chrome/common/profiler/main_thread_stack_sampling_profiler.cc

// Copyright 2019 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/common/profiler/main_thread_stack_sampling_profiler.h"

#include "base/bind.h"
#include "base/command_line.h"
#include "base/threading/platform_thread.h"
#include "chrome/common/profiler/thread_profiler.h"
#include "components/metrics/call_stack_profile_metrics_provider.h"
#include "content/public/common/content_switches.h"

namespace {

// Returns the profiler appropriate for the current process.
std::unique_ptr<ThreadProfiler> CreateThreadProfiler() {
  const base::CommandLine* command_line =
      base::CommandLine::ForCurrentProcess();

  // The browser process has an empty process type.
  // TODO(wittman): Do this for other process types too.
  if (!command_line->HasSwitch(switches::kProcessType)) {
    ThreadProfiler::SetBrowserProcessReceiverCallback(base::BindRepeating(
        &metrics::CallStackProfileMetricsProvider::ReceiveProfile));
    return ThreadProfiler::CreateAndStartOnMainThread();
  }

  // No other processes are currently supported.
  return nullptr;
}

}  // namespace

MainThreadStackSamplingProfiler::MainThreadStackSamplingProfiler() {
  sampling_profiler_ = CreateThreadProfiler();
}

// Note that it's important for the |sampling_profiler_| destructor to run, as
// it ensures program correctness on shutdown. Without it, the profiler thread's
// destruction can race with the profiled thread's destruction, which results in
// the sampling thread attempting to profile the sampled thread after the
// sampled thread has already been shut down.
MainThreadStackSamplingProfiler::~MainThreadStackSamplingProfiler() = default;