X-Git-Url: http://bilbo.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/8c4d4c169bacafe232f5af91236be37fcf45de35..f626888caadf3f7020eb820d9146772c1c349144:/src/surf/network_wifi.cpp

diff --git a/src/surf/network_wifi.cpp b/src/surf/network_wifi.cpp
index f7b761fbcc..29d1c5f330 100644
--- a/src/surf/network_wifi.cpp
+++ b/src/surf/network_wifi.cpp
@@ -1,4 +1,4 @@
-/* Copyright (c) 2019. The SimGrid Team. All rights reserved.          */
+/* Copyright (c) 2019-2020. The SimGrid Team. All rights reserved.          */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
@@ -27,14 +27,17 @@ NetworkWifiLink::NetworkWifiLink(NetworkCm02Model* model, const std::string& nam
   simgrid::s4u::Link::on_creation(*get_iface());
 }
 
-void NetworkWifiLink::set_host_rate(s4u::Host* host, int rate_level)
+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)
     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(sg_host_t host)
+double NetworkWifiLink::get_host_rate(const s4u::Host* host)
 {
   std::map<xbt::string, int>::iterator host_rates_it;
   host_rates_it = host_rates_.find(host->get_name());
@@ -46,7 +49,7 @@ double NetworkWifiLink::get_host_rate(sg_host_t host)
   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());
 
-  Metric rate = bandwidths_[rate_id];
+  Metric rate = use_decay_model_ ? decay_bandwidths_[rate_id] : bandwidths_[rate_id];
   return rate.peak * rate.scale;
 }
 
@@ -55,6 +58,35 @@ s4u::Link::SharingPolicy NetworkWifiLink::get_sharing_policy()
   return s4u::Link::SharingPolicy::WIFI;
 }
 
+void NetworkWifiLink::refresh_decay_bandwidths(){
+  // Compute number of STAtion on the Access Point
+  int nSTA=host_rates_.size();
+    
+  std::vector<Metric> new_bandwidths;
+  for (auto bandwidth : bandwidths_){
+    // Instanciate 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