| 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 */ |