HP-UX Reference (11i v2 04/09) - 2 System Calls (vol 5)

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getitimer(2) getitimer(2)

timerclear Set a time value to zero.

timerisset Test if a time value is non-zero.

timercmp Compare two time values. (Beware that >=

and <= do not work with the

timercmp macro.)

The timer used with

ITIMER_REAL is also used by

alarm() (see alarm (2)). Thus successive calls to

alarm(), getitimer(), and setitimer() set and return the state of a single timer. In addition, a

call to alarm() sets the timer interval to zero.

The interaction between

setitimer() and any of alarm()

, sleep() or usleep() is unspeciﬁed.

RETURN VALUE

Upon successful completion,

getitimer() or setitimer() returns 0. Otherwise, −1 is returned and

errno is set to indicate the error.

ERRORS

The

setitimer() function will fail if:

[EINVAL] The value argument is not in canonical form. (In canonical form, the number of

microseconds is a non-negative integer less than 1,000,000 and the number of

seconds is a non-negative integer.)

The

getitimer() and setitimer() functions may fail if:

[EINVAL] The which argument is not recognized.

[EFAULT] The value structure speciﬁed a bad address. Reliable detection of this error is

implementation dependent.

EXAMPLES

The following call to

setitimer() sets the real-time interval timer to expire initially after 10 seconds

and every 0.5 seconds thereafter:

struct itimerval rttimer;

struct itimerval old_rttimer;

rttimer.it_value.tv_sec = 10;

rttimer.it_value.tv_usec = 0;

rttimer.it_interval.tv_sec = 0;

rttimer.it_interval.tv_usec = 500000;

setitimer (ITIMER_REAL, &rttimer, &old_rttimer);

AUTHOR

getitimer() was developed by the University of California, Berkeley.