1/* Copyright (C) 2002-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 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 <semaphore.h>
20#include <futex-internal.h>
21#include "pthreadP.h"
22
23#define SEM_SHM_PREFIX "sem."
24
25/* Keeping track of currently used mappings. */
26struct inuse_sem
27{
28 dev_t dev;
29 ino_t ino;
30 int refcnt;
31 sem_t *sem;
32 char name[];
33};
34
35
36/* The search tree for existing mappings. */
37extern void *__sem_mappings attribute_hidden;
38
39/* Lock to protect the search tree. */
40extern int __sem_mappings_lock attribute_hidden;
41
42
43/* Comparison function for search in tree with existing mappings. */
44extern int __sem_search (const void *a, const void *b) attribute_hidden;
45
46static inline void __new_sem_open_init (struct new_sem *sem, unsigned value)
47{
48#if __HAVE_64B_ATOMICS
49 sem->data = value;
50#else
51 sem->value = value << SEM_VALUE_SHIFT;
52 sem->nwaiters = 0;
53#endif
54 /* pad is used as a mutex on pre-v9 sparc and ignored otherwise. */
55 sem->pad = 0;
56
57 /* This always is a shared semaphore. */
58 sem->private = FUTEX_SHARED;
59}
60
61/* Prototypes of functions with multiple interfaces. */
62extern int __new_sem_init (sem_t *sem, int pshared, unsigned int value);
63extern int __old_sem_init (sem_t *sem, int pshared, unsigned int value);
64extern int __new_sem_destroy (sem_t *sem);
65extern int __new_sem_post (sem_t *sem);
66extern int __new_sem_wait (sem_t *sem);
67extern int __old_sem_wait (sem_t *sem);
68extern int __new_sem_trywait (sem_t *sem);
69extern int __new_sem_getvalue (sem_t *sem, int *sval);
70
71#if __TIMESIZE == 64
72# define __sem_clockwait64 __sem_clockwait
73# define __sem_timedwait64 __sem_timedwait
74#else
75extern int
76__sem_clockwait64 (sem_t *sem, clockid_t clockid,
77 const struct __timespec64 *abstime);
78libpthread_hidden_proto (__sem_clockwait64)
79extern int
80__sem_timedwait64 (sem_t *sem, const struct __timespec64 *abstime);
81libpthread_hidden_proto (__sem_timedwait64)
82#endif
83