tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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stacktrace_benchmark.cc (1745B)


      1 // Copyright 2022 The Abseil Authors
      2 //
      3 // Licensed under the Apache License, Version 2.0 (the "License");
      4 // you may not use this file except in compliance with the License.
      5 // You may obtain a copy of the License at
      6 //
      7 //     https://www.apache.org/licenses/LICENSE-2.0
      8 //
      9 // Unless required by applicable law or agreed to in writing, software
     10 // distributed under the License is distributed on an "AS IS" BASIS,
     11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     12 // See the License for the specific language governing permissions and
     13 // limitations under the License.
     14 
     15 #include "absl/base/attributes.h"
     16 #include "absl/base/config.h"
     17 #include "absl/base/optimization.h"
     18 #include "absl/debugging/stacktrace.h"
     19 #include "benchmark/benchmark.h"
     20 
     21 namespace absl {
     22 ABSL_NAMESPACE_BEGIN
     23 namespace {
     24 
     25 static constexpr int kMaxStackDepth = 100;
     26 static constexpr int kCacheSize = (1 << 16);
     27 void* pcs[kMaxStackDepth];
     28 
     29 ABSL_ATTRIBUTE_NOINLINE void func(benchmark::State& state, int x, int depth) {
     30  if (x <= 0) {
     31    // Touch a significant amount of memory so that the stack is likely to be
     32    // not cached in the L1 cache.
     33    state.PauseTiming();
     34    int* arr = new int[kCacheSize];
     35    for (int i = 0; i < kCacheSize; ++i) benchmark::DoNotOptimize(arr[i] = 100);
     36    delete[] arr;
     37    state.ResumeTiming();
     38    benchmark::DoNotOptimize(absl::GetStackTrace(pcs, depth, 0));
     39    return;
     40  }
     41  ABSL_BLOCK_TAIL_CALL_OPTIMIZATION();
     42  func(state, --x, depth);
     43 }
     44 
     45 void BM_GetStackTrace(benchmark::State& state) {
     46  int depth = state.range(0);
     47  for (auto s : state) {
     48    func(state, depth, depth);
     49  }
     50 }
     51 
     52 BENCHMARK(BM_GetStackTrace)->DenseRange(10, kMaxStackDepth, 10);
     53 }  // namespace
     54 ABSL_NAMESPACE_END
     55 }  // namespace absl