lokinet/test/util/thread/test_llarp_util_queue.cpp
2021-03-04 15:41:42 -05:00

572 lines
12 KiB
C++

#include <util/thread/queue.hpp>
#include <util/thread/threading.hpp>
#include <util/thread/barrier.hpp>
#include <array>
#include <condition_variable>
#include <functional>
#include <thread>
#include <catch2/catch.hpp>
using namespace llarp;
using namespace llarp::thread;
using namespace std::literals;
using LockGuard = std::unique_lock<std::mutex>;
class Element
{
private:
double data;
bool shouldStop;
public:
Element(double d, bool _stop = false) : data(d), shouldStop(_stop)
{}
double
val() const
{
return data;
}
bool
stop() const
{
return shouldStop;
}
};
bool
operator==(const Element& lhs, const Element& rhs)
{
return lhs.val() == rhs.val();
}
using ObjQueue = Queue<Element>;
class Args
{
public:
std::condition_variable startCond;
std::condition_variable runCond;
std::mutex mutex;
std::condition_variable cv;
ObjQueue queue;
// Use volatile over atomic int in order to verify the thread safety.
// If we used atomics here, we would introduce new potential synchronisation
// points.
volatile size_t iterations;
volatile size_t count;
volatile size_t startSignal;
volatile size_t runSignal;
volatile size_t endSignal;
Args(size_t _iterations, size_t size = 20 * 1000)
: queue(size), iterations(_iterations), count(0), startSignal(0), runSignal(0), endSignal(0)
{}
bool
signal() const
{
return !!runSignal;
}
};
void
popFrontTester(Args& args)
{
{
LockGuard lock(args.mutex);
args.count++;
args.cv.wait(lock, [&] { return args.signal(); });
}
for (;;)
{
Element e = args.queue.popFront();
if (e.stop())
{
break;
}
}
}
void
pushBackTester(Args& args)
{
{
LockGuard lock(args.mutex);
args.count++;
args.cv.wait(lock, [&] { return args.signal(); });
}
for (size_t i = 0; i < args.iterations; ++i)
{
Element e{static_cast<double>(i)};
args.queue.pushBack(e);
}
args.queue.pushBack(Element{0, true});
}
void
abaThread(char* firstValue, char* lastValue, Queue<char*>& queue, util::Barrier& barrier)
{
barrier.Block();
for (char* val = firstValue; val <= lastValue; ++val)
{
queue.pushBack(val);
}
}
struct Exception : public std::exception
{};
struct ExceptionTester
{
static std::atomic<std::thread::id> throwFrom;
void
test()
{
if (throwFrom != std::thread::id() && std::this_thread::get_id() == throwFrom)
{
throw Exception();
}
}
ExceptionTester()
{}
ExceptionTester(const ExceptionTester&)
{
test();
}
ExceptionTester&
operator=(const ExceptionTester&)
{
test();
return *this;
}
};
std::atomic<std::thread::id> ExceptionTester::throwFrom = {std::thread::id()};
void
sleepNWait(std::chrono::microseconds microseconds, util::Barrier& barrier)
{
std::this_thread::sleep_for(microseconds);
barrier.Block();
}
void
exceptionProducer(
Queue<ExceptionTester>& queue, util::Semaphore& semaphore, std::atomic_size_t& caught)
{
static constexpr size_t iterations = 3;
for (size_t i = 0; i < iterations; ++i)
{
try
{
queue.pushBack(ExceptionTester());
}
catch (const Exception&)
{
++caught;
}
semaphore.notify();
}
}
struct MoveTester
{
bool moved;
size_t& moveCounter;
size_t value;
explicit MoveTester(size_t& counter, size_t val) : moved(false), moveCounter(counter), value(val)
{}
explicit MoveTester(const MoveTester& rhs) = delete;
MoveTester&
operator=(const MoveTester& rhs) = delete;
MoveTester(MoveTester&& rhs) : moved(false), moveCounter(rhs.moveCounter), value(rhs.value)
{
rhs.moved = true;
moveCounter++;
}
MoveTester&
operator=(MoveTester&& rhs)
{
value = rhs.value;
