Abseil Common Libraries (C++) (grcp 依赖)
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250 lines
8.6 KiB
250 lines
8.6 KiB
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// Copyright 2020 The Abseil Authors. |
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// |
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// Licensed under the Apache License, Version 2.0 (the "License"); |
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// you may not use this file except in compliance with the License. |
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// You may obtain a copy of the License at |
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// |
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// https://www.apache.org/licenses/LICENSE-2.0 |
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// |
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// Unless required by applicable law or agreed to in writing, software |
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// distributed under the License is distributed on an "AS IS" BASIS, |
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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// See the License for the specific language governing permissions and |
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// limitations under the License. |
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#include <stdint.h> |
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#include <string> |
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#include <vector> |
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#include "absl/flags/flag.h" |
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#include "absl/flags/marshalling.h" |
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#include "absl/flags/parse.h" |
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#include "absl/flags/reflection.h" |
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#include "absl/strings/string_view.h" |
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#include "absl/time/time.h" |
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#include "absl/types/optional.h" |
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#include "benchmark/benchmark.h" |
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namespace { |
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using String = std::string; |
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using VectorOfStrings = std::vector<std::string>; |
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using AbslDuration = absl::Duration; |
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// We do not want to take over marshalling for the types absl::optional<int>, |
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// absl::optional<std::string> which we do not own. Instead we introduce unique |
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// "aliases" to these types, which we do. |
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using AbslOptionalInt = absl::optional<int>; |
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struct OptionalInt : AbslOptionalInt { |
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using AbslOptionalInt::AbslOptionalInt; |
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}; |
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// Next two functions represent Abseil Flags marshalling for OptionalInt. |
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bool AbslParseFlag(absl::string_view src, OptionalInt* flag, |
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std::string* error) { |
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int val; |
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if (src.empty()) |
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flag->reset(); |
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else if (!absl::ParseFlag(src, &val, error)) |
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return false; |
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*flag = val; |
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return true; |
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} |
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std::string AbslUnparseFlag(const OptionalInt& flag) { |
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return !flag ? "" : absl::UnparseFlag(*flag); |
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} |
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using AbslOptionalString = absl::optional<std::string>; |
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struct OptionalString : AbslOptionalString { |
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using AbslOptionalString::AbslOptionalString; |
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}; |
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// Next two functions represent Abseil Flags marshalling for OptionalString. |
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bool AbslParseFlag(absl::string_view src, OptionalString* flag, |
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std::string* error) { |
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std::string val; |
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if (src.empty()) |
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flag->reset(); |
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else if (!absl::ParseFlag(src, &val, error)) |
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return false; |
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*flag = val; |
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return true; |
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} |
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std::string AbslUnparseFlag(const OptionalString& flag) { |
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return !flag ? "" : absl::UnparseFlag(*flag); |
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} |
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struct UDT { |
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UDT() = default; |
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UDT(const UDT&) {} |
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UDT& operator=(const UDT&) { return *this; } |
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}; |
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// Next two functions represent Abseil Flags marshalling for UDT. |
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bool AbslParseFlag(absl::string_view, UDT*, std::string*) { return true; } |
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std::string AbslUnparseFlag(const UDT&) { return ""; } |
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} // namespace |
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#define BENCHMARKED_TYPES(A) \ |
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A(bool) \ |
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A(int16_t) \ |
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A(uint16_t) \ |
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A(int32_t) \ |
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A(uint32_t) \ |
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A(int64_t) \ |
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A(uint64_t) \ |
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A(double) \ |
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A(float) \ |
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A(String) \ |
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A(VectorOfStrings) \ |
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A(OptionalInt) \ |
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A(OptionalString) \ |
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A(AbslDuration) \ |
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A(UDT) |
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#define REPLICATE_0(A, T, name, index) A(T, name, index) |
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#define REPLICATE_1(A, T, name, index) \ |
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REPLICATE_0(A, T, name, index##0) REPLICATE_0(A, T, name, index##1) |
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#define REPLICATE_2(A, T, name, index) \ |
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REPLICATE_1(A, T, name, index##0) REPLICATE_1(A, T, name, index##1) |
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#define REPLICATE_3(A, T, name, index) \ |
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REPLICATE_2(A, T, name, index##0) REPLICATE_2(A, T, name, index##1) |
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#define REPLICATE_4(A, T, name, index) \ |
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REPLICATE_3(A, T, name, index##0) REPLICATE_3(A, T, name, index##1) |
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#define REPLICATE_5(A, T, name, index) \ |
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REPLICATE_4(A, T, name, index##0) REPLICATE_4(A, T, name, index##1) |
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#define REPLICATE_6(A, T, name, index) \ |
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REPLICATE_5(A, T, name, index##0) REPLICATE_5(A, T, name, index##1) |
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#define REPLICATE_7(A, T, name, index) \ |
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REPLICATE_6(A, T, name, index##0) REPLICATE_6(A, T, name, index##1) |
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#define REPLICATE_8(A, T, name, index) \ |
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REPLICATE_7(A, T, name, index##0) REPLICATE_7(A, T, name, index##1) |
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#define REPLICATE_9(A, T, name, index) \ |
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REPLICATE_8(A, T, name, index##0) REPLICATE_8(A, T, name, index##1) |
