summary refs log tree commit diff
path: root/sysdeps/mach/hurd/bits/libc-lock.h
blob: 6e3835371c6a80cdc8a6a4d8339af20b13f7a2e9 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
/* libc-internal interface for mutex locks.  Hurd version using Mach cthreads.
   Copyright (C) 1996,97,98,2000,01 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef _BITS_LIBC_LOCK_H
#define _BITS_LIBC_LOCK_H 1

#if (_LIBC - 0) || (_CTHREADS_ - 0)
#include <cthreads.h>
#include <hurd/threadvar.h>

typedef struct mutex __libc_lock_t;
typedef struct
{
  struct mutex mutex;
  void *owner;
  int count;
} __libc_lock_recursive_t;

#define __libc_lock_owner_self() ((void *) __hurd_threadvar_location (0))

#else
typedef struct __libc_lock_opaque__ __libc_lock_t;
typedef struct __libc_lock_recursive_opaque__ __libc_lock_recursive_t;
#endif

/* Define a lock variable NAME with storage class CLASS.  The lock must be
   initialized with __libc_lock_init before it can be used (or define it
   with __libc_lock_define_initialized, below).  Use `extern' for CLASS to
   declare a lock defined in another module.  In public structure
   definitions you must use a pointer to the lock structure (i.e., NAME
   begins with a `*'), because its storage size will not be known outside
   of libc.  */
#define __libc_lock_define(CLASS,NAME) \
  CLASS __libc_lock_t NAME;

/* Define an initialized lock variable NAME with storage class CLASS.  */
#define __libc_lock_define_initialized(CLASS,NAME) \
  CLASS __libc_lock_t NAME = MUTEX_INITIALIZER;

/* Initialize the named lock variable, leaving it in a consistent, unlocked
   state.  */
#define __libc_lock_init(NAME) __mutex_init (&(NAME))

/* Finalize the named lock variable, which must be locked.  It cannot be
   used again until __libc_lock_init is called again on it.  This must be
   called on a lock variable before the containing storage is reused.  */
#define __libc_lock_fini(NAME) __mutex_unlock (&(NAME))
#define __libc_lock_fini_recursive(NAME) __mutex_unlock (&(NAME).mutex)


/* Lock the named lock variable.  */
#define __libc_lock_lock(NAME) __mutex_lock (&(NAME))

/* Lock the named lock variable.  */
#define __libc_lock_trylock(NAME) (!__mutex_trylock (&(NAME)))

/* Unlock the named lock variable.  */
#define __libc_lock_unlock(NAME) __mutex_unlock (&(NAME))


#define __libc_lock_define_recursive(CLASS,NAME) \
  CLASS __libc_lock_recursive_t NAME;
#define _LIBC_LOCK_RECURSIVE_INITIALIZER { MUTEX_INITIALIZER, 0, 0 }
#define __libc_lock_define_initialized_recursive(CLASS,NAME) \
  CLASS __libc_lock_recursive_t NAME = _LIBC_LOCK_RECURSIVE_INITIALIZER;

#define __libc_lock_init_recursive(NAME) \
  ({ __libc_lock_recursive_t *const __lock = &(NAME); \
     __lock->owner = 0; mutex_init (&__lock->mutex); })

#define __libc_lock_trylock_recursive(NAME)				      \
  ({ __libc_lock_recursive_t *const __lock = &(NAME);			      \
     void *__self = __libc_lock_owner_self ();				      \
     __mutex_trylock (&__lock->mutex)					      \
     ? (__lock->owner = __self, __lock->count = 1, 0)			      \
     : __lock->owner == __self ? (++__lock->count, 0) : 1; })

#define __libc_lock_lock_recursive(NAME)				      \
  ({ __libc_lock_recursive_t *const __lock = &(NAME);			      \
     void *__self = __libc_lock_owner_self ();				      \
     if (__mutex_trylock (&__lock->mutex)				      \
	 || (__lock->owner != __self					      \
	     && (__mutex_lock (&__lock->mutex), 1)))			      \
       __lock->owner = __self, __lock->count = 1;			      \
     else								      \
       ++__lock->count;							      \
  })
#define __libc_lock_unlock_recursive(NAME)				      \
  ({ __libc_lock_recursive_t *const __lock = &(NAME);			      \
     if (--__lock->count == 0)						      \
       {								      \
	 __lock->owner = 0;						      \
	 __mutex_unlock (&__lock->mutex);				      \
       }								      \
  })


/* XXX for now */
#define __libc_rwlock_define		__libc_lock_define
#define __libc_rwlock_define_initialized __libc_lock_define_initialized
#define __libc_rwlock_init		__libc_lock_init
#define __libc_rwlock_fini		__libc_lock_fini
#define __libc_rwlock_rdlock		__libc_lock_lock
#define __libc_rwlock_wrlock		__libc_lock_lock
#define __libc_rwlock_tryrdlock		__libc_lock_trylock
#define __libc_rwlock_trywrlock		__libc_lock_trylock
#define __libc_rwlock_unlock		__libc_lock_unlock


/* Start a critical region with a cleanup function */
#define __libc_cleanup_region_start(DOIT, FCT, ARG)			    \
{									    \
  typeof (***(FCT)) *__save_FCT = (DOIT) ? (FCT) : 0;			    \
  typeof (ARG) __save_ARG = ARG;					    \
  /* close brace is in __libc_cleanup_region_end below. */

/* End a critical region started with __libc_cleanup_region_start. */
#define __libc_cleanup_region_end(DOIT)					    \
  if ((DOIT) && __save_FCT != 0)					    \
    (*__save_FCT)(__save_ARG);						    \
}

/* Sometimes we have to exit the block in the middle.  */
#define __libc_cleanup_end(DOIT)					    \
  if ((DOIT) && __save_FCT != 0)					    \
    (*__save_FCT)(__save_ARG);						    \


#if (_CTHREADS_ - 0)

/* Use mutexes as once control variables. */

struct __libc_once
  {
    __libc_lock_t lock;
    int done;
  };

#define __libc_once_define(CLASS,NAME) \
  CLASS struct __libc_once NAME = { MUTEX_INITIALIZER, 0 }

/* Call handler iff the first call.  */
#define __libc_once(ONCE_CONTROL, INIT_FUNCTION) \
  do {									      \
    __libc_lock_lock (ONCE_CONTROL.lock);				      \
    if (!ONCE_CONTROL.done)						      \
      (INIT_FUNCTION) ();						      \
    ONCE_CONTROL.done = 1;						      \
    __libc_lock_unlock (ONCE_CONTROL.lock);				      \
  } while (0)

#ifdef _LIBC
/* We need portable names for some functions.  E.g., when they are
   used as argument to __libc_cleanup_region_start.  */
#define __libc_mutex_unlock __mutex_unlock
#endif

/* Type for key of thread specific data.  */
typedef cthread_key_t __libc_key_t;

#define __libc_key_create(KEY,DEST) cthread_keycreate (KEY)
#define __libc_setspecific(KEY,VAL) cthread_setspecific (KEY, VAL)
void *__libc_getspecific (__libc_key_t key);

#endif /* _CTHREADS_ */

#endif	/* bits/libc-lock.h */