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#pragma once
#ifndef RW_SPIN_LOCK_INL_H_
#error "Direct inclusion of this file is not allowed, include rw_spin_lock.h"
// For the sake of sane code completion.
#include "rw_spin_lock.h"
#endif
#undef RW_SPIN_LOCK_INL_H_
#include "spin_wait.h"
namespace NYT::NThreading {
////////////////////////////////////////////////////////////////////////////////
inline void TReaderWriterSpinLock::AcquireReader() noexcept
{
if (TryAcquireReader()) {
return;
}
AcquireReaderSlow();
}
inline void TReaderWriterSpinLock::AcquireReaderForkFriendly() noexcept
{
if (TryAcquireReaderForkFriendly()) {
return;
}
AcquireReaderForkFriendlySlow();
}
inline void TReaderWriterSpinLock::ReleaseReader() noexcept
{
auto prevValue = Value_.fetch_sub(ReaderDelta, std::memory_order_release);
Y_ASSERT((prevValue & ~WriterMask) != 0);
}
inline void TReaderWriterSpinLock::AcquireWriter() noexcept
{
if (TryAcquireWriter()) {
return;
}
AcquireWriterSlow();
}
inline void TReaderWriterSpinLock::ReleaseWriter() noexcept
{
auto prevValue = Value_.fetch_and(~WriterMask, std::memory_order_release);
Y_ASSERT(prevValue & WriterMask);
}
inline bool TReaderWriterSpinLock::IsLocked() const noexcept
{
return Value_.load() != UnlockedValue;
}
inline bool TReaderWriterSpinLock::IsLockedByReader() const noexcept
{
return Value_.load() >= ReaderDelta;
}
inline bool TReaderWriterSpinLock::IsLockedByWriter() const noexcept
{
return (Value_.load() & WriterMask) != 0;
}
inline bool TReaderWriterSpinLock::TryAcquireReader() noexcept
{
auto oldValue = Value_.fetch_add(ReaderDelta, std::memory_order_acquire);
if ((oldValue & WriterMask) != 0) {
Value_.fetch_sub(ReaderDelta, std::memory_order_relaxed);
return false;
}
return true;
}
inline bool TReaderWriterSpinLock::TryAndTryAcquireReader() noexcept
{
auto oldValue = Value_.load(std::memory_order_relaxed);
if ((oldValue & WriterMask) != 0) {
return false;
}
return TryAcquireReader();
}
inline bool TReaderWriterSpinLock::TryAcquireReaderForkFriendly() noexcept
{
auto oldValue = Value_.load(std::memory_order_relaxed);
if ((oldValue & WriterMask) != 0) {
return false;
}
auto newValue = oldValue + ReaderDelta;
return Value_.compare_exchange_weak(oldValue, newValue, std::memory_order_acquire);
}
inline bool TReaderWriterSpinLock::TryAcquireWriter() noexcept
{
auto expected = UnlockedValue;
return Value_.compare_exchange_weak(expected, WriterMask, std::memory_order_acquire);
}
inline bool TReaderWriterSpinLock::TryAndTryAcquireWriter() noexcept
{
auto oldValue = Value_.load(std::memory_order_relaxed);
if (oldValue != UnlockedValue) {
return false;
}
return TryAcquireWriter();
}
////////////////////////////////////////////////////////////////////////////////
template <class T>
void TReaderSpinlockTraits<T>::Acquire(T* spinlock)
{
spinlock->AcquireReader();
}
template <class T>
void TReaderSpinlockTraits<T>::Release(T* spinlock)
{
spinlock->ReleaseReader();
}
////////////////////////////////////////////////////////////////////////////////
template <class T>
void TForkFriendlyReaderSpinlockTraits<T>::Acquire(T* spinlock)
{
spinlock->AcquireReaderForkFriendly();
}
template <class T>
void TForkFriendlyReaderSpinlockTraits<T>::Release(T* spinlock)
{
spinlock->ReleaseReader();
}
////////////////////////////////////////////////////////////////////////////////
template <class T>
void TWriterSpinlockTraits<T>::Acquire(T* spinlock)
{
spinlock->AcquireWriter();
}
template <class T>
void TWriterSpinlockTraits<T>::Release(T* spinlock)
{
spinlock->ReleaseWriter();
}
////////////////////////////////////////////////////////////////////////////////
template <class T>
auto ReaderGuard(const T& lock)
{
return TReaderGuard<T>(lock);
}
template <class T>
auto ReaderGuard(const T* lock)
{
return TReaderGuard<T>(lock);
}
template <class T>
auto ForkFriendlyReaderGuard(const T& lock)
{
return TGuard<T, TForkFriendlyReaderSpinlockTraits<T>>(lock);
}
template <class T>
auto ForkFriendlyReaderGuard(const T* lock)
{
return TGuard<T, TForkFriendlyReaderSpinlockTraits<T>>(lock);
}
template <class T>
auto WriterGuard(const T& lock)
{
return TWriterGuard<T>(lock);
}
template <class T>
auto WriterGuard(const T* lock)
{
return TWriterGuard<T>(lock);
}
////////////////////////////////////////////////////////////////////////////////
} // namespace NYT::NThreading
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