Ichthyostega
c183045dfa
Over time, a collection of microbenchmark helper functions was
extracted from occasional use -- including a variant to perform
parallelised microbenchmarks. While not used beyond sporadic experiments yet,
this framework seems a perfect fit for measuring the SyncBarrier performance.
There is only one catch:
- it uses the old Threadpool + POSIX thread support
- these require the Threadpool service to be started...
- which in turn prohibits using them for libary tests
And last but not least: this setup already requires a barrier.
==> switch the existing microbenchmark setup to c++17 threads preliminarily
(until the thread-wrapper has been reworked).
==> also introduce the new SyncBarrier here immediately
==> use this as a validation test of the setup + SyncBarrier
116 lines
3.5 KiB
C++
116 lines
3.5 KiB
C++
/*
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SyncBarrierPerformance(Test) - investigate performance of yield-waiting synchronisation
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Copyright (C) Lumiera.org
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2023, Hermann Vosseler <Ichthyostega@web.de>
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2 of
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the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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* *****************************************************/
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/** @file sync-barrier-performance-test.cpp
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** Assess the performance characteristics of lib::SyncBarrier
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** Helpers and setup for the \ref SyncBarrierPerformance_test
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*/
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#include "lib/test/run.hpp"
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#include "lib/sync-barrier.hpp"
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//#include "lib/iter-explorer.hpp"
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//#include "lib/util-foreach.hpp"
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#include "lib/test/microbenchmark.hpp"
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#include "lib/test/diagnostic-output.hpp" /////////////////////TODO
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//#include <chrono>
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//#include <thread>
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//#include <atomic>
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#include <array>
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using test::Test;
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//using util::and_all;
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//using lib::explore;
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using std::array;
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//using std::atomic_uint;
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using std::this_thread::sleep_for;
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using namespace std::chrono_literals;
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namespace lib {
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namespace test {
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namespace {// Test setup for a concurrent calculation with checksum....
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const uint NUM_STAGES = 1024;
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/**
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*/
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class FakeBarrier
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{
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public:
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};
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}//(End)Test setup
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/*******************************************************************//**
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* @test investigate performance of N-fold thread synchronisation.
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* - start a _huge number_ of TestThread
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* - all those pick up the partial sum from stage1
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* @remark without coordinated synchronisation, some threads would see
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* an incomplete sum and thus the stage2 checksum would be lower
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* @see lib::SyncBarrier
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* @see steam::control::DispatcherLoop
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*/
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class SyncBarrierPerformance_test : public Test
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{
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template<size_t nThreads>
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double
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performanceTest()
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{
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auto testSubject = [&](size_t i) -> size_t
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{
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sleep_for (1us);
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return 1;
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};
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auto [micros, cnt] = threadBenchmark<nThreads> (testSubject, NUM_STAGES);
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CHECK (cnt == nThreads*NUM_STAGES);
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return micros;
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}
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virtual void
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run (Arg)
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{
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cout<<"\n\n■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■□■"<<endl;
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double time_emptySetup = performanceTest<100>();
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cout<<"\n___Microbenchmark____"
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<<"\nemptySetup : "<<time_emptySetup
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<<"\n_____________________\n"
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<<"\nbarriers..... "<<NUM_STAGES
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<<endl;
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}
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};
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/** Register this test class... */
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LAUNCHER (SyncBarrierPerformance_test, "function common");
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}} // namespace lib::test
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