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/* Copyright 2012 10gen Inc.
*
* Licensed 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.
*/
/**
* Implementation of the AtomicIntrinsics<T>::* operations for systems on any
* architecture using a new enough GCC-compatible compiler toolchain.
*/
#pragma once
#include <boost/utility.hpp>
namespace mongo {
/**
* Instantiation of AtomicIntrinsics<> for all word types T.
*/
template <typename T, typename IsTLarge=void>
class AtomicIntrinsics {
public:
static T compareAndSwap(volatile T* dest, T expected, T newValue) {
__atomic_compare_exchange(dest, &expected, &newValue, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
return expected;
}
static T swap(volatile T* dest, T newValue) {
T result;
__atomic_exchange(dest, &newValue, &result, __ATOMIC_SEQ_CST);
return result;
}
static T load(volatile const T* value) {
T result;
__atomic_load(value, &result, __ATOMIC_SEQ_CST);
return result;
}
static T loadRelaxed(volatile const T* value) {
T result;
__atomic_load(value, &result, __ATOMIC_RELAXED);
return result;
}
static void store(volatile T* dest, T newValue) {
__atomic_store(dest, &newValue, __ATOMIC_SEQ_CST);
}
static T fetchAndAdd(volatile T* dest, T increment) {
return __atomic_fetch_add(dest, increment, __ATOMIC_SEQ_CST);
}
private:
AtomicIntrinsics();
~AtomicIntrinsics();
};
} // namespace mongo
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