memgraph/tests/concurrent/conncurent_list.cpp

#include "common.hpp"

constexpr size_t THREADS_NO = std::min(max_no_threads, 8);
constexpr size_t key_range = 1e2;
constexpr size_t op_per_thread = 1e4;
// Depending on value there is a possiblity of numerical overflow
constexpr size_t max_number = 10;
constexpr size_t no_find_per_change = 2;
constexpr size_t no_insert_for_one_delete = 1;

// This test simulates behavior of a transactions.
// Each thread makes a series of finds interleaved with method which change.
// Exact ratio of finds per change and insert per delete can be regulated with
// no_find_per_change and no_insert_for_one_delete.
int main(int argc, char **argv) {
  google::InitGoogleLogging(argv[0]);
  ConcurrentList<std::pair<int, int>> list;
  CHECK(list.size() == 0) << "The list isn't empty";

  auto futures =
      run<std::pair<long long, long long>>(THREADS_NO, [&](auto index) mutable {
        auto rand = rand_gen(key_range);
        auto rand_change = rand_gen_bool(no_find_per_change);
        auto rand_delete = rand_gen_bool(no_insert_for_one_delete);
        long long sum = 0;
        long long count = 0;

        for (int i = 0; i < op_per_thread; i++) {
          auto num = rand();
          auto data = num % max_number;
          if (rand_change()) {
            if (rand_delete()) {
              for (auto it = list.begin(); it != list.end(); it++) {
                if (it->first == num) {
                  if (it.remove()) {
                    sum -= data;
                    count--;
                  }
                  break;
                }
              }
            } else {
              list.begin().push(std::make_pair(num, data));
              sum += data;
              count++;
            }
          } else {
            for (auto &v : list) {
              if (v.first == num) {
                CHECK(v.second == data) << "Data is invalid";
                break;
              }
            }
          }
        }

        return std::pair<long long, long long>(sum, count);
      });

  auto it = list.begin();
  long long sums = 0;
  long long counters = 0;
  for (auto &data : collect(futures)) {
    sums += data.second.first;
    counters += data.second.second;
  }

  for (auto &e : list) {
    sums -= e.second;
  }

  CHECK(sums == 0) << "Same values aren't present";
  check_size_list<ConcurrentList<std::pair<int, int>>>(list, counters);

  std::this_thread::sleep_for(1s);
}