*** UNIX MANUAL PAGE BROWSER ***

sched_getscheduler(3) Library Functions Manual sched_getscheduler(3) NAME sched_getscheduler - Return the scheduling policy of a process (P1003.1b) SYNOPSIS #include <sched.h> int sched_getscheduler ( pid_t pid); PARAMETERS pid The ID of the process for which the scheduling policy is ob- tained. 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 pri- ority of a process. Changing the scheduling policy and priority en- sures that an application can determine more effectively when a process will run. The realtime scheduling policies are as follows: o SCHED_FIFO - specifies the first-in, first-out (FIFO) scheduling policy o SCHED_RR - specifies the round-robin scheduling policy o SCHED_OTHER - specifies the standard timesharing scheduling pol- icy 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 func- tion. 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) delim off sched_getscheduler(3)