1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/ipc/chromium/src/base/system_monitor.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,129 @@
1.4 +// Copyright (c) 2008 The Chromium Authors. All rights reserved.
1.5 +// Use of this source code is governed by a BSD-style license that can be
1.6 +// found in the LICENSE file.
1.7 +
1.8 +#ifndef BASE_SYSTEM_MONITOR_H_
1.9 +#define BASE_SYSTEM_MONITOR_H_
1.10 +
1.11 +#include "base/observer_list_threadsafe.h"
1.12 +#include "base/singleton.h"
1.13 +
1.14 +// Windows HiRes timers drain the battery faster so we need to know the battery
1.15 +// status. This isn't true for other platforms.
1.16 +#if defined(OS_WIN)
1.17 +#define ENABLE_BATTERY_MONITORING 1
1.18 +#else
1.19 +#undef ENABLE_BATTERY_MONITORING
1.20 +#endif // !OS_WIN
1.21 +
1.22 +namespace base {
1.23 +
1.24 +// Class for monitoring various system-related subsystems
1.25 +// such as power management, network status, etc.
1.26 +// TODO(mbelshe): Add support beyond just power management.
1.27 +class SystemMonitor {
1.28 + public:
1.29 + // Access to the Singleton
1.30 + static SystemMonitor* Get() {
1.31 + // Uses the LeakySingletonTrait because cleanup is optional.
1.32 + return
1.33 + Singleton<SystemMonitor, LeakySingletonTraits<SystemMonitor> >::get();
1.34 + }
1.35 +
1.36 + // Start the System Monitor within a process. This method
1.37 + // is provided so that the battery check can be deferred.
1.38 + // The MessageLoop must be started before calling this
1.39 + // method.
1.40 + // This is a no-op on platforms for which ENABLE_BATTERY_MONITORING is
1.41 + // disabled.
1.42 + static void Start();
1.43 +
1.44 + //
1.45 + // Power-related APIs
1.46 + //
1.47 +
1.48 + // Is the computer currently on battery power.
1.49 + // Can be called on any thread.
1.50 + bool BatteryPower() {
1.51 + // Using a lock here is not necessary for just a bool.
1.52 + return battery_in_use_;
1.53 + }
1.54 +
1.55 + // Normalized list of power events.
1.56 + enum PowerEvent {
1.57 + POWER_STATE_EVENT, // The Power status of the system has changed.
1.58 + SUSPEND_EVENT, // The system is being suspended.
1.59 + RESUME_EVENT // The system is being resumed.
1.60 + };
1.61 +
1.62 + // Callbacks will be called on the thread which creates the SystemMonitor.
1.63 + // During the callback, Add/RemoveObserver will block until the callbacks
1.64 + // are finished. Observers should implement quick callback functions; if
1.65 + // lengthy operations are needed, the observer should take care to invoke
1.66 + // the operation on an appropriate thread.
1.67 + class PowerObserver {
1.68 + public:
1.69 + // Notification of a change in power status of the computer, such
1.70 + // as from switching between battery and A/C power.
1.71 + virtual void OnPowerStateChange(SystemMonitor*) = 0;
1.72 +
1.73 + // Notification that the system is suspending.
1.74 + virtual void OnSuspend(SystemMonitor*) = 0;
1.75 +
1.76 + // Notification that the system is resuming.
1.77 + virtual void OnResume(SystemMonitor*) = 0;
1.78 + };
1.79 +
1.80 + // Add a new observer.
1.81 + // Can be called from any thread.
1.82 + // Must not be called from within a notification callback.
1.83 + void AddObserver(PowerObserver* obs);
1.84 +
1.85 + // Remove an existing observer.
1.86 + // Can be called from any thread.
1.87 + // Must not be called from within a notification callback.
1.88 + void RemoveObserver(PowerObserver* obs);
1.89 +
1.90 +#if defined(OS_WIN)
1.91 + // Windows-specific handling of a WM_POWERBROADCAST message.
1.92 + // Embedders of this API should hook their top-level window
1.93 + // message loop and forward WM_POWERBROADCAST through this call.
1.94 + void ProcessWmPowerBroadcastMessage(int event_id);
1.95 +#endif
1.96 +
1.97 + // Cross-platform handling of a power event.
1.98 + void ProcessPowerMessage(PowerEvent event_id);
1.99 +
1.100 + // Constructor.
1.101 + // Don't use this; access SystemMonitor via the Singleton.
1.102 + SystemMonitor();
1.103 +
1.104 + private:
1.105 + // Platform-specific method to check whether the system is currently
1.106 + // running on battery power. Returns true if running on batteries,
1.107 + // false otherwise.
1.108 + bool IsBatteryPower();
1.109 +
1.110 + // Checks the battery status and notifies observers if the battery
1.111 + // status has changed.
1.112 + void BatteryCheck();
1.113 +
1.114 + // Functions to trigger notifications.
1.115 + void NotifyPowerStateChange();
1.116 + void NotifySuspend();
1.117 + void NotifyResume();
1.118 +
1.119 + scoped_refptr<ObserverListThreadSafe<PowerObserver> > observer_list_;
1.120 + bool battery_in_use_;
1.121 + bool suspended_;
1.122 +
1.123 +#if defined(ENABLE_BATTERY_MONITORING)
1.124 + base::OneShotTimer<SystemMonitor> delayed_battery_check_;
1.125 +#endif
1.126 +
1.127 + DISALLOW_COPY_AND_ASSIGN(SystemMonitor);
1.128 +};
1.129 +
1.130 +}
1.131 +
1.132 +#endif // BASE_SYSTEM_MONITOR_H_
