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// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2016 Dmitry Vyukov <dvyukov@google.com>
// Copyright (C) 2016 Benoit Steiner <benoit.steiner.goog@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
#define EIGEN_USE_THREADS
#include <cstdlib>
#include "main.h"
#include <Eigen/CXX11/ThreadPool>
// Visual studio doesn't implement a rand_r() function since its
// implementation of rand() is already thread safe
int rand_reentrant(unsigned int* s) {
#ifdef EIGEN_COMP_MSVC_STRICT
EIGEN_UNUSED_VARIABLE(s);
return rand();
#else
return rand_r(s);
#endif
}
void test_basic_runqueue()
{
RunQueue<int, 4> q;
// Check empty state.
VERIFY(q.Empty());
VERIFY_IS_EQUAL(0u, q.Size());
VERIFY_IS_EQUAL(0, q.PopFront());
std::vector<int> stolen;
VERIFY_IS_EQUAL(0u, q.PopBackHalf(&stolen));
VERIFY_IS_EQUAL(0u, stolen.size());
// Push one front, pop one front.
VERIFY_IS_EQUAL(0, q.PushFront(1));
VERIFY_IS_EQUAL(1u, q.Size());
VERIFY_IS_EQUAL(1, q.PopFront());
VERIFY_IS_EQUAL(0u, q.Size());
// Push front to overflow.
VERIFY_IS_EQUAL(0, q.PushFront(2));
VERIFY_IS_EQUAL(1u, q.Size());
VERIFY_IS_EQUAL(0, q.PushFront(3));
VERIFY_IS_EQUAL(2u, q.Size());
VERIFY_IS_EQUAL(0, q.PushFront(4));
VERIFY_IS_EQUAL(3u, q.Size());
VERIFY_IS_EQUAL(0, q.PushFront(5));
VERIFY_IS_EQUAL(4u, q.Size());
VERIFY_IS_EQUAL(6, q.PushFront(6));
VERIFY_IS_EQUAL(4u, q.Size());
VERIFY_IS_EQUAL(5, q.PopFront());
VERIFY_IS_EQUAL(3u, q.Size());
VERIFY_IS_EQUAL(4, q.PopFront());
VERIFY_IS_EQUAL(2u, q.Size());
VERIFY_IS_EQUAL(3, q.PopFront());
VERIFY_IS_EQUAL(1u, q.Size());
VERIFY_IS_EQUAL(2, q.PopFront());
VERIFY_IS_EQUAL(0u, q.Size());
VERIFY_IS_EQUAL(0, q.PopFront());
// Push one back, pop one back.
VERIFY_IS_EQUAL(0, q.PushBack(7));
VERIFY_IS_EQUAL(1u, q.Size());
VERIFY_IS_EQUAL(1u, q.PopBackHalf(&stolen));
VERIFY_IS_EQUAL(1u, stolen.size());
VERIFY_IS_EQUAL(7, stolen[0]);
VERIFY_IS_EQUAL(0u, q.Size());
stolen.clear();
// Push back to overflow.
VERIFY_IS_EQUAL(0, q.PushBack(8));
VERIFY_IS_EQUAL(1u, q.Size());
VERIFY_IS_EQUAL(0, q.PushBack(9));
VERIFY_IS_EQUAL(2u, q.Size());
VERIFY_IS_EQUAL(0, q.PushBack(10));
VERIFY_IS_EQUAL(3u, q.Size());
VERIFY_IS_EQUAL(0, q.PushBack(11));
VERIFY_IS_EQUAL(4u, q.Size());
VERIFY_IS_EQUAL(12, q.PushBack(12));
VERIFY_IS_EQUAL(4u, q.Size());
// Pop back in halves.
VERIFY_IS_EQUAL(2u, q.PopBackHalf(&stolen));
VERIFY_IS_EQUAL(2u, stolen.size());
VERIFY_IS_EQUAL(10, stolen[0]);
VERIFY_IS_EQUAL(11, stolen[1]);
VERIFY_IS_EQUAL(2u, q.Size());
stolen.clear();
VERIFY_IS_EQUAL(1u, q.PopBackHalf(&stolen));
VERIFY_IS_EQUAL(1u, stolen.size());
VERIFY_IS_EQUAL(9, stolen[0]);
VERIFY_IS_EQUAL(1u, q.Size());
stolen.clear();
VERIFY_IS_EQUAL(1u, q.PopBackHalf(&stolen));
VERIFY_IS_EQUAL(1u, stolen.size());
VERIFY_IS_EQUAL(8, stolen[0]);
stolen.clear();
VERIFY_IS_EQUAL(0u, q.PopBackHalf(&stolen));
VERIFY_IS_EQUAL(0u, stolen.size());
// Empty again.
