }
    return started_span_indexing ? 0 : -1;
}

inline int GetSpanDB(butil::intrusive_ptr<SpanDB>* db) {
    BAIDU_SCOPED_LOCK(g_span_db_mutex);