chrome/browser/performance_manager/browser_child_process_watcher.h

// Copyright 2017 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.

#ifndef CHROME_BROWSER_PERFORMANCE_MANAGER_BROWSER_CHILD_PROCESS_WATCHER_H_
#define CHROME_BROWSER_PERFORMANCE_MANAGER_BROWSER_CHILD_PROCESS_WATCHER_H_

#include <memory>

#include "base/containers/flat_map.h"
#include "base/process/process.h"
#include "content/public/browser/browser_child_process_observer.h"

namespace performance_manager {

class ProcessNodeImpl;

// Responsible for maintaining the process nodes for the browser, the GPU and
// utility process.
class BrowserChildProcessWatcher : public content::BrowserChildProcessObserver {
 public:
  BrowserChildProcessWatcher();

  BrowserChildProcessWatcher(const BrowserChildProcessWatcher&) = delete;
  BrowserChildProcessWatcher& operator=(const BrowserChildProcessWatcher&) =
      delete;

  ~BrowserChildProcessWatcher() override;

  // Initialize this watcher.
  void Initialize();

  // Tear down this watcher and any state it's gathered.
  void TearDown();

 private:
  // BrowserChildProcessObserver overrides.
  void BrowserChildProcessLaunchedAndConnected(
      const content::ChildProcessData& data) override;
  void BrowserChildProcessHostDisconnected(
      const content::ChildProcessData& data) override;
  void BrowserChildProcessCrashed(
      const content::ChildProcessData& data,
      const content::ChildProcessTerminationInfo& info) override;
  void BrowserChildProcessKilled(
      const content::ChildProcessData& data,
      const content::ChildProcessTerminationInfo& info) override;

  void TrackedProcessExited(int id, int exit_code);

  static void OnProcessLaunched(const base::Process& process,
                                const std::string& metrics_name,
                                ProcessNodeImpl* process_node);

  std::unique_ptr<ProcessNodeImpl> browser_process_node_;

  // This map keeps track of all GPU and Utility processes by their unique ID
  // from |content::ChildProcessData|. Apparently more than one GPU process can
  // be existent at a time, though secondaries are very transient.
  base::flat_map<int, std::unique_ptr<ProcessNodeImpl>> tracked_process_nodes_;
};

}  // namespace performance_manager

#endif  // CHROME_BROWSER_PERFORMANCE_MANAGER_BROWSER_CHILD_PROCESS_WATCHER_H_