tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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profiler_example.cc (3020B)

      1 // Copyright 2017 Google Inc. All Rights Reserved.
      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 //     http://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 <cmath>
     16 
     17 #include "hwy/base.h"           // Abort
     18 #include "hwy/cache_control.h"  // Pause
     19 #include "hwy/contrib/thread_pool/thread_pool.h"
     20 #include "hwy/profiler.h"
     21 #include "hwy/timer.h"
     22 
     23 namespace hwy {
     24 namespace {
     25 
     26 HWY_INLINE void Spin(const double min_time) {
     27  const double t0 = hwy::platform::Now();
     28  for (;;) {
     29    hwy::Pause();
     30    const double elapsed = hwy::platform::Now() - t0;
     31    if (elapsed > min_time) {
     32      break;
     33    }
     34  }
     35 }
     36 
     37 HWY_NOINLINE void Spin10us() {
     38  PROFILER_FUNC;
     39  Spin(10E-6);
     40 }
     41 
     42 HWY_NOINLINE void Spin20us() {
     43  PROFILER_FUNC;
     44  Spin(20E-6);
     45 }
     46 
     47 HWY_NOINLINE void CallTwoSpin() {
     48  PROFILER_ZONE("NearZeroBecauseOfChildZones");
     49  {
     50    PROFILER_ZONE("spin30");
     51    Spin(30E-6);
     52  }
     53  {
     54    PROFILER_ZONE("spin60");
     55    Spin(60E-6);
     56  }
     57 }
     58 
     59 HWY_NOINLINE void Compute(Profiler& p, HWY_MAYBE_UNUSED size_t thread) {
     60  static const auto zone = p.AddZone("Compute");
     61  PROFILER_ZONE3(p, static_cast<uint8_t>(thread), zone);
     62  for (int rep = 0; rep < 100; ++rep) {
     63    double total = 0.0;
     64    for (int i = 0; i < 200 - rep; ++i) {
     65      total += std::pow(0.9, i);
     66    }
     67    if (std::abs(total - 10.0) > 1E-2) {
     68      HWY_ABORT("unexpected total %f", total);
     69    }
     70  }
     71 }
     72 
     73 HWY_NOINLINE void TestThreads(Profiler& p) {
     74  PROFILER_ZONE("NearZeroBecauseOfThreadedChildZones");
     75  {
     76    PROFILER_ZONE("Create pool1");
     77    ThreadPool pool(3);
     78    pool.Run(0, 5, [&p](uint64_t /*task*/, HWY_MAYBE_UNUSED size_t thread) {
     79      Compute(p, thread);
     80    });
     81  }
     82 
     83  {
     84    PROFILER_ZONE("Create pool2");
     85    ThreadPool pool(8);
     86    pool.Run(0, 8, [&p](uint64_t /*task*/, HWY_MAYBE_UNUSED size_t thread) {
     87      Compute(p, thread);
     88    });
     89  }
     90 }
     91 
     92 HWY_NOINLINE void CallTestThreadPlus20us(Profiler& p) {
     93  PROFILER_FUNC;
     94  TestThreads(p);
     95  Spin(20E-6);
     96 }
     97 
     98 HWY_NOINLINE void CallCallTestThreadPlus10us(Profiler& p) {
     99  PROFILER_FUNC;
    100  CallTestThreadPlus20us(p);
    101  Spin(10E-6);
    102 }
    103 
    104 void ProfilerExample(Profiler& p) {
    105  PROFILER_ZONE("NearZeroDespiteInclusiveChildZone");
    106  {
    107    static const auto zone =
    108        p.AddZone("Inclusive 10+20", ProfilerFlags::kInclusive);
    109    PROFILER_ZONE3(p, 0, zone);
    110    Spin20us();
    111    Spin10us();
    112  }
    113  CallTwoSpin();
    114  CallCallTestThreadPlus10us(p);
    115 }
    116 
    117 }  // namespace
    118 }  // namespace hwy
    119 
    120 int main(int /*argc*/, char* /*argv*/[]) {
    121  hwy::ProfilerExample(hwy::Profiler::Get());
    122  PROFILER_PRINT_RESULTS();  // after all zones have exited
    123  return 0;
    124 }