media/audio/win/avrt_wrapper_win.h

   1 // Copyright (c) 2011 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 // The avrt namespace encapsulates the details needed to support MMCSS.
   6 //
   7 // The Multimedia Class Scheduler service (MMCSS) enables multimedia
   8 // applications to ensure that their time-sensitive processing receives
   9 // prioritized access to CPU resources. This service enables multimedia
  10 // applications to utilize as much of the CPU as possible without denying
  11 // CPU resources to lower-priority applications.
  12 // MMCSS requires Windows Vista or higher and that the Avrt DLL is loaded.
  13 //
  14 // TODO(henrika): refactor and merge into existing thread implementation
  15 // for Windows to ensure that MMCSS can be enabled for all threads.
  16 //
  17 #ifndef MEDIA_AUDIO_WIN_AVRT_WRAPPER_WIN_H_
  18 #define MEDIA_AUDIO_WIN_AVRT_WRAPPER_WIN_H_
  19
  20 #include <windows.h>
  21 #include <avrt.h>
  22
  23 #include "base/basictypes.h"
  24
  25 namespace avrt {
  26
  27 // Loads the Avrt.dll which is available on Windows Vista and later.
  28 bool Initialize();
  29
  30 // Function wrappers for the underlying MMCSS functions.
  31 bool AvRevertMmThreadCharacteristics(HANDLE avrt_handle);
  32 HANDLE AvSetMmThreadCharacteristics(const wchar_t* task_name,
  33                                     DWORD* task_index);
  34 bool AvSetMmThreadPriority(HANDLE avrt_handle, AVRT_PRIORITY priority);
  35
  36 }  // namespace avrt
  37
  38 #endif  // MEDIA_AUDIO_WIN_AVRT_WRAPPER_WIN_H_
  39