pthread_rwlockattr_setclock()
Set the clock attribute of a read-write lock attribute object
Synopsis:
#include <pthread.h>
int pthread_rwlockattr_setclock(
pthread_rwlockattr_t * attr,
clockid_t id );
Arguments:
- attr
- A pointer to the pthread_rwlockattr_t object for which you want to set the clock. You must have initialized this object by calling pthread_rwlockattr_init() before calling pthread_rwlockattr_setclock().
- id
- A clockid_t object that specifies the ID of the clock
that you want to use for
pthread_rwlock_timedrdlock()
or
pthread_rwlock_timedwrlock();
one of:
- CLOCK_REALTIME — the standard POSIX-defined clock. Timers based on this clock wake up the processor if it's in a power-saving mode.
- CLOCK_SOFTTIME — (a QNX Neutrino extension)
this clock is active only when
the processor isn't in a power-saving mode.
For example, an application using a CLOCK_SOFTTIME timer
to sleep wouldn't wake up
the processor when the application was due to wake up.
This will allow the processor to enter a power-saving mode.
While the processor isn't in a power-saving mode, CLOCK_SOFTTIME behaves the same as CLOCK_REALTIME.
- CLOCK_MONOTONIC — this clock always increases at a constant rate and can't be adjusted.
For more information about the different clocks, see
Other clock sources
in the Clocks, Timers, and Getting a Kick Every So Often of Getting Started with QNX Neutrino.
Library:
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
Description:
The pthread_rwlockattr_setclock() function sets the clock attribute in an initialized attributes object referenced by attr.
The clock attribute is the clock ID of the clock that's used (as a QNX Neutrino extension) to measure the timeout service of pthread_rwlock_timedrdlock() or pthread_rwlock_timedwrlock(). The default value of the clock attribute is CLOCK_REALTIME.
Returns:
- EOK
- Success.
Classification:
| Safety: | |
|---|---|
| Cancellation point | No |
| Interrupt handler | No |
| Signal handler | Yes |
| Thread | Yes |