LUMIERA.clone/tests/library/incidence-count-test.cpp
Ichthyostega a20e233ca0 Library: now using controlled seed and replaced rand (closes #1378)
After augmenting our `lib/random.hpp` abstraction framework to add the necessary flexibility,
a common seeding scheme was ''built into the Test-Runner.''
 * all tests relying on some kind of randomness should invoke `seedRand()`
 * this draws a seed from the `entropyGen` — which is also documented in the log
 * individual tests can now be launched with `--seed` to force a dedicated seed
 * moreover, tests should build a coherent structure of linked generators,
   especially when running concurrently. The existing tests were adapted accordingly

All usages of `rand()` in the code base were investigated and replaced
by suitable calls to our abstraction framework; the code base is thus
isolated from the actual implementation, simplifying further adaptation.
2024-11-17 19:45:41 +01:00

272 lines
10 KiB
C++

/*
IncidenceCount(Test) - observe and evaluate concurrent activations
Copyright (C) Lumiera.org
2024, Hermann Vosseler <Ichthyostega@web.de>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
* *****************************************************/
/** @file incidence-count-test.cpp
** unit test \ref IncidenceCount_test
*/
#include "lib/test/run.hpp"
#include "lib/test/microbenchmark.hpp"
#include "lib/incidence-count.hpp"
#include "lib/thread.hpp"
#include "lib/util.hpp"
#include <thread>
using util::isLimited;
using std::this_thread::sleep_for;
using std::chrono_literals::operator ""ms;
using std::chrono_literals::operator ""us;
using std::chrono::microseconds;
namespace lib {
namespace test{
namespace {
inline bool
isNumEq (double d1, double d2)
{
return 0.001 > abs(d1-d2);
};
}
/***************************************************************//**
* @test verify recording and evaluation of concurrent invocations
* of a piece of code instrumented for investigation.
* @see incidence-count.hpp
* @see vault::gear::TestChainLoad::ScheduleCtx
*/
class IncidenceCount_test
: public Test
{
void
run (Arg)
{
demonstrate_usage();
verify_incidentCount();
verify_concurrencyStatistic();
perform_multithreadStressTest();
}
/** @test watch time spent in code bracketed by measurement calls.
*/
void
demonstrate_usage()
{
IncidenceCount watch;
watch.markEnter();
sleep_for (1ms);
watch.markLeave();
//
sleep_for (5ms);
//
watch.markEnter();
sleep_for (1ms);
watch.markLeave();
double time = watch.calcCumulatedTime();
CHECK (time > 1900);
CHECK (time < 2500);
}
/** @test verify proper counting of possibly overlapping incidences. */
void
verify_incidentCount()
{
IncidenceCount watch;
watch.expectThreads(1)
.expectIncidents(20);
watch.markEnter(1);
sleep_for (1ms);
watch.markEnter(3);
sleep_for (2ms);
watch.markEnter(2);
watch.markLeave(3);
sleep_for (1ms);
watch.markLeave(1);
watch.markEnter(3);
sleep_for (3ms);
watch.markEnter(1);
watch.markLeave(2);
sleep_for (1ms);
watch.markLeave(3);
sleep_for (1ms);
watch.markLeave(1);
auto stat = watch.evaluate();
CHECK (isLimited (15500, stat.cumulatedTime, 17800)); // ≈ 16ms
CHECK (isLimited ( 8500, stat.coveredTime, 10000)); // ≈ 9ms
CHECK (10== stat.eventCnt);
CHECK (5 == stat.activationCnt);
CHECK (0 == stat.cntCase(0));
CHECK (2 == stat.cntCase(1));
CHECK (1 == stat.cntCase(2));
CHECK (2 == stat.cntCase(3));
CHECK (0 == stat.cntCase(4));
CHECK (0 == stat.timeCase(0));
CHECK (isLimited ( 5500, stat.timeCase(1), 6800)); // ≈ 6ms
CHECK (isLimited ( 3500, stat.timeCase(2), 4500)); // ≈ 4ms
CHECK (isLimited ( 5500, stat.timeCase(3), 6800)); // ≈ 6ms
CHECK (0 == stat.timeCase(4));
CHECK (5 == stat.cntThread(0));
CHECK (0 == stat.cntThread(1));
CHECK (stat.activeTime == stat.timeThread(0));
CHECK (0 == stat.timeThread(1));
CHECK (isNumEq (stat.activeTime, stat.coveredTime));
CHECK (isNumEq (stat.cumulatedTime , stat.timeCase(1) + stat.timeCase(2) + stat.timeCase(3)));
}
/** @test verify observation of concurrency degree. */
void
verify_concurrencyStatistic()
{
