mirror of
https://github.com/Icinga/icinga2.git
synced 2025-09-26 11:08:51 +02:00
8df52ed8c1
std::conditional_t was added in C++14, is_trivially_copyable_v in C++17, both do the same as the previous implementation and are a bit more compact.
79 lines
1.6 KiB
C++
79 lines
1.6 KiB
C++
/* Icinga 2 | (c) 2019 Icinga GmbH | GPLv2+ */
|
|
|
|
#ifndef ATOMIC_H
|
|
#define ATOMIC_H
|
|
|
|
#include <atomic>
|
|
#include <mutex>
|
|
#include <type_traits>
|
|
#include <utility>
|
|
|
|
namespace icinga
|
|
{
|
|
|
|
/**
|
|
* Like std::atomic, but enforces usage of its only safe constructor.
|
|
*
|
|
* "The default-initialized std::atomic<T> does not contain a T object,
|
|
* and its only valid uses are destruction and
|
|
* initialization by std::atomic_init, see LWG issue 2334."
|
|
* -- https://en.cppreference.com/w/cpp/atomic/atomic/atomic
|
|
*
|
|
* @ingroup base
|
|
*/
|
|
template<class T>
|
|
class Atomic : public std::atomic<T> {
|
|
public:
|
|
/**
|
|
* The only safe constructor of std::atomic#atomic
|
|
*
|
|
* @param desired Initial value
|
|
*/
|
|
inline Atomic(T desired) : std::atomic<T>(desired)
|
|
{
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Wraps any T into a std::atomic<T>-like interface that locks using a mutex.
|
|
*
|
|
* In contrast to std::atomic<T>, Locked<T> is also valid for types that are not trivially copyable.
|
|
* In case T is trivially copyable, std::atomic<T> is almost certainly the better choice.
|
|
*
|
|
* @ingroup base
|
|
*/
|
|
template<typename T>
|
|
class Locked
|
|
{
|
|
public:
|
|
inline T load() const
|
|
{
|
|
std::unique_lock<std::mutex> lock(m_Mutex);
|
|
|
|
return m_Value;
|
|
}
|
|
|
|
inline void store(T desired)
|
|
{
|
|
std::unique_lock<std::mutex> lock(m_Mutex);
|
|
|
|
m_Value = std::move(desired);
|
|
}
|
|
|
|
private:
|
|
mutable std::mutex m_Mutex;
|
|
T m_Value;
|
|
};
|
|
|
|
/**
|
|
* Type alias for std::atomic<T> if possible, otherwise Locked<T> is used as a fallback.
|
|
*
|
|
* @ingroup base
|
|
*/
|
|
template <typename T>
|
|
using AtomicOrLocked = std::conditional_t<std::is_trivially_copyable_v<T>, std::atomic<T>, Locked<T>>;
|
|
|
|
}
|
|
|
|
#endif /* ATOMIC_H */
|