X-Git-Url: http://bilbo.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/8c4d4c169bacafe232f5af91236be37fcf45de35..19e1048a7009c4144b0f361ad85fb9dff44761ea:/src/surf/network_wifi.cpp

diff --git a/src/surf/network_wifi.cpp b/src/surf/network_wifi.cpp
index f7b761fbcc..c82d321548 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) 2019-2021. 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. */
@@ -7,7 +7,7 @@
 #include "simgrid/s4u/Host.hpp"
 #include "src/surf/surf_interface.hpp"
 
-XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(surf_network);
+XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(res_network);
 
 namespace simgrid {
 namespace kernel {
@@ -17,44 +17,84 @@ namespace resource {
  * Resource *
  ************/
 
-NetworkWifiLink::NetworkWifiLink(NetworkCm02Model* model, const std::string& name, std::vector<double> bandwidths,
-                                 lmm::System* system)
-    : LinkImpl(model, name, system->constraint_new(this, 1))
+NetworkWifiLink::NetworkWifiLink(const std::string& name, std::vector<double> bandwidths, lmm::System* system)
+    : LinkImpl(name)
 {
+  this->set_constraint(system->constraint_new(this, 1));
   for (auto bandwidth : bandwidths)
     bandwidths_.push_back({bandwidth, 1.0, nullptr});
-
-  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)
+  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(sg_host_t 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 const& 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_ = not use_decay_model_;
+  return use_decay_model_;
+}
+
+void NetworkWifiLink::set_latency(double value)
+{
+  xbt_assert(value == 0, "Latency cannot be set for WiFi Links.");
+}
 } // namespace resource
 } // namespace kernel
 } // namespace simgrid