VERIFY(q.Empty());
VERIFY_IS_EQUAL(0u, q.Size());
VERIFY_IS_EQUAL(0, q.PushFront(1));
VERIFY_IS_EQUAL(0, q.PushFront(2));
VERIFY_IS_EQUAL(0, q.PushFront(3));
VERIFY_IS_EQUAL(1, q.PopBack());
VERIFY_IS_EQUAL(2, q.PopBack());
VERIFY_IS_EQUAL(3, q.PopBack());
VERIFY(q.Empty());
VERIFY_IS_EQUAL(0u, q.Size());
}
// Empty tests that the queue is not claimed to be empty when is is in fact not.
// Emptiness property is crucial part of thread pool blocking scheme,
// so we go to great effort to ensure this property. We create a queue with
// 1 element and then push 1 element (either front or back at random) and pop
// 1 element (either front or back at random). So queue always contains at least
// 1 element, but otherwise changes chaotically. Another thread constantly tests
// that the queue is not claimed to be empty.
void test_empty_runqueue()
{
RunQueue<int, 4> q;
q.PushFront(1);
std::atomic<bool> done(false);
std::thread mutator([&q, &done]() {
unsigned rnd = 0;
std::vector<int> stolen;
for (int i = 0; i < 1 << 18; i++) {
if (rand_reentrant(&rnd) % 2)
VERIFY_IS_EQUAL(0, q.PushFront(1));
else
VERIFY_IS_EQUAL(0, q.PushBack(1));
if (rand_reentrant(&rnd) % 2)
VERIFY_IS_EQUAL(1, q.PopFront());
else {
for (;;) {
if (q.PopBackHalf(&stolen) == 1) {
stolen.clear();
break;
}
VERIFY_IS_EQUAL(0u, stolen.size());
}
}
}
done = true;
});
while (!done) {
VERIFY(!q.Empty());
int size = q.Size();
VERIFY_GE(size, 1);
VERIFY_LE(size, 2);
}
VERIFY_IS_EQUAL(1, q.PopFront());
mutator.join();
}
// Stress is a chaotic random test.
// One thread (owner) calls PushFront/PopFront, other threads call PushBack/
// PopBack. Ensure that we don't crash, deadlock, and all sanity checks pass.
void test_stress_runqueue()
{
static const int kEvents = 1 << 18;
RunQueue<int, 8> q;
std::atomic<int> total(0);
std::vector<std::unique_ptr<std::thread>> threads;
threads.emplace_back(new std::thread([&q, &total]() {
int sum = 0;
int pushed = 1;
int popped = 1;
while (pushed < kEvents || popped < kEvents) {
if (pushed < kEvents) {
if (q.PushFront(pushed) == 0) {
sum += pushed;
pushed++;
}
}
if (popped < kEvents) {
int v = q.PopFront();
if (v != 0) {
sum -= v;
popped++;
}
}
}
total += sum;
}));
for (int i = 0; i < 2; i++) {
threads.emplace_back(new std::thread([&q, &total]() {
int sum = 0;
for (int j = 1; j < kEvents; j++) {
if (q.PushBack(j) == 0) {
sum += j;
continue;
}
EIGEN_THREAD_YIELD();
j--;
}
total += sum;
}));
threads.emplace_back(new std::thread([&q, &total]() {
int sum = 0;
std::vector<int> stolen;
for (int j = 1; j < kEvents;) {
if (q.PopBackHalf(&stolen) == 0) {
EIGEN_THREAD_YIELD();
continue;
}
while (stolen.size() && j < kEvents) {
int v = stolen.back();
stolen.pop_back();
VERIFY_IS_NOT_EQUAL(v, 0);
sum += v;
j++;
}
}
while (stolen.size()) {
int v = stolen.back();
stolen.pop_back();
VERIFY_IS_NOT_EQUAL(v, 0);
while ((v = q.PushBack(v)) != 0) EIGEN_THREAD_YIELD();
}
total -= sum;
}));
}
for (size_t i = 0; i < threads.size(); i++) threads[i]->join();
VERIFY(q.Empty());
VERIFY(total.load() == 0);
}
EIGEN_DECLARE_TEST(cxx11_runqueue)
{
CALL_SUBTEST_1(test_basic_runqueue());
CALL_SUBTEST_2(test_empty_runqueue());
CALL_SUBTEST_3(test_stress_runqueue());
}
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