memgraph/tests/concurrent/sl_memory_leak.cpp

#include "common.hpp"

constexpr size_t THREADS_NO = std::min(max_no_threads, 1);
constexpr size_t elems_per_thread = 16e5;

// TODO: Memory leak at 1,600,000 elements (Kruno wrote this here but
// the previous (now deleted) memory_check method had invalid implementation)
//     1. implement valid memory_check
//     2. analyse this code
//     3. fix the memory leak
//     4. write proper test
int main(int, char **argv) {
  google::InitGoogleLogging(argv[0]);

  std::vector<std::thread> threads;
  map_t skiplist;

  // put THREADS_NO * elems_per_thread items to the skiplist
  for (size_t thread_i = 0; thread_i < THREADS_NO; ++thread_i) {
    threads.emplace_back(
        [&skiplist](size_t start, size_t end) {
          auto accessor = skiplist.access();
          for (size_t elem_i = start; elem_i < end; ++elem_i) {
            accessor.insert(elem_i, elem_i);
          }
        },
        thread_i * elems_per_thread,
        thread_i * elems_per_thread + elems_per_thread);
  }
  // wait all threads
  for (auto &thread : threads) {
    thread.join();
  }

  // get skiplist size
  {
    auto accessor = skiplist.access();
    CHECK(accessor.size() == THREADS_NO * elems_per_thread)
        << "all elements in skiplist";
  }

  for (size_t thread_i = 0; thread_i < THREADS_NO; ++thread_i) {
    threads[thread_i] = std::thread(
        [&skiplist](size_t start, size_t end) {
          auto accessor = skiplist.access();
          for (size_t elem_i = start; elem_i < end; ++elem_i) {
            CHECK(accessor.remove(elem_i) == true) << "";
          }
        },
        thread_i * elems_per_thread,
        thread_i * elems_per_thread + elems_per_thread);
  }
  // // wait all threads
  for (auto &thread : threads) {
    thread.join();
  }

  // check size
  {
    auto accessor = skiplist.access();
    CHECK(accessor.size() == 0)
        << "Size should be 0, but size is " << accessor.size();
  }

  // check count
  {
    size_t iterator_counter = 0;
    auto accessor = skiplist.access();
    for (auto elem : accessor) {
      ++iterator_counter;
      cout << elem.first << " ";
    }
    CHECK(iterator_counter == 0) << "deleted elements";
  }
  return 0;
}