SystemMonitor refactoring: move power state monitor into a separate class called PowerMonitor

base/power_monitor/power_monitor.cc

 // 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 "base/threading/worker_pool.h"

[vandebo (ex-Chrome), 2012/10/11 20:49:57]

It detected this as a copy from the wrong file, you might try dialing back the
similarity factor.

[Hongbo Min, 2012/10/12 14:43:53]

Done.

-
-#include "base/bind.h"
-#include "base/callback.h"
-#include "base/debug/trace_event.h"
-#include "base/logging.h"
-#include "base/pending_task.h"
-#include "base/threading/thread_local.h"
-#include "base/tracked_objects.h"
+#include "base/power_monitor/power_monitor.h"
 
 namespace base {
 
-namespace {
+#if defined(ENABLE_BATTERY_MONITORING)
+// The amount of time (in ms) to wait before running the initial
+// battery check.
+static int kDelayedBatteryCheckMs = 10 * 1000;
+#endif  // defined(ENABLE_BATTERY_MONITORING)
 
-base::LazyInstance<ThreadLocalBoolean>::Leaky
-    g_worker_pool_running_on_this_thread = LAZY_INSTANCE_INITIALIZER;
+PowerMonitor::PowerMonitor()
+    : observers_(new ObserverListThreadSafe<PowerObserver>()),
+      battery_in_use_(false),
+      suspended_(false) {
+  DCHECK(MessageLoop::current());
+#if defined(ENABLE_BATTERY_MONITORING)
+  delayed_battery_check_.Start(FROM_HERE,
+      base::TimeDelta::FromMilliseconds(kDelayedBatteryCheckMs), this,
+      &PowerMonitor::BatteryCheck);
+#endif  // defined(ENABLE_BATTERY_MONITORING)
 
-DWORD CALLBACK WorkItemCallback(void* param) {
-  PendingTask* pending_task = static_cast<PendingTask*>(param);
-  TRACE_EVENT2("task", "WorkItemCallback::Run",
-               "src_file", pending_task->posted_from.file_name(),
-               "src_func", pending_task->posted_from.function_name());
-
-  tracked_objects::TrackedTime start_time =
-      tracked_objects::ThreadData::NowForStartOfRun(pending_task->birth_tally);
-
-  g_worker_pool_running_on_this_thread.Get().Set(true);
-  pending_task->task.Run();
-  g_worker_pool_running_on_this_thread.Get().Set(false);
-
-  tracked_objects::ThreadData::TallyRunOnWorkerThreadIfTracking(
-      pending_task->birth_tally,
-      tracked_objects::TrackedTime(pending_task->time_posted), start_time,
-      tracked_objects::ThreadData::NowForEndOfRun());
-
-  delete pending_task;
-  return 0;
+#if defined(OS_MACOSX)
+  PlatformInit();
+#endif
 }
 
-// Takes ownership of |pending_task|
-bool PostTaskInternal(PendingTask* pending_task, bool task_is_slow) {
-  ULONG flags = 0;
-  if (task_is_slow)
-    flags |= WT_EXECUTELONGFUNCTION;
-
-  if (!QueueUserWorkItem(WorkItemCallback, pending_task, flags)) {
-    DLOG(ERROR) << "QueueUserWorkItem failed: " << GetLastError();
-    delete pending_task;
-    return false;
-  }
-
-  return true;
-}
-
-}  // namespace
-
-// static
-bool WorkerPool::PostTask(const tracked_objects::Location& from_here,
-                          const base::Closure& task, bool task_is_slow) {
-  PendingTask* pending_task = new PendingTask(from_here, task);
-  return PostTaskInternal(pending_task, task_is_slow);
+PowerMonitor::~PowerMonitor() {
+#if defined(OS_MACOSX)
+  PlaformDestory();
+#endif
 }
 
 // static
-bool WorkerPool::RunsTasksOnCurrentThread() {
-  return g_worker_pool_running_on_this_thread.Get().Get();
+PowerMonitor* PowerMonitor::GetInstance() {
+  return Singleton<PowerMonitor>::get();
+}
+
+void PowerMonitor::AddObserver(PowerObserver* obs) {
+  observers_->AddObserver(obs);
+}
+
+void PowerMonitor::RemoveObserver(PowerObserver* obs) {
+  observers_->RemoveObserver(obs);
+}
+
+void PowerMonitor::ProcessPowerMessage(PowerEvent event_id) {
+  // Suppress duplicate notifications.  Some platforms may
+  // send multiple notifications of the same event.
+  switch (event_id) {
+    case POWER_STATE_EVENT:
+      {
+        bool on_battery = IsBatteryPower();
+        if (on_battery != battery_in_use_) {
+          battery_in_use_ = on_battery;
+          NotifyPowerStateChange();
+        }
+      }
+      break;
+    case RESUME_EVENT:
+      if (suspended_) {
+        suspended_ = false;
+        NotifyResume();
+      }
+      break;
+    case SUSPEND_EVENT:
+      if (!suspended_) {
+        suspended_ = true;
+        NotifySuspend();
+      }
+      break;
+  }
+}
+
+void PowerMonitor::NotifyPowerStateChange() {
+  DVLOG(1) << "PowerStateChange: " << (BatteryPower() ? "On" : "Off")
+           << " battery";
+  observers_->Notify(&PowerObserver::OnPowerStateChange,
+                               BatteryPower());
+}
+
+void PowerMonitor::NotifySuspend() {
+  DVLOG(1) << "Power Suspending";
+  observers_->Notify(&PowerObserver::OnSuspend);
+}
+
+void PowerMonitor::NotifyResume() {
+  DVLOG(1) << "Power Resuming";
+  observers_->Notify(&PowerObserver::OnResume);
+}
+
+void PowerMonitor::BatteryCheck() {
+  ProcessPowerMessage(PowerMonitor::POWER_STATE_EVENT);
 }
 
 }  // namespace base
+