/***************************************************************************** * vlc_atomic.h: ***************************************************************************** * Copyright (C) 2010 Rémi Denis-Courmont * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program; if not, write to the Free Software Foundation, * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA. *****************************************************************************/ #ifndef VLC_ATOMIC_H # define VLC_ATOMIC_H /** * \file * Atomic operations do not require locking, but they are not very powerful. */ # if !defined (__cplusplus) && (__STDC_VERSION__ >= 201112L) \ && !defined (__STDC_NO_ATOMICS__) /*** Native C11 atomics ***/ # include # else # define ATOMIC_FLAG_INIT false # define ATOMIC_VAR_INIT(value) (value) # define atomic_init(obj, value) \ do { *(obj) = (value); } while(0) # define kill_dependency(y) \ ((void)0) # define atomic_thread_fence(order) \ __sync_synchronize() # define atomic_signal_fence(order) \ ((void)0) # define atomic_is_lock_free(obj) \ false /* In principles, __sync_*() only supports int, long and long long and their * unsigned equivalents, i.e. 4-bytes and 8-bytes types, although GCC also * supports 1 and 2-bytes types. Some non-x86 architectures do not support * 8-byte atomic types (or not efficiently). */ # if defined (_MSC_VER) /* Some atomic operations of the Interlocked API are only available for desktop apps. Thus we define the atomic types to be at least 32 bits wide. */ typedef int_least32_t atomic_flag; typedef int_least32_t atomic_bool; typedef int_least32_t atomic_char; typedef int_least32_t atomic_schar; typedef uint_least32_t atomic_uchar; typedef int_least32_t atomic_short; typedef uint_least32_t atomic_ushort; # else typedef bool atomic_flag; typedef bool atomic_bool; typedef char atomic_char; typedef signed char atomic_schar; typedef unsigned char atomic_uchar; typedef short atomic_short; typedef unsigned short atomic_ushort; # endif typedef int atomic_int; typedef unsigned int atomic_uint; typedef long atomic_long; typedef unsigned long atomic_ulong; typedef long long atomic_llong; typedef unsigned long long atomic_ullong; //typedef char16_t atomic_char16_t; //typedef char32_t atomic_char32_t; typedef wchar_t atomic_wchar_t; typedef int_least8_t atomic_int_least8_t; typedef uint_least8_t atomic_uint_least8_t; typedef int_least16_t atomic_int_least16_t; typedef uint_least16_t atomic_uint_least16_t; typedef int_least32_t atomic_int_least32_t; typedef uint_least32_t atomic_uint_least32_t; typedef int_least64_t atomic_int_least64_t; typedef uint_least64_t atomic_uint_least64_t; typedef int_fast8_t atomic_int_fast8_t; typedef uint_fast8_t atomic_uint_fast8_t; typedef int_fast16_t atomic_int_fast16_t; typedef uint_fast16_t atomic_uint_fast16_t; typedef int_fast32_t atomic_int_fast32_t; typedef uint_fast32_t atomic_uint_fast32_t; typedef int_fast64_t atomic_int_fast64_t; typedef uint_fast64_t atomic_uint_fast64_t; typedef intptr_t atomic_intptr_t; typedef uintptr_t atomic_uintptr_t; typedef size_t atomic_size_t; typedef ptrdiff_t atomic_ptrdiff_t; typedef intmax_t atomic_intmax_t; typedef uintmax_t atomic_uintmax_t; # if defined (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) || (defined (__clang__) && (defined (__x86_64__) || defined (__i386__))) /*** Intel/GCC atomics ***/ # define atomic_store(object,desired) \ do { \ *(object) = (desired); \ __sync_synchronize(); \ } while (0) # define atomic_store_explicit(object,desired,order) \ atomic_store(object,desired) # define atomic_load(object) \ (__sync_synchronize(), *(object)) # define atomic_load_explicit(object,order) \ atomic_load(object) # define atomic_exchange(object,desired) \ ({ \ typeof (object) _obj = (object); \ typeof (*object) _old; \ do \ _old = atomic_load(_obj); \ while (!