1 /* Copyright (C) 2002-2022 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 <sched.h>
20 #include <string.h>
21 #include <sched.h>
22 #include "pthreadP.h"
23 #include <lowlevellock.h>
24 #include <shlib-compat.h>
25 
26 int
__pthread_setschedprio(pthread_t threadid,int prio)27 __pthread_setschedprio (pthread_t threadid, int prio)
28 {
29   struct pthread *pd = (struct pthread *) threadid;
30 
31   /* Make sure the descriptor is valid.  */
32   if (INVALID_TD_P (pd))
33     /* Not a valid thread handle.  */
34     return ESRCH;
35 
36   int result = 0;
37   struct sched_param param;
38   param.sched_priority = prio;
39 
40   /* See CREATE THREAD NOTES in nptl/pthread_create.c.  */
41   lll_lock (pd->lock, LLL_PRIVATE);
42 
43   /* If the thread should have higher priority because of some
44      PTHREAD_PRIO_PROTECT mutexes it holds, adjust the priority.  */
45   if (__builtin_expect (pd->tpp != NULL, 0) && pd->tpp->priomax > prio)
46     param.sched_priority = pd->tpp->priomax;
47 
48   /* Try to set the scheduler information.  */
49   if (__glibc_unlikely (__sched_setparam (pd->tid, &param) == -1))
50     result = errno;
51   else
52     {
53       /* We succeeded changing the kernel information.  Reflect this
54 	 change in the thread descriptor.  */
55       param.sched_priority = prio;
56       memcpy (&pd->schedparam, &param, sizeof (struct sched_param));
57       pd->flags |= ATTR_FLAG_SCHED_SET;
58     }
59 
60   lll_unlock (pd->lock, LLL_PRIVATE);
61 
62   return result;
63 }
64 versioned_symbol (libc, __pthread_setschedprio, pthread_setschedprio,
65 		  GLIBC_2_34);
66 
67 #if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_3_4, GLIBC_2_34)
68 compat_symbol (libpthread, __pthread_setschedprio, pthread_setschedprio,
69 	       GLIBC_2_3_4);
70 #endif
71