1 /* Thread package specific definitions of stream lock type.  NPTL version.
2    Copyright (C) 2000, 2001, 2002, 2003, 2007 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    <http://www.gnu.org/licenses/>.  */
18 
19 #ifndef _BITS_STDIO_LOCK_H
20 #define _BITS_STDIO_LOCK_H 1
21 
22 #include <bits/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 
29 typedef struct { int lock; int cnt; void *owner; } _IO_lock_t;
30 
31 #define _IO_lock_initializer { LLL_LOCK_INITIALIZER, 0, NULL }
32 
33 #define _IO_lock_init(_name) \
34   ((_name) = (_IO_lock_t) _IO_lock_initializer , 0)
35 
36 #define _IO_lock_fini(_name) \
37   ((void) 0)
38 
39 #define _IO_lock_lock(_name) \
40   do {									      \
41     void *__meself = THREAD_SELF;						      \
42     if ((_name).owner != __meself)					      \
43       {									      \
44 	lll_lock ((_name).lock, LLL_PRIVATE);				      \
45         (_name).owner = __meself;						      \
46       }									      \
47     ++(_name).cnt;							      \
48   } while (0)
49 
50 #define _IO_lock_trylock(_name) \
51   ({									      \
52     int __result = 0;							      \
53     void *__meself = THREAD_SELF;						      \
54     if ((_name).owner != __meself)					      \
55       {									      \
56         if (lll_trylock ((_name).lock) == 0)				      \
57           {								      \
58             (_name).owner = __meself;					      \
59             (_name).cnt = 1;						      \
60           }								      \
61         else								      \
62           __result = EBUSY;						      \
63       }									      \
64     else								      \
65       ++(_name).cnt;							      \
66     __result;								      \
67   })
68 
69 #define _IO_lock_unlock(_name) \
70   do {									      \
71     if (--(_name).cnt == 0)						      \
72       {									      \
73         (_name).owner = NULL;						      \
74 	lll_unlock ((_name).lock, LLL_PRIVATE);				      \
75       }									      \
76   } while (0)
77 
78 
79 
80 #define _IO_cleanup_region_start(_fct, _fp) \
81   __libc_cleanup_region_start (((_fp)->_flags & _IO_USER_LOCK) == 0, _fct, _fp)
82 #define _IO_cleanup_region_start_noarg(_fct) \
83   __libc_cleanup_region_start (1, _fct, NULL)
84 #define _IO_cleanup_region_end(_doit) \
85   __libc_cleanup_region_end (_doit)
86 
87 #if defined _LIBC && !defined NOT_IN_libc
88 
89 # ifdef __EXCEPTIONS
90 #  define _IO_acquire_lock(_fp) \
91   do {									      \
92     _IO_FILE *_IO_acquire_lock_file					      \
93 	__attribute__((cleanup (_IO_acquire_lock_fct)))			      \
94 	= (_fp);							      \
95     _IO_flockfile (_IO_acquire_lock_file);
96 #  define _IO_acquire_lock_clear_flags2(_fp) \
97   do {									      \
98     _IO_FILE *_IO_acquire_lock_file					      \
99 	__attribute__((cleanup (_IO_acquire_lock_clear_flags2_fct)))	      \
100 	= (_fp);							      \
101     _IO_flockfile (_IO_acquire_lock_file);
102 # else
103 #  define _IO_acquire_lock(_fp) _IO_acquire_lock_needs_exceptions_enabled
104 #  define _IO_acquire_lock_clear_flags2(_fp) _IO_acquire_lock (_fp)
105 # endif
106 # define _IO_release_lock(_fp) ; } while (0)
107 
108 #endif
109 
110 #endif /* bits/stdio-lock.h */
111