Originální popis anglicky:
sched_get_priority_max, sched_get_priority_min - get static priority range
Návod, kniha: Linux Programmer's Manual
#include <sched.h>
int sched_get_priority_max(int policy);
int sched_get_priority_min(int policy);
sched_get_priority_max returns the maximum priority value that can be
used with the scheduling algorithm identified by
policy.
sched_get_priority_min returns the minimum priority value that can be
used with the scheduling algorithm identified by
policy. Supported
policy values are
SCHED_FIFO,
SCHED_RR, and
SCHED_OTHER.
Processes with numerically higher priority values are scheduled before processes
with numerically lower priority values. Thus, the value returned by
sched_get_priority_max will be greater than the value returned by
sched_get_priority_min.
Linux allows the static priority value range 1 to 99 for
SCHED_FIFO and
SCHED_RR and the priority 0 for
SCHED_OTHER. Scheduling priority
ranges for the various policies are not alterable.
The range of scheduling priorities may vary on other POSIX systems, thus it is a
good idea for portable applications to use a virtual priority range and map it
to the interval given by
sched_get_priority_max and
sched_get_priority_min. POSIX.1b requires a spread of at least 32
between the maximum and the minimum values for
SCHED_FIFO and
SCHED_RR.
POSIX systems on which
sched_get_priority_max and
sched_get_priority_min are available define
_POSIX_PRIORITY_SCHEDULING in <unistd.h>.
On success,
sched_get_priority_max and
sched_get_priority_min
return the maximum/minimum priority value for the named scheduling policy. On
error, -1 is returned,
errno is set appropriately.
- EINVAL
- The parameter policy does not identify a defined
scheduling policy.
POSIX.1b (formerly POSIX.4)
sched_getaffinity(2),
sched_getparam(2),
sched_getscheduler(2),
sched_setaffinity(2),
sched_setparam(2),
sched_setscheduler(2)
sched_setscheduler(2) has a description of the Linux scheduling scheme.
Programming for the real world - POSIX.4 by Bill O. Gallmeister, O'Reilly
& Associates, Inc., ISBN 1-56592-074-0
IEEE Std 1003.1b-1993 (POSIX.1b standard)
ISO/IEC 9945-1:1996
