board/MAI/bios_emulator/scitech/src/pm/win32/cpuinfo.c

   1 /****************************************************************************
   2 *
   3 *                         Ultra Long Period Timer
   4 *
   5 *  ========================================================================
   6 *
   7 *    The contents of this file are subject to the SciTech MGL Public
   8 *    License Version 1.0 (the "License"); you may not use this file
   9 *    except in compliance with the License. You may obtain a copy of
  10 *    the License at http://www.scitechsoft.com/mgl-license.txt
  11 *
  12 *    Software distributed under the License is distributed on an
  13 *    "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
  14 *    implied. See the License for the specific language governing
  15 *    rights and limitations under the License.
  16 *
  17 *    The Original Code is Copyright (C) 1991-1998 SciTech Software, Inc.
  18 *
  19 *    The Initial Developer of the Original Code is SciTech Software, Inc.
  20 *    All Rights Reserved.
  21 *
  22 *  ========================================================================
  23 *
  24 * Language:     ANSI C
  25 * Environment:  Win32
  26 *
  27 * Description:  Module to implement OS specific services to measure the
  28 *               CPU frequency.
  29 *
  30 ****************************************************************************/
  31
  32 /*---------------------------- Global variables ---------------------------*/
  33
  34 static ibool havePerformanceCounter;
  35
  36 /*----------------------------- Implementation ----------------------------*/
  37
  38 /****************************************************************************
  39 REMARKS:
  40 Increase the thread priority to maximum, if possible.
  41 ****************************************************************************/
  42 static int SetMaxThreadPriority(void)
  43 {
  44     int     oldPriority;
  45     HANDLE  hThread = GetCurrentThread();
  46
  47     oldPriority = GetThreadPriority(hThread);
  48     if (oldPriority != THREAD_PRIORITY_ERROR_RETURN)
  49         SetThreadPriority(hThread, THREAD_PRIORITY_TIME_CRITICAL);
  50     return oldPriority;
  51 }
  52
  53 /****************************************************************************
  54 REMARKS:
  55 Restore the original thread priority.
  56 ****************************************************************************/
  57 static void RestoreThreadPriority(
  58     int oldPriority)
  59 {
  60     HANDLE  hThread = GetCurrentThread();
  61
  62     if (oldPriority != THREAD_PRIORITY_ERROR_RETURN)
  63         SetThreadPriority(hThread, oldPriority);
  64 }
  65
  66 /****************************************************************************
  67 REMARKS:
  68 Initialise the counter and return the frequency of the counter.
  69 ****************************************************************************/
  70 static void GetCounterFrequency(
  71     CPU_largeInteger *freq)
  72 {
  73     if (!QueryPerformanceFrequency((LARGE_INTEGER*)freq)) {
  74         havePerformanceCounter = false;
  75         freq->low = 100000;
  76         freq->high = 0;
  77         }
  78     else
  79         havePerformanceCounter = true;
  80 }
  81
  82 /****************************************************************************
  83 REMARKS:
  84 Read the counter and return the counter value.
  85 ****************************************************************************/
  86 #define GetCounter(t)                                       \
  87 {                                                           \
  88     if (havePerformanceCounter)                             \
  89         QueryPerformanceCounter((LARGE_INTEGER*)t);         \
  90     else {                                                  \
  91         (t)->low = timeGetTime() * 100;                     \
  92         (t)->high = 0;                                      \
  93         }                                                   \
  94 }