1/* Thread package specific definitions of stream lock type. NPTL version.
2 Copyright (C) 2000-2020 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
26/* The locking here is very inexpensive, even for inlining. */
27#define _IO_lock_inexpensive 1
28
29typedef struct { int lock; int cnt; void *owner; } _IO_lock_t;
30#define _IO_lock_t_defined 1
31
32#define _IO_lock_initializer { LLL_LOCK_INITIALIZER, 0, NULL }
33
34#define _IO_lock_init(_name) \
35 ((void) ((_name) = (_IO_lock_t) _IO_lock_initializer))
36
37#define _IO_lock_fini(_name) \
38 ((void) 0)
39
40#define _IO_lock_lock(_name) \
41 do { \
42 void *__self = THREAD_SELF; \
43 if ((_name).owner != __self) \
44 { \
45 lll_lock ((_name).lock, LLL_PRIVATE); \
46 (_name).owner = __self; \
47 } \
48 ++(_name).cnt; \
49 } while (0)
50
51#define _IO_lock_trylock(_name) \
52 ({ \
53 int __result = 0; \
54 void *__self = THREAD_SELF; \
55 if ((_name).owner != __self) \
56 { \
57 if (lll_trylock ((_name).lock) == 0) \
58 { \
59 (_name).owner = __self; \
60 (_name).cnt = 1; \
61 } \
62 else \
63 __result = EBUSY; \
64 } \
65 else \
66 ++(_name).cnt; \
67 __result; \
68 })
69
70#define _IO_lock_unlock(_name) \
71 do { \
72 if (--(_name).cnt == 0) \
73 { \
74 (_name).owner = NULL; \
75 lll_unlock ((_name).lock, LLL_PRIVATE); \
76 } \
77 } while (0)
78
79
80
81#define _IO_cleanup_region_start(_fct, _fp) \
82 __libc_cleanup_region_start (((_fp)->_flags & _IO_USER_LOCK) == 0, _fct, _fp)
83#define _IO_cleanup_region_start_noarg(_fct) \
84 __libc_cleanup_region_start (1, _fct, NULL)
85#define _IO_cleanup_region_end(_doit) \
86 __libc_cleanup_region_end (_doit)
87
88#if defined _LIBC && IS_IN (libc)
89
90# ifdef __EXCEPTIONS
91# define _IO_acquire_lock(_fp) \
92 do { \
93 FILE *_IO_acquire_lock_file \
94 __attribute__((cleanup (_IO_acquire_lock_fct))) \
95 = (_fp); \
96 _IO_flockfile (_IO_acquire_lock_file);
97# else
98# define _IO_acquire_lock(_fp) _IO_acquire_lock_needs_exceptions_enabled
99# endif
100# define _IO_release_lock(_fp) ; } while (0)
101
102#endif
103
104#endif /* stdio-lock.h */
105