content/browser/power_save_blocker_mac.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 "content/browser/power_save_blocker_impl.h"
   6
   7 #include <IOKit/pwr_mgt/IOPMLib.h>
   8
   9 #include "base/bind.h"
  10 #include "base/lazy_instance.h"
  11 #include "base/mac/scoped_cftyperef.h"
  12 #include "base/strings/sys_string_conversions.h"
  13 #include "base/threading/platform_thread.h"
  14 #include "base/threading/thread.h"
  15
  16 namespace content {
  17 namespace {
  18
  19 // Power management cannot be done on the UI thread. IOPMAssertionCreate does a
  20 // synchronous MIG call to configd, so if it is called on the main thread the UI
  21 // is at the mercy of another process. See http://crbug.com/79559 and
  22 // http://www.opensource.apple.com/source/IOKitUser/IOKitUser-514.16.31/pwr_mgt.subproj/IOPMLibPrivate.c .
  23 struct PowerSaveBlockerLazyInstanceTraits {
  24   static const bool kRegisterOnExit = false;
  25 #ifndef NDEBUG
  26   static const bool kAllowedToAccessOnNonjoinableThread = true;
  27 #endif
  28
  29   static base::Thread* New(void* instance) {
  30     base::Thread* thread = new (instance) base::Thread("PowerSaveBlocker");
  31     thread->Start();
  32     return thread;
  33   }
  34   static void Delete(base::Thread* instance) { }
  35 };
  36 base::LazyInstance<base::Thread, PowerSaveBlockerLazyInstanceTraits>
  37     g_power_thread = LAZY_INSTANCE_INITIALIZER;
  38
  39 }  // namespace
  40
  41 class PowerSaveBlockerImpl::Delegate
  42     : public base::RefCountedThreadSafe<PowerSaveBlockerImpl::Delegate> {
  43  public:
  44   Delegate(PowerSaveBlockerType type, const std::string& description)
  45       : type_(type),
  46         description_(description),
  47         assertion_(kIOPMNullAssertionID) {}
  48
  49   // Does the actual work to apply or remove the desired power save block.
  50   void ApplyBlock();
  51   void RemoveBlock();
  52
  53  private:
  54   friend class base::RefCountedThreadSafe<Delegate>;
  55   ~Delegate() {}
  56   PowerSaveBlockerType type_;
  57   std::string description_;
  58   IOPMAssertionID assertion_;
  59 };
  60
  61 void PowerSaveBlockerImpl::Delegate::ApplyBlock() {
  62   DCHECK_EQ(base::PlatformThread::CurrentId(),
  63             g_power_thread.Pointer()->GetThreadId());
  64
  65   CFStringRef level = NULL;
  66   // See QA1340 <http://developer.apple.com/library/mac/#qa/qa1340/> for more
  67   // details.
  68   switch (type_) {
  69     case PowerSaveBlocker::kPowerSaveBlockPreventAppSuspension:
  70       level = kIOPMAssertionTypeNoIdleSleep;
  71       break;
  72     case PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep:
  73       level = kIOPMAssertionTypeNoDisplaySleep;
  74       break;
  75     default:
  76       NOTREACHED();
  77       break;
  78   }
  79   if (level) {
  80     base::ScopedCFTypeRef<CFStringRef> cf_description(
  81         base::SysUTF8ToCFStringRef(description_));
  82     IOReturn result = IOPMAssertionCreateWithName(level, kIOPMAssertionLevelOn,
  83                                                   cf_description, &assertion_);
  84     LOG_IF(ERROR, result != kIOReturnSuccess)
  85         << "IOPMAssertionCreate: " << result;
  86   }
  87 }
  88
  89 void PowerSaveBlockerImpl::Delegate::RemoveBlock() {
  90   DCHECK_EQ(base::PlatformThread::CurrentId(),
  91             g_power_thread.Pointer()->GetThreadId());
  92
  93   if (assertion_ != kIOPMNullAssertionID) {
  94     IOReturn result = IOPMAssertionRelease(assertion_);
  95     LOG_IF(ERROR, result != kIOReturnSuccess)
  96         << "IOPMAssertionRelease: " << result;
  97   }
  98 }
  99
 100 PowerSaveBlockerImpl::PowerSaveBlockerImpl(PowerSaveBlockerType type,
 101                                            Reason reason,
 102                                            const std::string& description)
 103     : delegate_(new Delegate(type, description)) {
 104   g_power_thread.Pointer()->message_loop()->PostTask(
 105       FROM_HERE,
 106       base::Bind(&Delegate::ApplyBlock, delegate_));
 107 }
 108
 109 PowerSaveBlockerImpl::~PowerSaveBlockerImpl() {
 110   g_power_thread.Pointer()->message_loop()->PostTask(
 111       FROM_HERE,
 112       base::Bind(&Delegate::RemoveBlock, delegate_));
 113 }
 114
 115 }  // namespace content