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/* Copyright (c) 2010-2025. 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. */
/* This example shows how to simulate variability for CPUs, using multiplicative factors
*/
#include "simgrid/s4u/Engine.hpp"
#include <simgrid/s4u.hpp>
namespace sg4 = simgrid::s4u;
XBT_LOG_NEW_DEFAULT_CATEGORY(s4u_test, "Messages specific for this s4u example");
/*************************************************************************************************/
static void runner()
{
double computation_amount = sg4::this_actor::get_host()->get_speed();
XBT_INFO("Executing 1 tasks of %g flops, should take 1 second.", computation_amount);
sg4::this_actor::execute(computation_amount);
XBT_INFO("Executing 1 tasks of %g flops, it would take .001s without factor. It'll take .002s",
computation_amount / 10);
sg4::this_actor::execute(computation_amount / 1000);
XBT_INFO("Finished executing. Goodbye now!");
}
/*************************************************************************************************/
/** @brief Variability for CPU */
static double cpu_variability(const sg4::Host& host, double flops)
{
/* creates variability for tasks smaller than 1% of CPU power.
* unrealistic, for learning purposes */
double factor = (flops < host.get_speed() / 100) ? 0.5 : 1.0;
XBT_INFO("Host %s, task with %lf flops, new factor %lf", host.get_cname(), flops, factor);
return factor;
}
/** @brief Create a simple 1-host platform */
static void load_platform(sg4::Engine& e)
{
auto* zone = e.get_netzone_root();
auto* runner_host = zone->add_host("runner", 1e6);
runner_host->set_cpu_factor_cb(cpu_variability);
zone->seal();
/* create actor runner */
e.add_actor("runner", runner_host, runner);
}
/*************************************************************************************************/
int main(int argc, char* argv[])
{
sg4::Engine e(&argc, argv);
/* create platform */
load_platform(e);
/* runs the simulation */
e.run();
return 0;
}
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