Method OnRPCBegin

src/brpc/controller.h:774–778

    void SubmitSpan();

    void OnRPCBegin(int64_t begin_time_us) {
        _begin_time_us = begin_time_us;
        // make latency_us() return 0 when RPC is not over
        _end_time_us = begin_time_us;
    }

    void OnRPCEnd(int64_t end_time_us);