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
Newcontent::__anon7affa39f0111::PowerSaveBlockerLazyInstanceTraits29 static base::Thread* New(void* instance) {
30 base::Thread* thread = new (instance) base::Thread("PowerSaveBlocker");
31 thread->Start();
32 return thread;
33 }
Deletecontent::__anon7affa39f0111::PowerSaveBlockerLazyInstanceTraits34 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:
Delegate(PowerSaveBlockerType type,const std::string & reason)44 Delegate(PowerSaveBlockerType type, const std::string& reason)
45 : type_(type), reason_(reason), assertion_(kIOPMNullAssertionID) {}
46
47 // Does the actual work to apply or remove the desired power save block.
48 void ApplyBlock();
49 void RemoveBlock();
50
51 private:
52 friend class base::RefCountedThreadSafe<Delegate>;
~Delegate()53 ~Delegate() {}
54 PowerSaveBlockerType type_;
55 std::string reason_;
56 IOPMAssertionID assertion_;
57 };
58
ApplyBlock()59 void PowerSaveBlockerImpl::Delegate::ApplyBlock() {
60 DCHECK_EQ(base::PlatformThread::CurrentId(),
61 g_power_thread.Pointer()->thread_id());
62
63 CFStringRef level = NULL;
64 // See QA1340 <http://developer.apple.com/library/mac/#qa/qa1340/> for more
65 // details.
66 switch (type_) {
67 case PowerSaveBlocker::kPowerSaveBlockPreventAppSuspension:
68 level = kIOPMAssertionTypeNoIdleSleep;
69 break;
70 case PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep:
71 level = kIOPMAssertionTypeNoDisplaySleep;
72 break;
73 default:
74 NOTREACHED();
75 break;
76 }
77 if (level) {
78 base::ScopedCFTypeRef<CFStringRef> cf_reason(
79 base::SysUTF8ToCFStringRef(reason_));
80 IOReturn result = IOPMAssertionCreateWithName(level,
81 kIOPMAssertionLevelOn,
82 cf_reason,
83 &assertion_);
84 LOG_IF(ERROR, result != kIOReturnSuccess)
85 << "IOPMAssertionCreate: " << result;
86 }
87 }
88
RemoveBlock()89 void PowerSaveBlockerImpl::Delegate::RemoveBlock() {
90 DCHECK_EQ(base::PlatformThread::CurrentId(),
91 g_power_thread.Pointer()->thread_id());
92
93 if (assertion_ != kIOPMNullAssertionID) {
94 IOReturn result = IOPMAssertionRelease(assertion_);
95 LOG_IF(ERROR, result != kIOReturnSuccess)
96 << "IOPMAssertionRelease: " << result;
97 }
98 }
99
PowerSaveBlockerImpl(PowerSaveBlockerType type,const std::string & reason)100 PowerSaveBlockerImpl::PowerSaveBlockerImpl(PowerSaveBlockerType type,
101 const std::string& reason)
102 : delegate_(new Delegate(type, reason)) {
103 g_power_thread.Pointer()->message_loop()->PostTask(
104 FROM_HERE,
105 base::Bind(&Delegate::ApplyBlock, delegate_));
106 }
107
~PowerSaveBlockerImpl()108 PowerSaveBlockerImpl::~PowerSaveBlockerImpl() {
109 g_power_thread.Pointer()->message_loop()->PostTask(
110 FROM_HERE,
111 base::Bind(&Delegate::RemoveBlock, delegate_));
112 }
113
114 } // namespace content
115