Function test_stress_runqueue

python/include/unsupported/test/cxx11_runqueue.cpp:160–228

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.

// 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();