7
* MPE lacks adjtime(), so we define our own. But note that time slewing has
8
* a sub-second accuracy bug documented in SR 5003462838 which prevents ntpd
9
* from being able to maintain clock synch. Because of the bug, this adjtime()
10
* implementation as used by ntpd has a side-effect of screwing up the hardware
11
* PDC clock, which will need to be reset with a reboot.
13
* This problem affects all versions of MPE at the time of this writing (when
14
* MPE/iX 7.0 is the most current). It only causes bad things to happen when
15
* doing continuous clock synchronization with ntpd; note that you CAN run ntpd
16
* with "disable ntp" in ntp.conf if you wish to provide a time server.
18
* The one-time clock adjustment functionality of ntpdate and ntp_timeset can
19
* be used without screwing up the PDC clock.
24
int adjtime(struct timeval *delta, struct timeval *olddelta);
26
int adjtime(struct timeval *delta, struct timeval *olddelta)
29
/* Documented, supported MPE system intrinsics. */
31
extern void GETPRIVMODE(void);
32
extern void GETUSERMODE(void);
34
/* Undocumented, unsupported MPE internal functions. */
36
extern long long current_correction_usecs(void);
37
extern long long get_time(void);
38
extern void get_time_change_info(long long *, char *, char *);
39
extern long long pdc_time(int *);
40
extern void set_time_correction(long long, int, int);
41
extern long long ticks_to_micro(long long);
43
long long big_sec, big_usec, new_correction = 0LL;
44
long long prev_correction;
47
/* Adjustment required. Convert delta to 64-bit microseconds. */
48
big_sec = (long)delta->tv_sec;
49
big_usec = delta->tv_usec;
50
new_correction = (big_sec * 1000000LL) + big_usec;
55
/* Determine how much of a previous correction (if any) we're interrupting. */
56
prev_correction = current_correction_usecs();
59
/* Adjustment required. */
62
/* Speculative code disabled until bug SR 5003462838 is fixed. This bug
63
prevents accurate time slewing, and indeed renders ntpd inoperable. */
65
if (prev_correction != 0LL) {
66
/* A previous adjustment did not complete. Since the PDC UTC clock was
67
immediately jumped at the start of the previous adjustment, we must
68
explicitly reset it to the value of the MPE local time clock minus the
71
char pwf_since_boot, recover_pwf_time;
72
long long offset_ticks, offset_usecs, pdc_usecs_current, pdc_usecs_wanted;
75
get_time_change_info(&offset_ticks, &pwf_since_boot, &recover_pwf_time);
76
offset_usecs = ticks_to_micro(offset_ticks);
77
pdc_usecs_wanted = get_time() - offset_usecs;
78
pdc_usecs_current = pdc_time(&hpe_status);
80
/* Force new PDC time by starting an extra correction. */
81
set_time_correction(pdc_usecs_wanted - pdc_usecs_current,0,1);
85
/* Immediately jump the PDC time to the new value, and then initiate a
86
gradual MPE time correction slew. */
87
set_time_correction(new_correction,0,1);
92
if (olddelta != NULL) {
93
/* Caller wants to know remaining amount of previous correction. */
94
(long)olddelta->tv_sec = prev_correction / 1000000LL;
95
olddelta->tv_usec = prev_correction % 1000000LL;
5
102
#ifdef NEED_HPUX_ADJTIME
6
103
/*************************************************************************/
7
104
/* (c) Copyright Tai Jin, 1988. All Rights Reserved. */
150
#else /* not NEED_HPUX_ADJTIME */
248
# if NEED_QNX_ADJTIME
250
* Emulate adjtime() using QNX ClockAdjust().
251
* Chris Burghart <burghart@atd.ucar.edu>, 11/2001
253
* This is a *very* simple implementation of adjtime() for QNX.
254
* ClockAdjust() is used to tweak the system clock by about +- 1/10
255
* of its current clock period per tick until the desired delta is
260
# include <sys/neutrino.h>
261
# include <sys/time.h>
263
# include <ntp_stdlib.h>
266
adjtime (struct timeval *delta, struct timeval *olddelta)
269
double delta_nsec_old;
270
struct _clockadjust adj;
271
struct _clockadjust oldadj;
273
* How many nanoseconds are we adjusting?
275
delta_nsec = delta->tv_sec * 1e9 + delta->tv_usec * 1000;
277
* Build the adjust structure and call ClockAdjust()
281
struct _clockperiod period;
286
* Get the current clock period (nanoseconds)
288
if (ClockPeriod (CLOCK_REALTIME, 0, &period, 0) < 0)
292
* Set the adjust increment to approximately 1/10 timer period per
295
count = 1 + (long)(fabs(10 * delta_nsec / period.nsec));
296
increment = (long)(delta_nsec / count);
298
adj.tick_nsec_inc = increment;
299
adj.tick_count = count;
303
adj.tick_nsec_inc = 0;
307
if (ClockAdjust (CLOCK_REALTIME, &adj, &oldadj) < 0)
313
delta_nsec_old = oldadj.tick_count * oldadj.tick_nsec_inc;
314
olddelta->tv_sec = (int)(delta_nsec_old / 1e9);
315
olddelta->tv_usec = (int)((delta_nsec_old - 1.0e9 * olddelta->tv_sec) /
320
# else /* no special adjtime() needed */
152
#endif /* not NEED_HPUX_ADJTIME */
added
removed
libntp/adjtime.c
