getpriority.2

来自「minix操作系统最新版本（3.1.1）的源代码」· 2 代码 · 共 38 行

.TH GETPRIORITY 2 "Jul 1, 2005"
.UC 4
.SH NAME
getpriority, setpriority \- get and set scheduling priority
.SH SYNOPSIS
.nf
.ft B
#include <sys/resource.h>

int getpriority(int \fIwhich\fP, int \fIwho\fP)
int setpriority(int \fIwhich\fP, int \fIwho\fP, int \fIprio\fP)
.SH DESCRIPTION
.B Getpriority
returns the scheduling priority of the process, process group, or user
referred to in \fIwho\fP. Which of the three is indicated in
\fIwhich\fP, by PRIO_PROCESS, PRIO_PGRP and PRIO_USER, respectively.
In MINIX 3, currently only PRIO_PROCESS is implemented.

The range of the returned value is between PRIO_MIN and PRIO_MAX,
currently between -20 and 20, and is the so-called nice value of
a process. The higher the nice value, the less favourable the scheduling
priority.

.B Setpriority
sets the priority indicated by \fIwho\fP and \fIwhich\fP to \fIprio\fP.
\fIprio\fP, which is the nice value, may only be lowered by the super-user.
.SH RETURN VALUES
These functions both return -1 on failure, and set errno in this case.
Because
.B getpriority
can return -1 as the real nice value, the caller has to reset errno
and check errno afterwards to distinguish between an error condition
and a negative nice value.
.SH SEE ALSO
nice(1)
.SH AUTHOR
Ben Gras <[e-mail]>