Function fillUpMemoryPool

cachelib/allocator/memory/tests/MemoryPoolTest.cpp:189–223

fills up the memory pool and returns the allocations in the outparam

// fills up the memory pool and returns the allocations in the outparam
void fillUpMemoryPool(MemoryPool& mp,
                      const std::set<uint32_t>& allocSizes,
                      AllocInfoT& poolAllocs) {
  for (const auto size : allocSizes) {
    // ensure it is power of two.
    ASSERT_EQ(size & (size - 1), 0);
  }

  const auto maxSize = mp.getPoolSize();
  using ClassFullT = std::unordered_map<uint32_t, bool>;
  ClassFullT isClassFull;

  // pick a random class and allocate from that until the memory is full. If
  // an allocation class fails allocation, it should not succeed any later.
  while (mp.getCurrentAllocSize() < maxSize) {
    const unsigned int randomClass =
        folly::Random::rand32() % allocSizes.size();
    const auto classSize = *(std::next(allocSizes.begin(), randomClass));
    void* memory = mp.allocate(classSize);
    if (memory != nullptr) {
      poolAllocs[classSize].push_back(memory);
      const auto it = isClassFull.find(classSize);
      if (it != isClassFull.end()) {
        ASSERT_FALSE(isClassFull[classSize]);
      }
    } else {
      const auto it = isClassFull.find(classSize);
      if (it == isClassFull.end()) {
        isClassFull[classSize] = true;
      } else {
        ASSERT_TRUE(isClassFull[classSize]);
      }
    }
  }
}

TEST_F(MemoryPoolTest, Free) {
  auto slabAlloc = createSlabAllocator(35);