rhs.moved = true;
moveCounter = rhs.moveCounter;
moveCounter++;
return *this;
}
};
TEST_CASE("single")
{
ObjQueue queue(1u);
REQUIRE(0u == queue.size());
REQUIRE(1u == queue.capacity());
}
TEST_CASE("breathing")
{
static constexpr size_t DEFAULT_CAP = 10 * 1000;
ObjQueue queue(DEFAULT_CAP);
REQUIRE(0u == queue.size());
REQUIRE(DEFAULT_CAP == queue.capacity());
Element e1(1.0);
Element e2(2.0);
Element e3(3.0);
queue.pushBack(e1);
queue.pushBack(e2);
queue.pushBack(e3);
Element p1 = queue.popFront();
Element p2 = queue.popFront();
Element p3 = queue.popFront();
REQUIRE(e1 == p1);
REQUIRE(e2 == p2);
REQUIRE(e3 == p3);
}
TEST_CASE("Single producer many consumer")
{
static constexpr size_t iterations = 100 * 1000;
static constexpr size_t numThreads = 5;
std::array<std::thread, numThreads> threads;
Args args{iterations};
{
LockGuard lock(args.mutex);
for (size_t i = 0; i < threads.size(); ++i)
{
threads[i] = std::thread(std::bind(&popFrontTester, std::ref(args)));
args.cv.wait(lock, [&] { return args.count != i + 1; });
}
args.runSignal++;
}
for (size_t i = 0; i < iterations; ++i)
{
Element e{static_cast<double>(i)};
args.queue.pushBack(e);
}
for (size_t i = 0; i < numThreads; ++i)
{
Element e{0.0, true};
args.queue.pushBack(e);
}
for (size_t i = 0; i < numThreads; ++i)
{
threads[i].join();
}
REQUIRE(0u == args.queue.size());
}
TEST_CASE("Many producer many consumer")
{
static constexpr size_t iterations = 100 * 1000;
static constexpr size_t numThreads = 5;
std::array<std::thread, numThreads * 2> threads;
Args args{iterations};
{
LockGuard lock(args.mutex);
for (size_t i = 0; i < numThreads; ++i)
{
threads[i] = std::thread(std::bind(&popFrontTester, std::ref(args)));
args.cv.wait(lock, [&] { return args.count != i + 1; });
}
for (size_t i = 0; i < numThreads; ++i)
{
threads[i + numThreads] = std::thread(std::bind(&pushBackTester, std::ref(args)));
args.cv.wait(lock, [&] { return args.count != numThreads + i + 1; });
}
args.runSignal++;
}
for (auto& thread : threads)
{
thread.join();
}
REQUIRE(0u == args.queue.size());
}
TEST_CASE("ABA empty")
{
// Verify we avoid the ABA problem, where multiple threads try to push an
// object to the same "empty" position in the queue.
static constexpr size_t numThreads = 50;
static constexpr size_t numValues = 6;
static constexpr size_t numIterations = 1000;
static constexpr size_t numEntries = numThreads * numValues;
char block[numEntries];
for (size_t i = 0; i < numIterations; ++i)
{
util::Barrier barrier{numThreads + 1};
Queue<char*> queue{numEntries + 1};
std::array<std::thread, numThreads + 1> threads;
char* nextValue[numThreads];
char* lastValue[numThreads];
for (size_t j = 0; j < numThreads; ++j)
{
nextValue[j] = block + (numValues * j);
lastValue[j] = block + (numValues * (j + 1)) - 1;
threads[j] =
std::thread([&, n = nextValue[j], l = lastValue[j]] { abaThread(n, l, queue, barrier); });
}
threads[numThreads] = std::thread([&] {
std::this_thread::sleep_for(100us);
barrier.Block();
});
for (size_t j = 0; j < numEntries; ++j)
{
char* val = queue.popFront();
size_t k = 0;
for (k = 0; k < numThreads; ++k)
{
if (val == nextValue[k])
{
nextValue[k] += (val == lastValue[k] ? 0 : 1);
REQUIRE(nextValue[k] <= lastValue[k]);
break;
}
}
REQUIRE(k < numThreads);
}
for (auto& thread : threads)
{
thread.join();
}
REQUIRE(0u == queue.size());
}
}
TEST_CASE("Generation count")
{
// Verify functionality after running through a full cycle (and invoking the
// generation rollover logic).
