Re: What is a leap second

[Peter Ekberg]

> > with the following output on win2k.
> > 9 0 10 0 9 10
> 
> This is weird, I would have expected to get an output like: 2002 10
27 8 9 10
> with the followingo patch applied...
> 
> nog.

Eeek, sorry about that. I forgot a WINAPI in the typedef, see my new
version in the attachment...

The following output is more in line with your expectations:
2002 10 27 8 9 10

I have also attached the output of timetest2.c after some adjustments
to make it compile on my box which is missing winternl.h. (I didn't
take the time to download the SDK.)

However, I don't follow the part about appling patches. I have
compiled the code using msvc and executed the code on windows 2000.

/peda
#include <stdio.h>
#include <windows.h>

typedef short CSHORT;
typedef struct {
	CSHORT Year;
	CSHORT Month;
	CSHORT Day;
	CSHORT Hour;
	CSHORT Minute;
	CSHORT Second;
	CSHORT Milliseconds;
	CSHORT Weekday;
} TIME_FIELDS, *PTIME_FIELDS;


typedef VOID (WINAPI *RtlTimeToTimeFieldsT)
	(PLARGE_INTEGER Time, PTIME_FIELDS TimeFields);

int
main()
{
	LARGE_INTEGER RtlTime;
	TIME_FIELDS tf;
	HINSTANCE hLib;
	RtlTimeToTimeFieldsT RtlTimeToTimeFields;

	RtlTime.LowPart = 0x20de5700;
	RtlTime.HighPart = 0x1c27d90;

	hLib = LoadLibrary("ntdll");

	RtlTimeToTimeFields = (RtlTimeToTimeFieldsT)
		GetProcAddress(hLib, "RtlTimeToTimeFields");

	RtlTimeToTimeFields(&RtlTime, &tf);

	FreeLibrary(hLib);

	printf("%d %d %d %d %d %d\n",
		tf.Year, tf.Month, tf.Day,
		tf.Hour, tf.Minute, tf.Second);
	return 0;
}

#include <stdio.h>
#include <windows.h>

typedef short CSHORT;
typedef struct {
	CSHORT Year;
	CSHORT Month;
	CSHORT Day;
	CSHORT Hour;
	CSHORT Minute;
	CSHORT Second;
	CSHORT Milliseconds;
	CSHORT Weekday;
} TIME_FIELDS, *PTIME_FIELDS;


typedef VOID (WINAPI *RtlTimeToTimeFieldsT)(PLARGE_INTEGER Time, PTIME_FIELDS TimeFields);

#define testtime(HighTime, LowTime) \
	RtlTime.HighPart = HighTime; \
	RtlTime.LowPart = LowTime; \
	RtlTimeToTimeFields(&RtlTime, &tf); \
	printf("%04d %02d %02d %02d %02d %02d\n", tf.Year, tf.Month, tf.Day,\
		tf.Hour, tf.Minute, tf.Second);

/* The year to which to test */
#define TargetYear         2222

/* Taken from dlls/ntdll/time.c */
#define EPOCHYEAR          1601
#define TICKSPERSEC        10000000
#define SECSPERDAY         86400
#define MONSPERYEAR        12
static const int MonthLengths[2][MONSPERYEAR] =
{
	{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
	{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
};

int IsLeapYear(int Year)
{
	return Year % 4 == 0 && (Year % 100 != 0 || Year % 400 == 0) ? 1 : 0;
}

int
main()
{
	int Month, Year;
	UINT64 time = 0, tmp;

	LARGE_INTEGER RtlTime;
	TIME_FIELDS tf;
	HINSTANCE hLib;
	RtlTimeToTimeFieldsT RtlTimeToTimeFields;

	hLib = LoadLibrary("ntdll");

	RtlTimeToTimeFields =
		(RtlTimeToTimeFieldsT)GetProcAddress
			(hLib, "RtlTimeToTimeFields");

	for(Year = 0; Year <= (TargetYear - EPOCHYEAR); Year++) {
		for(Month = 0; Month < MONSPERYEAR; Month++) {
			tmp = MonthLengths[IsLeapYear(Year + EPOCHYEAR)][Month] * SECSPERDAY;
			tmp *= TICKSPERSEC;
			time += tmp;
			testtime(time >> 32, (time & 0xffffffff));
		}
	}

	FreeLibrary(hLib);

	return 0;
}

timetest2.zip
Description: Zip archive