int issue_operation()

in rpc/out-of-order-execution.cpp [61:106]
45 lines of code
7 McCabe index (conditional complexity)

        int issue_operation(OutOfOrderContext& args) //firing issue
        {
            SCOPED_LOCK(m_mutex_w);
            m_issuing ++;
            DEFER(m_issuing --);
            if (!m_running)
                LOG_ERROR_RETURN(ESHUTDOWN, -1, "engine is been shuting down");
            if (!args.flag_tag_valid)
            {
            again:
                args.tag = ++m_tag; // auto increase if it is not user defined tag
            }
            args.th = CURRENT;
            {
                SCOPED_LOCK(args.phaselock);
                args.phase = OooPhase::BEFORE_ISSUE;
            }
            args.ret = 0;
            {
                SCOPED_LOCK(m_mutex_map);
                auto ret = m_map.insert({args.tag, &args}); //the return value is {iter, bool}
                if (!ret.second) // means insert failed because of key already exists
                {
                    auto tag = args.tag;
                    auto th = (ret.first == m_map.end()) ? nullptr : ret.first->second->th;
                    LOG_ERROR("failed to insert record into unordered hash map",
                            VALUE(tag), VALUE(CURRENT), VALUE(th));
                    if (args.flag_tag_valid) // user set tag, need to tell user it is a failure
                        LOG_ERROR_RETURN(EINVAL, -1, "the tag in argument is NOT valid");
                    goto again;
                }
            }

            int ret2 = args.do_issue(&args);
            if (ret2 < 0) {
                SCOPED_LOCK(m_mutex_map);
                m_map.erase(args.tag);
                m_cond_collected.notify_one();
                LOG_ERROR_RETURN(0, -1, "failed to do_issue()");
            }
            {
                SCOPED_LOCK(args.phaselock);
                args.phase = OooPhase::ISSUED;
            }
            return 0;
        }