eglib/src/gtimer-win32.c

   1 /*
   2  * Timer
   3  *
   4  * Author:
   5  *   Gonzalo Paniagua Javier (gonzalo@novell.com
   6  *
   7  * (C) 2006 Novell, Inc.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining
  10  * a copy of this software and associated documentation files (the
  11  * "Software"), to deal in the Software without restriction, including
  12  * without limitation the rights to use, copy, modify, merge, publish,
  13  * distribute, sublicense, and/or sell copies of the Software, and to
  14  * permit persons to whom the Software is furnished to do so, subject to
  15  * the following conditions:
  16  *
  17  * The above copyright notice and this permission notice shall be
  18  * included in all copies or substantial portions of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27  */
  28 #include <glib.h>
  29 #include <windows.h>
  30
  31 struct _GTimer {
  32         guint64 start;
  33         guint64 stop;
  34 };
  35
  36 GTimer *g_timer_new (void)
  37 {
  38         GTimer *timer;
  39
  40         timer = g_new0 (GTimer, 1);
  41         g_timer_start (timer);
  42         return timer;
  43 }
  44
  45 void
  46 g_timer_destroy (GTimer *timer)
  47 {
  48         g_return_if_fail (timer != NULL);
  49         g_free (timer);
  50 }
  51
  52 void
  53 g_timer_start (GTimer *timer)
  54 {
  55         g_return_if_fail (timer != NULL);
  56
  57         QueryPerformanceCounter ((LARGE_INTEGER*)&timer->start);
  58 }
  59
  60 void
  61 g_timer_stop (GTimer *timer)
  62 {
  63         g_return_if_fail (timer != NULL);
  64
  65         QueryPerformanceCounter ((LARGE_INTEGER*)&timer->stop);
  66 }
  67
  68 gdouble
  69 g_timer_elapsed (GTimer *timer, gulong *microseconds)
  70 {
  71         static guint64 freq = 0;
  72         guint64 delta, stop;
  73
  74         if (freq == 0) {
  75                 if (!QueryPerformanceFrequency ((LARGE_INTEGER *)&freq))
  76                         freq = 1;
  77         }
  78
  79         if (timer->stop == 0) {
  80                 QueryPerformanceCounter ((LARGE_INTEGER*)&stop);
  81         }
  82         else {
  83                 stop = timer->stop;
  84         }
  85
  86         delta = stop - timer->start;
  87
  88         if (microseconds)
  89                 *microseconds = (gulong) (delta * (1000000.0 / freq));
  90
  91         return (gdouble) delta / (gdouble) freq;
  92 }
  93
  94