Commit 597ce610 authored by Howard Chu's avatar Howard Chu
Browse files

ITS#8295 fix Windows microsecond timer

Also add ldap_pvt_gettimeofday() to
emulate gettimeofday on Windows
parent 291b6a1a
......@@ -127,6 +127,12 @@ struct lutil_tm;
LDAP_F( void )
ldap_pvt_gettime LDAP_P(( struct lutil_tm * ));
#ifdef _WIN32
#define gettimeofday(tv,tz) ldap_pvt_gettimeofday(tv,tz)
LDAP_F( int )
ldap_pvt_gettimeofday LDAP_P(( struct timeval *tv, void *unused ));
#endif
/* use this macro to allocate buffer for ldap_pvt_csnstr */
#define LDAP_PVT_CSNSTR_BUFSIZE 64
LDAP_F( size_t )
......
......@@ -174,93 +174,195 @@ ldap_pvt_localtime( const time_t *timep, struct tm *result )
}
#endif /* !USE_LOCALTIME_R */
/* return a broken out time, with microseconds
*/
static int _ldap_pvt_gt_subs;
#ifdef _WIN32
/* Windows SYSTEMTIME only has 10 millisecond resolution, so we
* also need to use a high resolution timer to get microseconds.
* This is pretty clunky.
*/
void
ldap_pvt_gettime( struct lutil_tm *tm )
static LARGE_INTEGER _ldap_pvt_gt_freq;
static LARGE_INTEGER _ldap_pvt_gt_prev;
static int _ldap_pvt_gt_offset;
#define SEC_TO_UNIX_EPOCH 11644473600LL
#define TICKS_PER_SECOND 10000000
static int
ldap_pvt_gettimeusec(int *sec)
{
static LARGE_INTEGER cFreq;
static LARGE_INTEGER prevCount;
static int subs;
static int offset;
LARGE_INTEGER count;
SYSTEMTIME st;
GetSystemTime( &st );
QueryPerformanceCounter( &count );
/* It shouldn't ever go backwards, but multiple CPUs might
* be able to hit in the same tick.
*/
LDAP_MUTEX_LOCK( &ldap_int_gettime_mutex );
if ( count.QuadPart <= prevCount.QuadPart ) {
subs++;
} else {
subs = 0;
prevCount = count;
}
LDAP_MUTEX_UNLOCK( &ldap_int_gettime_mutex );
/* We assume Windows has at least a vague idea of
* when a second begins. So we align our microsecond count
* with the Windows millisecond count using this offset.
* We retain the submillisecond portion of our own count.
*
* Note - this also assumes that the relationship between
* the PerformanceCouunter and SystemTime stays constant;
* the PerformanceCounter and SystemTime stays constant;
* that assumption breaks if the SystemTime is adjusted by
* an external action.
*/
if ( !cFreq.QuadPart ) {
if ( !_ldap_pvt_gt_freq.QuadPart ) {
LARGE_INTEGER c2;
ULARGE_INTEGER ut;
FILETIME ft0, ft1;
long long t;
int usec;
QueryPerformanceFrequency( &cFreq );
/* just get sub-second portion of counter */
t = count.QuadPart % cFreq.QuadPart;
/* Initialize our offset */
QueryPerformanceFrequency( &_ldap_pvt_gt_freq );
/* Wait for a tick of the system time: 10-15ms */
GetSystemTimeAsFileTime( &ft0 );
do {
GetSystemTimeAsFileTime( &ft1 );
} while ( ft1.dwLowDateTime == ft0.dwLowDateTime );
ut.LowPart = ft1.dwLowDateTime;
ut.HighPart = ft1.dwHighDateTime;
QueryPerformanceCounter( &c2 );
/* get second and fraction portion of counter */
t = c2.QuadPart % (_ldap_pvt_gt_freq.QuadPart*10);
/* convert to microseconds */
t *= 1000000;
usec = t / cFreq.QuadPart;
usec = t / _ldap_pvt_gt_freq.QuadPart;
offset = usec - st.wMilliseconds * 1000;
ut.QuadPart /= 10;
ut.QuadPart %= 10000000;
_ldap_pvt_gt_offset = usec - ut.QuadPart;
count = c2;
}
tm->tm_usub = subs;
if ( count.QuadPart <= _ldap_pvt_gt_prev.QuadPart ) {
_ldap_pvt_gt_subs++;
} else {
_ldap_pvt_gt_subs = 0;
_ldap_pvt_gt_prev = count;
}
LDAP_MUTEX_UNLOCK( &ldap_int_gettime_mutex );
/* convert to microseconds */
count.QuadPart %= cFreq.QuadPart;
count.QuadPart %= _ldap_pvt_gt_freq.QuadPart*10;
count.QuadPart *= 1000000;
count.QuadPart /= cFreq.QuadPart;
count.QuadPart -= offset;
count.QuadPart /= _ldap_pvt_gt_freq.QuadPart;
count.QuadPart -= _ldap_pvt_gt_offset;
/* We've extracted the 1s and microseconds.
