sched_rr_get_interval - 獲得SCHED_RR間隔爲命名過程

內容簡介

#include <sched.h>

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

struct timespec {
    time_t  tv_sec;     /* seconds */
    long    tv_nsec;    /* nanoseconds */
};

描述

sched_rr_get_interval () writes into the  timespec  structure pointed to by  tp  the round robin time quantum for the process identified by  pid . If  pid  is zero, the time quantum for the calling process is written into * tp . The identified process should be running under the  SCHED_RR  scheduling policy.

The round robin time quantum value is not alterable under Linux 1.3.81.

POSIX systems on which sched_rr_get_interval() is available define_POSIX_PRIORITY_SCHEDULING in <unistd.h>.

返回值

On success,  sched_rr_get_interval () returns 0. On error, -1 is returned, and  errno  is set appropriately.

錯誤

標籤

描述

EFAULT

Problem with copying information to userspace.

EINVAL

Invalid pid.

ENOSYS

The system call is not yet implemented.

ESRCH

The process whose ID is pid could not be found.

遵循於

POSIX.1-2001.

BUGS

As of Linux 1.3.81  sched_rr_get_interval () returns with error ENOSYS, because SCHED_RR has not yet been fully implemented and tested properly.

另請參閱

• sched_setscheduler (2)

Programming for the real world - POSIX.4 by Bill O. Gallmeister, O’Reilly & Associates, Inc., ISBN 1-56592-074-0