1/* Thread package specific definitions of stream lock type. NPTL version.
2 Copyright (C) 2000-2021 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
19#ifndef _STDIO_LOCK_H
20#define _STDIO_LOCK_H 1
21
22#include <libc-lock.h>
23#include <lowlevellock.h>
24
25
26typedef struct { int lock; int cnt; void *owner; } _IO_lock_t;
27#define _IO_lock_t_defined 1
28
29#define _IO_lock_initializer { LLL_LOCK_INITIALIZER, 0, NULL }
30
31#define _IO_lock_init(_name) \
32 ((void) ((_name) = (_IO_lock_t) _IO_lock_initializer))
33
34#define _IO_lock_fini(_name) \
35 ((void) 0)
36
37#define _IO_lock_lock(_name) \
38 do { \
39 void *__self = THREAD_SELF; \
40 if ((_name).owner != __self) \
41 { \
42 lll_lock ((_name).lock, LLL_PRIVATE); \
43 (_name).owner = __self; \
44 } \
45 ++(_name).cnt; \
46 } while (0)
47
48#define _IO_lock_trylock(_name) \
49 ({ \
50 int __result = 0; \
51 void *__self = THREAD_SELF; \
52 if ((_name).owner != __self) \
53 { \
54 if (lll_trylock ((_name).lock) == 0) \
55 { \
56 (_name).owner = __self; \
57 (_name).cnt = 1; \
58 } \
59 else \
60 __result = EBUSY; \
61 } \
62 else \
63 ++(_name).cnt; \
64 __result; \
65 })
66
67#define _IO_lock_unlock(_name) \
68 do { \
69 if (--(_name).cnt == 0) \
70 { \
71 (_name).owner = NULL; \
72 lll_unlock ((_name).lock, LLL_PRIVATE); \
73 } \
74 } while (0)
75
76
77
78#define _IO_cleanup_region_start(_fct, _fp) \
79 __libc_cleanup_region_start (((_fp)->_flags & _IO_USER_LOCK) == 0, _fct, _fp)
80#define _IO_cleanup_region_start_noarg(_fct) \
81 __libc_cleanup_region_start (1, _fct, NULL)
82#define _IO_cleanup_region_end(_doit) \
83 __libc_cleanup_region_end (_doit)
84
85#if defined _LIBC && IS_IN (libc)
86
87# ifdef __EXCEPTIONS
88# define _IO_acquire_lock(_fp) \
89 do { \
90 FILE *_IO_acquire_lock_file \
91 __attribute__((cleanup (_IO_acquire_lock_fct))) \
92 = (_fp); \
93 _IO_flockfile (_IO_acquire_lock_file);
94# else
95# define _IO_acquire_lock(_fp) _IO_acquire_lock_needs_exceptions_enabled
96# endif
97# define _IO_release_lock(_fp) ; } while (0)
98
99#endif
100
101#endif /* stdio-lock.h */
102