mirror of https://github.com/Icinga/icinga2.git
92 lines
1.9 KiB
C++
92 lines
1.9 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
|
|
{
|
|
|
|
/**
|
|
* Extends std::atomic with an atomic constructor.
|
|
*
|
|
* @ingroup base
|
|
*/
|
|
template<class T>
|
|
class Atomic : public std::atomic<T> {
|
|
public:
|
|
/**
|
|
* Like std::atomic#atomic, but operates atomically
|
|
*
|
|
* @param desired Initial value
|
|
*/
|
|
inline Atomic(T desired)
|
|
{
|
|
this->store(desired);
|
|
}
|
|
|
|
/**
|
|
* Like std::atomic#atomic, but operates atomically
|
|
*
|
|
* @param desired Initial value
|
|
* @param order Initial store operation's memory order
|
|
*/
|
|
inline Atomic(T desired, std::memory_order order)
|
|
{
|
|
this->store(desired, order);
|
|
}
|
|
};
|
|
|
|
/**
|
|
* 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 =
|
|
#if defined(__GNUC__) && __GNUC__ < 5
|
|
// GCC does not implement std::is_trivially_copyable until version 5.
|
|
typename std::conditional<std::is_fundamental<T>::value || std::is_pointer<T>::value, std::atomic<T>, Locked<T>>::type;
|
|
#else /* defined(__GNUC__) && __GNUC__ < 5 */
|
|
typename std::conditional<std::is_trivially_copyable<T>::value, std::atomic<T>, Locked<T>>::type;
|
|
#endif /* defined(__GNUC__) && __GNUC__ < 5 */
|
|
|
|
}
|
|
|
|
#endif /* ATOMIC_H */
|