summary refs log tree commit diff
path: root/include/atomic.h
blob: 8b76435a8168c64c57b7577eb41ff38c13a80586 (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
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
/* Internal macros for atomic operations for GNU C Library.
   Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.

   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 _ATOMIC_H
#define _ATOMIC_H	1

#include <stdlib.h>

#include <bits/atomic.h>

/* Wrapper macros to call pre_NN_post (mem, ...) where NN is the
   bit width of *MEM.  The calling macro puts parens around MEM
   and following args.  */
#define __atomic_val_bysize(pre, post, mem, ...)			      \
  ({									      \
    __typeof (*mem) __result;						      \
    if (sizeof (*mem) == 1)						      \
      __result = pre##_8_##post (mem, __VA_ARGS__);			      \
    else if (sizeof (*mem) == 2)					      \
      __result = pre##_16_##post (mem, __VA_ARGS__);			      \
    else if (sizeof (*mem) == 4)					      \
      __result = pre##_32_##post (mem, __VA_ARGS__);			      \
    else if (sizeof (*mem) == 8)					      \
      __result = pre##_64_##post (mem, __VA_ARGS__);			      \
    else								      \
      abort ();								      \
    __result;								      \
  })
#define __atomic_bool_bysize(pre, post, mem, ...)			      \
  ({									      \
    int __result;							      \
    if (sizeof (*mem) == 1)						      \
      __result = pre##_8_##post (mem, __VA_ARGS__);			      \
    else if (sizeof (*mem) == 2)					      \
      __result = pre##_16_##post (mem, __VA_ARGS__);			      \
    else if (sizeof (*mem) == 4)					      \
      __result = pre##_32_##post (mem, __VA_ARGS__);			      \
    else if (sizeof (*mem) == 8)					      \
      __result = pre##_64_##post (mem, __VA_ARGS__);			      \
    else								      \
      abort ();								      \
    __result;								      \
  })


/* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL.
   Return the old *MEM value.  */
#if !defined atomic_compare_and_exchange_val_acq \
    && defined __arch_compare_and_exchange_val_32_acq
# define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \
  __atomic_val_bysize (__arch_compare_and_exchange_val,acq,		      \
		       mem, newval, oldval)
#endif


#ifndef atomic_compare_and_exchange_val_rel
# define atomic_compare_and_exchange_val_rel(mem, newval, oldval)	      \
  atomic_compare_and_exchange_val_acq (mem, newval, oldval)
#endif


/* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL.
   Return zero if *MEM was changed or non-zero if no exchange happened.  */
#ifndef atomic_compare_and_exchange_bool_acq
# ifdef __arch_compare_and_exchange_bool_32_acq
#  define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
  __atomic_bool_bysize (__arch_compare_and_exchange_bool,acq,		      \
		        mem, newval, oldval)
#  else
#   define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
  ({ /* Cannot use __oldval here, because macros later in this file might     \
	call this macro with __oldval argument.	 */			      \
     __typeof (oldval) __old = (oldval);				      \
     atomic_compare_and_exchange_val_acq (mem, newval, __old) != __old;	      \
  })
# endif
#endif


#ifndef atomic_compare_and_exchange_bool_rel
# define atomic_compare_and_exchange_bool_rel(mem, newval, oldval) \
  atomic_compare_and_exchange_bool_acq (mem, newval, oldval)
#endif


/* Store NEWVALUE in *MEM and return the old value.  */
#ifndef atomic_exchange_acq
# define atomic_exchange_acq(mem, newvalue) \
  ({ __typeof (*(mem)) __oldval;					      \
     __typeof (mem) __memp = (mem);					      \
     __typeof (*(mem)) __value = (newvalue);				      \
									      \
     do									      \
       __oldval = *__memp;						      \
     while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp,   \
								    __value,  \
								    __oldval),\
			      0));					      \
									      \
     __oldval; })
#endif

#ifndef atomic_exchange_rel
# define atomic_exchange_rel(mem, newvalue) atomic_exchange_acq (mem, newvalue)
#endif


/* Add VALUE to *MEM and return the old value of *MEM.  */
#ifndef atomic_exchange_and_add
# define atomic_exchange_and_add(mem, value) \
  ({ __typeof (*(mem)) __oldval;					      \
     __typeof (mem) __memp = (mem);					      \
     __typeof (*(mem)) __value = (value);				      \
									      \
     do									      \
       __oldval = *__memp;						      \
     while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp,   \
								    __oldval  \
								    + __value,\
								    __oldval),\
			      0));					      \
									      \
     __oldval; })
#endif



