u_atomic.c revision 01e04c3f 
1/*
2 * Copyright © 2017 Gražvydas Ignotas
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24#if defined(MISSING_64BIT_ATOMICS) && defined(HAVE_PTHREAD)
25
26#include <stdint.h>
27#include <pthread.h>
28
29#if defined(HAVE_FUNC_ATTRIBUTE_WEAK) && !defined(__CYGWIN__)
30#define WEAK __attribute__((weak))
31#else
32#define WEAK
33#endif
34
35static pthread_mutex_t sync_mutex = PTHREAD_MUTEX_INITIALIZER;
36
37WEAK uint64_t
38__sync_add_and_fetch_8(uint64_t *ptr, uint64_t val)
39{
40   uint64_t r;
41
42   pthread_mutex_lock(&sync_mutex);
43   *ptr += val;
44   r = *ptr;
45   pthread_mutex_unlock(&sync_mutex);
46
47   return r;
48}
49
50WEAK uint64_t
51__sync_sub_and_fetch_8(uint64_t *ptr, uint64_t val)
52{
53   uint64_t r;
54
55   pthread_mutex_lock(&sync_mutex);
56   *ptr -= val;
57   r = *ptr;
58   pthread_mutex_unlock(&sync_mutex);
59
60   return r;
61}
62
63WEAK uint64_t
64__sync_val_compare_and_swap_8(uint64_t *ptr, uint64_t oldval, uint64_t newval)
65{
66   uint64_t r;
67
68   pthread_mutex_lock(&sync_mutex);
69   r = *ptr;
70   if (*ptr == oldval)
71      *ptr = newval;
72   pthread_mutex_unlock(&sync_mutex);
73
74   return r;
75}
76
77#endif
78