X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/b8be0a3a0322cb22b312549b0e8af9156b221abf..5ed37babb2fa9097abe82df299c0aa259ed84d5a:/src/kernel/resource/WifiLinkImpl.cpp

diff --git a/src/kernel/resource/WifiLinkImpl.cpp b/src/kernel/resource/WifiLinkImpl.cpp
index afa0c00905..52e5222614 100644
--- a/src/kernel/resource/WifiLinkImpl.cpp
+++ b/src/kernel/resource/WifiLinkImpl.cpp
@@ -1,4 +1,4 @@
-/* Copyright (c) 2019-2022. The SimGrid Team. All rights reserved.          */
+/* Copyright (c) 2019-2023. 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. */
@@ -7,12 +7,11 @@
 
 #include "src/kernel/resource/WifiLinkImpl.hpp"
 #include "src/surf/surf_interface.hpp"
+#include "src/kernel/activity/CommImpl.hpp"
 
 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(res_network);
 
-namespace simgrid {
-namespace kernel {
-namespace resource {
+namespace simgrid::kernel::resource {
 
 /************
  * Resource *
@@ -24,14 +23,13 @@ WifiLinkImpl::WifiLinkImpl(const std::string& name, const std::vector<double>& b
   this->set_constraint(system->constraint_new(this, 1));
   for (auto bandwidth : bandwidths)
     bandwidths_.push_back({bandwidth, 1.0, nullptr});
+  kernel::activity::CommImpl::on_start.connect(&update_bw_comm_start);
+  s4u::Link::on_communication_state_change_cb(&update_bw_comm_end);
 }
 
 void WifiLinkImpl::set_host_rate(const s4u::Host* host, int rate_level)
 {
   host_rates_[host->get_name()] = rate_level;
-
-  // Each time we add a host, we refresh the decay model
-  refresh_decay_bandwidths();
 }
 
 double WifiLinkImpl::get_host_rate(const s4u::Host* host) const
@@ -49,7 +47,7 @@ double WifiLinkImpl::get_host_rate(const s4u::Host* host) const
              "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 = use_decay_model_ ? decay_bandwidths_[rate_id] : bandwidths_[rate_id];
+  Metric rate = bandwidths_[rate_id];
   return rate.peak * rate.scale;
 }
 
@@ -63,37 +61,87 @@ size_t WifiLinkImpl::get_host_count() const
   return host_rates_.size();
 }
 
-void WifiLinkImpl::refresh_decay_bandwidths()
+double WifiLinkImpl::wifi_link_dynamic_sharing(const WifiLinkImpl& link, double /*capacity*/, int /*n*/)
+{
+  double ratio = link.get_max_ratio();
+  XBT_DEBUG("New ratio value concurrency %d: %lf of link capacity on link %s", link.nb_active_flux_, ratio, link.get_name().c_str());
+  return ratio;
+}
+
+void WifiLinkImpl::inc_active_flux()
+{
+  xbt_assert(nb_active_flux_ >= 0, "Negative nb_active_flux should not exist");
+  nb_active_flux_++;
+}
+
+void WifiLinkImpl::dec_active_flux()
 {
-  // Compute number of STAtion on the Access Point
-  size_t 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_);
-
-    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});
+  xbt_assert(nb_active_flux_ > 0, "Negative nb_active_flux should not exist");
+  nb_active_flux_--;
+}
+
+void WifiLinkImpl::update_bw_comm_start(const kernel::activity::CommImpl& comm)
+{
+  auto const* actionWifi = dynamic_cast<const simgrid::kernel::resource::WifiLinkAction*>(comm.surf_action_);
+  if (actionWifi == nullptr)
+    return;
+
+  if (auto* link_src = actionWifi->get_src_link()) {
+    link_src->inc_active_flux();
+  }
+  if (auto* link_dst = actionWifi->get_dst_link()) {
+    link_dst->inc_active_flux();
   }
-  decay_bandwidths_ = new_bandwidths;
 }
 
-bool WifiLinkImpl::toggle_decay_model()
+void WifiLinkImpl::update_bw_comm_end(const simgrid::kernel::resource::NetworkAction& action,
+                                      simgrid::kernel::resource::Action::State /*state*/)
 {
-  use_decay_model_ = not use_decay_model_;
-  return use_decay_model_;
+  if (action.get_state() != kernel::resource::Action::State::FINISHED)
+    return;
+
+  auto const* actionWifi = dynamic_cast<const simgrid::kernel::resource::WifiLinkAction*>(&action);
+  if (actionWifi == nullptr)
+    return;
+
+  if (auto* link_src = actionWifi->get_src_link()) {
+    link_src->dec_active_flux();
+  }
+  if (auto* link_dst = actionWifi->get_dst_link()) {
+    link_dst->dec_active_flux();
+  }
+}
+
+double WifiLinkImpl::get_max_ratio() const
+{
+  double new_peak;
+  if (nb_active_flux_ > conc_lim_) {
+    new_peak = (nb_active_flux_-conc_lim_) * co_acc_ + x0_;
+    XBT_DEBUG("Wi-Fi link peak=(%d-%d)*%lf+%lf=%lf", nb_active_flux_, conc_lim_, co_acc_, x0_, new_peak);
+  } else {
+    new_peak = x0_;
+    XBT_DEBUG("Wi-Fi link peak=%lf", x0_);
+  }
+  // should be the new maximum bandwidth ratio (comparison between max throughput without concurrency and with it)
+  double propCap = new_peak / x0_;
+
+  return propCap;
+}
+
+bool WifiLinkImpl::toggle_callback()
+{
+  if (not use_callback_) {
+      XBT_DEBUG("Activate throughput reduction mechanism");
+    use_callback_ = true;
+    this->set_sharing_policy(
+        simgrid::s4u::Link::SharingPolicy::WIFI,
+        std::bind(&wifi_link_dynamic_sharing, std::cref(*this), std::placeholders::_1, std::placeholders::_2));
+  }
+  return use_callback_;
 }
 
 void WifiLinkImpl::set_latency(double value)
 {
   xbt_assert(value == 0, "Latency cannot be set for WiFi Links.");
 }
-} // namespace resource
-} // namespace kernel
-} // namespace simgrid
+} // namespace simgrid::kernel::resource