Method evict

net/pooled_socket.cpp:205–229

        return new PooledTCPSocketStream(stream, this, remote);
    }
    uint64_t evict() {
        // remove empty entry in fdmap
        intrusive_list<StreamListNode> freelist;
        uint64_t near_expire = TTL_us + now;
        for (auto it = fdmap.begin(); it != fdmap.end();) {
            auto& list = it->second;
            uint64_t exp;
            while (!list.empty() && now >=
                   (exp = list.front()->timeout.expiration())) {
                freelist.push_back(list.pop_front());
            }
            if (list.empty()) {
                it = fdmap.erase(it);
            } else {
                near_expire = std::min(near_expire, exp);
                it++;
            }
        }
        for (auto node : freelist) {
            rm_watch(node);
        }
        freelist.delete_all();
        assert(near_expire > now);
        return sat_sub(near_expire, now);
    }

    bool release(const EndPoint& ep, ISocketStream* stream) {
        auto fd = stream->get_underlay_fd();