save-buffer commented on code in PR #13669: URL: https://github.com/apache/arrow/pull/13669#discussion_r1068638736
########## cpp/src/arrow/util/atomic_util.h: ########## @@ -0,0 +1,112 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +#pragma once + +#include <atomic> +#include <type_traits> + +namespace arrow { +namespace util { +template <typename T> +inline T AtomicMax(std::atomic<T>& to_max, T val) { + static_assert(std::is_arithmetic<T>::value, + "Maximum only makes sense on numeric types!"); + T local_to_max = to_max.load(std::memory_order_relaxed); + while (val > local_to_max && + !to_max.compare_exchange_weak(local_to_max, val, std::memory_order_release, + std::memory_order_relaxed)) { + } + return to_max.load(std::memory_order_relaxed); +} + +#if defined(__clang) || defined(__GNUC__) +template <typename T> +inline T AtomicLoad(T* addr, + std::memory_order order = std::memory_order_seq_cst) noexcept { + T ret; + __atomic_load(addr, &ret, order); + return ret; +} + +template <typename T> +inline void AtomicStore(T* addr, T& val, + std::memory_order order = std::memory_order_seq_cst) noexcept { + __atomic_store(addr, val, order); +} + +template <typename T> +inline T AtomicFetchAdd(T* addr, T& val, + std::memory_order order = std::memory_order_seq_cst) noexcept { + static_assert(std::is_integral<T>::value, + "AtomicFetchAdd can only be used on integral types"); + return __atomic_fetch_add(addr, val, order); +} + +template <typename T> +inline T AtomicFetchSub(T* addr, T& val, + std::memory_order order = std::memory_order_seq_cst) noexcept { + static_assert(std::is_integral<T>::value, + "AtomicFetchSub can only be used on integral types"); + return __atomic_fetch_sub(addr, val, order); +} + +#elif defined(_MSC_VER) +#include <intrin.h> +template <typename T> +inline T AtomicLoad(T* addr, std::memory_order /*order*/) noexcept { + T val = *addr; + _ReadWriteBarrier(); + return val; +} + +template <typename T> +inline void AtomicStore(T* addr, T& val, std::memory_order /*order*/) noexcept { + _ReadWriteBarrier(); + *addr = val; +} + +template <typename T> +inline T AtomicFetchAdd(T* addr, T& val, std::memory_order /*order*/) noexcept { + static_assert(std::is_integral<T>::value, + "AtomicFetchAdd can only be used on integral types"); + if constexpr (sizeof(T) == 1) return _InterlockedExchangeAdd8(addr, val); + if constexpr (sizeof(T) == 2) return _InterlockedExchangeAdd16(addr, val); + if constexpr (sizeof(T) == 4) return _InterlockedExchangeAdd(addr, val); + if constexpr (sizeof(T) == 8) { +#if _WIN64 + return _InterlockedExchangeAdd64(addr, val); +#else + _ReadWriteBarrier(); + T expected = *addr; + for (;;) { + T new_val = expected + val; + T prev = _InterlockedCompareExchange64(addr, new_val, expected); + if (prev == expected) return prev; + expected = prev; + } + } +#endif + } + + template <typename T> + inline T AtomicFetchSub(T * addr, T & val, std::memory_order /*order*/) noexcept { + return AtomicFetchAdd(addr, -val); + } +#endif Review Comment: Removed everything except AtomicMax. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
