void runFindMultiThreads()

in cachelib/benchmarks/CacheAllocatorOpsMicroBench.cpp [122:196]
67 lines of code
11 McCabe index (conditional complexity)

void runFindMultiThreads(int numThreads,
                         bool isPeek,
                         uint64_t objSize,
                         uint64_t writePct) {
  constexpr uint64_t kObjects = 100'000;
  constexpr uint64_t kLoops = 10'000'000;

  auto cache = getCache();
  std::vector<std::string> keys;
  for (uint64_t i = 0; i < kObjects; i++) {
    // Length of key should be 10 bytes
    auto key = folly::sformat("k_{: <8}", i);
    auto hdl = cache->allocate(0, key, objSize);
    XCHECK(hdl);
    cache->insertOrReplace(hdl);
    keys.push_back(key);
  }

  navy::SeqPoints sp;
  auto readOps = [&] {
    sp.wait(0);

    std::mt19937 gen;
    std::uniform_int_distribution<uint64_t> dist(0, kObjects - 1);
    for (uint64_t loop = 0; loop < kLoops; loop++) {
      const auto& key = keys[dist(gen)];
      auto hdl = isPeek ? cache->peek(key) : cache->find(key);
      folly::doNotOptimizeAway(hdl);
    }
  };
  auto writeOps = [&] {
    sp.wait(0);

    if (writePct == 0) {
      return;
    }

    std::mt19937 gen;
    std::uniform_int_distribution<uint64_t> dist(0,
                                                 kObjects * writePct / 100 - 1);
    for (uint64_t loop = 0; loop < kLoops / 10; loop++) {
      const auto& key = keys[dist(gen)];
      auto hdl = cache->allocate(0, key, objSize);
      XCHECK(hdl);
      cache->insertOrReplace(hdl);
      folly::doNotOptimizeAway(hdl);
    }
  };

  // Create readers
  std::vector<std::thread> rs;
  for (int i = 0; i < numThreads; i++) {
    rs.push_back(std::thread{readOps});
  }

  // Create writers
  std::vector<std::thread> ws;
  for (int i = 0; i < 4; i++) {
    ws.push_back(std::thread{writeOps});
  }

  {
    Timer t{folly::sformat("{} - {: <2} Threads, {: <4} Bytes, {: <2}% Write",
                           isPeek ? "Peek" : "Find", numThreads, objSize,
                           writePct),
            kLoops};
    sp.reached(0); // Start the operations
    for (auto& r : rs) {
      r.join();
    }
  }
  for (auto& w : ws) {
    w.join();
  }
}