1/* getpriority for Linux.
2 Copyright (C) 1996-2020 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <errno.h>
20#include <sys/resource.h>
21
22#include <sysdep.h>
23#include <sys/syscall.h>
24
25/* The return value of getpriority syscall is biased by this value
26 to avoid returning negative values. */
27#define PZERO 20
28
29/* Return the highest priority of any process specified by WHICH and WHO
30 (see above); if WHO is zero, the current process, process group, or user
31 (as specified by WHO) is used. A lower priority number means higher
32 priority. Priorities range from PRIO_MIN to PRIO_MAX. */
33
34int
35__getpriority (enum __priority_which which, id_t who)
36{
37 int res;
38
39 res = INLINE_SYSCALL (getpriority, 2, (int) which, who);
40 if (res >= 0)
41 res = PZERO - res;
42 return res;
43}
44libc_hidden_def (__getpriority)
45weak_alias (__getpriority, getpriority)
46