pthread_condattr_setclock()
QNX SDP8.0C Library ReferenceAPIDeveloper
Set the clock attribute of a condition-variable attribute object
Synopsis:
#include <pthread.h>
int pthread_condattr_setclock(
pthread_condattr_t * attr,
clockid_t id );
Arguments:
- attr
- A pointer to the pthread_condattr_t object for which you want to set the clock. You must have initialized this object by calling pthread_condattr_init() before calling pthread_condattr_setclock().
- id
- A clockid_t object that specifies the ID of the clock
that you want to use for the condition variable; 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 OS 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.
Library:
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
Description:
The pthread_condattr_setclock() function sets the clock attribute in an initialized attributes object referenced by attr. If pthread_condattr_setclock() is called with an id argument that refers to a CPU-time clock, the call fails.
The clock attribute is the clock ID of the clock that you want to use to measure the timeout service of pthread_cond_timedwait(). The default value of the clock attribute refers to the system clock.
Returns:
- EOK
- Success.
- EINVAL
- The clock ID doesn't refer to a known clock or refers to a CPU-time clock.
Classification:
Safety: | |
---|---|
Cancellation point | No |
Signal handler | Yes |
Thread | Yes |
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