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#if defined(_MSC_VER) |
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#define REPLICATE(A, T, name) \ |
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REPLICATE_7(A, T, name, 0) REPLICATE_7(A, T, name, 1) |
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#define SINGLE_FLAG(T) FLAGS_##T##_flag_00000000 |
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#else |
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#define REPLICATE(A, T, name) \ |
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REPLICATE_9(A, T, name, 0) REPLICATE_9(A, T, name, 1) |
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#define SINGLE_FLAG(T) FLAGS_##T##_flag_0000000000 |
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#endif |
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#define REPLICATE_ALL(A, T, name) \ |
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REPLICATE_9(A, T, name, 0) REPLICATE_9(A, T, name, 1) |
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#define COUNT(T, name, index) +1 |
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constexpr size_t kNumFlags = 0 REPLICATE(COUNT, _, _); |
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#if defined(__clang__) && defined(__linux__) |
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// Force the flags used for benchmarks into a separate ELF section. |
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// This ensures that, even when other parts of the code might change size, |
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// the layout of the flags across cachelines is kept constant. This makes |
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// benchmark results more reproducible across unrelated code changes. |
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#pragma clang section data = ".benchmark_flags" |
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#endif |
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#define DEFINE_FLAG(T, name, index) ABSL_FLAG(T, name##_##index, {}, ""); |
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#define FLAG_DEF(T) REPLICATE(DEFINE_FLAG, T, T##_flag); |
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BENCHMARKED_TYPES(FLAG_DEF) |
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#if defined(__clang__) && defined(__linux__) |
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#pragma clang section data = "" |
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#endif |
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// Register thousands of flags to bloat up the size of the registry. |
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// This mimics real life production binaries. |
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#define BLOAT_FLAG(_unused1, _unused2, index) \ |
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ABSL_FLAG(int, bloat_flag_##index, 0, ""); |
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REPLICATE_ALL(BLOAT_FLAG, _, _) |
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namespace { |
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#define FLAG_PTR(T, name, index) &FLAGS_##name##_##index, |
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#define FLAG_PTR_ARR(T) \ |
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static constexpr absl::Flag<T>* FlagPtrs_##T[] = { \ |
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REPLICATE(FLAG_PTR, T, T##_flag)}; |
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BENCHMARKED_TYPES(FLAG_PTR_ARR) |
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#define BM_SingleGetFlag(T) \ |
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void BM_SingleGetFlag_##T(benchmark::State& state) { \ |
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for (auto _ : state) { \ |
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benchmark::DoNotOptimize(absl::GetFlag(SINGLE_FLAG(T))); \ |
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} \ |
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} \ |
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BENCHMARK(BM_SingleGetFlag_##T)->ThreadRange(1, 16); |
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BENCHMARKED_TYPES(BM_SingleGetFlag) |
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template <typename T> |
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struct Accumulator { |
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using type = T; |
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}; |
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template <> |
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struct Accumulator<String> { |
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using type = size_t; |
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}; |
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template <> |
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struct Accumulator<VectorOfStrings> { |
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using type = size_t; |
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}; |
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template <> |
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struct Accumulator<OptionalInt> { |
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using type = bool; |
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}; |
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template <> |
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struct Accumulator<OptionalString> { |
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using type = bool; |
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}; |
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template <> |
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struct Accumulator<UDT> { |
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using type = bool; |
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}; |
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template <typename T> |
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void Accumulate(typename Accumulator<T>::type& a, const T& f) { |
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a += f; |
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} |
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void Accumulate(bool& a, bool f) { a = a || f; } |
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void Accumulate(size_t& a, const std::string& f) { a += f.size(); } |
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void Accumulate(size_t& a, const std::vector<std::string>& f) { a += f.size(); } |
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void Accumulate(bool& a, const OptionalInt& f) { a |= f.has_value(); } |
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void Accumulate(bool& a, const OptionalString& f) { a |= f.has_value(); } |
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void Accumulate(bool& a, const UDT& f) { |
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a |= reinterpret_cast<int64_t>(&f) & 0x1; |
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} |
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#define BM_ManyGetFlag(T) \ |
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void BM_ManyGetFlag_##T(benchmark::State& state) { \ |
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Accumulator<T>::type res = {}; \ |
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while (state.KeepRunningBatch(kNumFlags)) { \ |
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for (auto* flag_ptr : FlagPtrs_##T) { \ |
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Accumulate(res, absl::GetFlag(*flag_ptr)); \ |
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} \ |
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} \ |
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benchmark::DoNotOptimize(res); \ |
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} \ |
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BENCHMARK(BM_ManyGetFlag_##T)->ThreadRange(1, 8); |
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BENCHMARKED_TYPES(BM_ManyGetFlag) |
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void BM_ThreadedFindCommandLineFlag(benchmark::State& state) { |
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char dummy[] = "dummy"; |
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char* argv[] = {dummy}; |
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// We need to ensure that flags have been parsed. That is where the registry |
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// is finalized. |
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absl::ParseCommandLine(1, argv); |
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while (state.KeepRunningBatch(kNumFlags)) { |
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for (auto* flag_ptr : FlagPtrs_bool) { |
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benchmark::DoNotOptimize(absl::FindCommandLineFlag(flag_ptr->Name())); |
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} |
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} |
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} |
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BENCHMARK(BM_ThreadedFindCommandLineFlag)->ThreadRange(1, 16); |
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} // namespace |
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#define InvokeGetFlag(T) \ |
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T AbslInvokeGetFlag##T() { return absl::GetFlag(SINGLE_FLAG(T)); } \ |
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int odr##T = (benchmark::DoNotOptimize(AbslInvokeGetFlag##T), 1); |
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BENCHMARKED_TYPES(InvokeGetFlag) |
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// To veiw disassembly use: gdb ${BINARY} -batch -ex "disassemble /s $FUNC"
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