1/* Pthread mutex backoff configuration.
2 Copyright (C) 2022-2023 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#ifndef _PTHREAD_MUTEX_BACKOFF_H
19#define _PTHREAD_MUTEX_BACKOFF_H 1
20
21#include <fast-jitter.h>
22
23static inline unsigned int
24get_jitter (void)
25{
26 return get_fast_jitter ();
27}
28
29#define MAX_BACKOFF 16
30
31static inline int
32get_next_backoff (int backoff)
33{
34 /* Binary expontial backoff. Limiting max backoff
35 can reduce latency in large critical section. */
36 return (backoff < MAX_BACKOFF) ? backoff << 1 : backoff;
37}
38
39#endif
40