memgraph/tests/concurrent/conncurent_list.cpp

#include "common.h"

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()
{
    init_log();
    memory_check(THREADS_NO, [] {
        ConcurrentList<std::pair<int, int>> list;
        permanent_assert(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)
                            {
                                permanent_assert(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;
        }

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

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