Function idler

thread/thread.cpp:2005–2034

        return false;
    }
    static void* idler(void*) {
        RunQ rq;
        auto last_idle = now;
        auto vcpu = rq.current->get_vcpu();
        while (vcpu->state != states::DONE) {
            while (unlikely(resume_threads_inlined(vcpu, rq) > 0) ||
                   likely(!AtomicRunQ(rq).single())   ||
                   likely(try_work_stealing(vcpu))) {
                thread_yield();
                if (vcpu->state == states::DONE)
                    break;
                if (unlikely(sat_sub(now, last_idle) >= 1000UL)) {
                    vcpu->master_event_engine->wait_and_fire_events(0);
                    last_idle = now;
                }
            }
            if (vcpu->state == states::DONE)
                break;
            // only idle stub aliving
            // other threads must be sleeping
            // fall in actual sleep
            auto usec = 10 * 1024 * 1024; // max
            auto& sleepq = vcpu->sleepq;
            if (!sleepq.empty()) usec = min(usec,
                sat_sub(sleepq.front()->ts_wakeup, now));
            vcpu->master_event_engine->wait_and_fire_events(usec);
            last_idle = now;
        }
        return nullptr;
    }
    /**
     * Waiting for all current vcpu photon threads finish
     * @return 0 for all done, -1 for failure