winhog.c

   1 #define WIN32_LEAN_AND_MEAN
   2 #include <windows.h>
   3 #include <mmsystem.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6
   7 #define NITERS 10
   8 static volatile stop;
   9
  10 static DWORD_PTR hog (DWORD_PTR count)
  11 {
  12     DWORD_PTR i = 0;
  13     while (i < count && !stop) ++i;
  14     return i;
  15 }
  16
  17 static void CALLBACK timer_callback (
  18     UINT uTimerID,
  19     UINT uMsg,
  20     DWORD_PTR dwUser,
  21     DWORD_PTR dw1,
  22     DWORD_PTR dw2
  23     )
  24 {
  25     if (!dwUser)
  26         stop = 1;
  27     else {
  28         stop = 0;
  29         hog (dwUser);
  30     }
  31 }
  32
  33 static UINT settimer (DWORD_PTR val)
  34 {
  35     MMRESULT mr;
  36
  37     mr = timeSetEvent (1, 0, timer_callback, val,
  38                        TIME_PERIODIC | TIME_CALLBACK_FUNCTION);
  39     if (!mr) {
  40         fprintf (stderr, "timeSetEvent failed: %ld\n", GetLastError ());
  41         exit (EXIT_FAILURE);
  42     }
  43     return mr;
  44 }
  45
  46 int main (int argc, char **argv)
  47 {
  48     int i, mini, maxi;
  49     UINT id;
  50     MMRESULT mr;
  51     DWORD prevmask, wr;
  52     DWORD_PTR est[NITERS];
  53     double d;
  54     DWORD_PTR mask;
  55
  56     if (argc > 1)
  57         mask = atoi (argv[1]);
  58     else
  59         mask = 1;
  60
  61     prevmask = SetProcessAffinityMask (GetCurrentProcess (), mask);
  62     if (!prevmask) {
  63         fprintf (stderr, "SetProcessAffinityMask failed: %ld\n", GetLastError ());
  64         exit (EXIT_FAILURE);
  65     }
  66     id = settimer (0);
  67
  68     for (i = 0; i < NITERS; ++i) {
  69         stop = 0;
  70         est[i] = hog ((DWORD_PTR) 0 - 1);
  71     }
  72
  73     mr = timeKillEvent (id);
  74     if (mr != TIMERR_NOERROR) {
  75         fprintf (stderr, "timeKillEvent failed: %ld\n", GetLastError ());
  76         exit (EXIT_FAILURE);
  77     }
  78
  79     mini = 0;
  80     maxi = 0;
  81
  82     for (i = 0; i < NITERS; ++i) {
  83         if (est[i] < est[mini]) mini = i;
  84         if (est[i] > est[maxi]) maxi = i;
  85     }
  86
  87     d = 0.0;
  88     for (i = 0; i < NITERS; ++i) {
  89         fprintf (stderr, "%f\n", (double) est[i]);
  90         if (i == mini || i == maxi) continue;
  91         d += est[i];
  92     }
  93     d = d / (NITERS - 2);
  94     d = d - d / 10;
  95     fprintf (stderr, "%f\n", d);
  96
  97     settimer (d);
  98
  99     Sleep (INFINITE);
 100     return 0;
 101 }