#include <sys/timex.h>
sys/timex.h 44 macros · 2 structs · 2 functions
#define NTP_API 4 NTP API version
#define MAXPHASE 500000000L max phase error (ns)
#define MAXFREQ 500000L max freq error (ns/s)
#define MINSEC 256 min FLL update interval (s)
#define MAXSEC 2048 max PLL update interval (s)
#define NANOSECOND 1000000000L nanoseconds in one second
#define SCALE_PPM (65536 / 1000) crude ns/s to scaled PPM
#define MAXTC 10 max time constant
Control mode codes (timex.modes)
#define MOD_OFFSET 0x0001 set time offset
#define MOD_FREQUENCY 0x0002 set frequency offset
#define MOD_MAXERROR 0x0004 set maximum time error
#define MOD_ESTERROR 0x0008 set estimated time error
#define MOD_STATUS 0x0010 set clock status bits
#define MOD_TIMECONST 0x0020 set PLL time constant
#define MOD_PPSMAX 0x0040 set PPS maximum averaging time
#define MOD_TAI 0x0080 set TAI offset
#define MOD_MICRO 0x1000 select microsecond resolution
#define MOD_NANO 0x2000 select nanosecond resolution
#define MOD_CLKB 0x4000 select clock B
#define MOD_CLKA 0x8000 select clock A
Status codes (timex.status)
#define STA_PLL 0x0001 enable PLL updates (rw)
#define STA_PPSFREQ 0x0002 enable PPS freq discipline (rw)
#define STA_PPSTIME 0x0004 enable PPS time discipline (rw)
#define STA_FLL 0x0008 enable FLL mode (rw)
#define STA_INS 0x0010 insert leap (rw)
#define STA_DEL 0x0020 delete leap (rw)
#define STA_UNSYNC 0x0040 clock unsynchronized (rw)
#define STA_FREQHOLD 0x0080 hold frequency (rw)
#define STA_PPSSIGNAL 0x0100 PPS signal present (ro)
#define STA_PPSJITTER 0x0200 PPS signal jitter exceeded (ro)
#define STA_PPSWANDER 0x0400 PPS signal wander exceeded (ro)
#define STA_PPSERROR 0x0800 PPS signal calibration error (ro)
#define STA_CLOCKERR 0x1000 clock hardware fault (ro)
#define STA_NANO 0x2000 resolution (0 = us, 1 = ns) (ro)
#define STA_MODE 0x4000 mode (0 = PLL, 1 = FLL) (ro)
#define STA_CLK 0x8000 clock source (0 = A, 1 = B) (ro)
Clock states (ntptimeval.time_state)
#define TIME_OK 0 no leap second warning
#define TIME_INS 1 insert leap second warning
#define TIME_DEL 2 delete leap second warning
#define TIME_OOP 3 leap second in progress
#define TIME_WAIT 4 leap second has occurred
#define TIME_ERROR 5 error (see status word)
NTP user interface --
ntp_gettime - used to read kernel clock values
size 48, align 8
struct timespec time current time (ns) (ro) long maxerror maximum error (us) (ro) long esterror estimated error (us) (ro) long tai TAI offset int time_state time status
NTP daemon interface --
ntp_adjtime -- used to discipline CPU clock
oscillator and control/determine status.
Note: The offset, precision and jitter members are in microseconds if
STA_NANO is zero and nanoseconds if not.
size 136, align 8
unsigned int modes clock mode bits (wo) long offset time offset (ns/us) (rw) long freq frequency offset (scaled PPM) (rw) long maxerror maximum error (us) (rw) long esterror estimated error (us) (rw) int status clock status bits (rw) long constant poll interval (log2 s) (rw) long precision clock precision (ns/us) (ro) long tolerance clock frequency tolerance (scaled
PPM) (ro) long ppsfreq The following read-only structure members are used by
the PPS signal discipline that is currently not supported.
They are included for compatibility. PPS frequency (scaled PPM) (ro) long jitter PPS jitter (ns/us) (ro) int shift interval duration (s) (shift) (ro) long stabil PPS stability (scaled PPM) (ro) long jitcnt jitter limit exceeded (ro) long calcnt calibration intervals (ro) long errcnt calibration errors (ro) long stbcnt stability limit exceeded (ro)
int ntp_adjtime(struct timex *) Generated 2026-09-08 from the headers of one specific machine (macOS 26.4.1, SDK 26.4, arm64) — not official documentation. About & caveats