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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2001, 2012 Oracle and/or its affiliates. All rights reserved.
*
* $Id$
*/
#include "db_config.h"
#include "db_int.h"
/*
* __os_gettime --
* Return the current time-of-day clock in seconds and nanoseconds.
*/
void
__os_gettime(env, tp, monotonic)
ENV *env;
db_timespec *tp;
int monotonic;
{
if (monotonic) {
/*
* The elapsed time is stored as a DWORD value, so time wraps
* around to zero if the system runs for 49.7 days. Initialize
* a base value with 50 days worth of seconds, and add 50 more
* days every time the counter wraps. That ensures we always
* move forward.
*
* It's possible this code could race, but the danger is we
* would increment base_seconds more than once per wrap and
* eventually overflow, which is a pretty remote possibility.
*/
#define TIMER_WRAP_SECONDS (50 * 24 * 60 * 60)
static DWORD last_ticks;
static time_t base_seconds;
DWORD ticks;
ticks = GetTickCount();
if (ticks < last_ticks)
base_seconds += TIMER_WRAP_SECONDS;
last_ticks = ticks;
tp->tv_sec = base_seconds + (u_int32_t)(ticks / 1000);
tp->tv_nsec = (u_int32_t)((ticks % 1000) * NS_PER_MS);
} else {
#ifdef DB_WINCE
FILETIME ft;
LARGE_INTEGER large_int;
LONGLONG ns_since_epoch, utc1970;
SYSTEMTIME st;
(void)GetSystemTime(&st);
(void)SystemTimeToFileTime(&st, &ft);
/*
* A FILETIME expresses time as 100 nanosecond chunks from
* Jan 1, 1601; convert to a timespec where the time is
* is expressed in seconds and nanoseconds from Jan 1, 1970.
*
* UTC_1970 is the number of 100-nano-second chunks from
* 1601 to 1970.
*/
#define NS100_PER_SEC (NS_PER_SEC / 100)
#define UTC_1970 (((LONGLONG)27111902 << 32) + (LONGLONG)3577643008)
memcpy(&large_int, &ft, sizeof(large_int));
utc1970 = UTC_1970;
ns_since_epoch = (large_int.QuadPart - utc1970);
tp->tv_sec = (time_t)(ns_since_epoch / NS100_PER_SEC);
tp->tv_nsec = (long)(ns_since_epoch % NS100_PER_SEC);
#else
struct _timeb now;
_ftime(&now);
tp->tv_sec = now.time;
tp->tv_nsec = now.millitm * NS_PER_MS;
#endif
}
}
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