87 lines
1.8 KiB
C++
87 lines
1.8 KiB
C++
/*
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* \brief CPU burner
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* \author Norman Feske
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* \date 2015-06-30
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*/
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/*
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* Copyright (C) 2015-2017 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU Affero General Public License version 3.
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*/
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/* Genode includes */
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#include <base/component.h>
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#include <base/attached_rom_dataspace.h>
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#include <timer_session/connection.h>
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using namespace Genode;
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struct Cpu_burner
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{
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Genode::Env &_env;
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Timer::Connection _timer { _env };
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unsigned long _percent = 100;
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Genode::Attached_rom_dataspace _config { _env, "config" };
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void _handle_config()
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{
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_config.update();
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_percent = _config.xml().attribute_value("percent", 100L);
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}
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Genode::Signal_handler<Cpu_burner> _config_handler {
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_env.ep(), *this, &Cpu_burner::_handle_config };
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unsigned _burn_per_iteration = 10;
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void _handle_period()
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{
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uint64_t const start_ms = _timer.elapsed_ms();
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unsigned iterations = 0;
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for (;; iterations++) {
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uint64_t const curr_ms = _timer.elapsed_ms();
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uint64_t passed_ms = curr_ms - start_ms;
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if (passed_ms >= 10*_percent)
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break;
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/* burn some time */
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for (unsigned volatile i = 0; i < _burn_per_iteration; i++)
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for (unsigned volatile j = 0; j < 1000*1000; j++)
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(void) (i*j);
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}
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/* adjust busy loop duration */
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if (iterations > 10)
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_burn_per_iteration *= 2;
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if (iterations < 5)
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_burn_per_iteration /= 2;
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}
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Genode::Signal_handler<Cpu_burner> _period_handler {
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_env.ep(), *this, &Cpu_burner::_handle_period };
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Cpu_burner(Genode::Env &env) : _env(env)
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{
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_config.sigh(_config_handler);
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_handle_config();
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_timer.sigh(_period_handler);
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_timer.trigger_periodic(1000*1000);
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}
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};
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void Component::construct(Genode::Env &env)
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{
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static Cpu_burner cpu_burner(env);
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}
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