Function DEBUG_ONLY_TEST_F

bolt/common/caching/tests/AsyncDataCacheTest.cpp:1062–1127

}

DEBUG_ONLY_TEST_F(AsyncDataCacheTest, shrinkWithSsdWrite) {
  constexpr uint64_t kRamBytes = 128UL << 20;
  constexpr uint64_t kSsdBytes = 512UL << 20;
  constexpr int kDataSize = 4096;
  initializeCache(kRamBytes, kSsdBytes);
  const int numEntries{10};
  std::vector<CachePin> cachePins;
  uint64_t offset = 0;
  for (int i = 0; i < numEntries; ++i) {
    cachePins.push_back(newEntry(offset, kDataSize));
    offset += kDataSize;
  }
  for (auto& pin : cachePins) {
    pin.entry()->setExclusiveToShared();
  }

  std::atomic_bool writeStartFlag{false};
  folly::EventCount writeStartWait;
  std::atomic_bool writeWaitFlag{true};
  folly::EventCount writeWait;
  SCOPED_TESTVALUE_SET(
      "bytedance::bolt::cache::SsdCache::write",
      std::function<void(const SsdCache*)>(([&](const SsdCache* cache) {
        writeStartFlag = true;
        writeStartWait.notifyAll();
        writeWait.await([&]() { return !writeWaitFlag.load(); });
      })));

  // Starts a write thread running at background.
  std::thread ssdWriteThread([&]() {
    cache_->ssdCache()->startWrite();
    cache_->saveToSsd();
  });

  // Wait for the write thread to start, and block it while do cache shrink.
  writeStartWait.await([&]() { return writeStartFlag.load(); });
  ASSERT_TRUE(cache_->ssdCache()->writeInProgress());

  cachePins.clear();
  cache_->shrink(kRamBytes);
  auto stats = cache_->refreshStats();
  // Shrink can only reclaim some entries but not all as some of the cache
  // entries have been pickup for ssd write which is not evictable.
  ASSERT_LT(stats.numEntries, numEntries);
  ASSERT_GT(stats.numEmptyEntries, 0);
  ASSERT_GT(stats.numEvict, 0);
  ASSERT_GT(stats.numShared, 0);
  ASSERT_EQ(stats.numExclusive, 0);
  ASSERT_EQ(stats.numWaitExclusive, 0);

  // Wait for write to complete.
  writeWaitFlag = false;
  writeWait.notifyAll();
  ssdWriteThread.join();
  while (cache_->ssdCache()->writeInProgress()) {
    std::this_thread::sleep_for(std::chrono::milliseconds(100)); // NOLINT
  }