1 /* Copyright (c) 2019-2022. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 #include <simgrid/s4u/Host.hpp>
8 #include "src/kernel/resource/WifiLinkImpl.hpp"
9 #include "src/surf/surf_interface.hpp"
10 #include "src/kernel/activity/CommImpl.hpp"
12 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(res_network);
14 namespace simgrid::kernel::resource {
20 WifiLinkImpl::WifiLinkImpl(const std::string& name, const std::vector<double>& bandwidths, lmm::System* system)
21 : StandardLinkImpl(name)
23 this->set_constraint(system->constraint_new(this, 1));
24 for (auto bandwidth : bandwidths)
25 bandwidths_.push_back({bandwidth, 1.0, nullptr});
26 kernel::activity::CommImpl::on_start.connect(&update_bw_comm_start);
27 s4u::Link::on_communication_state_change_cb(&update_bw_comm_end);
30 void WifiLinkImpl::set_host_rate(const s4u::Host* host, int rate_level)
32 host_rates_[host->get_name()] = rate_level;
35 double WifiLinkImpl::get_host_rate(const s4u::Host* host) const
37 auto host_rates_it = host_rates_.find(host->get_name());
39 if (host_rates_it == host_rates_.end())
42 int rate_id = host_rates_it->second;
43 xbt_assert(rate_id >= 0,
44 "Negative host wifi rate levels are invalid but host '%s' uses %d as a rate level on link '%s'",
45 host->get_cname(), rate_id, this->get_cname());
46 xbt_assert(rate_id < (int)bandwidths_.size(),
47 "Link '%s' only has %zu wifi rate levels, so the provided level %d is invalid for host '%s'.",
48 this->get_cname(), bandwidths_.size(), rate_id, host->get_cname());
50 Metric rate = bandwidths_[rate_id];
51 return rate.peak * rate.scale;
54 s4u::Link::SharingPolicy WifiLinkImpl::get_sharing_policy() const
56 return s4u::Link::SharingPolicy::WIFI;
59 size_t WifiLinkImpl::get_host_count() const
61 return host_rates_.size();
64 double WifiLinkImpl::wifi_link_dynamic_sharing(WifiLinkImpl* link, double capacity, int n)
66 double ratio = link->get_max_ratio(n);
67 XBT_DEBUG("New ratio value concurrency %d: %lf of link capacity on link %s", n, ratio, link->get_name().c_str());
71 void WifiLinkImpl::inc_active_flux()
73 xbt_assert(nb_active_flux_ >= 0, "Negative nb_active_flux should not exist");
77 void WifiLinkImpl::dec_active_flux()
79 xbt_assert(nb_active_flux_ > 0, "Negative nb_active_flux should not exist");
83 void WifiLinkImpl::update_bw_comm_start(const kernel::activity::CommImpl& comm)
85 auto* action = static_cast<kernel::resource::NetworkAction*>(comm.surf_action_);
87 auto const* actionWifi = dynamic_cast<const simgrid::kernel::resource::WifiLinkAction*>(action);
88 if (actionWifi == nullptr)
91 auto* link_src = actionWifi->get_src_link();
92 auto* link_dst = actionWifi->get_dst_link();
93 if (link_src != nullptr) {
94 link_src->inc_active_flux();
96 if (link_dst != nullptr) {
97 link_dst->inc_active_flux();
101 void WifiLinkImpl::update_bw_comm_end(simgrid::kernel::resource::NetworkAction& action, simgrid::kernel::resource::Action::State state)
103 if (action.get_state() != kernel::resource::Action::State::FINISHED)
106 auto const* actionWifi = dynamic_cast<const simgrid::kernel::resource::WifiLinkAction*>(&action);
107 if (actionWifi == nullptr)
110 if (auto* link_src = actionWifi->get_src_link()) {
111 link_src->dec_active_flux();
113 if (auto* link_dst = actionWifi->get_dst_link()) {
114 link_dst->dec_active_flux();
118 double WifiLinkImpl::get_max_ratio(int nb_active_flux) const
120 double new_peak = -1;
121 if (nb_active_flux_ > conc_lim_) {
122 new_peak = (nb_active_flux_-conc_lim_) * co_acc_ + x0_;
123 XBT_DEBUG("Wi-Fi link peak=(%d-%d)*%lf+%lf=%lf", nb_active_flux_, conc_lim_, co_acc_, x0_, new_peak);
126 XBT_DEBUG("Wi-Fi link peak=%lf", x0_);
128 // should be the new maximum bandwidth ratio (comparison between max throughput without concurrency and with it)
129 double propCap = new_peak / x0_;
134 bool WifiLinkImpl::toggle_callback()
136 if (not use_callback_) {
137 XBT_DEBUG("Activate throughput reduction mechanism");
138 use_callback_ = true;
139 this->set_sharing_policy(simgrid::s4u::Link::SharingPolicy::WIFI,
140 std::bind(&wifi_link_dynamic_sharing, this, std::placeholders::_1, std::placeholders::_2));
142 return use_callback_;
145 void WifiLinkImpl::set_latency(double value)
147 xbt_assert(value == 0, "Latency cannot be set for WiFi Links.");
149 } // namespace simgrid::kernel::resource