sched_rr_get_interval

SCHED_GET_PRIORITY_MAX(2)    BSD System Calls Manual   SCHED_GET_PRIORITY_MAX(2)

NAME
     sched_get_priority_max, sched_get_priority_min, sched_rr_get_interval — get
     scheduling parameter limits

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sched.h>

     int
     sched_get_priority_max(int policy);

     int
     sched_get_priority_min(int policy);

     int
     sched_rr_get_interval(pid_t pid, struct timespec *interval);

DESCRIPTION
     The sched_get_priority_max() and sched_get_priority_min() system calls
     return the appropriate maximum or minimum, respectively, for the scheduling
     policy specified by policy.  The sched_rr_get_interval() system call
     updates the timespec structure referenced by the interval argument to
     contain the current execution time limit (i.e., time quantum) for the
     process specified by pid.  If pid is zero, the current execution time limit
     for the calling process is returned.

     The value of policy should be one of the scheduling policy values defined
     in <sched.h>:

     [SCHED_FIFO]   First-in-first-out fixed priority scheduling with no round
                    robin scheduling;

     [SCHED_OTHER]  The standard time sharing scheduler;

     [SCHED_RR]     Round-robin scheduling across same priority processes.

RETURN VALUES
     If successful, the sched_get_priority_max() and sched_get_priority_min()
     system calls shall return the appropriate maximum or minimum values,
     respectively.  If unsuccessful, they shall return a value of -1 and set
     errno to indicate the error.

     The sched_rr_get_interval() function returns the value 0 if successful;
     otherwise the value -1 is returned and the global variable errno is set to
     indicate the error.

ERRORS
     On failure errno will be set to the corresponding value:

     [EINVAL]           The value of the policy argument does not represent a
                        defined scheduling policy.

     [ENOSYS]           The sched_get_priority_max(), sched_get_priority_min(),
                        and sched_rr_get_interval() system calls are not
                        supported by the implementation.

     [ESRCH]            No process can be found corresponding to that specified
                        by pid.

SEE ALSO
     sched_getparam(2), sched_getscheduler(2), sched_setparam(2),
     sched_setscheduler(2)

STANDARDS
     The sched_get_priority_max(), sched_get_priority_min(), and
     sched_rr_get_interval() system calls conform to IEEE Std 1003.1b-1993
     (“POSIX.1”).

BSD                              March 12, 1998                              BSD