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BufferProvider: add implementation for the asynchronous hand-over

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...and define a test case, to perform the typical usage sequence
within a lot of threads in parallel.
This commit is contained in:
Fischlurch 2026-05-13 01:47:51 +02:00
parent 76542e873a
commit 0567633bd9
3 changed files with 151 additions and 10 deletions
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7
src/vault/mem/engine-buffer-manager.hpp
View file

@ -160,7 +160,7 @@ namespace mem {
* @warning when the returned Alloc is [non-empty](\ref Alloc::empty),
* the receiver is responsible for returning it after use.
*/
void async_requestAllocation (AllocRequest const&);
void async_requestAllocation (AllocReceiver&, size_t sizRequest);
/**
* Handle all enqueued asynchronous requests
@ -181,9 +181,10 @@ namespace mem {
inline void
EngineBufferManager::async_requestAllocation (AllocRequest const& req)
EngineBufferManager::async_requestAllocation (AllocReceiver& receiver, size_t sizRequest)
{
REQUIRE (sizRequest);
requestQueue_.push ({&receiver, sizRequest});
}

98
tests/vault/mem/engine-buffer-manager-test.cpp
View file

@ -21,17 +21,26 @@
//#include "vault/mem/engine-buffer-metadata.hpp"
#include "vault/mem/engine-buffer-manager.hpp"
#include "vault/mem/engine-buffer-allocator.hpp"
#include "lib/scoped-collection.hpp"
#include "lib/iter-explorer.hpp"
//#include "lib/depend-inject.hpp"
//#include "lib/thread.hpp"
#include "lib/thread.hpp"
//#include "lib/error.hpp"
#include "lib/symbol.hpp"
#include "test/diagnostic-output.hpp"////////////TODO
#include <algorithm>
//#include <thread>
#include <array>
//using std::this_thread::yield;
//using lib::Thread;
using lib::Thread;
using lib::Literal;
using lib::explore;
//using lib::ScopedCollection;
using std::this_thread::yield;
using std::this_thread::sleep_for;
using std::chrono::microseconds;
using std::chrono_literals::operator ""ms;
namespace vault {
namespace mem {
@ -43,6 +52,8 @@ namespace test {
namespace { // Test helper
const size_t ALLOC_REQ = 1024*1024;
const size_t NUM_THREADS = 100;
// template<typename X>
// Buff*
// mark_as_Buffer(X& something)
@ -66,7 +77,7 @@ namespace test {
virtual void
run (Arg)
{
// seedRand();
seedRand();
demonstrate_AllocatorInterface();
verify_syncRequest();
@ -164,10 +175,87 @@ namespace test {
/** @test show that an working allocation request across thread boundaries */
/** @test show that an working allocation request passes thread boundaries */
void
verify_asyncRequest()
{
struct LocalTestPool
: AllocReceiver
{
Alloc
retrieveAlloc()
{
Alloc received{nullptr, 0};
inQueue_.pop (received); // Note: no-op if queue is empty
return received;
}
bool
empty() const
{
return inQueue_.empty();
}
};
EngineBufferManager manager;
using WorkBuff = std::array<uint64_t, ALLOC_REQ / sizeof(uint64_t)>;
std::atomic_int cnt{0};
auto workSeq = [&, gen = makeRandGen()]// local random generator per thread
() mutable
{// sequence of actions within a worker thread
int i=++cnt;
LocalTestPool myPool;
CHECK (myPool.empty());
manager.async_requestAllocation (myPool, ALLOC_REQ);
// meanwhile the worker does some other "work"
uint delay = 100 + gen.i(800);
sleep_for (microseconds(delay));
SHOW_EXPR(delay)
Alloc alloc = myPool.retrieveAlloc();
if (alloc.empty())
// they let us down ...
// insist harder to be serviced thusly
alloc = manager.requestAllocation (ALLOC_REQ);
CHECK (not alloc.empty());
CHECK (ALLOC_REQ <= alloc.siz);
// can use that allocation for some "serious work"...
auto content = new(alloc.mem) WorkBuff;
std::ranges::generate (*content, [&]{ return gen.u64(); });
sleep_for (10ms);
// pass allocation back to the central hub
manager.supply (alloc);
SHOW_EXPR(i)
};
using Threads = lib::ScopedCollection<Thread>;
auto startThread = [&](auto& storage){ storage.template create<Thread> (workSeq); };
// Start a collection of workers....
Threads threads{NUM_THREADS, startThread};
// wait for all threads to finish...
while (explore(threads).has_any())
yield();
// all the allocations sent back by the workers
// should sit in the EngineBufferManager's input queue
SHOW_EXPR(watch(manager).numAllocs());
// CHECK (NUM_THREADS == watch(manager).numAllocs());
SHOW_EXPR(watch(manager).bytesLeased());
// CHECK (NUM_THREADS*ALLOC_REQ <= watch(manager).bytesLeased());
// process in-queue and retrieve all allocations..
manager.processPendingRequests();
SHOW_EXPR(watch(manager).numAllocs());
SHOW_EXPR(watch(manager).bytesLeased());
// CHECK (0 == watch(manager).bytesLeased());
}