IncidenceCount watch;
watch.expectThreads(2)
.expectIncidents(2);
auto act = [&]{ // two nested activities
watch.markEnter();
sleep_for (600us);
watch.markEnter(2);
sleep_for (200us);
watch.markLeave(2);
watch.markLeave();
};
auto run_parallel = [&]
{
ThreadJoinable t1("test-1", act);
ThreadJoinable t2("test-2", act);
t1.join();
t2.join();
};
double runTime = test::benchmarkTime (run_parallel);
// join ensures visibility of all data changes from within threads,
// which is a prerequisite for performing the data evaluation safely.
auto stat = watch.evaluate();
CHECK (runTime > stat.coveredTime);
CHECK (stat.coveredTime < stat.cumulatedTime);
CHECK (stat.activeTime <= stat.cumulatedTime);
CHECK (8 == stat.eventCnt);
CHECK (4 == stat.activationCnt);
CHECK (2 == stat.cntCase(0));
CHECK (0 == stat.cntCase(1));
CHECK (2 == stat.cntCase(2));
CHECK (0 == stat.cntCase(3));
CHECK (2 == stat.cntThread(0));
CHECK (2 == stat.cntThread(1));
CHECK (0 == stat.cntThread(3));
CHECK (isLimited(1, stat.avgConcurrency, 2));
CHECK (0 == stat.timeAtConc(0));
CHECK (0 < stat.timeAtConc(1));
CHECK (0 < stat.timeAtConc(2));
CHECK (0 == stat.timeAtConc(3));
CHECK (stat.timeAtConc(1) < stat.coveredTime);
CHECK (stat.timeAtConc(2) < stat.coveredTime);
CHECK (isNumEq (stat.avgConcurrency, (1*stat.timeAtConc(1) + 2*stat.timeAtConc(2)) // average concurrency is a weighted mean
/ stat.coveredTime)); // of the times spent at each concurrency level
CHECK (isNumEq (stat.cumulatedTime , stat.timeCase(0) + stat.timeCase(2))); // cumulated time compounds all cases, including overlap
CHECK (isNumEq (stat.activeTime , stat.timeThread(0) + stat.timeThread(1))); // while active time disregards overlapping activities per thread
CHECK (isNumEq (stat.coveredTime , stat.timeAtConc(1) + stat.timeAtConc(2))); // the covered time happens at any non-zero concurrency level
CHECK (stat.timeCase(2) < stat.timeCase(0)); // Note: case-2 is nested into case-0
CHECK (isNumEq (stat.coveredTime , stat.timeCase(0) - stat.timeAtConc(2))); // Thus, case-0 brackets all time, minus the overlapping segment
}
/** @test verify thread-safe operation under pressure. */
void
perform_multithreadStressTest()
{
constexpr size_t CONCURR = 16;
const size_t REPETITIONS = 100;
IncidenceCount watch;
watch.expectThreads(CONCURR)
.expectIncidents(10000);
auto act = [&
,gen = makeRandGen()]// local random generator per thread
() mutable
{ // two nested activities with random delay
uint delay = 100 + gen.i(800);
watch.markEnter();
sleep_for (microseconds(delay));
watch.markEnter(2);
sleep_for (microseconds(delay));
watch.markLeave(2);
watch.markLeave();
};
// Invoke these two nested activations numerous times in several threads
auto [runTime, sum] = test::threadBenchmark<CONCURR> (act, REPETITIONS);
CHECK (sum == CONCURR*REPETITIONS); // each invocation contributes +1
CHECK (isLimited (900, runTime, 1400)); // delay is 500µs on average
// compute statistics over recorded events
auto stat = watch.evaluate();
// on average two times 500µs per invocation
CHECK (isLimited (900*REPETITIONS, stat.coveredTime, 1400*REPETITIONS));
CHECK (stat.activeTime > 900 * REPETITIONS*CONCURR);
CHECK (stat.activationCnt == 2*REPETITIONS*CONCURR);
CHECK (stat.cntCase(0) == REPETITIONS*CONCURR);
CHECK (stat.cntCase(1) == 0);
CHECK (stat.cntCase(2) == REPETITIONS*CONCURR);
CHECK (isLimited(CONCURR/2, stat.avgConcurrency, CONCURR));
// if there are enough cores, ∅ concurrency should even be close to CONCURR
for (uint i=0; i<CONCURR; ++i)
CHECK (isLimited(REPETITIONS*900, stat.timeThread(i), REPETITIONS*1400));
CHECK (0 == stat.timeThread(CONCURR)); // there should not be any idle time recorded
CHECK (0 == stat.timeAtConc(CONCURR+1)); // there should be never more concurrency than number of threads
// most of the time, concurrency should be close to the defined maximum
CHECK (isLimited(REPETITIONS*900, stat.timeAtConc(CONCURR), REPETITIONS*1200));
}
};
LAUNCHER (IncidenceCount_test, "unit common");
}} // namespace lib::test