void BM_async()

in benchmarks/nested_for_benchmark.cpp [231:263]

• 28 lines of code
• 5 McCabe index (conditional complexity)

void BM_async(benchmark::State& state) {
  g_numThreads = state.range(0);
  const int numElements = state.range(1);
  uint64_t sum = 0;
  int foo = 0;

  auto input = getInputs(numElements);
  for (auto UNUSED_VAR : state) {
    std::vector<uint64_t> sums;
    ++foo;

    size_t chunkSize = (numElements + g_numThreads - 1) / g_numThreads;

    std::vector<std::future<uint64_t>> futures;

    for (int i = 0; i < numElements; i += chunkSize) {
      futures.push_back(std::async(
          [numElements, input, foo, i, end = std::min<int>(numElements, i + chunkSize)]() mutable {
            uint64_t lsum = 0;
            for (; i != end; ++i) {
              lsum += calculateInnerAsync(input, foo, numElements);
            }
            return lsum;
          }));
    }
    sum = 0;
    for (auto& s : futures) {
      sum += s.get();
    }
  }

  checkResults(input, sum, foo, numElements);
}