1/* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements.  See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License.  You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17
18#include "apr.h"
19#include "apr_atomic.h"
20
21#include <stdlib.h>
22
23apr_status_t apr_atomic_init(apr_pool_t *p)
24{
25    return APR_SUCCESS;
26}
27
28apr_uint32_t apr_atomic_add32(volatile apr_uint32_t *mem, apr_uint32_t val)
29{
30    apr_uint32_t old, new_val;
31
32    old = *mem;   /* old is automatically updated on cs failure */
33    do {
34        new_val = old + val;
35    } while (__cs(&old, (cs_t *)mem, new_val));
36    return old;
37}
38
39void apr_atomic_sub32(volatile apr_uint32_t *mem, apr_uint32_t val)
40{
41     apr_uint32_t old, new_val;
42
43     old = *mem;   /* old is automatically updated on cs failure */
44     do {
45         new_val = old - val;
46     } while (__cs(&old, (cs_t *)mem, new_val));
47}
48
49apr_uint32_t apr_atomic_inc32(volatile apr_uint32_t *mem)
50{
51    return apr_atomic_add32(mem, 1);
52}
53
54int apr_atomic_dec32(volatile apr_uint32_t *mem)
55{
56    apr_uint32_t old, new_val;
57
58    old = *mem;   /* old is automatically updated on cs failure */
59    do {
60        new_val = old - 1;
61    } while (__cs(&old, (cs_t *)mem, new_val));
62
63    return new_val != 0;
64}
65
66apr_uint32_t apr_atomic_read32(volatile apr_uint32_t *mem)
67{
68    return *mem;
69}
70
71void apr_atomic_set32(volatile apr_uint32_t *mem, apr_uint32_t val)
72{
73    *mem = val;
74}
75
76apr_uint32_t apr_atomic_cas32(volatile apr_uint32_t *mem, apr_uint32_t swap,
77                              apr_uint32_t cmp)
78{
79    apr_uint32_t old = cmp;
80
81    __cs(&old, (cs_t *)mem, swap);
82    return old; /* old is automatically updated from mem on cs failure */
83}
84
85#if APR_SIZEOF_VOIDP == 4
86void *apr_atomic_casptr(volatile void **mem_ptr,
87                        void *swap_ptr,
88                        const void *cmp_ptr)
89{
90     __cs1(&cmp_ptr,     /* automatically updated from mem on __cs1 failure  */
91           mem_ptr,      /* set from swap when __cs1 succeeds                */
92           &swap_ptr);
93     return (void *)cmp_ptr;
94}
95#elif APR_SIZEOF_VOIDP == 8
96void *apr_atomic_casptr(volatile void **mem_ptr,
97                        void *swap_ptr,
98                        const void *cmp_ptr)
99{
100     __csg(&cmp_ptr,     /* automatically updated from mem on __csg failure  */
101           mem_ptr,      /* set from swap when __csg succeeds                */
102           &swap_ptr);
103     return (void *)cmp_ptr;
104}
105#else
106#error APR_SIZEOF_VOIDP value not supported
107#endif /* APR_SIZEOF_VOIDP */
108
109apr_uint32_t apr_atomic_xchg32(volatile apr_uint32_t *mem, apr_uint32_t val)
110{
111    apr_uint32_t old, new_val;
112
113    old = *mem;   /* old is automatically updated on cs failure */
114    do {
115        new_val = val;
116    } while (__cs(&old, (cs_t *)mem, new_val));
117
118    return old;
119}
120
121APR_DECLARE(void*) apr_atomic_xchgptr(volatile void **mem_ptr, void *new_ptr)
122{
123    void *old_ptr;
124
125    old_ptr = *(void **)mem_ptr; /* old is automatically updated on cs failure */
126#if APR_SIZEOF_VOIDP == 4
127    do {
128    } while (__cs1(&old_ptr, mem_ptr, &new_ptr));
129#elif APR_SIZEOF_VOIDP == 8
130    do {
131    } while (__csg(&old_ptr, mem_ptr, &new_ptr));
132#else
133#error APR_SIZEOF_VOIDP value not supported
134#endif /* APR_SIZEOF_VOIDP */
135
136    return old_ptr;
137}
138