Ryan Macnak
6c933a4488
Change-Id: I195232311a146248c601ef84640758db59083d12 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/121200 Reviewed-by: Siva Annamalai <asiva@google.com> Commit-Queue: Ryan Macnak <rmacnak@google.com>
69 lines
2.1 KiB
C++
69 lines
2.1 KiB
C++
// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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#ifndef RUNTIME_PLATFORM_ATOMIC_H_
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#define RUNTIME_PLATFORM_ATOMIC_H_
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#include <atomic>
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#include "platform/allocation.h"
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#include "platform/globals.h"
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namespace dart {
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// Like std::atomic, but operations default to relaxed ordering instead of
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// acquire-release ordering.
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template <typename T>
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class RelaxedAtomic {
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public:
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constexpr RelaxedAtomic() : value_() {}
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constexpr RelaxedAtomic(T arg) : value_(arg) {} // NOLINT
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RelaxedAtomic(const RelaxedAtomic& arg) : value_(arg) {} // NOLINT
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T load() const { return value_.load(std::memory_order_relaxed); }
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void store(T arg) { value_.store(arg, std::memory_order_relaxed); }
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T fetch_add(T arg) {
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return value_.fetch_add(arg, std::memory_order_relaxed);
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}
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T fetch_sub(T arg) {
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return value_.fetch_sub(arg, std::memory_order_relaxed);
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}
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T fetch_or(T arg) { return value_.fetch_or(arg, std::memory_order_relaxed); }
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T fetch_and(T arg) {
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return value_.fetch_and(arg, std::memory_order_relaxed);
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}
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bool compare_exchange_weak(T& expected, T desired) { // NOLINT
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return value_.compare_exchange_weak(expected, desired,
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std::memory_order_relaxed,
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std::memory_order_relaxed);
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}
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bool compare_exchange_strong(T& expected, T desired) { // NOLINT
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return value_.compare_exchange_strong(expected, desired,
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std::memory_order_relaxed,
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std::memory_order_relaxed);
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}
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operator T() const { return load(); }
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T operator=(T arg) {
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store(arg);
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return arg;
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}
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T operator=(const RelaxedAtomic& arg) {
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T loaded_once = arg;
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store(loaded_once);
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return loaded_once;
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}
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T operator+=(T arg) { return fetch_add(arg) + arg; }
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T operator-=(T arg) { return fetch_sub(arg) - arg; }
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private:
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std::atomic<T> value_;
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};
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} // namespace dart
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#endif // RUNTIME_PLATFORM_ATOMIC_H_
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