// For a queue of size 3, this is currently 508 cycles, implying we need to go
// through at least 3048 objects (3 * 508 * 2) to trigger this logic twice.
static constexpr size_t numThreads = 6;
static constexpr size_t queueSize = 3;
static constexpr size_t numEntries = 3060;
static constexpr size_t numValues = numEntries / numThreads;
char block[numEntries];
util::Barrier barrier{numThreads + 1};
Queue<char*> queue{queueSize};
std::array<std::thread, numThreads + 1> threads;
char* nextValue[numThreads];
char* lastValue[numThreads];
for (size_t j = 0; j < numThreads; ++j)
{
nextValue[j] = block + (numValues * j);
lastValue[j] = block + (numValues * (j + 1)) - 1;
threads[j] =
std::thread([&, n = nextValue[j], l = lastValue[j]] { abaThread(n, l, queue, barrier); });
}
threads[numThreads] = std::thread([&] {
std::this_thread::sleep_for(100ms);
barrier.Block();
});
for (size_t j = 0; j < numEntries; ++j)
{
char* val = queue.popFront();
size_t k = 0;
for (k = 0; k < numThreads; ++k)
{
if (val == nextValue[k])
{
nextValue[k] += (val == lastValue[k] ? 0 : 1);
REQUIRE(nextValue[k] <= lastValue[k]);
break;
}
}
REQUIRE(k < numThreads);
}
for (auto& thread : threads)
{
thread.join();
}
REQUIRE(0u == queue.size());
}
TEST_CASE("Basic exception safety")
{
ExceptionTester::throwFrom = std::this_thread::get_id();
Queue<ExceptionTester> queue{1};
REQUIRE_THROWS_AS(queue.pushBack(ExceptionTester()), Exception);
ExceptionTester::throwFrom = std::thread::id();
}
TEST_CASE("Exception safety")
{
ExceptionTester::throwFrom = std::thread::id();
static constexpr size_t queueSize = 3;
Queue<ExceptionTester> queue{queueSize};
REQUIRE(QueueReturn::Success == queue.pushBack(ExceptionTester()));
REQUIRE(QueueReturn::Success == queue.pushBack(ExceptionTester()));
REQUIRE(QueueReturn::Success == queue.pushBack(ExceptionTester()));
REQUIRE(QueueReturn::Success != queue.tryPushBack(ExceptionTester()));
util::Semaphore semaphore{0};
std::atomic_size_t caught = {0};
std::thread producer(
std::bind(&exceptionProducer, std::ref(queue), std::ref(semaphore), std::ref(caught)));
ExceptionTester::throwFrom = std::this_thread::get_id();
REQUIRE_THROWS_AS(queue.popFront(), Exception);
using namespace std::literals;
// Now the queue is not full, and the producer thread can start adding items.
REQUIRE(semaphore.waitFor(1s));
REQUIRE(queueSize == queue.size());
REQUIRE_THROWS_AS(queue.popFront(), Exception);
// Now the queue is not full, and the producer thread can start adding items.
REQUIRE(semaphore.waitFor(1s));
REQUIRE(queueSize == queue.size());
// Pushing into the queue with exception empties the queue.
ExceptionTester::throwFrom = producer.get_id();
// pop an item to unblock the pusher
(void)queue.popFront();
REQUIRE(semaphore.waitFor(1s));
REQUIRE(1u == caught);
REQUIRE(0u == queue.size());
REQUIRE(queue.empty());
// after throwing, the queue works fine.
REQUIRE(QueueReturn::Success == queue.pushBack(ExceptionTester()));
REQUIRE(QueueReturn::Success == queue.pushBack(ExceptionTester()));
REQUIRE(QueueReturn::Success == queue.pushBack(ExceptionTester()));
REQUIRE(QueueReturn::Success != queue.tryPushBack(ExceptionTester()));
ExceptionTester::throwFrom = std::thread::id();
producer.join();
}
TEST_CASE("Move it")
{
static constexpr size_t queueSize = 40;
Queue<MoveTester> queue{queueSize};
size_t counter = 0;
queue.pushBack(MoveTester{counter, 0});
REQUIRE(1u == counter);
MoveTester tester2(counter, 2);
queue.pushBack(std::move(tester2));
REQUIRE(tester2.moved);
REQUIRE(2u == counter);
REQUIRE(QueueReturn::Success == queue.tryPushBack(MoveTester{counter, 3}));
REQUIRE(3u == counter);
MoveTester tester4(counter, 4);
REQUIRE(QueueReturn::Success == queue.tryPushBack(std::move(tester4)));
REQUIRE(tester4.moved);
REQUIRE(4u == counter);
MoveTester popped = queue.popFront();
(void)popped;
REQUIRE(5u == counter);
std::optional<MoveTester> optPopped = queue.tryPopFront();
REQUIRE(optPopped);
// Moved twice here to construct the optional.
REQUIRE(6u == counter);
}