blob: 935fc03e60d4ad923f8c303f27a2aac07c615d63 [file] [log] [blame]
// Copyright (c) 2012 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 <map>
#include <string>
#include <vector>
#include "base/base_export.h"
#include "base/basictypes.h"
#include "base/file_path.h"
#include "base/string16.h"
#include "base/synchronization/lock.h"
#include "build/build_config.h"
// Windows HiRes timers drain the battery faster so we need to know the battery
// status. This isn't true for other platforms.
#if defined(OS_WIN)
#endif // !OS_WIN
#include "base/observer_list_threadsafe.h"
#include "base/timer.h"
#if defined(OS_MACOSX) && !defined(OS_IOS)
#include <IOKit/pwr_mgt/IOPMLib.h>
#include <IOKit/IOMessage.h>
#endif // OS_MACOSX && !OS_IOS
#if defined(OS_IOS)
#include <objc/runtime.h>
#endif // OS_IOS
namespace base {
// Class for monitoring various system-related subsystems
// such as power management, network status, etc.
// TODO(mbelshe): Add support beyond just power management.
class BASE_EXPORT SystemMonitor {
// Normalized list of power events.
enum PowerEvent {
POWER_STATE_EVENT, // The Power status of the system has changed.
SUSPEND_EVENT, // The system is being suspended.
RESUME_EVENT // The system is being resumed.
// Type of devices whose change need to be monitored, such as add/remove.
enum DeviceType {
DEVTYPE_AUDIO_CAPTURE, // Audio capture device, e.g., microphone.
DEVTYPE_VIDEO_CAPTURE, // Video capture device, e.g., webcam.
DEVTYPE_UNKNOWN, // Other devices.
struct BASE_EXPORT RemovableStorageInfo {
RemovableStorageInfo(const std::string& id,
const string16& device_name,
const FilePath::StringType& device_location);
// Unique device id - persists between device attachments.
std::string device_id;
// Human readable removable storage device name.
string16 name;
// Current attached removable storage device location.
FilePath::StringType location;
// Create SystemMonitor. Only one SystemMonitor instance per application
// is allowed.
// Get the application-wide SystemMonitor (if not present, returns NULL).
static SystemMonitor* Get();
#if defined(OS_MACOSX)
// Allocate system resources needed by the SystemMonitor class.
// This function must be called before instantiating an instance of the class
// and before the Sandbox is initialized.
#if !defined(OS_IOS)
static void AllocateSystemIOPorts();
static void AllocateSystemIOPorts() {}
#endif // OS_IOS
#endif // OS_MACOSX
// Returns information for attached removable storage.
std::vector<RemovableStorageInfo> GetAttachedRemovableStorage() const;
// Power-related APIs
// Is the computer currently on battery power.
// Can be called on any thread.
bool BatteryPower() const {
// Using a lock here is not necessary for just a bool.
return battery_in_use_;
// Callbacks will be called on the thread which creates the SystemMonitor.
// During the callback, Add/RemoveObserver will block until the callbacks
// are finished. Observers should implement quick callback functions; if
// lengthy operations are needed, the observer should take care to invoke
// the operation on an appropriate thread.
class BASE_EXPORT PowerObserver {
// Notification of a change in power status of the computer, such
// as from switching between battery and A/C power.
virtual void OnPowerStateChange(bool /*on_battery_power*/) {}
// Notification that the system is suspending.
virtual void OnSuspend() {}
// Notification that the system is resuming.
virtual void OnResume() {}
virtual ~PowerObserver() {}
class BASE_EXPORT DevicesChangedObserver {
// Notification that the devices connected to the system have changed.
// This is only implemented on Windows currently.
virtual void OnDevicesChanged(DeviceType /*device_type*/) {}
// When a removable storage device is attached or detached, one of these
// two events is triggered.
virtual void OnRemovableStorageAttached(
const std::string& /*id*/,
const string16& /*name*/,
const FilePath::StringType& /*location*/) {}
virtual void OnRemovableStorageDetached(const std::string& /*id*/) {}
virtual ~DevicesChangedObserver() {}
// Add a new observer.
// Can be called from any thread.
// Must not be called from within a notification callback.
void AddPowerObserver(PowerObserver* obs);
void AddDevicesChangedObserver(DevicesChangedObserver* obs);
// Remove an existing observer.
// Can be called from any thread.
// Must not be called from within a notification callback.
void RemovePowerObserver(PowerObserver* obs);
void RemoveDevicesChangedObserver(DevicesChangedObserver* obs);
// The ProcessFoo() style methods are a broken pattern and should not
// be copied. Any significant addition to this class is blocked on
// refactoring to improve the state of affairs. See
#if defined(OS_WIN)
// Windows-specific handling of a WM_POWERBROADCAST message.
// Embedders of this API should hook their top-level window
// message loop and forward WM_POWERBROADCAST through this call.
void ProcessWmPowerBroadcastMessage(int event_id);
// Cross-platform handling of a power event.
void ProcessPowerMessage(PowerEvent event_id);
// Cross-platform handling of a device change event.
void ProcessDevicesChanged(DeviceType device_type);
void ProcessRemovableStorageAttached(const std::string& id,
const string16& name,
const FilePath::StringType& location);
void ProcessRemovableStorageDetached(const std::string& id);
// Mapping of unique device id to device info tuple.
typedef std::map<std::string, RemovableStorageInfo> RemovableStorageMap;
#if defined(OS_MACOSX)
void PlatformInit();
void PlatformDestroy();
// Platform-specific method to check whether the system is currently
// running on battery power. Returns true if running on batteries,
// false otherwise.
bool IsBatteryPower();
// Checks the battery status and notifies observers if the battery
// status has changed.
void BatteryCheck();
// Functions to trigger notifications.
void NotifyDevicesChanged(DeviceType device_type);
void NotifyRemovableStorageAttached(const std::string& id,
const string16& name,
const FilePath::StringType& location);
void NotifyRemovableStorageDetached(const std::string& id);
void NotifyPowerStateChange();
void NotifySuspend();
void NotifyResume();
scoped_refptr<ObserverListThreadSafe<PowerObserver> > power_observer_list_;
scoped_refptr<ObserverListThreadSafe<DevicesChangedObserver> >
bool battery_in_use_;
bool suspended_;
base::OneShotTimer<SystemMonitor> delayed_battery_check_;
#if defined(OS_IOS)
// Holds pointers to system event notification observers.
std::vector<id> notification_observers_;
// For manipulating removable_storage_map_ structure.
mutable base::Lock removable_storage_lock_;
// Map of all the attached removable storage devices.
RemovableStorageMap removable_storage_map_;
} // namespace base