56
wiki/thinkPad.ichthyo.mm
View file

@ -146914,8 +146914,60 @@ StM_bind(Builder&lt;R1&gt; b1, Extension&lt;R1,R2&gt; extension)
<node CREATED="1778635075937" ID="ID_1005055901" MODIFIED="1778635080660" TEXT="alles wieder freigeben"/>
<node CREATED="1778635083791" ID="ID_227876159" MODIFIED="1778635088455" TEXT="Diagnostik pr&#xfc;fen"/>
</node>
<node BACKGROUND_COLOR="#d2beaf" COLOR="#5c4d6e" CREATED="1778599975152" ID="ID_1790536650" MODIFIED="1778599980968" TEXT="verify_asyncRequest">
<icon BUILTIN="hourglass"/>
<node BACKGROUND_COLOR="#eef0c5" COLOR="#990000" CREATED="1778599975152" ID="ID_1790536650" MODIFIED="1778641424697" TEXT="verify_asyncRequest">
<icon BUILTIN="pencil"/>
<node CREATED="1778641426736" ID="ID_460139955" MODIFIED="1778641441187" TEXT="sollte hier gleich etwas &#xbb;massives&#xab; machen"/>
<node CREATED="1778641442270" ID="ID_1826595532" MODIFIED="1778641456169" TEXT="f&#xfc;hre eine typische usage-sequence in jedem Thread aus">
<node CREATED="1778641462236" ID="ID_51963277" MODIFIED="1778641469666" TEXT="fordere eine Allokation"/>
<node CREATED="1778641470523" ID="ID_1338437091" MODIFIED="1778641482349" TEXT="&#x2014; delay &#x2014;"/>
<node CREATED="1778641485269" ID="ID_1979457912" MODIFIED="1778641494779" TEXT="hole die Allokation">
<node CREATED="1778641496587" ID="ID_818471680" MODIFIED="1778641501576" TEXT="entweder aus der Queue"/>
<node CREATED="1778641502490" ID="ID_909654376" MODIFIED="1778641512097" TEXT="ansonsten fordere sie synchron an"/>
</node>
<node CREATED="1778641515186" ID="ID_1850061858" MODIFIED="1778641527135" TEXT="schreibe Zufallszahlen in die Allokation"/>
<node CREATED="1778641528055" ID="ID_572369413" MODIFIED="1778641532894" TEXT="&#x2014; delay &#x2014;"/>
<node CREATED="1778641533746" ID="ID_1255059129" MODIFIED="1778641540762" TEXT="schicke die Allokation zur&#xfc;ck"/>
</node>
<node CREATED="1778641582324" ID="ID_723485846" MODIFIED="1778641604860" TEXT="danach sollten....">
<node CREATED="1778641588959" ID="ID_857089658" MODIFIED="1778641600492" TEXT="NUM_THREADS Allokationen erfolgt sein"/>
<node CREATED="1778641607696" ID="ID_514432880" MODIFIED="1778641618195" TEXT="alle diese Allokationen wieder in der Queue sitzen"/>
<node BACKGROUND_COLOR="#fafe99" COLOR="#fa002a" CREATED="1778642703060" ID="ID_378615107" MODIFIED="1778642712701" TEXT="funktioniert nicht...">
<icon BUILTIN="broken-line"/>
<node CREATED="1778642715157" ID="ID_723545359" MODIFIED="1778642718343" TEXT="Beobachtungen">