#ifndef atomic_max
# define atomic_max(mem, value) \
  do {									      \
    __typeof (*(mem)) __oldval;						      \
    __typeof (mem) __memp = (mem);					      \
    __typeof (*(mem)) __value = (value);				      \
    do {								      \
      __oldval = *__memp;						      \
      if (__oldval >= __value)						      \
	break;								      \
    } while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp,  \
								     __value, \
								     __oldval),\
			       0));					      \
  } while (0)
#endif

#ifndef atomic_min
# define atomic_min(mem, value) \
  do {									      \
    __typeof (*(mem)) __oldval;						      \
    __typeof (mem) __memp = (mem);					      \
    __typeof (*(mem)) __value = (value);				      \
    do {								      \
      __oldval = *__memp;						      \
      if (__oldval <= __value)						      \
	break;								      \
    } while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp,  \
								     __value, \
								     __oldval),\
			       0));					      \
  } while (0)
#endif

#ifndef atomic_add
# define atomic_add(mem, value) (void) atomic_exchange_and_add ((mem), (value))
#endif


#ifndef atomic_increment
# define atomic_increment(mem) atomic_add ((mem), 1)
#endif


#ifndef atomic_increment_val
# define atomic_increment_val(mem) (atomic_exchange_and_add ((mem), 1) + 1)
#endif


/* Add one to *MEM and return true iff it's now zero.  */
#ifndef atomic_increment_and_test
# define atomic_increment_and_test(mem) \
  (atomic_exchange_and_add ((mem), 1) + 1 == 0)
#endif


#ifndef atomic_decrement
# define atomic_decrement(mem) atomic_add ((mem), -1)
#endif


#ifndef atomic_decrement_val
# define atomic_decrement_val(mem) (atomic_exchange_and_add ((mem), -1) - 1)
#endif


/* Subtract 1 from *MEM and return true iff it's now zero.  */
#ifndef atomic_decrement_and_test
# define atomic_decrement_and_test(mem) \
  (atomic_exchange_and_add ((mem), -1) == 1)
#endif


/* Decrement *MEM if it is > 0, and return the old value.  */
#ifndef atomic_decrement_if_positive
# define atomic_decrement_if_positive(mem) \
  ({ __typeof (*(mem)) __oldval;					      \
     __typeof (mem) __memp = (mem);					      \
									      \
     do									      \
       {								      \
	 __oldval = *__memp;						      \
	 if (__builtin_expect (__oldval <= 0, 0))			      \
	   break;							      \
       }								      \
     while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp,   \
								    __oldval  \
								    - 1,      \
								    __oldval),\
			      0));\
     __oldval; })
#endif


#ifndef atomic_add_negative
# define atomic_add_negative(mem, value)				      \
  ({ __typeof (value) __aan_value = (value);				      \
     atomic_exchange_and_add (mem, __aan_value) < -__aan_value; })
#endif


#ifndef atomic_add_zero
# define atomic_add_zero(mem, value)					      \
  ({ __typeof (value) __aaz_value = (value);				      \
     atomic_exchange_and_add (mem, __aaz_value) == -__aaz_value; })
#endif


#ifndef atomic_bit_set
# define atomic_bit_set(mem, bit) \
  (void) atomic_bit_test_set(mem, bit)
#endif


#ifndef atomic_bit_test_set
# define atomic_bit_test_set(mem, bit) \
  ({ __typeof (*(mem)) __oldval;					      \
     __typeof (mem) __memp = (mem);					      \
     __typeof (*(mem)) __mask = ((__typeof (*(mem))) 1 << (bit));	      \
									      \
     do									      \
       __oldval = (*__memp);						      \
     while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp,   \
								    __oldval  \
								    | __mask, \
								    __oldval),\
			      0));					      \
									      \
     __oldval & __mask; })
#endif


#ifndef atomic_full_barrier
# define atomic_full_barrier() __asm ("" ::: "memory")
#endif


#ifndef atomic_read_barrier
# define atomic_read_barrier() atomic_full_barrier ()
#endif


#ifndef atomic_write_barrier
# define atomic_write_barrier() atomic_full_barrier ()
#endif


#ifndef atomic_delay
# define atomic_delay() do { /* nothing */ } while (0)
#endif

#endif	/* atomic.h */