Atomic.h

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// Copyright Onix Solutions Limited [OnixS]. All rights reserved.
//
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// protected by copyright law and international copyright treaties.
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// in the Agreement.
//
// Except as otherwise granted within the terms of the Agreement, copying or
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// amendments to this copyright notice, are expressly prohibited.
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#pragma once
 
#include <type_traits>
 
#if defined(_MSC_VER)
#  include <intrin.h>
#endif
 
#include <OnixS/CME/MDH/Bootstrap.h>
 
ONIXS_CMEMDH_NAMESPACE_BEGIN
 
#if defined(_MSC_VER)
 
template <size_t SizeOf>
class AtomicOps;
 
template <>
class AtomicOps<1>
{
    typedef char Integral;
 
public:
    template <class Atomic, class Target>
    static void read(volatile Atomic* atomic, Target* target)
    {
        *(Integral*) target = *(volatile Integral*) atomic;
 
        _ReadWriteBarrier();
    }
 
    template <class Atomic, class Addend>
    static void add(volatile Atomic* atomic, Addend* addend)
    {
        const Integral addendValue = *static_cast<Integral*>(addend);
 
        *(Integral*) addend = (_InterlockedExchangeAdd8((volatile Integral*) atomic, addendValue) + addendValue);
    }
 
    template <class Atomic, class Value>
    static void store(volatile Atomic* atomic, const Value* value)
    {
        _InterlockedExchange8((volatile Integral*) atomic, *(const Integral*) value);
    }
 
    template <class Atomic, class Value>
    static void exchange(volatile Atomic* atomic, Value* value)
    {
        *(Integral*) value = _InterlockedExchange8((volatile Integral*) atomic, *static_cast<Integral*>(value));
    }
 
    template <class Atomic, class Comparand, class Value>
    static bool compareExchange(volatile Atomic* atomic, Comparand* comparand, const Value* value)
    {
        const Integral comparandValue = *(Integral*) comparand;
 
        const Integral previous =
            _InterlockedCompareExchange8((volatile Integral*) atomic, *(const Integral*) value, comparandValue);
 
        if (previous == comparandValue)
        {
            return true;
        }
 
        *(Integral*) value = previous;
 
        return false;
    }
};
 
template <>
class AtomicOps<2>
{
    typedef short Integral;
 
public:
    template <class Atomic, class Target>
    static void read(volatile Atomic* atomic, Target* target)
    {
        *(Integral*) target = *(volatile Integral*) atomic;
 
        _ReadWriteBarrier();
    }
 
    template <class Atomic, class Addend>
    static void add(volatile Atomic* atomic, Addend* addend)
    {
        const Integral addendValue = *static_cast<Integral*>(addend);
 
        *(Integral*) addend = (_InterlockedExchangeAdd16((volatile Integral*) atomic, addendValue) + addendValue);
    }
 
    template <class Atomic, class Value>
    static void store(volatile Atomic* atomic, const Value* value)
    {
        _InterlockedExchange16((volatile Integral*) atomic, *(const Integral*) value);
    }
 
    template <class Atomic, class Value>
    static void exchange(volatile Atomic* atomic, Value* value)
    {
        *(Integral*) value = _InterlockedExchange16((volatile Integral*) atomic, *static_cast<Integral*>(value));
    }
 
    template <class Atomic, class Comparand, class Value>
    static bool compareExchange(volatile Atomic* atomic, Comparand* comparand, const Value* value)
    {
        const Integral comparandValue = *(Integral*) comparand;
 
        const Integral previous =
            _InterlockedCompareExchange16((volatile Integral*) atomic, *(const Integral*) value, comparandValue);
 
        if (previous == comparandValue)
        {
            return true;
        }
 
        *(Integral*) value = previous;
 
        return false;
    }
};
 
template <>
class AtomicOps<4>
{
    typedef long Integral;
 
public:
    template <class Atomic, class Target>
    static void read(volatile Atomic* atomic, Target* target)
    {
        *(Integral*) target = *(volatile Integral*) atomic;
 
        _ReadWriteBarrier();
    }
 
    template <class Atomic, class Addend>
    static void add(volatile Atomic* atomic, Addend* addend)
    {
        const Integral addendValue = *static_cast<Integral*>(addend);
 
        *(Integral*) addend = (_InterlockedExchangeAdd((volatile Integral*) atomic, addendValue) + addendValue);
    }
 
    template <class Atomic, class Value>
    static void store(volatile Atomic* atomic, const Value* value)
    {
        _InterlockedExchange((volatile Integral*) atomic, *(const Integral*) value);
    }
 
    template <class Atomic, class Value>
    static void exchange(volatile Atomic* atomic, Value* value)
    {
        *(Integral*) value = _InterlockedExchange((volatile Integral*) atomic, *static_cast<Integral*>(value));
    }
 
    template <class Atomic, class Comparand, class Value>
    static bool compareExchange(volatile Atomic* atomic, Comparand* comparand, const Value* value)
    {
        const Integral comparandValue = *(Integral*) comparand;
 
        const Integral previous =
            _InterlockedCompareExchange((volatile Integral*) atomic, *(const Integral*) value, comparandValue);
 
        if (previous == comparandValue)
        {
            return true;
        }
 
        *(Integral*) value = previous;
 
        return false;
    }
};
 
template <>
class AtomicOps<8>
{
    typedef long long Integral;
 
public:
    template <class Atomic, class Target>
    static void read(volatile Atomic* atomic, Target* target)
    {
        *(Integral*) target = *(volatile Integral*) atomic;
 
