2 * Copyright (c) 2003 by Hewlett-Packard Company. All rights reserved.
4 * Permission is hereby granted, free of charge, to any person obtaining a copy
5 * of this software and associated documentation files (the "Software"), to deal
6 * in the Software without restriction, including without limitation the rights
7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 * copies of the Software, and to permit persons to whom the Software is
9 * furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
24 * Ensure, if at all possible, that AO_compare_and_swap_full() is
25 * available. The emulation should be brute-force signal-safe, even
26 * though it actually blocks.
27 * Including this file will generate an error if AO_compare_and_swap_full()
28 * cannot be made available.
29 * This will be included from platform-specific atomic_ops files
30 * id appropriate, and if AO_FORCE_CAS is defined. It should not be
31 * included directly, especially since it affects the implementation
32 * of other atomic update primitives.
33 * The implementation assumes that only AO_store_XXX and AO_test_and_set_XXX
34 * variants are defined, and that AO_test_and_set_XXX is not used to
35 * operate on compare_and_swap locations.
38 #if !defined(ATOMIC_OPS_H)
39 # error This file should not be included directly.
42 #ifndef AO_HAVE_double_t
43 # include "standard_ao_double_t.h"
46 int AO_compare_and_swap_emulation(volatile AO_t *addr, AO_t old,
49 int AO_compare_double_and_swap_double_emulation(volatile AO_double_t *addr,
50 AO_t old_val1, AO_t old_val2,
51 AO_t new_val1, AO_t new_val2);
53 void AO_store_full_emulation(volatile AO_t *addr, AO_t val);
55 #define AO_compare_and_swap_full(addr, old, newval) \
56 AO_compare_and_swap_emulation(addr, old, newval)
57 #define AO_HAVE_compare_and_swap_full
59 #ifndef AO_HAVE_compare_double_and_swap_double
60 # define AO_compare_double_and_swap_double_full(addr, old1, old2, \
62 AO_compare_double_and_swap_double_emulation(addr, old1, old2, \
64 # define AO_HAVE_compare_double_and_swap_double_full
70 #undef AO_HAVE_store_write
71 #undef AO_store_release
72 #undef AO_HAVE_store_release
74 #undef AO_HAVE_store_full
75 #define AO_store_full(addr, val) AO_store_full_emulation(addr, val)
76 #define AO_HAVE_store_full