sched_getscheduler(3)					     Library Functions Manual					     sched_getscheduler(3)

sched_getscheduler - Returns the scheduling policy of a process (P1003.1b) LIBRARY
Realtime Library (, librt.a) SYNOPSIS
#include <sched.h> int sched_getscheduler ( pid_t pid); PARAMETERS
pid 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
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: SCHED_FIFO Specifies the first-in, first-out (FIFO) scheduling policy SCHED_RR Specifies the round-robin (RR) scheduling policy SCHED_OTHER Specifies the standard timesharing scheduling policy The SCHED_FIFO and SCHED_RR scheduling policies are fixed-priority 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 in-first 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
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
The sched_getscheduler function fails under the following condition: [ESRCH] No process can be found corresponding to that specified by pid. RELATED INFORMATION
Functions: getpid(2), sched_getparam(3), sched_setparam(3), sched_setscheduler(3) Guide to Realtime Programming delim off sched_getscheduler(3)

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