1/* Copyright (C) 2003-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <errno.h>
19#include <stdio.h>
20#include <unistd.h>
21
22
23/* Test that nice() does not incorrectly return 0. */
24static int
25do_test (void)
26{
27 int ret;
28 const int incr = 10;
29 int old;
30
31 /* Discover current nice value. */
32 errno = 0;
33 old = nice (inc: 0);
34 if (old == -1 && errno != 0)
35 {
36 printf (format: "break: nice(%d) return: %d, %m\n", 0, old);
37 return 1;
38 }
39
40 /* Nice ourselves up. */
41 errno = 0;
42 ret = nice (inc: incr);
43 if (ret == -1 && errno != 0)
44 {
45 printf (format: "break: nice(%d) return: %d, %m\n", incr, ret);
46 return 1;
47 }
48
49 /* Check for return value being zero when it shouldn't. Cannot simply
50 check for expected value since nice values are capped at 2^n-1.
51 But we assume that we didn't start at the cap and so should have
52 increased some. */
53 if (ret <= old)
54 {
55 printf (format: "FAIL: retval (%d) of nice(%d) != %d\n", ret, incr, old + incr);
56 return 1;
57 }
58
59 /* BZ #18086. Make sure we don't reset errno. */
60 errno = EBADF;
61 nice (inc: 0);
62 if (errno != EBADF)
63 {
64 printf (format: "FAIL: errno = %i, but wanted EBADF (%i)\n", errno, EBADF);
65 return 1;
66 }
67
68
69 printf (format: "PASS: nice(%d) from %d return: %d\n", incr, old, ret);
70 return 0;
71}
72
73#define TEST_FUNCTION do_test ()
74#include "../test-skeleton.c"
75

source code of glibc/posix/tst-nice.c