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#include "future.h"
#include <library/cpp/testing/unittest/registar.h>
#include <util/generic/noncopyable.h>
#include <util/generic/xrange.h>
#include <util/thread/pool.h>
#include <atomic>
#include <exception>
using NThreading::NewPromise;
using NThreading::TFuture;
using NThreading::TPromise;
using NThreading::TWaitPolicy;
namespace {
// Wait* implementation without optimizations, to test TWaitGroup better
template <class WaitPolicy, class TContainer>
TFuture<void> WaitNoOpt(const TContainer& futures) {
NThreading::TWaitGroup<WaitPolicy> wg;
for (const auto& fut : futures) {
wg.Add(fut);
}
return std::move(wg).Finish();
}
class TRelaxedBarrier {
public:
explicit TRelaxedBarrier(i64 size)
: Waiting_{size} {
}
void Arrive() {
// barrier is not for synchronization, just to ensure good timings, so
// std::memory_order_relaxed is enough
Waiting_.fetch_add(-1, std::memory_order_relaxed);
while (Waiting_.load(std::memory_order_relaxed)) {
}
Y_ASSERT(Waiting_.load(std::memory_order_relaxed) >= 0);
}
private:
std::atomic<i64> Waiting_;
};
THolder<TThreadPool> MakePool() {
auto pool = MakeHolder<TThreadPool>(TThreadPool::TParams{}.SetBlocking(false).SetCatching(false));
pool->Start(8);
return pool;
}
template <class T>
TVector<TFuture<T>> ToFutures(const TVector<TPromise<T>>& promises) {
TVector<TFuture<void>> futures;
for (auto&& p : promises) {
futures.emplace_back(p);
}
return futures;
}
struct TStateSnapshot {
i64 Started = -1;
i64 StartedException = -1;
const TVector<TFuture<void>>* Futures = nullptr;
};
// note: std::memory_order_relaxed should be enough everywhere, because TFuture::SetValue must provide the
// needed synchronization
template <class TFactory>
void RunWaitTest(TFactory global) {
auto pool = MakePool();
const auto exception = std::make_exception_ptr(42);
for (auto numPromises : xrange(1, 5)) {
for (auto loopIter : xrange(1024 * 64)) {
const auto numParticipants = numPromises + 1;
TRelaxedBarrier barrier{numParticipants};
std::atomic<i64> started = 0;
std::atomic<i64> startedException = 0;
std::atomic<i64> completed = 0;
TVector<TPromise<void>> promises;
for (auto i : xrange(numPromises)) {
Y_UNUSED(i);
promises.push_back(NewPromise());
}
const auto futures = ToFutures(promises);
auto snapshotter = [&] {
return TStateSnapshot{
.Started = started.load(std::memory_order_relaxed),
.StartedException = startedException.load(std::memory_order_relaxed),
.Futures = &futures,
};
};
for (auto i : xrange(numPromises)) {
pool->SafeAddFunc([&, i] {
barrier.Arrive();
// subscribers must observe effects of this operation
// after .Set*
started.fetch_add(1, std::memory_order_relaxed);
if ((loopIter % 4 == 0) && i == 0) {
startedException.fetch_add(1, std::memory_order_relaxed);
promises[i].SetException(exception);
} else {
promises[i].SetValue();
}
completed.fetch_add(1, std::memory_order_release);
});
}
pool->SafeAddFunc([&] {
auto local = global(snapshotter);
barrier.Arrive();
local();
completed.fetch_add(1, std::memory_order_release);
});
while (completed.load() != numParticipants) {
}
}
}
}
}
Y_UNIT_TEST_SUITE(TFutureMultiThreadedTest) {
Y_UNIT_TEST(WaitAll) {
RunWaitTest(
[](auto snapshotter) {
return [=]() {
auto* futures = snapshotter().Futures;
auto all = WaitNoOpt<TWaitPolicy::TAll>(*futures);
// tests safety part
all.Subscribe([=] (auto&& all) {
TStateSnapshot snap = snapshotter();
// value safety: all is set => every future is set
UNIT_ASSERT(all.HasValue() <= ((snap.Started == (i64)snap.Futures->size()) && !snap.StartedException));
// safety for hasException: all is set => every future is set and some has exception
UNIT_ASSERT(all.HasException() <= ((snap.Started == (i64)snap.Futures->size()) && snap.StartedException > 0));
});
// test liveness
all.Wait();
};
});
}
Y_UNIT_TEST(WaitAny) {
RunWaitTest(
[](auto snapshotter) {
return [=]() {
auto* futures = snapshotter().Futures;
auto any = WaitNoOpt<TWaitPolicy::TAny>(*futures);
// safety: any is ready => some f is ready
any.Subscribe([=](auto&&) {
UNIT_ASSERT(snapshotter().Started > 0);
});
// do we need better multithreaded liveness tests?
any.Wait();
};
});
}
Y_UNIT_TEST(WaitExceptionOrAll) {
RunWaitTest(
[](auto snapshotter) {
return [=]() {
NThreading::WaitExceptionOrAll(*snapshotter().Futures)
.Subscribe([=](auto&&) {
auto* futures = snapshotter().Futures;
auto exceptionOrAll = WaitNoOpt<TWaitPolicy::TExceptionOrAll>(*futures);
exceptionOrAll.Subscribe([snapshotter](auto&& exceptionOrAll) {
TStateSnapshot snap = snapshotter();
// safety for hasException: exceptionOrAll has exception => some has exception
UNIT_ASSERT(exceptionOrAll.HasException() ? snap.StartedException > 0 : true);
// value safety: exceptionOrAll has value => all have value
UNIT_ASSERT(exceptionOrAll.HasValue() == ((snap.Started == (i64)snap.Futures->size()) && !snap.StartedException));
});
// do we need better multithreaded liveness tests?
exceptionOrAll.Wait();
});
};
});
}
}
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