content/browser/power_save_blocker_win.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 <windows.h>
   8
   9 #include "base/logging.h"
  10 #include "base/strings/utf_string_conversions.h"
  11 #include "base/win/scoped_handle.h"
  12 #include "base/win/windows_version.h"
  13 #include "content/public/browser/browser_thread.h"
  14
  15 namespace content {
  16 namespace {
  17
  18 int g_blocker_count[2];
  19
  20 HANDLE CreatePowerRequest(POWER_REQUEST_TYPE type, const std::string& reason) {
  21   typedef HANDLE (WINAPI* PowerCreateRequestPtr)(PREASON_CONTEXT);
  22   typedef BOOL (WINAPI* PowerSetRequestPtr)(HANDLE, POWER_REQUEST_TYPE);
  23
  24   if (type == PowerRequestExecutionRequired &&
  25       base::win::GetVersion() < base::win::VERSION_WIN8) {
  26     return INVALID_HANDLE_VALUE;
  27   }
  28
  29   static PowerCreateRequestPtr PowerCreateRequestFn = NULL;
  30   static PowerSetRequestPtr PowerSetRequestFn = NULL;
  31
  32   if (!PowerCreateRequestFn || !PowerSetRequestFn) {
  33     HMODULE module = GetModuleHandle(L"kernel32.dll");
  34     PowerCreateRequestFn = reinterpret_cast<PowerCreateRequestPtr>(
  35         GetProcAddress(module, "PowerCreateRequest"));
  36     PowerSetRequestFn = reinterpret_cast<PowerSetRequestPtr>(
  37         GetProcAddress(module, "PowerSetRequest"));
  38
  39     if (!PowerCreateRequestFn || !PowerSetRequestFn)
  40       return INVALID_HANDLE_VALUE;
  41   }
  42   string16 wide_reason = ASCIIToUTF16(reason);
  43   REASON_CONTEXT context = {0};
  44   context.Version = POWER_REQUEST_CONTEXT_VERSION;
  45   context.Flags = POWER_REQUEST_CONTEXT_SIMPLE_STRING;
  46   context.Reason.SimpleReasonString = const_cast<wchar_t*>(wide_reason.c_str());
  47
  48   base::win::ScopedHandle handle(PowerCreateRequestFn(&context));
  49   if (!handle.IsValid())
  50     return INVALID_HANDLE_VALUE;
  51
  52   if (PowerSetRequestFn(handle, type))
  53     return handle.Take();
  54
  55   // Something went wrong.
  56   return INVALID_HANDLE_VALUE;
  57 }
  58
  59 // Takes ownership of the |handle|.
  60 void DeletePowerRequest(POWER_REQUEST_TYPE type, HANDLE handle) {
  61   base::win::ScopedHandle request_handle(handle);
  62   if (!request_handle.IsValid())
  63     return;
  64
  65   if (type == PowerRequestExecutionRequired &&
  66       base::win::GetVersion() < base::win::VERSION_WIN8) {
  67     return;
  68   }
  69
  70   typedef BOOL (WINAPI* PowerClearRequestPtr)(HANDLE, POWER_REQUEST_TYPE);
  71   HMODULE module = GetModuleHandle(L"kernel32.dll");
  72   PowerClearRequestPtr PowerClearRequestFn =
  73       reinterpret_cast<PowerClearRequestPtr>(
  74           GetProcAddress(module, "PowerClearRequest"));
  75
  76   if (!PowerClearRequestFn)
  77     return;
  78
  79   BOOL success = PowerClearRequestFn(request_handle, type);
  80   DCHECK(success);
  81 }
  82
  83 void ApplySimpleBlock(PowerSaveBlocker::PowerSaveBlockerType type,
  84                       int delta) {
  85   g_blocker_count[type] += delta;
  86   DCHECK_GE(g_blocker_count[type], 0);
  87
  88   if (g_blocker_count[type] > 1)
  89     return;
  90
  91   DWORD this_flag = 0;
  92   if (type == PowerSaveBlocker::kPowerSaveBlockPreventAppSuspension)
  93     this_flag |= ES_SYSTEM_REQUIRED;
  94   else
  95     this_flag |= ES_DISPLAY_REQUIRED;
  96
  97   DCHECK(this_flag);
  98
  99   static DWORD flags = ES_CONTINUOUS;
 100   if (!g_blocker_count[type])
 101     flags &= ~this_flag;
 102   else
 103     flags |= this_flag;
 104
 105   SetThreadExecutionState(flags);
 106 }
 107
 108 }  // namespace
 109
 110 class PowerSaveBlockerImpl::Delegate
 111     : public base::RefCountedThreadSafe<PowerSaveBlockerImpl::Delegate> {
 112  public:
 113   Delegate(PowerSaveBlockerType type, const std::string& reason)
 114       : type_(type), reason_(reason) {}
 115
 116   // Does the actual work to apply or remove the desired power save block.
 117   void ApplyBlock();
 118   void RemoveBlock();
 119
 120   // Returns the equivalent POWER_REQUEST_TYPE for this request.
 121   POWER_REQUEST_TYPE RequestType();
 122
 123  private:
 124   friend class base::RefCountedThreadSafe<Delegate>;
 125   ~Delegate() {}
 126
 127   PowerSaveBlockerType type_;
 128   const std::string reason_;
 129   base::win::ScopedHandle handle_;
 130
 131   DISALLOW_COPY_AND_ASSIGN(Delegate);
 132 };
 133
 134 void PowerSaveBlockerImpl::Delegate::ApplyBlock() {
 135   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 136   if (base::win::GetVersion() < base::win::VERSION_WIN7)
 137     return ApplySimpleBlock(type_, 1);
 138
 139   handle_.Set(CreatePowerRequest(RequestType(), reason_));
 140 }
 141
 142 void PowerSaveBlockerImpl::Delegate::RemoveBlock() {
 143   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 144   if (base::win::GetVersion() < base::win::VERSION_WIN7)
 145     return ApplySimpleBlock(type_, -1);
 146
 147   DeletePowerRequest(RequestType(), handle_.Take());
 148 }
 149
 150 POWER_REQUEST_TYPE PowerSaveBlockerImpl::Delegate::RequestType() {
 151   if (type_ == kPowerSaveBlockPreventDisplaySleep)
 152     return PowerRequestDisplayRequired;
 153
 154   if (base::win::GetVersion() < base::win::VERSION_WIN8)
 155     return PowerRequestSystemRequired;
 156
 157   return PowerRequestExecutionRequired;
 158 }
 159
 160 PowerSaveBlockerImpl::PowerSaveBlockerImpl(PowerSaveBlockerType type,
 161                                            const std::string& reason)
 162     : delegate_(new Delegate(type, reason)) {
 163   BrowserThread::PostTask(
 164       BrowserThread::UI, FROM_HERE,
 165       base::Bind(&Delegate::ApplyBlock, delegate_));
 166 }
 167
 168 PowerSaveBlockerImpl::~PowerSaveBlockerImpl() {
 169   BrowserThread::PostTask(
 170       BrowserThread::UI, FROM_HERE,
 171       base::Bind(&Delegate::RemoveBlock, delegate_));
 172 }
 173
 174 }  // namespace content