+++ /dev/null
-/* Copyright (c) 2017-2021. 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. */
-
-#include <simgrid/s4u.hpp>
-
-/* This example shows how to use simgrid::s4u::Engine::get_filtered_hosts() to retrieve
- * all hosts that match a given criteria. This criteria can be specified either with:
- * - an inlined callback
- * - a boolean function, such as filter_speed_more_than_50Mf() below
- * - a functor (= function object), that can either be stateless such as filter::SingleCore below, or that can save
- * state such as filter::FrequencyChanged below
- *
- * This file provides examples for each of these categories. You should implement your own filters in your code.
- */
-
-XBT_LOG_NEW_DEFAULT_CATEGORY(s4u_engine_filtering, "Messages specific for this s4u example");
-
-namespace filter {
-/* First example of thing that we can use as a filtering criteria: a simple boolean function */
-static bool filter_speed_more_than_50Mf(const simgrid::s4u::Host* host)
-{
- return host->get_speed() > 50E6;
-}
-
-/* Second kind of thing that we can use as a filtering criteria: a functor (=function object).
- * This one is a bit stupid: it's a lot of boilerplate over a dummy boolean function.
- */
-class SingleCore {
-public:
- bool operator()(const simgrid::s4u::Host* host) const { return host->get_core_count() == 1; }
-};
-
-/* This functor is a bit more complex, as it saves the current state when created.
- * Then, it allows one to easily retrieve the hosts which frequency changed since the functor creation.
- */
-class FrequencyChanged {
- std::map<simgrid::s4u::Host*, int> host_list;
-
-public:
- explicit FrequencyChanged(const simgrid::s4u::Engine& e)
- {
- std::vector<simgrid::s4u::Host*> list = e.get_all_hosts();
- for (auto& host : list) {
- host_list.insert({host, host->get_pstate()});
- }
- }
-
- bool operator()(simgrid::s4u::Host* host) { return host->get_pstate() != host_list.at(host); }
-
- double get_old_speed(simgrid::s4u::Host* host) { return host_list.at(host); }
-};
-}
-int main(int argc, char* argv[])
-{
- simgrid::s4u::Engine e(&argc, argv);
- e.load_platform(argv[1]);
-
- /* Use a lambda function to filter hosts: We only want multicore hosts */
- XBT_INFO("Hosts currently registered with this engine: %zu", e.get_host_count());
- std::vector<simgrid::s4u::Host*> list =
- e.get_filtered_hosts([](const simgrid::s4u::Host* host) { return host->get_core_count() > 1; });
-
- for (auto& host : list)
- XBT_INFO("The following hosts have more than one core: %s", host->get_cname());
-
- xbt_assert(list.size() == 1);
-
- /* Use a function object (functor) without memory */
- list = e.get_filtered_hosts(filter::SingleCore());
-
- for (auto& host : list)
- XBT_INFO("The following hosts are SingleCore: %s", host->get_cname());
-
- /* Use a function object that uses memory to filter */
- XBT_INFO("A simple example: Let's retrieve all hosts that changed their frequency");
- filter::FrequencyChanged filter(e);
- e.host_by_name("MyHost2")->set_pstate(2);
- list = e.get_filtered_hosts(filter);
-
- for (auto& host : list)
- XBT_INFO("The following hosts changed their frequency: %s (from %.1ff to %.1ff)", host->get_cname(),
- host->get_pstate_speed(filter.get_old_speed(host)), host->get_speed());
-
- /* You can also just use any regular function (namespaced on need) to filter */
- list = e.get_filtered_hosts(filter::filter_speed_more_than_50Mf);
-
- for (auto& host : list)
- XBT_INFO("The following hosts have a frequency > 50Mf: %s", host->get_cname());
-
- return 0;
-}
