On success, adjtimex() and ntp_adjtime() return the clock state;
that is, one of the following values:
TIME_OK
Clock synchronized, no leap second adjustment pending.
TIME_INS
Indicates that a leap second will be added at the end of
the UTC day.
TIME_DEL
Indicates that a leap second will be deleted at the end of
the UTC day.
TIME_OOP
Insertion of a leap second is in progress.
TIME_WAIT
A leap-second insertion or deletion has been completed.
This value will be returned until the next ADJ_STATUS
operation clears the STA_INS and STA_DEL flags.
TIME_ERROR
The system clock is not synchronized to a reliable server.
This value is returned when any of the following holds
true:
* Either STA_UNSYNC or STA_CLOCKERR is set.
* STA_PPSSIGNAL is clear and either STA_PPSFREQ or
STA_PPSTIME is set.
* STA_PPSTIME and STA_PPSJITTER are both set.
* STA_PPSFREQ is set and either STA_PPSWANDER or
STA_PPSJITTER is set.
The symbolic name TIME_BAD is a synonym for TIME_ERROR,
provided for backward compatibility.
Note that starting with Linux 3.4, the call operates
asynchronously and the return value usually will not reflect a
state change caused by the call itself.
On failure, these calls return -1 and set errno to indicate the
error.
