winsup/cygwin/hires.h

   1 /* hires.h: Definitions for hires clock calculations
   2
   3 This file is part of Cygwin.
   4
   5 This software is a copyrighted work licensed under the terms of the
   6 Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
   7 details. */
   8
   9 #ifndef __HIRES_H__
  10 #define __HIRES_H__
  11
  12 #include <mmsystem.h>
  13
  14 /* Conversions for per-process and per-thread clocks */
  15 #define PID_TO_CLOCKID(pid) (pid * 8 + CLOCK_PROCESS_CPUTIME_ID)
  16 #define CLOCKID_TO_PID(cid) ((cid - CLOCK_PROCESS_CPUTIME_ID) / 8)
  17 #define CLOCKID_IS_PROCESS(cid) ((cid % 8) == CLOCK_PROCESS_CPUTIME_ID)
  18 #define THREADID_TO_CLOCKID(tid) (tid * 8 + CLOCK_THREAD_CPUTIME_ID)
  19 #define CLOCKID_TO_THREADID(cid) ((cid - CLOCK_THREAD_CPUTIME_ID) / 8)
  20 #define CLOCKID_IS_THREAD(cid) ((cid % 8) == CLOCK_THREAD_CPUTIME_ID)
  21
  22 /* Largest delay in ms for sleep and alarm calls.
  23    Allow actual delay to exceed requested delay by 10 s.
  24    Express as multiple of 1000 (i.e. seconds) + max resolution
  25    The tv_sec argument in timeval structures cannot exceed
  26    HIRES_DELAY_MAX / 1000 - 1, so that adding fractional part
  27    and rounding won't exceed HIRES_DELAY_MAX */
  28 #define HIRES_DELAY_MAX ((((UINT_MAX - 10000) / 1000) * 1000) + 10)
  29
  30 /* 100ns difference between Windows and UNIX timebase. */
  31 #define FACTOR (0x19db1ded53e8000LL)
  32 /* # of nanosecs per second. */
  33 #define NSPERSEC (1000000000)
  34 /* # of 100ns intervals per second. */
  35 #define NS100PERSEC (10000000)
  36 /* # of millisecs per second. */
  37 #define USPERSEC (1000000)
  38
  39 class hires_base
  40 {
  41  protected:
  42   int inited;
  43  public:
  44   void reset() {inited = false;}
  45 };
  46
  47 class hires_ns : public hires_base
  48 {
  49   LARGE_INTEGER primed_pc;
  50   double freq;
  51   void prime ();
  52  public:
  53   LONGLONG nsecs (bool monotonic = false);
  54   LONGLONG usecs () {return nsecs () / 1000LL;}
  55   LONGLONG resolution();
  56 };
  57
  58 class hires_ms : public hires_base
  59 {
  60  public:
  61   LONGLONG nsecs ();
  62   LONGLONG usecs () {return nsecs () / 10LL;}
  63   LONGLONG msecs () {return nsecs () / 10000LL;}
  64   UINT resolution ();
  65 };
  66
  67 extern hires_ms gtod;
  68 #endif /*__HIRES_H__*/