reactos/lib/drivers/sound/shared/time.c

   1 /*
   2     ReactOS Sound System
   3     Timing helper
   4
   5     Author:
   6         Andrew Greenwood (silverblade@reactos.org)
   7
   8     History:
   9         31 May 2008 - Created
  10
  11     Notes:
  12         Have checked timing in DebugView. A 10,000ms delay covered a period
  13         of 124.305 sec to 134.308 sec. Not 100% accurate but likely down to
  14         the delays in submitting the debug strings?
  15 */
  16
  17 /*
  18     Nanoseconds are fun! You must try some!
  19     1 ns        = .000000001 seconds    = .0000001 ms
  20     100 ns      = .0000001 seconds      = .00001 ms
  21     10000 ns    = .00001 seconds        = .001 ms
  22     1000000 ns  = .001 seconds          = 1 ms
  23 */
  24
  25 #include <ntddk.h>
  26
  27 VOID
  28 SleepMs(ULONG Milliseconds)
  29 {
  30     LARGE_INTEGER Period;
  31
  32     Period.QuadPart = -Milliseconds;
  33     Period.QuadPart *= 10000;
  34
  35     KeDelayExecutionThread(KernelMode, FALSE, &Period);
  36 }
  37
  38 ULONG
  39 QuerySystemTimeMs()
  40 {
  41     LARGE_INTEGER Time;
  42
  43     KeQuerySystemTime(&Time);
  44
  45     Time.QuadPart /= 10000;
  46
  47     return (ULONG) Time.QuadPart;
  48 }
  49