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Scheduler: torture test the thread access logic

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Ensure the GroomingToken mechanism indeed creates an
exclusive section protected against concurrent corruption:

Use a without / with-protection test and verify
the results are exact vs. grossly broken
This commit is contained in:
Fischlurch 2023-10-17 21:35:37 +02:00
parent 1223772f14
commit fa391d1267
2 changed files with 82 additions and 6 deletions
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56
tests/vault/gear/scheduler-commutator-test.cpp
View file

@ -28,14 +28,18 @@
#include "lib/test/run.hpp"
#include "activity-detector.hpp"
#include "vault/gear/scheduler-commutator.hpp"
#include "lib/test/microbenchmark.hpp"
#include "lib/time/timevalue.hpp"
#include "lib/format-cout.hpp"
//#include "lib/util.hpp"
#include "lib/test/diagnostic-output.hpp"///////////////////////////TODO TOD-Oh
//#include <utility>
#include <thread>
#include <chrono>
using test::Test;
using lib::test::threadBenchmark;
//using std::move;
//using util::isSameObject;
@ -47,6 +51,14 @@ namespace test {
// using lib::time::FrameRate;
// using lib::time::Offset;
using lib::time::Time;
using std::this_thread::yield;
using std::this_thread::sleep_for;
using std::chrono_literals::operator ""us;
namespace {// Test parameters
const size_t NUM_THREADS = 20;
const size_t REPETITIONS = 100;
}
@ -65,6 +77,7 @@ namespace test {
{
demonstrateSimpleUsage();
verify_GroomingToken();
torture_GroomingToken();
verify_DispatchDecision();
verify_findWork();
verify_postDispatch();
@ -95,8 +108,8 @@ namespace test {
/** @test TODO verify logic to control concurrent execution
* @todo WIP 10/23 🔁 define ⟶ ✔ implement
/** @test verify logic to control concurrent execution
* @todo WIP 10/23 ✔ define ⟶ ✔ implement
*/
void
verify_GroomingToken()
@ -115,6 +128,45 @@ namespace test {
/** @test ensure the GroomingToken mechanism indeed creates an
* exclusive section protected against concurrent corruption.
* @todo WIP 10/23 ✔ define ⟶ ✔ implement
*/
void
torture_GroomingToken()
{
SchedulerCommutator sched;
size_t checkSum{0};
auto pause_and_sum = [&](size_t i) -> size_t
{
auto oldSum = checkSum;
sleep_for (500us);
checkSum = oldSum + i;
return 1;
};
auto protected_sum = [&](size_t i) -> size_t
{
while (not sched.acquireGoomingToken())
yield();
pause_and_sum(i);
sched.dropGroomingToken();
return 1;
};
threadBenchmark<NUM_THREADS> (pause_and_sum, REPETITIONS);
size_t brokenSum = checkSum;
checkSum = 0;
threadBenchmark<NUM_THREADS> (protected_sum, REPETITIONS);
CHECK (brokenSum < checkSum);
CHECK (checkSum = NUM_THREADS * REPETITIONS*(REPETITIONS-1)/2);
}
/** @test TODO verify the decision logic where and when
* to perform the dispatch of an Scheduler Activity chain.
* @todo WIP 10/23 🔁 define ⟶ implement

32
wiki/thinkPad.ichthyo.mm
View file

@ -86130,13 +86130,37 @@ Date:&#160;&#160;&#160;Thu Apr 20 18:53:17 2023 +0200<br/>
<node BACKGROUND_COLOR="#eef0c5" COLOR="#990000" CREATED="1697560628310" ID="ID_670606112" MODIFIED="1697562328081" TEXT="demonstrateSimpleUsage">
<icon BUILTIN="pencil"/>
</node>
<node BACKGROUND_COLOR="#eef0c5" COLOR="#990000" CREATED="1697560505486" ID="ID_1321080717" LINK="#ID_409935766" MODIFIED="1697567781570" TEXT="verify_GroomingToken">
<icon BUILTIN="pencil"/>
<node COLOR="#338800" CREATED="1697560505486" ID="ID_1321080717" LINK="#ID_409935766" MODIFIED="1697571165841" TEXT="verify_GroomingToken">
<icon BUILTIN="button_ok"/>
<node COLOR="#338800" CREATED="1697567790616" ID="ID_1691764279" MODIFIED="1697567807166" TEXT="API-Reaktion direkt im aktuellen Thread verifizieren">
<icon BUILTIN="button_ok"/>
</node>
<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1697567807797" ID="ID_727144222" MODIFIED="1697567830467" TEXT="Multithread-Exclusion pr&#xfc;fen">
<icon BUILTIN="flag-yellow"/>
<node COLOR="#338800" CREATED="1697567807797" ID="ID_727144222" MODIFIED="1697571095208" TEXT="Multithread-Exclusion pr&#xfc;fen">
<icon BUILTIN="button_ok"/>
<node CREATED="1697570731407" ID="ID_1686773037" MODIFIED="1697570736338" TEXT="mit / ohne Test"/>
<node CREATED="1697570737358" ID="ID_1684442461" MODIFIED="1697571093390" TEXT="microbenchmark verwenden">
<icon BUILTIN="idea"/>
</node>
<node CREATED="1697570844041" ID="ID_744923834" MODIFIED="1697570856555" TEXT="100 Wiederholungen in 20 Threads"/>
<node CREATED="1697570748133" ID="ID_1723527988" MODIFIED="1697571093396" TEXT="Ergebnisse sind sehr deutlich">
<richcontent TYPE="NOTE"><html>
<head>
</head>
<body>
<ul>
<li>
ohne Schutz braucht die Operation &#8709; 600&#181;s (bei 500&#181;s Schlafpause) und die Checksumme ist viel zu klein (~6000 statt wie erwartet 99000)
</li>
<li>
mit Schutz braucht die Operation im Schnitt 10ms und die Summe 0...N-1 stimmt exakt
</li>
</ul>
</body>
</html>
</richcontent>
<icon BUILTIN="list"/>
</node>
</node>
</node>
<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1697560511607" ID="ID_764686457" MODIFIED="1697560620825" TEXT="verify_DispatchDecision">