NAME    [Toc]    [Back]

       sched_getscheduler  -  Returns  the scheduling policy of a
       process (P1003.1b)

SYNOPSIS    [Toc]    [Back]

       #include <sched.h>

       int sched_getscheduler ( pid_t pid);

LIBRARY    [Toc]    [Back]

       Realtime Library (librt.so, librt.a)

PARAMETERS    [Toc]    [Back]

       Specifies the ID of the process for which  the  scheduling
       policy  is  to be obtained. If pid is zero, the scheduling
       policy of the calling process is obtained.

DESCRIPTION    [Toc]    [Back]

       The  sched_getscheduler  function  returns   the   current
       scheduling  policy  of  a  process. The values that can be
       returned are defined in the header file <sched.h>.

       The sched_setscheduler  function  changes  the  scheduling
       policy  and priority of a process. Changing the scheduling
       policy and priority ensures that an application can determine
 more effectively when a process will run.

       The realtime scheduling policies are as follows: Specifies
       the first-in, first-out (FIFO) scheduling policy Specifies
       the round-robin (RR) scheduling policy Specifies the standard
 timesharing scheduling policy

       The SCHED_FIFO and SCHED_RR scheduling policies are fixedpriority
  scheduling  policies. You can specify a priority
       for your process and the scheduler  will  not  adjust  it.
       Setting   priorities  in  conjunction  with  a  SCHED_FIFO
       scheduling policy allows a critical process to run as soon
       as  it  is  ready, for as long as it needs to run, because
       the process will preempt other lower-priority processes.

       The round-robin scheduling policy is similar to first  infirst
  out,  but also imposes a quantum on execution time.
       Use the sched_rr_get_interval function  to  determine  the
       current  quantum  for process execution under the SCHED_RR
       scheduling policy.

       The scheduler adjusts process priorities running under the
       timesharing scheduling policy.

       No    special   privileges   are   needed   to   use   the
       sched_getscheduler function.

RETURN VALUES    [Toc]    [Back]

       On a successful call to sched_getscheduler, the scheduling
       policy  of  the process is returned. If there is an error,
       -1 is returned and errno is set to indicate the error.

ERRORS    [Toc]    [Back]

       The sched_getscheduler function fails under the  following
       condition:  No  process can be found corresponding to that
       specified by pid.

SEE ALSO    [Toc]    [Back]

       Functions:   getpid(2),   sched_getparam(3),    sched_setparam(3), sched_setscheduler(3)

       Guide to Realtime Programming



                                            sched_getscheduler(3)