| // Copyright 2018 The Abseil Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // https://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "gmock/gmock.h" |
| #include "gtest/gtest.h" |
| #include "absl/container/flat_hash_map.h" |
| #include "absl/container/flat_hash_set.h" |
| #include "absl/container/node_hash_map.h" |
| #include "absl/container/node_hash_set.h" |
| |
| namespace absl { |
| ABSL_NAMESPACE_BEGIN |
| namespace container_internal { |
| namespace { |
| |
| #if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) |
| // Create some tables of type `Table`, then look at all the new |
| // `HashtablezInfo`s to make sure that the `inline_element_size == |
| // expected_element_size`. The `inline_element_size` is the amount of memory |
| // allocated for each slot of a hash table, that is `sizeof(slot_type)`. Add |
| // the new `HashtablezInfo`s to `preexisting_info`. Store all the new tables |
| // into `tables`. |
| template <class Table> |
| void TestInlineElementSize( |
| HashtablezSampler& sampler, |
| // clang-tidy gives a false positive on this declaration. This unordered |
| // set cannot be flat_hash_set, however, since that would introduce a mutex |
| // deadlock. |
| std::unordered_set<const HashtablezInfo*>& preexisting_info, // NOLINT |
| std::vector<Table>& tables, const typename Table::value_type& elt, |
| size_t expected_element_size) { |
| for (int i = 0; i < 10; ++i) { |
| // We create a new table and must store it somewhere so that when we store |
| // a pointer to the resulting `HashtablezInfo` into `preexisting_info` |
| // that we aren't storing a dangling pointer. |
| tables.emplace_back(); |
| // We must insert an element to get a hashtablez to instantiate. |
| tables.back().insert(elt); |
| } |
| size_t new_count = 0; |
| sampler.Iterate([&](const HashtablezInfo& info) { |
| if (preexisting_info.insert(&info).second) { |
| EXPECT_EQ(info.inline_element_size, expected_element_size); |
| ++new_count; |
| } |
| }); |
| // Make sure we actually did get a new hashtablez. |
| EXPECT_GT(new_count, 0); |
| } |
| |
| struct bigstruct { |
| char a[1000]; |
| friend bool operator==(const bigstruct& x, const bigstruct& y) { |
| return memcmp(x.a, y.a, sizeof(x.a)) == 0; |
| } |
| template <typename H> |
| friend H AbslHashValue(H h, const bigstruct& c) { |
| return H::combine_contiguous(std::move(h), c.a, sizeof(c.a)); |
| } |
| }; |
| #endif |
| |
| TEST(FlatHashMap, SampleElementSize) { |
| #if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) |
| // Enable sampling even if the prod default is off. |
| SetHashtablezEnabled(true); |
| SetHashtablezSampleParameter(1); |
| |
| auto& sampler = GlobalHashtablezSampler(); |
| std::vector<flat_hash_map<int, bigstruct>> flat_map_tables; |
| std::vector<flat_hash_set<bigstruct>> flat_set_tables; |
| std::vector<node_hash_map<int, bigstruct>> node_map_tables; |
| std::vector<node_hash_set<bigstruct>> node_set_tables; |
| |
| // It takes thousands of new tables after changing the sampling parameters |
| // before you actually get some instrumentation. And if you must actually |
| // put something into those tables. |
| for (int i = 0; i < 10000; ++i) { |
| flat_map_tables.emplace_back(); |
| flat_map_tables.back()[i] = bigstruct{}; |
| } |
| |
| // clang-tidy gives a false positive on this declaration. This unordered set |
| // cannot be a flat_hash_set, however, since that would introduce a mutex |
| // deadlock. |
| std::unordered_set<const HashtablezInfo*> preexisting_info; // NOLINT |
| sampler.Iterate( |
| [&](const HashtablezInfo& info) { preexisting_info.insert(&info); }); |
| TestInlineElementSize(sampler, preexisting_info, flat_map_tables, |
| {0, bigstruct{}}, sizeof(int) + sizeof(bigstruct)); |
| TestInlineElementSize(sampler, preexisting_info, node_map_tables, |
| {0, bigstruct{}}, sizeof(void*)); |
| TestInlineElementSize(sampler, preexisting_info, flat_set_tables, // |
| bigstruct{}, sizeof(bigstruct)); |
| TestInlineElementSize(sampler, preexisting_info, node_set_tables, // |
| bigstruct{}, sizeof(void*)); |
| #endif |
| } |
| |
| } // namespace |
| } // namespace container_internal |
| ABSL_NAMESPACE_END |
| } // namespace absl |