<node CREATED="1778642721100" ID="ID_454509509" MODIFIED="1778642737405" TEXT="einige Threads sind anscheinend schon fertig bevor andere &#xfc;berhaupt erst anfangen"/>
<node CREATED="1778642739266" ID="ID_1618120303" MODIFIED="1778642753195" TEXT="damit werden nat&#xfc;rlich einige Allokationen bereits wegger&#xe4;umt"/>
<node BACKGROUND_COLOR="#f0d5c5" COLOR="#990033" CREATED="1778642777488" ID="ID_735364209" MODIFIED="1778642799183" TEXT="unklar: warum sind nach processPending() noch Allocs offen?">
<icon BUILTIN="help"/>
</node>
</node>
<node CREATED="1778642807208" ID="ID_1933157461" MODIFIED="1778642812460" TEXT="genauere Analyse">
<node BACKGROUND_COLOR="#f8f1cb" COLOR="#a50125" CREATED="1778642813695" ID="ID_241071013" MODIFIED="1778643259773" TEXT="Problem-1: brauche wirklich unabh&#xe4;ngige Random-Generatoren">
<richcontent TYPE="NOTE"><html>
<head>
</head>
<body>
<p>
hatte diese Technik vom incidence-count-test kopiert; der Code dort ist aber <i>nicht ganz korrekt &#8212;</i>&#160;was dort aber nicht auff&#228;llt, da das thread-Microbenchmark seine test-Funktion (das &#187;subjekt&#171;) nochmal kopiert, n&#228;mlich in die closure des jeweiligen Thread. Diese Kopie bewirkt dann einfach, da&#223; der Generator nochmal kopiert wird ... bin mir aber trotzdem nicht sicher, so wirklich verschiedene Zufallszahlen gezogen werden.
</p>
<p>
</p>
<p>
Jedenfalls in dem Setup, das ich jetzt hier f&#252;r diesen neuen Test gebaut habe, verwenden alle Threads dasselbe Lamba f&#252;r die Thread-Funktion <i>gemeinsam</i>. Das bedeutet, das makeRandomGen() wird tats&#228;chlich nur einmal aufgerufen, und daher haben wir nur einen einzigen Seed (selbst wenn die Lambdas dann im Thread-Wrapper nochmal kopiert werden)
</p>
</body>
</html>
</richcontent>
<icon BUILTIN="messagebox_warning"/>
<node CREATED="1778643262156" ID="ID_46315611" MODIFIED="1778643274742" TEXT="sehe in allen Threads exakt den gleichen Delay"/>
<node CREATED="1778643275676" ID="ID_284051539" MODIFIED="1778643284600" TEXT="daher wachen die auch alle gemeinsam auf"/>
<node CREATED="1778643339650" ID="ID_1840909466" MODIFIED="1778643355371" TEXT="und dann sind die ersten schon fertig bevor die sp&#xe4;teren &#xfc;berhaupt zum Zug kommen"/>
<node CREATED="1778643357162" ID="ID_512680760" MODIFIED="1778643379727" TEXT="kann aber auch daran liegen, da&#xdf; wir einfach nicht so viele Threads gleichzeitig laufen lassen k&#xf6;nnen"/>
</node>
</node>
</node>
</node>
</node>
</node>
<node BACKGROUND_COLOR="#f0d5c5" COLOR="#990033" CREATED="1777330585249" ID="ID_1415692101" MODIFIED="1777330598348" TEXT="Ergebnis / Einsichten">