Subj : sched_get_priority_min/max on aix and solaris
To   : comp.programming.threads
From : Kurt Berg
Date : Wed May 11 2005 11:34 pm

(1) On AIX 5.2, the library functions sched_get_priority_min/max()
seem to be defined. That is, they have prototypes in sched.h, and a
program referencing them links without error using both the xlc and
xlc_r compilation commands. Furthermore, they are documented at the
online AIX website. However, when executed, they return ENOSYS,
meaning that they are unsupported. Unfortunately, there is no way to
tell whether this error is being generated by the library function, or
the system call itself. Has anyone had any experience with this?

(2) On Solaris 8, the above-mentioned two functions seem to work fine.
In fact, the min/max priority values returned are (-20,20) for
SCHED_OTHER, and (0,59) for SCHED_FIFO and SCHED_RR. However, an
attempt to modify the priority of the main thread (via
pthread_setschedparam()) to a value outside the indicated range
appears to succeed! In fact, when the priority of the thread is then
retrieved, the out-of-range value is returned. Does anyone know what
this means?

Thanks,
Tom Dailey

.