* The 1sec digit is used to detect wraparound in microsecnds.
*/
if (count.QuadPart < 0)
count.QuadPart += 10000000;
else if (count.QuadPart >= 10000000)
count.QuadPart -= 10000000;
*sec = count.QuadPart / 1000000;
return count.QuadPart % 1000000;
}
tm->tm_usec = count.QuadPart % 1000000;
if ( tm->tm_usec < 0 )
tm->tm_usec += 1000000;
/* emulate POSIX gettimeofday */
int
ldap_pvt_gettimeofday( struct timeval *tv, void *unused )
{
FILETIME ft;
ULARGE_INTEGER ut;
int sec, sec0;
GetSystemTimeAsFileTime( &ft );
ut.LowPart = ft.dwLowDateTime;
ut.HighPart = ft.dwHighDateTime;
/* convert to usec */
ut.QuadPart /= (TICKS_PER_SECOND / 1000000);
tv->tv_usec = ldap_pvt_gettimeusec(&sec);
tv->tv_sec = ut.QuadPart / 1000000 - SEC_TO_UNIX_EPOCH;
/* check for carry from microseconds */
sec0 = tv->tv_sec % 10;
if (sec0 < sec || (sec0 == 9 && !sec))
tv->tv_sec++;
return 0;
}
/* return a broken out time, with microseconds
*/
void
ldap_pvt_gettime( struct lutil_tm *tm )
{
SYSTEMTIME st;
int sec, sec0;
static const char daysPerMonth[] = {
31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
GetSystemTime( &st );
tm->tm_usec = ldap_pvt_gettimeusec(&sec);
tm->tm_usub = _ldap_pvt_gt_subs;
/* any difference larger than microseconds is
* already reflected in st
*/
tm->tm_sec = st.wSecond;
tm->tm_min = st.wMinute;
tm->tm_hour = st.wHour;
tm->tm_mday = st.wDay;
tm->tm_mon = st.wMonth - 1;
tm->tm_year = st.wYear - 1900;
/* check for carry from microseconds */
sec0 = tm->tm_sec % 10;
if (sec0 < sec || (sec0 == 9 && !sec)) {
tm->tm_sec++;
/* FIXME: we don't handle leap seconds */
if (tm->tm_sec > 59) {
tm->tm_sec = 0;
tm->tm_min++;
if (tm->tm_min > 59) {
tm->tm_min = 0;
tm->tm_hour++;
if (tm->tm_hour > 23) {
int days = daysPerMonth[tm->tm_mon];
tm->tm_hour = 0;
tm->tm_mday++;
/* if it's February of a leap year,
* add 1 day to this month
*/
if (tm->tm_mon == 1 &&
((!(st.wYear % 4) && (st.wYear % 100)) ||
!(st.wYear % 400)))
days++;
if (tm->tm_mday > days) {
tm->tm_mday = 1;
tm->tm_mon++;
if (tm->tm_mon > 11) {
tm->tm_mon = 0;
tm->tm_year++;
}
}
}
}
}
}
}
#else
static struct timeval _ldap_pvt_gt_prevTv;
void
ldap_pvt_gettime( struct lutil_tm *ltm )
{
struct timeval tv;
static struct timeval prevTv;
static int subs;
struct tm tm;
time_t t;
......@@ -269,16 +371,17 @@ ldap_pvt_gettime( struct lutil_tm *ltm )
t = tv.tv_sec;
LDAP_MUTEX_LOCK( &ldap_int_gettime_mutex );
if ( tv.tv_sec < prevTv.tv_sec
|| ( tv.tv_sec == prevTv.tv_sec && tv.tv_usec <= prevTv.tv_usec )) {
subs++;
if ( tv.tv_sec < _ldap_pvt_gt_prevTv.tv_sec
|| ( tv.tv_sec == _ldap_pvt_gt_prevTv.tv_sec
&& tv.tv_usec <= _ldap_pvt_gt_prevTv.tv_usec )) {
_ldap_pvt_gt_subs++;
} else {
subs = 0;
prevTv = tv;
_ldap_pvt_gt_subs = 0;
_ldap_pvt_gt_prevTv = tv;
}
LDAP_MUTEX_UNLOCK( &ldap_int_gettime_mutex );
ltm->tm_usub = subs;
ltm->tm_usub = _ldap_pvt_gt_subs;
ldap_pvt_gmtime( &t, &tm );
......
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