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33 .Nd NTP daemon application interface
38 .Fn ntp_adjtime "struct timex *tp"
42 system call is used as a kernel interface
43 for the Network Time Protocol daemon,
47 structure are interpreted in either
48 microseconds or nanoseconds, according to the state of the
60 system calls can be used to determine which
61 resolution is in use, and to select either one at any time.
62 The resolution selected affects the scaling of certain fields in the
70 is extremely complex and stateful.
71 Users should not attempt modification without first
77 * NTP daemon interface (ntp_adjtime()) - used to discipline CPU clock
78 * oscillator and determine status.
80 * Note: The offset, precision and jitter members are in microseconds if
81 * STA_NANO is zero and nanoseconds if not.
84 unsigned int modes; /* clock mode bits (wo) */
85 long offset; /* time offset (ns/us) (rw) */
86 long freq; /* frequency offset (scaled PPM) (rw) */
87 long maxerror; /* maximum error (us) (rw) */
88 long esterror; /* estimated error (us) (rw) */
89 int status; /* clock status bits (rw) */
90 long constant; /* poll interval (log2 s) (rw) */
91 long precision; /* clock precision (ns/us) (ro) */
92 long tolerance; /* clock frequency tolerance (scaled
95 * The following read-only structure members are implemented
96 * only if the PPS signal discipline is configured in the
97 * kernel. They are included in all configurations to insure
100 long ppsfreq; /* PPS frequency (scaled PPM) (ro) */
101 long jitter; /* PPS jitter (ns/us) (ro) */
102 int shift; /* interval duration (s) (shift) (ro) */
103 long stabil; /* PPS stability (scaled PPM) (ro) */
104 long jitcnt; /* jitter limit exceeded (ro) */
105 long calcnt; /* calibration intervals (ro) */
106 long errcnt; /* calibration errors (ro) */
107 long stbcnt; /* stability limit exceeded (ro) */
111 Upon successful completion,
115 argument with the current clock state.
117 Upon successful completion the clock state is returned.
118 Otherwise a -1 is returned and the global variable
120 is set to indicate the error.
122 Possible states of the clock are:
124 .Bl -tag -compact -width ".Dv TIME_ERROR"
126 Everything okay, no leap second warning.
128 insert leap second warning.
130 delete leap second warning.
132 Leap second in progress.
134 Leap second has occurred.
136 Clock not synchronized.
141 system call may return
144 does not have sufficient permissions.
149 This manual page was written by
150 .An Tom Rhodes Aq trhodes@FreeBSD.org .