66 lines
1.6 KiB
C
66 lines
1.6 KiB
C
|
// Copyright (c) 2017 Computer Vision Center (CVC) at the Universitat Autonoma
|
||
|
|
// de Barcelona (UAB).
|
||
|
|
//
|
||
|
|
// This work is licensed under the terms of the MIT license.
|
||
|
|
// For a copy, see <https://opensource.org/licenses/MIT>.
|
||
|
|
|
||
|
|
#pragma once
|
||
|
|
|
||
|
|
#include <memory>
|
||
|
|
|
||
|
|
namespace carla {
|
||
|
|
|
||
|
|
/// A very simple atomic shared ptr with release-acquire memory order.
|
||
|
|
template <typename T>
|
||
|
|
class AtomicSharedPtr {
|
||
|
|
public:
|
||
|
|
|
||
|
|
template <typename... Args>
|
||
|
|
explicit AtomicSharedPtr(Args &&... args)
|
||
|
|
: _ptr(std::forward<Args>(args)...) {}
|
||
|
|
|
||
|
|
AtomicSharedPtr(const AtomicSharedPtr &rhs)
|
||
|
|
: _ptr(rhs.load()) {}
|
||
|
|
|
||
|
|
AtomicSharedPtr(AtomicSharedPtr &&) = delete;
|
||
|
|
|
||
|
|
void store(std::shared_ptr<T> ptr) noexcept {
|
||
|
|
std::atomic_store_explicit(&_ptr, ptr, std::memory_order_release);
|
||
|
|
}
|
||
|
|
|
||
|
|
void reset(std::shared_ptr<T> ptr = nullptr) noexcept {
|
||
|
|
store(ptr);
|
||
|
|
}
|
||
|
|
|
||
|
|
std::shared_ptr<T> load() const noexcept {
|
||
|
|
return std::atomic_load_explicit(&_ptr, std::memory_order_acquire);
|
||
|
|
}
|
||
|
|
|
||
|
|
bool compare_exchange(std::shared_ptr<T> *expected, std::shared_ptr<T> desired) noexcept {
|
||
|
|
return std::atomic_compare_exchange_strong_explicit(
|
||
|
|
&_ptr,
|
||
|
|
expected,
|
||
|
|
desired,
|
||
|
|
std::memory_order_acq_rel,
|
||
|
|
std::memory_order_acq_rel);
|
||
|
|
}
|
||
|
|
|
||
|
|
AtomicSharedPtr &operator=(std::shared_ptr<T> ptr) noexcept {
|
||
|
|
store(std::move(ptr));
|
||
|
|
return *this;
|
||
|
|
}
|
||
|
|
|
||
|
|
AtomicSharedPtr &operator=(const AtomicSharedPtr &rhs) noexcept {
|
||
|
|
store(rhs.load());
|
||
|
|
return *this;
|
||
|
|
}
|
||
|
|
|
||
|
|
AtomicSharedPtr &operator=(AtomicSharedPtr &&) = delete;
|
||
|
|
|
||
|
|
private:
|
||
|
|
|
||
|
|
std::shared_ptr<T> _ptr;
|
||
|
|
};
|
||
|
|
|
||
|
|
} // namespace carla
|