Set the clock attribute of a condition-variable attribute object
#include <pthread.h> int pthread_condattr_setclock( pthread_condattr_t * attr, clockid_t id );
- 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().
- 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 — 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.
Use the -l c option to qcc to link against this library. This library is usually included automatically.
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.
- Invalid value attr.