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
|
/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "apr_arch_atomic.h"
#ifdef USE_ATOMICS_BUILTINS
#if defined(__i386__) || defined(__x86_64__) \
|| defined(__s390__) || defined(__s390x__)
#define WEAK_MEMORY_ORDERING 0
#else
#define WEAK_MEMORY_ORDERING 1
#endif
APR_DECLARE(apr_status_t) apr_atomic_init(apr_pool_t *p)
{
#if defined (USE_ATOMICS_GENERIC64)
return apr__atomic_generic64_init(p);
#else
return APR_SUCCESS;
#endif
}
APR_DECLARE(apr_uint32_t) apr_atomic_read32(volatile apr_uint32_t *mem)
{
#if HAVE__ATOMIC_BUILTINS
return __atomic_load_n(mem, __ATOMIC_SEQ_CST);
#elif WEAK_MEMORY_ORDERING
/* No __sync_load() available => apr_atomic_add32(mem, 0) */
return __sync_fetch_and_add(mem, 0);
#else
return *mem;
#endif
}
APR_DECLARE(void) apr_atomic_set32(volatile apr_uint32_t *mem, apr_uint32_t val)
{
#if HAVE__ATOMIC_BUILTINS
__atomic_store_n(mem, val, __ATOMIC_SEQ_CST);
#elif WEAK_MEMORY_ORDERING
/* No __sync_store() available => apr_atomic_xchg32(mem, val) */
__sync_synchronize();
__sync_lock_test_and_set(mem, val);
#else
*mem = val;
#endif
}
APR_DECLARE(apr_uint32_t) apr_atomic_add32(volatile apr_uint32_t *mem, apr_uint32_t val)
{
#if HAVE__ATOMIC_BUILTINS
return __atomic_fetch_add(mem, val, __ATOMIC_SEQ_CST);
#else
return __sync_fetch_and_add(mem, val);
#endif
}
APR_DECLARE(void) apr_atomic_sub32(volatile apr_uint32_t *mem, apr_uint32_t val)
{
#if HAVE__ATOMIC_BUILTINS
__atomic_fetch_sub(mem, val, __ATOMIC_SEQ_CST);
#else
__sync_fetch_and_sub(mem, val);
#endif
}
APR_DECLARE(apr_uint32_t) apr_atomic_inc32(volatile apr_uint32_t *mem)
{
#if HAVE__ATOMIC_BUILTINS
return __atomic_fetch_add(mem, 1, __ATOMIC_SEQ_CST);
#else
return __sync_fetch_and_add(mem, 1);
#endif
}
APR_DECLARE(int) apr_atomic_dec32(volatile apr_uint32_t *mem)
{
#if HAVE__ATOMIC_BUILTINS
return __atomic_sub_fetch(mem, 1, __ATOMIC_SEQ_CST);
#else
return __sync_sub_and_fetch(mem, 1);
#endif
}
APR_DECLARE(apr_uint32_t) apr_atomic_cas32(volatile apr_uint32_t *mem, apr_uint32_t val,
apr_uint32_t cmp)
{
#if HAVE__ATOMIC_BUILTINS
__atomic_compare_exchange_n(mem, &cmp, val, 0, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
return cmp;
#else
return __sync_val_compare_and_swap(mem, cmp, val);
#endif
}
APR_DECLARE(apr_uint32_t) apr_atomic_xchg32(volatile apr_uint32_t *mem, apr_uint32_t val)
{
#if HAVE__ATOMIC_BUILTINS
return __atomic_exchange_n(mem, val, __ATOMIC_SEQ_CST);
#else
__sync_synchronize();
return __sync_lock_test_and_set(mem, val);
#endif
}
APR_DECLARE(void*) apr_atomic_casptr(void *volatile *mem, void *ptr, const void *cmp)
{
#if HAVE__ATOMIC_BUILTINS
__atomic_compare_exchange_n(mem, (void *)&cmp, ptr, 0, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
return (void *)cmp;
#else
return (void *)__sync_val_compare_and_swap(mem, (void *)cmp, ptr);
#endif
}
APR_DECLARE(void*) apr_atomic_xchgptr(void *volatile *mem, void *ptr)
{
#if HAVE__ATOMIC_BUILTINS
return __atomic_exchange_n(mem, ptr, __ATOMIC_SEQ_CST);
#else
__sync_synchronize();
return __sync_lock_test_and_set(mem, ptr);
#endif
}
#endif /* USE_ATOMICS_BUILTINS */
|
