void NetworkWifiLink::set_host_rate(const s4u::Host* host, int rate_level)
{
auto insert_done = host_rates_.insert(std::make_pair(host->get_name(), rate_level));
- if (insert_done.second == false)
+ if (not insert_done.second)
insert_done.first->second = rate_level;
+
+ // Each time we add a host, we refresh the decay model
+ refresh_decay_bandwidths();
}
-double NetworkWifiLink::get_host_rate(const s4u::Host* host)
+double NetworkWifiLink::get_host_rate(const s4u::Host* host) const
{
- std::map<xbt::string, int>::iterator host_rates_it;
- host_rates_it = host_rates_.find(host->get_name());
+ auto host_rates_it = host_rates_.find(host->get_name());
if (host_rates_it == host_rates_.end())
return -1;
int rate_id = host_rates_it->second;
- xbt_assert(rate_id >= 0 && rate_id < (int)bandwidths_.size(), "Host '%s' has an invalid rate '%d' on wifi link '%s'",
- host->get_name().c_str(), rate_id, this->get_cname());
+ xbt_assert(rate_id >= 0,
+ "Negative host wifi rate levels are invalid but host '%s' uses %d as a rate level on link '%s'",
+ host->get_cname(), rate_id, this->get_cname());
+ xbt_assert(rate_id < (int)bandwidths_.size(),
+ "Link '%s' only has %zu wifi rate levels, so the provided level %d is invalid for host '%s'.",
+ this->get_cname(), bandwidths_.size(), rate_id, host->get_cname());
- Metric rate = bandwidths_[rate_id];
+ Metric rate = use_decay_model_ ? decay_bandwidths_[rate_id] : bandwidths_[rate_id];
return rate.peak * rate.scale;
}
-s4u::Link::SharingPolicy NetworkWifiLink::get_sharing_policy()
+s4u::Link::SharingPolicy NetworkWifiLink::get_sharing_policy() const
{
return s4u::Link::SharingPolicy::WIFI;
}
+int NetworkWifiLink::get_host_count() const
+{
+ return static_cast<int>(host_rates_.size());
+}
+
+void NetworkWifiLink::refresh_decay_bandwidths(){
+ // Compute number of STAtion on the Access Point
+ int nSTA = get_host_count();
+
+ std::vector<Metric> new_bandwidths;
+ for (auto bandwidth : bandwidths_){
+ // Instantiate decay model relatively to the actual bandwidth
+ double max_bw=bandwidth.peak;
+ double min_bw=bandwidth.peak-(wifi_max_rate_-wifi_min_rate_);
+ double model_rate=bandwidth.peak-(wifi_max_rate_-model_rate_);
+
+ xbt_assert(min_bw > 0, "Your WIFI link is using bandwidth(s) which is too low for the decay model.");
+
+ double N0=max_bw-min_bw;
+ double lambda=(-log(model_rate-min_bw)+log(N0))/model_n_;
+ // Since decay model start at 0 we should use (nSTA-1)
+ double new_peak=N0*exp(-lambda*(nSTA-1))+min_bw;
+ new_bandwidths.push_back({new_peak, 1.0, nullptr});
+ }
+ decay_bandwidths_=new_bandwidths;
+}
+
+bool NetworkWifiLink::toggle_decay_model(){
+ use_decay_model_=!use_decay_model_;
+ return(use_decay_model_);
+}
+
+
} // namespace resource
} // namespace kernel
} // namespace simgrid
