Program Listing for File AssignID.hpp
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/*
* Copyright (C) 2022 Open Source Robotics Foundation
*
* 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.
*
*/
#ifndef RMF_UTILS__ASSIGNID_HPP
#define RMF_UTILS__ASSIGNID_HPP
#include <atomic>
namespace rmf_utils {
//==============================================================================
template<typename T>
class AssignID
{
public:
AssignID(T initial_value = 0)
: _value(std::move(initial_value))
{
// Do nothing
}
T assign() const
{
return _value.fetch_add(1);
}
void fast_forward_to(const T desired_value) const
{
// TODO(MXG): We could give more consideration to what memory models we are
// using in these atomic operations.
auto current_value = _value.load();
while (current_value < desired_value)
{
const bool success =
_value.compare_exchange_weak(current_value, desired_value);
if (success)
return;
current_value = _value.load();
}
}
private:
mutable std::atomic<T> _value;
};
} // namespace rmf_utils
#endif // RMF_UTILS__ASSIGNID_HPP