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

base/power_monitor/power_monitor_mac.mm

 // 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.
 
 // Implementation based on sample code from
 // http://developer.apple.com/library/mac/#qa/qa1340/_index.html.
 
-#include "base/system_monitor/system_monitor.h"
+#include "base/power_monitor/power_monitor.h"
 
 #include <IOKit/pwr_mgt/IOPMLib.h>
 #include <IOKit/IOMessage.h>
 
 namespace base {
 
 namespace {
 
 io_connect_t g_system_power_io_port = 0;
 IONotificationPortRef g_notification_port_ref = 0;
 io_object_t g_notifier_object = 0;
+PowerMonitor::Notifier* g_power_notifier = NULL;
 
 void SystemPowerEventCallback(void*,
                               io_service_t service,
                               natural_t message_type,
                               void* message_argument) {
-  SystemMonitor* sys_monitor = SystemMonitor::Get();
-  DCHECK(sys_monitor);
+  if (g_power_notifier == NULL)
+    g_power_notifier = PowerMonitor::GetInstance()->GetNotifierOnce();

[vandebo (ex-Chrome), 2012/10/23 01:27:57]

Set this in PlatformInit and assert that we get it?

+
   switch (message_type) {
     case kIOMessageSystemWillSleep:
-      sys_monitor->ProcessPowerMessage(SystemMonitor::SUSPEND_EVENT);
+      if (g_power_notifier)
+        g_power_notifier->ProcessPowerEvent(base::PowerMonitor::SUSPEND_EVENT);
       IOAllowPowerChange(g_system_power_io_port,
           reinterpret_cast<intptr_t>(message_argument));
       break;
 
     case kIOMessageSystemWillPowerOn:
-      sys_monitor->ProcessPowerMessage(SystemMonitor::RESUME_EVENT);
+      if (g_power_notifier)
+        g_power_notifier->ProcessPowerEvent(PowerMonitor::RESUME_EVENT);
       break;
   }
 }
 
 }  // namespace
 
 // The reason we can't include this code in the constructor is because
 // PlatformInit() requires an active runloop and the IO port needs to be
 // allocated at sandbox initialization time, before there's a runloop.
 // See crbug.com/83783 .
 
 // static
-void SystemMonitor::AllocateSystemIOPorts() {
-  DCHECK_EQ(g_system_power_io_port, 0u);

[Hongbo Min, 2012/10/21 09:56:03]

If I keep the original DCHECK_EQ stmt, lots of test will fail. The root cause
is, AllocateSystemIOPorts is only allowed to be called once, but each test needs
to call it at the beginning of testing, as descried by vandebo.

The thing makes me confused is, DCHECK_EQ should only have an effect in debug
mode, according to the trybot result, the DCHECK also happens although building
mac_rel with Relase mode, and therefore the test fails.

[vandebo (ex-Chrome), 2012/10/23 01:27:57]

DCHECKs are used on the bots even in release mode.  We started doing this
because debug mode would often fail on DCHECKs without people noticing.

+void PowerMonitor::AllocateSystemIOPorts() {
+  if (g_system_power_io_port != 0u)
+    return;
 
   // Notification port allocated by IORegisterForSystemPower.
 
   g_system_power_io_port = IORegisterForSystemPower(
       NULL, &g_notification_port_ref, SystemPowerEventCallback,
       &g_notifier_object);
 
   DCHECK_NE(g_system_power_io_port, 0u);
 }
 
-void SystemMonitor::PlatformInit() {
-  // Need to call AllocateSystemIOPorts() before constructing a SystemMonitor
+void PowerMonitor::PlatformInit() {
+  // Need to call AllocateSystemIOPorts() before creating a PowerMonitor
   // object.
-  DCHECK_NE(g_system_power_io_port, 0u);
-  if (g_system_power_io_port == 0)
-    return;
+  CHECK_NE(g_system_power_io_port, 0u);
 
   // Add the notification port to the application runloop
   CFRunLoopAddSource(
       CFRunLoopGetCurrent(),
       IONotificationPortGetRunLoopSource(g_notification_port_ref),
       kCFRunLoopCommonModes);
 }
 
-void SystemMonitor::PlatformDestroy() {
-  DCHECK_NE(g_system_power_io_port, 0u);
-  if (g_system_power_io_port == 0)
-    return;
+
+void PowerMonitor::PlatformDestroy() {
+  CHECK_NE(g_system_power_io_port, 0u);
 
   // Remove the sleep notification port from the application runloop
   CFRunLoopRemoveSource(
       CFRunLoopGetCurrent(),
       IONotificationPortGetRunLoopSource(g_notification_port_ref),
       kCFRunLoopCommonModes);
 
   // Deregister for system sleep notifications
   IODeregisterForSystemPower(&g_notifier_object);
 
   // IORegisterForSystemPower implicitly opens the Root Power Domain IOService,
   // so we close it here.
   IOServiceClose(g_system_power_io_port);
 
   g_system_power_io_port = 0;
 
   // Destroy the notification port allocated by IORegisterForSystemPower.
   IONotificationPortDestroy(g_notification_port_ref);
 }
 
 }  // namespace base