ffmpeg/libavutil/atomic_gcc.h

   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_GCC_H
  22 #define AVUTIL_ATOMIC_GCC_H
  23
  24 #include <stdint.h>
  25
  26 #include "atomic.h"
  27
  28 #define avpriv_atomic_int_get atomic_int_get_gcc
  29 static inline int atomic_int_get_gcc(volatile int *ptr)
  30 {
  31 #if HAVE_ATOMIC_COMPARE_EXCHANGE
  32     return __atomic_load_n(ptr, __ATOMIC_SEQ_CST);
  33 #else
  34     __sync_synchronize();
  35     return *ptr;
  36 #endif
  37 }
  38
  39 #define avpriv_atomic_int_set atomic_int_set_gcc
  40 static inline void atomic_int_set_gcc(volatile int *ptr, int val)
  41 {
  42 #if HAVE_ATOMIC_COMPARE_EXCHANGE
  43     __atomic_store_n(ptr, val, __ATOMIC_SEQ_CST);
  44 #else
  45     *ptr = val;
  46     __sync_synchronize();
  47 #endif
  48 }
  49
  50 #define avpriv_atomic_int_add_and_fetch atomic_int_add_and_fetch_gcc
  51 static inline int atomic_int_add_and_fetch_gcc(volatile int *ptr, int inc)
  52 {
  53 #if HAVE_ATOMIC_COMPARE_EXCHANGE
  54     return __atomic_add_fetch(ptr, inc, __ATOMIC_SEQ_CST);
  55 #else
  56     return __sync_add_and_fetch(ptr, inc);
  57 #endif
  58 }
  59
  60 #define avpriv_atomic_ptr_cas atomic_ptr_cas_gcc
  61 static inline void *atomic_ptr_cas_gcc(void * volatile *ptr,
  62                                        void *oldval, void *newval)
  63 {
  64 #if HAVE_SYNC_VAL_COMPARE_AND_SWAP
  65 #ifdef __ARMCC_VERSION
  66     // armcc will throw an error if ptr is not an integer type
  67     volatile uintptr_t *tmp = (volatile uintptr_t*)ptr;
  68     return (void*)__sync_val_compare_and_swap(tmp, oldval, newval);
  69 #else
  70     return __sync_val_compare_and_swap(ptr, oldval, newval);
  71 #endif
  72 #else
  73     __atomic_compare_exchange_n(ptr, &oldval, newval, 0, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
  74     return oldval;
  75 #endif
  76 }
  77
  78 #endif /* AVUTIL_ATOMIC_GCC_H */