        _ReadWriteBarrier();
    }
 
    template <class Atomic, class Addend>
    static void add(volatile Atomic* atomic, Addend* addend)
    {
        const Integral addendValue = *static_cast<Integral*>(addend);
 
        *(Integral*) addend = (_InterlockedExchangeAdd64((volatile Integral*) atomic, addendValue) + addendValue);
    }
 
    template <class Atomic, class Value>
    static void store(volatile Atomic* atomic, const Value* value)
    {
        _InterlockedExchange64((volatile Integral*) atomic, *(const Integral*) value);
    }
 
    template <class Atomic, class Value>
    static void exchange(volatile Atomic* atomic, Value* value)
    {
        *(Integral*) value = _InterlockedExchange64((volatile Integral*) atomic, *static_cast<Integral*>(value));
    }
 
    template <class Atomic, class Comparand, class Value>
    static bool compareExchange(volatile Atomic* atomic, Comparand* comparand, const Value* value)
    {
        const Integral comparandValue = *(Integral*) comparand;
 
        const Integral previous =
            _InterlockedCompareExchange64((volatile Integral*) atomic, *(const Integral*) value, comparandValue);
 
        if (previous == comparandValue)
        {
            return true;
        }
 
        *(Integral*) value = previous;
 
        return false;
    }
};
 
template <typename Type>
struct Atomic
{
    static_assert(
        std::is_integral<Type>::value || std::is_enum<Type>::value || std::is_pointer<Type>::value,
        "Atomic<T> requires an integral, enumeration, or pointer type"
    );
 
    static Type read(volatile Type& atomic) noexcept
    {
        Type value = Type();
 
        AtomicOps<sizeof(Type)>::read(&atomic, &value);
 
        return value;
    }
 
    static void store(volatile Type& atomic, Type value) noexcept
    {
        AtomicOps<sizeof(Type)>::store(&atomic, &value);
    }
 
    static void exchange(volatile Type& atomic, Type& value) noexcept
    {
        AtomicOps<sizeof(Type)>::exchange(&atomic, &value);
    }
 
    static bool compareStore(volatile Type& atomic, Type comparand, Type value) noexcept
    {
        return AtomicOps<sizeof(Type)>::compareExchange(&atomic, &comparand, &value);
    }
 
    static bool compareExchange(volatile Type& atomic, Type comparand, Type& value) noexcept
    {
        return AtomicOps<sizeof(Type)>::compareExchange(&atomic, &comparand, &value);
    }
};
 
#elif defined(__GNUC__)
 
template <typename Type>
struct Atomic
{
    static_assert(
        std::is_integral<Type>::value || std::is_enum<Type>::value || std::is_pointer<Type>::value,
        "Atomic<T> requires an integral, enumeration, or pointer type"
    );
 
    static Type read(volatile Type& atomic) noexcept
    {
        Type value{};
 
        __atomic_load(&atomic, &value, __ATOMIC_SEQ_CST);
        __atomic_thread_fence(__ATOMIC_SEQ_CST);
 
        return value;
    }
 
    static void store(volatile Type& atomic, Type value) noexcept
    {
        __atomic_store(&atomic, &value, __ATOMIC_SEQ_CST);
    }
 
    static void exchange(volatile Type& atomic, Type& value) noexcept
    {
        Type previous{};
 
        __atomic_exchange(&atomic, &value, &previous, __ATOMIC_SEQ_CST);
 
        value = previous;
    }
 
    static bool compareStore(volatile Type& atomic, Type comparand, Type value) noexcept
    {
        return compareExchange(atomic, comparand, value);
    }
 
    static bool compareExchange(volatile Type& atomic, Type comparand, Type& value) noexcept
    {
        if (__atomic_compare_exchange(&atomic, &comparand, &value, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST))
            return true;
 
        value = comparand;
 
        return false;
    }
};
 
#endif // Toolset selector.
 
template <typename Type, Type Value>
class ONIXS_CMEMDH_DEPRECATED AtomicScopedStore
{
public:
    AtomicScopedStore(volatile Type& variable)
        : variable_(variable)
    {
    }
 
    ~AtomicScopedStore()
    {
        Atomic<Type>::store(variable_, Value);
    }
 
private:
    volatile Type& variable_;
 
    AtomicScopedStore(const AtomicScopedStore&);
 
    AtomicScopedStore& operator=(const AtomicScopedStore&);
};
 
ONIXS_CMEMDH_NAMESPACE_END