base/system_monitor/system_monitor.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/system_monitor/system_monitor.h"
   6
   7 #include <utility>
   8
   9 #include "base/logging.h"
  10 #include "base/message_loop/message_loop.h"
  11 #include "base/time/time.h"
  12
  13 namespace base {
  14
  15 static SystemMonitor* g_system_monitor = NULL;
  16
  17 SystemMonitor::SystemMonitor()
  18     :  devices_changed_observer_list_(
  19           new ObserverListThreadSafe<DevicesChangedObserver>()) {
  20   DCHECK(!g_system_monitor);
  21   g_system_monitor = this;
  22 }
  23
  24 SystemMonitor::~SystemMonitor() {
  25   DCHECK_EQ(this, g_system_monitor);
  26   g_system_monitor = NULL;
  27 }
  28
  29 // static
  30 SystemMonitor* SystemMonitor::Get() {
  31   return g_system_monitor;
  32 }
  33
  34 void SystemMonitor::ProcessDevicesChanged(DeviceType device_type) {
  35   NotifyDevicesChanged(device_type);
  36 }
  37
  38 void SystemMonitor::AddDevicesChangedObserver(DevicesChangedObserver* obs) {
  39   devices_changed_observer_list_->AddObserver(obs);
  40 }
  41
  42 void SystemMonitor::RemoveDevicesChangedObserver(DevicesChangedObserver* obs) {
  43   devices_changed_observer_list_->RemoveObserver(obs);
  44 }
  45
  46 void SystemMonitor::NotifyDevicesChanged(DeviceType device_type) {
  47   DVLOG(1) << "DevicesChanged with device type " << device_type;
  48   devices_changed_observer_list_->Notify(
  49       FROM_HERE, &DevicesChangedObserver::OnDevicesChanged, device_type);
  50 }
  51
  52 }  // namespace base