newlib/winsup/cygwin/hires.h

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/* hires.h: Definitions for hires clock calculations
Copyright 2002 Red Hat, Inc.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#ifndef __HIRES_H__
#define __HIRES_H__
#include <mmsystem.h>
/* Largest delay in ms for sleep and alarm calls.
Allow actual delay to exceed requested delay by 10 s.
Express as multiple of 1000 (i.e. seconds) + max resolution
The tv_sec argument in timeval structures cannot exceed
HIRES_DELAY_MAX / 1000 - 1, so that adding fractional part
and rounding won't exceed HIRES_DELAY_MAX */
#define HIRES_DELAY_MAX (((UINT_MAX - 10000) / 1000) * 1000) + 10
class hires_base
{
protected:
int inited;
public:
virtual LONGLONG usecs (bool justdelta) {return 0LL;}
};
class hires_us : hires_base
{
LARGE_INTEGER primed_ft;
LARGE_INTEGER primed_pc;
double freq;
void prime ();
public:
LONGLONG usecs (bool justdelta);
};
class hires_ms : hires_base
{
DWORD initime_ms;
LARGE_INTEGER initime_us;
static UINT minperiod;
UINT prime ();
public:
LONGLONG usecs (bool justdelta);
UINT dmsecs () { return timeGetTime (); }
UINT resolution () { return minperiod ?: prime (); }
};
extern hires_ms gtod;
#endif /*__HIRES_H__*/