1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
|
/* Copyright (C) 1992, 1996, 1997, 2001 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <errno.h>
#include <unistd.h>
#include <sys/resource.h>
/* Increment the scheduling priority of the calling process by INCR.
The superuser may use a negative INCR to decrement the priority. */
int
nice (int incr)
{
int save;
int prio;
int result;
/* -1 is a valid priority, so we use errno to check for an error. */
save = errno;
__set_errno (0);
prio = getpriority (PRIO_PROCESS, 0);
if (prio == -1)
{
if (errno != 0)
return -1;
else
__set_errno (save);
}
result = setpriority (PRIO_PROCESS, 0, prio + incr);
if (result != -1)
return prio + incr;
else
return -1;
}
|