__sync_bool_compare_and_swap(_obj, _old, (desired))); \ _old; \ }) # define atomic_exchange_explicit(object,desired,order) \ atomic_exchange(object,desired) # define atomic_compare_exchange(object,expected,desired) \ ({ \ typeof (object) _exp = (expected); \ typeof (*object) _old = *_exp; \ *_exp = __sync_val_compare_and_swap((object), _old, (desired)); \ *_exp == _old; \ }) # define atomic_compare_exchange_strong(object,expected,desired) \ atomic_compare_exchange(object, expected, desired) # define atomic_compare_exchange_strong_explicit(object,expected,desired,order) \ atomic_compare_exchange_strong(object, expected, desired) # define atomic_compare_exchange_weak(object,expected,desired) \ atomic_compare_exchange(object, expected, desired) # define atomic_compare_exchange_weak_explicit(object,expected,desired,order) \ atomic_compare_exchange_weak(object, expected, desired) # define atomic_fetch_add(object,operand) \ __sync_fetch_and_add(object, operand) # define atomic_fetch_add_explicit(object,operand,order) \ atomic_fetch_add(object,operand) # define atomic_fetch_sub(object,operand) \ __sync_fetch_and_sub(object, operand) # define atomic_fetch_sub_explicit(object,operand,order) \ atomic_fetch_sub(object,operand) # define atomic_fetch_or(object,operand) \ __sync_fetch_and_or(object, operand) # define atomic_fetch_or_explicit(object,operand,order) \ atomic_fetch_or(object,operand) # define atomic_fetch_xor(object,operand) \ __sync_fetch_and_sub(object, operand) # define atomic_fetch_xor_explicit(object,operand,order) \ atomic_fetch_sub(object,operand) # define atomic_fetch_and(object,operand) \ __sync_fetch_and_and(object, operand) # define atomic_fetch_and_explicit(object,operand,order) \ atomic_fetch_and(object,operand) # define atomic_flag_test_and_set(object) \ atomic_exchange(object, true) # define atomic_flag_test_and_set_explicit(object,order) \ atomic_flag_test_and_set(object) # define atomic_flag_clear(object) \ atomic_store(object, false) # define atomic_flag_clear_explicit(object,order) \ atomic_flag_clear(object) # elif defined (__GNUC__) /*** No atomics ***/ # define atomic_store(object,desired) \ do { \ typeof (object) _obj = (object); \ typeof (*object) _des = (desired); \ vlc_global_lock(VLC_ATOMIC_MUTEX); \ *_obj = _des; \ vlc_global_unlock(VLC_ATOMIC_MUTEX); \ } while (0) # define atomic_store_explicit(object,desired,order) \ atomic_store(object,desired) # define atomic_load(object) \ ({ \ typeof (object) _obj = (object); \ typeof (*object) _old; \ vlc_global_lock(VLC_ATOMIC_MUTEX); \ _old = *_obj; \ vlc_global_unlock(VLC_ATOMIC_MUTEX); \ _old; \ }) # define atomic_load_explicit(object,order) \ atomic_load(object) # define atomic_exchange(object,desired) \ ({ \ typeof (object) _obj = (object); \ typeof (*object) _des = (desired); \ typeof (*object) _old; \ vlc_global_lock(VLC_ATOMIC_MUTEX); \ _old = *_obj; \ *_obj = _des; \ vlc_global_unlock(VLC_ATOMIC_MUTEX); \ _old; \ }) # define atomic_exchange_explicit(object,desired,order) \ atomic_exchange(object,desired) # define atomic_compare_exchange_strong(object,expected,desired) \ ({ \ typeof (object) _obj = (object); \ typeof (object) _exp = (expected); \ typeof (*object) _des = (desired); \ bool ret; \ vlc_global_lock(VLC_ATOMIC_MUTEX); \ ret = *_obj == *_exp; \ if (ret) \ *_obj = _des; \ else \ *_exp = *_obj; \ vlc_global_unlock(VLC_ATOMIC_MUTEX); \ ret; \ }) # define atomic_compare_exchange_strong_explicit(object,expected,desired,order) \ atomic_compare_exchange_strong(object, expected, desired) # define atomic_compare_exchange_weak(object,expected,desired) \ atomic_compare_exchange_strong(object, expected, desired) # define atomic_compare_exchange_weak_explicit(object,expected,desired,order) \ atomic_compare_exchange_weak(object, expected, desired) # define atomic_fetch_OP(object,desired,op) \ ({ \ typeof (object) _obj = (object); \ typeof (*object) _des = (desired); \ typeof (*object) _old; \ vlc_global_lock(VLC_ATOMIC_MUTEX); \ _old = *_obj; \ *_obj = (*_obj) op (_des); \ vlc_global_unlock(VLC_ATOMIC_MUTEX); \ _old; \ }) # define atomic_fetch_add(object,operand) \ atomic_fetch_OP(object,operand,+) # define atomic_fetch_add_explicit(object,operand,order) \ atomic_fetch_add(object,operand) # define atomic_fetch_sub(object,operand) \ atomic_fetch_OP(object,operand,-) # define atomic_fetch_sub_explicit(object,operand,order) \ atomic_fetch_sub(object,operand) # define atomic_fetch_or(object,operand) \ atomic_fetch_OP(object,operand,|) # define atomic_fetch_or_explicit(object,operand,order) \ atomic_fetch_or(object,operand) # define atomic_fetch_xor(object,operand) \ atomic_fetch_OP(object,operand,^) # define atomic_fetch_xor_explicit(object,operand,order) \ atomic_fetch_sub(object,operand) # define atomic_fetch_and(object,operand) \ atomic_fetch_OP(object,operand,&) # define