chromium/chrome/browser/performance_monitor/system_monitor.h

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

#ifndef CHROME_BROWSER_PERFORMANCE_MONITOR_SYSTEM_MONITOR_H_
#define CHROME_BROWSER_PERFORMANCE_MONITOR_SYSTEM_MONITOR_H_

#include <array>
#include <memory>
#include <optional>
#include <vector>

#include "base/containers/flat_map.h"
#include "base/memory/weak_ptr.h"
#include "base/observer_list.h"
#include "base/process/process_metrics.h"
#include "base/sequence_checker.h"
#include "base/task/sequenced_task_runner.h"
#include "base/timer/timer.h"

namespace performance_monitor {

class MetricEvaluatorsHelper;

// Monitors various various system metrics such as free memory, disk idle time,
// etc.
//
// Must be created and used from the UI thread.
//
// Users of this class need to subscribe as observers via the
// AddOrUpdateObserver method. They need to specify which metrics they're
// interested in and at which frequency they should be refreshed. This set of
// metrics and frequencies can then be updated at runtime.
//
// Platforms that want to use this class need to provide a platform specific
// implementation of the MetricEvaluatorHelper class.
class SystemMonitor { … };

// A builder class used to easily create a MetricRefreshFrequencies object.
class SystemMonitor::SystemObserver::MetricRefreshFrequencies::Builder { … };

// An helper class used by the MetricEvaluator object to retrieve the info
// they need.
class MetricEvaluatorsHelper { … };

}  // namespace performance_monitor

#endif  // CHROME_BROWSER_PERFORMANCE_MONITOR_SYSTEM_MONITOR_H_