-/* 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. */
#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 *
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)
{
- auto insert_done = host_rates_.insert(std::make_pair(host->get_name(), rate_level));
- 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();
+ host_rates_[host->get_name()] = rate_level;
}
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;
}
return s4u::Link::SharingPolicy::WIFI;
}
-int WifiLinkImpl::get_host_count() const
+size_t WifiLinkImpl::get_host_count() const
+{
+ return host_rates_.size();
+}
+
+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()
{
- return static_cast<int>(host_rates_.size());
+ xbt_assert(nb_active_flux_ >= 0, "Negative nb_active_flux should not exist");
+ nb_active_flux_++;
}
-void WifiLinkImpl::refresh_decay_bandwidths()
+void WifiLinkImpl::dec_active_flux()
{
- // 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});
+ 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