atomic_fetch_and_explicit(object,operand,order) \ atomic_fetch_and(object,operand) # define atomic_flag_test_and_set(object) \ atomic_exchange(object, true) # define atomic_flag_test_and_set_explicit(object,order) \ atomic_flag_test_and_set(object) # define atomic_flag_clear(object) \ atomic_store(object, false) # define atomic_flag_clear_explicit(object,order) \ atomic_flag_clear(object) # elif defined (_MSC_VER) # include /*** Use the Interlocked API. ***/ /* Define macros in order to dispatch to the correct function depending on the type. Several ranges are need because some operations are not implemented for all types. */ # define atomic_type_dispatch_32_64(operation, object, ...) \ (sizeof(*object) == 4 ? operation((LONG *)object, __VA_ARGS__) : \ sizeof(*object) == 8 ? operation##64((LONGLONG *)object, __VA_ARGS__) : \ (abort(), 0)) # define atomic_type_dispatch_16_64(operation, object, ...) \ (sizeof(*object) == 2 ? operation##16((short *)object, __VA_ARGS__) : \ atomic_type_dispatch_32_64(operation, object, __VA_ARGS__)) # define atomic_type_dispatch_8_64(operation, object, ...) \ (sizeof(*object) == 1 ? operation##8((char *)object, __VA_ARGS__) : \ atomic_type_dispatch_16_64(operation, object, __VA_ARGS__)) # define atomic_store(object,desired) \ atomic_type_dispatch_16_64(InterlockedExchange, object, desired) # define atomic_store_explicit(object,desired,order) \ atomic_store(object, desired) # define atomic_load(object) \ atomic_type_dispatch_16_64(InterlockedCompareExchange, object, 0, 0) # define atomic_load_explicit(object,order) \ atomic_load(object) # define atomic_exchange(object,desired) \ atomic_type_dispatch_16_64(InterlockedExchange, object, desired) # define atomic_exchange_explicit(object,desired,order) \ atomic_exchange(object, desired) # define atomic_compare_exchange_strong(object,expected,desired) \ atomic_type_dispatch_16_64(InterlockedCompareExchange, object, *expected, desired) == *expected # define atomic_compare_exchange_strong_explicit(object,expected,desired,order) \ atomic_compare_exchange_strong(object, expected, desired) # define atomic_compare_exchange_weak(object,expected,desired) \ atomic_compare_exchange_strong(object, expected, desired) # define atomic_compare_exchange_weak_explicit(object,expected,desired,order) \ atomic_compare_exchange_weak(object, expected, desired) # define atomic_fetch_add(object,operand) \ atomic_type_dispatch_32_64(InterlockedExchangeAdd, object, operand) # define atomic_fetch_add_explicit(object,operand,order) \ atomic_fetch_add(object, operand) # define atomic_fetch_sub(object,operand) \ atomic_type_dispatch_32_64(InterlockedExchangeAdd, object, -(LONGLONG)operand) # define atomic_fetch_sub_explicit(object,operand,order) \ atomic_fetch_sub(object, operand) # define atomic_fetch_or(object,operand) \ atomic_type_dispatch_8_64(InterlockedOr, object, operand) # define atomic_fetch_or_explicit(object,operand,order) \ atomic_fetch_or(object, operand) # define atomic_fetch_xor(object,operand) \ atomic_type_dispatch_8_64(InterlockedXor, object, operand) # define atomic_fetch_xor_explicit(object,operand,order) \ atomic_fetch_sub(object, operand) # define atomic_fetch_and(object,operand) \ atomic_type_dispatch_8_64(InterlockedAnd, object, operand) # define atomic_fetch_and_explicit(object,operand,order) \ atomic_fetch_and(object, operand) # define atomic_flag_test_and_set(object) \ atomic_exchange(object, true) # define atomic_flag_test_and_set_explicit(object,order) \ atomic_flag_test_and_set(object) # define atomic_flag_clear(object) \ atomic_store(object, false) # define atomic_flag_clear_explicit(object,order) \ atomic_flag_clear(object) # else # error FIXME: implement atomic operations for this compiler. # endif # endif typedef atomic_uint_least32_t vlc_atomic_float; static inline void vlc_atomic_init_float(vlc_atomic_float *var, float f) { union { float f; uint32_t i; } u; u.f = f; atomic_init(var, u.i); } /** Helper to retrieve a single precision from an atom. */ static inline float vlc_atomic_load_float(vlc_atomic_float *atom) { union { float f; uint32_t i; } u; u.i = atomic_load(atom); return u.f; } /** Helper to store a single precision into an atom. */ static inline void vlc_atomic_store_float(vlc_atomic_float *atom, float f) { union { float f; uint32_t i; } u; u.f = f; atomic_store(atom, u.i); } #endif