diff options
Diffstat (limited to 'src/include/atomic_support.h')
-rw-r--r-- | src/include/atomic_support.h | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/src/include/atomic_support.h b/src/include/atomic_support.h new file mode 100644 index 000000000000..dbf3b9c81ea4 --- /dev/null +++ b/src/include/atomic_support.h @@ -0,0 +1,149 @@ +#ifndef ATOMIC_SUPPORT_H +#define ATOMIC_SUPPORT_H + +#include "__config" +#include "memory" // for __libcpp_relaxed_load + +#if defined(__clang__) && __has_builtin(__atomic_load_n) \ + && __has_builtin(__atomic_store_n) \ + && __has_builtin(__atomic_add_fetch) \ + && __has_builtin(__atomic_compare_exchange_n) \ + && defined(__ATOMIC_RELAXED) \ + && defined(__ATOMIC_CONSUME) \ + && defined(__ATOMIC_ACQUIRE) \ + && defined(__ATOMIC_RELEASE) \ + && defined(__ATOMIC_ACQ_REL) \ + && defined(__ATOMIC_SEQ_CST) +# define _LIBCPP_HAS_ATOMIC_BUILTINS +#elif !defined(__clang__) && defined(_GNUC_VER) && _GNUC_VER >= 407 +# define _LIBCPP_HAS_ATOMIC_BUILTINS +#endif + +#if !defined(_LIBCPP_HAS_ATOMIC_BUILTINS) && !defined(_LIBCPP_HAS_NO_THREADS) +# if defined(_MSC_VER) && !defined(__clang__) + _LIBCPP_WARNING("Building libc++ without __atomic builtins is unsupported") +# else +# warning Building libc++ without __atomic builtins is unsupported +# endif +#endif + +_LIBCPP_BEGIN_NAMESPACE_STD + +namespace { + +#if defined(_LIBCPP_HAS_ATOMIC_BUILTINS) && !defined(_LIBCPP_HAS_NO_THREADS) + +enum __libcpp_atomic_order { + _AO_Relaxed = __ATOMIC_RELAXED, + _AO_Consume = __ATOMIC_CONSUME, + _AO_Aquire = __ATOMIC_ACQUIRE, + _AO_Release = __ATOMIC_RELEASE, + _AO_Acq_Rel = __ATOMIC_ACQ_REL, + _AO_Seq = __ATOMIC_SEQ_CST +}; + +template <class _ValueType, class _FromType> +inline _LIBCPP_INLINE_VISIBILITY +void __libcpp_atomic_store(_ValueType* __dest, _FromType __val, + int __order = _AO_Seq) +{ + __atomic_store_n(__dest, __val, __order); +} + +template <class _ValueType, class _FromType> +inline _LIBCPP_INLINE_VISIBILITY +void __libcpp_relaxed_store(_ValueType* __dest, _FromType __val) +{ + __atomic_store_n(__dest, __val, _AO_Relaxed); +} + +template <class _ValueType> +inline _LIBCPP_INLINE_VISIBILITY +_ValueType __libcpp_atomic_load(_ValueType const* __val, + int __order = _AO_Seq) +{ + return __atomic_load_n(__val, __order); +} + +template <class _ValueType, class _AddType> +inline _LIBCPP_INLINE_VISIBILITY +_ValueType __libcpp_atomic_add(_ValueType* __val, _AddType __a, + int __order = _AO_Seq) +{ + return __atomic_add_fetch(__val, __a, __order); +} + +template <class _ValueType> +inline _LIBCPP_INLINE_VISIBILITY +bool __libcpp_atomic_compare_exchange(_ValueType* __val, + _ValueType* __expected, _ValueType __after, + int __success_order = _AO_Seq, + int __fail_order = _AO_Seq) +{ + return __atomic_compare_exchange_n(__val, __expected, __after, true, + __success_order, __fail_order); +} + +#else // _LIBCPP_HAS_NO_THREADS + +enum __libcpp_atomic_order { + _AO_Relaxed, + _AO_Consume, + _AO_Acquire, + _AO_Release, + _AO_Acq_Rel, + _AO_Seq +}; + +template <class _ValueType, class _FromType> +inline _LIBCPP_INLINE_VISIBILITY +void __libcpp_atomic_store(_ValueType* __dest, _FromType __val, + int = 0) +{ + *__dest = __val; +} + +template <class _ValueType, class _FromType> +inline _LIBCPP_INLINE_VISIBILITY +void __libcpp_relaxed_store(_ValueType* __dest, _FromType __val) +{ + *__dest = __val; +} + +template <class _ValueType> +inline _LIBCPP_INLINE_VISIBILITY +_ValueType __libcpp_atomic_load(_ValueType const* __val, + int = 0) +{ + return *__val; +} + +template <class _ValueType, class _AddType> +inline _LIBCPP_INLINE_VISIBILITY +_ValueType __libcpp_atomic_add(_ValueType* __val, _AddType __a, + int = 0) +{ + return *__val += __a; +} + +template <class _ValueType> +inline _LIBCPP_INLINE_VISIBILITY +bool __libcpp_atomic_compare_exchange(_ValueType* __val, + _ValueType* __expected, _ValueType __after, + int = 0, int = 0) +{ + if (*__val == *__expected) { + *__val = __after; + return true; + } + *__expected = *__val; + return false; +} + +#endif // _LIBCPP_HAS_NO_THREADS + +} // end namespace + +_LIBCPP_END_NAMESPACE_STD + +#endif // ATOMIC_SUPPORT_H |