1/* Copyright (C) 2002-2020 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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 <sched.h>
21#include <string.h>
22#include <sched.h>
23#include "pthreadP.h"
24#include <lowlevellock.h>
25
26
27int
28pthread_setschedprio (pthread_t threadid, int prio)
29{
30 struct pthread *pd = (struct pthread *) threadid;
31
32 /* Make sure the descriptor is valid. */
33 if (INVALID_TD_P (pd))
34 /* Not a valid thread handle. */
35 return ESRCH;
36
37 int result = 0;
38 struct sched_param param;
39 param.sched_priority = prio;
40
41 /* See CREATE THREAD NOTES in nptl/pthread_create.c. */
42 lll_lock (pd->lock, LLL_PRIVATE);
43
44 /* If the thread should have higher priority because of some
45 PTHREAD_PRIO_PROTECT mutexes it holds, adjust the priority. */
46 if (__builtin_expect (pd->tpp != NULL, 0) && pd->tpp->priomax > prio)
47 param.sched_priority = pd->tpp->priomax;
48
49 /* Try to set the scheduler information. */
50 if (__glibc_unlikely (sched_setparam (pd->tid, &param) == -1))
51 result = errno;
52 else
53 {
54 /* We succeeded changing the kernel information. Reflect this
55 change in the thread descriptor. */
56 param.sched_priority = prio;
57 memcpy (&pd->schedparam, &param, sizeof (struct sched_param));
58 pd->flags |= ATTR_FLAG_SCHED_SET;
59 }
60
61 lll_unlock (pd->lock, LLL_PRIVATE);
62
63 return result;
64}
65