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#ifndef ATOMIC_INTRUSIVE_PTR_INL_H_
#error "Direct inclusion of this file is not allowed, include atomic_intrusive_ptr.h"
// For the sake of sane code completion.
#include "atomic_intrusive_ptr.h"
#endif
#undef ATOMIC_INTRUSIVE_PTR_INL_H_
#include <util/system/spinlock.h>
namespace NYT {
////////////////////////////////////////////////////////////////////////////////
template <class T>
TAtomicIntrusivePtr<T>::TAtomicIntrusivePtr(std::nullptr_t)
{ }
template <class T>
TAtomicIntrusivePtr<T>::TAtomicIntrusivePtr(TIntrusivePtr<T> other)
: Ptr_(AcquireObject(other.Release(), true))
{ }
template <class T>
TAtomicIntrusivePtr<T>::TAtomicIntrusivePtr(TAtomicIntrusivePtr&& other)
: Ptr_(other.Ptr_.load(std::memory_order_relaxed))
{
other.Ptr_.store(nullptr, std::memory_order_relaxed);
}
template <class T>
TAtomicIntrusivePtr<T>::~TAtomicIntrusivePtr()
{
ReleaseObject(Ptr_.load());
}
template <class T>
TAtomicIntrusivePtr<T>& TAtomicIntrusivePtr<T>::operator=(TIntrusivePtr<T> other)
{
ReleaseObject(Ptr_.exchange(AcquireObject(other.Release(), true)));
return *this;
}
template <class T>
TAtomicIntrusivePtr<T>& TAtomicIntrusivePtr<T>::operator=(std::nullptr_t)
{
Reset();
return *this;
}
template <class T>
TIntrusivePtr<T> TAtomicIntrusivePtr<T>::Acquire()
{
char* ptr = Ptr_.load();
while (true) {
auto [localRefs, obj] = UnpackPointer<T>(ptr);
if (!obj) {
return TIntrusivePtr<T>();
}
YT_VERIFY(localRefs < ReservedRefCount);
auto newLocalRefs = localRefs + 1;
if (newLocalRefs == ReservedRefCount) {
SpinLockPause();
ptr = Ptr_.load();
continue;
}
// Can not Ref(obj) here because it can be destroyed.
if (Ptr_.compare_exchange_weak(ptr, PackPointer(obj, newLocalRefs))) {
if (Y_UNLIKELY(newLocalRefs > ReservedRefCount / 2)) {
Ref(obj, ReservedRefCount / 2);
// Decrease local ref count.
while (true) {
auto [localRefs, currentObj] = UnpackPointer<T>(ptr);
if (currentObj != obj || localRefs <= ReservedRefCount / 2) {
Unref(obj, ReservedRefCount / 2);
break;
}
if (Ptr_.compare_exchange_weak(ptr, PackPointer(obj, localRefs - ReservedRefCount / 2))) {
break;
}
}
}
return TIntrusivePtr<T>(obj, false);
}
}
}
template <class T>
TIntrusivePtr<T> TAtomicIntrusivePtr<T>::Exchange(TIntrusivePtr<T> other)
{
auto [localRefs, obj] = UnpackPointer<T>(Ptr_.exchange(AcquireObject(other.Release(), true)));
DoRelease(obj, localRefs + 1);
return TIntrusivePtr<T>(obj, false);
}
template <class T>
void TAtomicIntrusivePtr<T>::Reset()
{
ReleaseObject(Ptr_.exchange(nullptr));
}
template <class T>
bool TAtomicIntrusivePtr<T>::CompareAndSwap(void*& comparePtr, T* target)
{
auto targetPtr = AcquireObject(target, false);
auto currentPtr = Ptr_.load();
if (UnpackPointer<T>(currentPtr).Ptr == comparePtr && Ptr_.compare_exchange_strong(currentPtr, targetPtr)) {
ReleaseObject(currentPtr);
return true;
}
comparePtr = UnpackPointer<T>(currentPtr).Ptr;
ReleaseObject(targetPtr);
return false;
}
template <class T>
bool TAtomicIntrusivePtr<T>::CompareAndSwap(void*& comparePtr, TIntrusivePtr<T> target)
{
// TODO(lukyan): Make helper for packed owning ptr?
auto targetPtr = AcquireObject(target.Release(), true);
auto currentPtr = Ptr_.load();
if (UnpackPointer<T>(currentPtr).Ptr == comparePtr && Ptr_.compare_exchange_strong(currentPtr, targetPtr)) {
ReleaseObject(currentPtr);
return true;
}
comparePtr = UnpackPointer<T>(currentPtr).Ptr;
ReleaseObject(targetPtr);
return false;
}
template <class T>
void* TAtomicIntrusivePtr<T>::Get() const
{
return UnpackPointer<void>(Ptr_.load()).Ptr;
}
template <class T>
TAtomicIntrusivePtr<T>::operator bool() const
{
return Get();
}
template <class T>
char* TAtomicIntrusivePtr<T>::AcquireObject(T* obj, bool consumeRef)
{
if (obj) {
Ref(obj, static_cast<int>(ReservedRefCount - consumeRef));
}
return PackPointer(obj, 0);
}
template <class T>
void TAtomicIntrusivePtr<T>::ReleaseObject(void* packedPtr)
{
auto [localRefs, obj] = UnpackPointer<T>(packedPtr);
DoRelease(obj, localRefs);
}
template <class T>
void TAtomicIntrusivePtr<T>::DoRelease(T* obj, int refs)
{
if (obj) {
Unref(obj, static_cast<int>(ReservedRefCount - refs));
}
}
////////////////////////////////////////////////////////////////////////////////
template <class T>
bool operator==(const TAtomicIntrusivePtr<T>& lhs, const TIntrusivePtr<T>& rhs)
{
return lhs.Get() == rhs.Get();
}
template <class T>
bool operator==(const TIntrusivePtr<T>& lhs, const TAtomicIntrusivePtr<T>& rhs)
{
return lhs.Get() == rhs.Get();
}
template <class T>
bool operator!=(const TAtomicIntrusivePtr<T>& lhs, const TIntrusivePtr<T>& rhs)
{
return lhs.Get() != rhs.Get();
}
template <class T>
bool operator!=(const TIntrusivePtr<T>& lhs, const TAtomicIntrusivePtr<T>& rhs)
{
return lhs.Get() != rhs.Get();
}
////////////////////////////////////////////////////////////////////////////////
} // namespace NYT
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