blob: 15906d24c9cb8ba573edf0b55e6eef335b2e59f8
1 | /* |
2 | * Copyright (c) 2012 Ronald S. Bultje <rsbultje@gmail.com> |
3 | * |
4 | * This file is part of FFmpeg. |
5 | * |
6 | * FFmpeg is free software; you can redistribute it and/or |
7 | * modify it under the terms of the GNU Lesser General Public |
8 | * License as published by the Free Software Foundation; either |
9 | * version 2.1 of the License, or (at your option) any later version. |
10 | * |
11 | * FFmpeg is distributed in the hope that it will be useful, |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
14 | * Lesser General Public License for more details. |
15 | * |
16 | * You should have received a copy of the GNU Lesser General Public |
17 | * License along with FFmpeg; if not, write to the Free Software |
18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
19 | */ |
20 | |
21 | #ifndef AVUTIL_ATOMIC_H |
22 | #define AVUTIL_ATOMIC_H |
23 | |
24 | #include "config.h" |
25 | |
26 | #if HAVE_ATOMICS_NATIVE |
27 | |
28 | #if HAVE_ATOMICS_GCC |
29 | #include "atomic_gcc.h" |
30 | #elif HAVE_ATOMICS_WIN32 |
31 | #include "atomic_win32.h" |
32 | #elif HAVE_ATOMICS_SUNCC |
33 | #include "atomic_suncc.h" |
34 | #endif |
35 | |
36 | #else |
37 | |
38 | /** |
39 | * Load the current value stored in an atomic integer. |
40 | * |
41 | * @param ptr atomic integer |
42 | * @return the current value of the atomic integer |
43 | * @note This acts as a memory barrier. |
44 | */ |
45 | int avpriv_atomic_int_get(volatile int *ptr); |
46 | |
47 | /** |
48 | * Store a new value in an atomic integer. |
49 | * |
50 | * @param ptr atomic integer |
51 | * @param val the value to store in the atomic integer |
52 | * @note This acts as a memory barrier. |
53 | */ |
54 | void avpriv_atomic_int_set(volatile int *ptr, int val); |
55 | |
56 | /** |
57 | * Add a value to an atomic integer. |
58 | * |
59 | * @param ptr atomic integer |
60 | * @param inc the value to add to the atomic integer (may be negative) |
61 | * @return the new value of the atomic integer. |
62 | * @note This does NOT act as a memory barrier. This is primarily |
63 | * intended for reference counting. |
64 | */ |
65 | int avpriv_atomic_int_add_and_fetch(volatile int *ptr, int inc); |
66 | |
67 | /** |
68 | * Atomic pointer compare and swap. |
69 | * |
70 | * @param ptr pointer to the pointer to operate on |
71 | * @param oldval do the swap if the current value of *ptr equals to oldval |
72 | * @param newval value to replace *ptr with |
73 | * @return the value of *ptr before comparison |
74 | */ |
75 | void *avpriv_atomic_ptr_cas(void * volatile *ptr, void *oldval, void *newval); |
76 | |
77 | #endif /* HAVE_ATOMICS_NATIVE */ |
78 | |
79 | #endif /* AVUTIL_ATOMIC_H */ |
80 |