getitimer()
Get the value of an interval timer
Synopsis:
#include <sys/time.h>
int getitimer ( int which,
struct itimerval *value );
Arguments:
- which
- The interval timer whose value you want to get. Currently, this must be ITIMER_REAL.
- value
- A pointer to an itimerval structure where the function can store the value of the interval timer.
Library:
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
Description:
The getitimer() function stores the current value of the timer specified by which into the structure pointed to by value.
A timer value is defined by the itimerval structure, which includes the following members:
struct timeval it_interval; /* timer interval */
struct timeval it_value; /* current value */
Each struct timeval contains the following members:
- time_t tv_sec — the number of seconds.
- suseconds_t tv_usec — the number of microseconds.
The it_value member indicates the time to the next timer expiration. The it_interval member specifies a value to be used in reloading it_value when the timer expires. An it_value of 0 represents a timer that is disabled, regardless of the value of it_interval. An it_interval of 0 represents a timer that will not be reloaded after its next expiration (assuming it_value is nonzero).
Time values smaller than the resolution of the system clock are rounded up to the resolution of the system clock.
The interval timers include:
- ITIMER_REAL
- Decrements in real time. A SIGALRM signal is delivered when this timer expires.
Returns:
- 0
- Success.
- -1
- An error occurred (errno is set).
Errors:
- EINVAL
- The which argument is unrecognized.
Classification:
POSIX 1003.1 OB XSI. This function is marked as obsolescent, and may be removed from a future version of the standard.
| Safety: | |
|---|---|
| Cancellation point | No |
| Signal handler | Yes |
| Thread | Yes |