Get the maximum priority for the scheduling policy
Synopsis:
#include <sched.h>
int sched_get_priority_max( int policy );
Arguments:
- policy
- The scheduling policy, which must be one of:
- SCHED_FIFO — a fixed-priority scheduler in which
the highest priority ready thread runs until it blocks or is preempted
by a higher priority thread.
- SCHED_RR — similar to SCHED_FIFO,
except that threads at the same priority level timeslice (round robin)
every 4 × the clock period (see
ClockPeriod()).
- SCHED_OTHER — currently the same as
SCHED_RR.
- SCHED_SPORADIC — sporadic scheduling.
For more information, see
pthread_attr_setschedpolicy(),
and
“Scheduling policies”
in the chapter on the microkernel in the
System Architecture guide.
Library:
libc
Use the -l c option to
qcc
to link against this library.
This library is usually included automatically.
Description:
The sched_get_priority_max() function returns the
maximum value for the scheduling policy specified by policy.
Note: If you query the highest allowable priority for a process, it might result in the denial of
a secpolmonitor ability.
Returns:
The appropriate minimum for success, or -1 (errno is set).
Errors:
- EINVAL
- The value of the policy parameter doesn't represent a defined scheduling policy.
- ENOSYS
- The sched_get_priority_max() function isn't currently supported.
Classification:
POSIX 1003.1 PS|TPS
| Safety: |
|
|---|
| Cancellation point |
No |
| Interrupt handler |
No |
| Signal handler |
Yes |
| Thread |
Yes |