AuroraSupport/AuroraRuntime
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[*] RWLock improvements

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This commit is contained in:
Reece Wilson 2023-07-30 11:10:08 +01:00
parent 8bede175e3
commit 9a2e5674e8
2 changed files with 58 additions and 42 deletions
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95
Source/Threading/Primitives/AuRWLock.cpp
View File

@ -18,6 +18,8 @@ namespace Aurora::Threading::Primitives
#define ViewParent ((T *)(((char *)this) - (bIsReadView ? RWLockImpl<true>::kOffsetOfRead : RWLockImpl<true>::kOffsetOfWrite)))
#endif
static const auto kRWThreadWriterHardContextSwitchBias = 15;
template<bool bIsReadView, typename T>
void RWLockAccessView<bIsReadView, T>::Unlock()
{
@ -152,12 +154,6 @@ namespace Aurora::Threading::Primitives
{
return false;
}
if (this->writersPending_)
{
this->GetConditionWriter().Broadcast();
continue;
}
}
}
}
@ -198,8 +194,9 @@ namespace Aurora::Threading::Primitives
}
}
AuAtomicAdd(&this->writersPending_, 1);
AU_LOCK_GUARD(this->mutex_);
this->writersPending_++;
AuInt64 uEndTime = uTimeout ? AuTime::SteadyClockNS() + uTimeout : 0;
@ -215,7 +212,7 @@ namespace Aurora::Threading::Primitives
if (uSecondTimeout <= 0)
{
this->writersPending_--;
AuAtomicSub(&this->writersPending_, 1);
return false;
}
}
@ -226,7 +223,7 @@ namespace Aurora::Threading::Primitives
if (!this->GetConditionWriter().WaitForSignalNsEx(AuUnsafeRaiiToShared(&this->mutex_), uSecondTimeout))
#endif
{
this->writersPending_--;
AuAtomicSub(&this->writersPending_, 1);
return false;
}
}
@ -234,12 +231,13 @@ namespace Aurora::Threading::Primitives
if (AuAtomicCompareExchange(&this->state_, -1, 0) == 0)
{
this->reentrantWriteLockHandle_ = GetThreadCookie();
this->writersPending_--;
AuAtomicSub(&this->writersPending_, 1);
return true;
}
else
{
this->GetConditionWriter().Broadcast();
this->GetCondition().Broadcast();
}
}
@ -265,7 +263,7 @@ namespace Aurora::Threading::Primitives
template<bool bIsWriteRecursionAllowed>
bool RWLockImpl<bIsWriteRecursionAllowed>::TryLockWrite()
{
for (AuUInt i = 0; i < 20; i++)
for (AU_ITERATE_N(i, kRWThreadWriterHardContextSwitchBias))
{
auto curVal = this->state_;
@ -309,61 +307,82 @@ namespace Aurora::Threading::Primitives
template<bool bIsWriteRecursionAllowed>
void RWLockImpl<bIsWriteRecursionAllowed>::UnlockRead()
{
AuInt32 uVal {};
if (this->state_ < 0)
{
SysAssertDbg(this->reentrantWriteLockHandle_ == GetThreadCookie());
return;
}
AuInt32 val {};
bool bElevation {};
uVal = AuAtomicSub(&this->state_, 1);
if (uVal == 0)
{
AU_LOCK_GUARD(this->mutex_);
val = AuAtomicSub(&this->state_, 1);
bElevation = this->bElevaterPending_;
}
bool bElevation {};
{
AU_LOCK_GUARD(this->mutex_);
bElevation = this->writersPending_ > 0;
}
if ((val == 0) && (bElevation))
{
this->GetConditionWriter().Signal();
}
if (val == 0)
{
this->GetCondition().Signal();
this->GetConditionWriter().Signal();
if (bElevation)
{
this->GetConditionWriter().Signal();
}
else
{
this->GetCondition().Broadcast();
}
}
}
template<bool bIsWriteRecursionAllowed>
void RWLockImpl<bIsWriteRecursionAllowed>::UnlockWrite()
{
bool bElevationPending {};
if constexpr (!bIsWriteRecursionAllowed)
{
this->reentrantWriteLockHandle_ = 0;
{
AU_LOCK_GUARD(this->mutex_);
this->reentrantWriteLockHandle_ = 0;
this->state_ = 0;
bElevationPending = this->writersPending_ > 0;
}
this->GetConditionWriter().Broadcast();
this->GetCondition().Broadcast();
if (bElevationPending)
{
this->GetConditionWriter().Signal();
}
else
{
this->GetCondition().Broadcast();
}
}
else
{
AuInt32 val {};
{
AU_LOCK_GUARD(this->mutex_);
val = AuAtomicAdd(&this->state_, 1);
this->reentrantWriteLockHandle_ = 0;
}
this->reentrantWriteLockHandle_ = 0;
val = AuAtomicAdd(&this->state_, 1);
if (val == 0)
{
this->GetConditionWriter().Broadcast();
this->GetCondition().Broadcast();
{
AU_LOCK_GUARD(this->mutex_);
bElevationPending = this->writersPending_ > 0;
}
if (bElevationPending)
{
this->GetConditionWriter().Signal();
}
else
{
this->GetCondition().Broadcast();
}
}
}
}
@ -375,7 +394,7 @@ namespace Aurora::Threading::Primitives
while (this->state_ != 1)
{
this->bElevaterPending_ = true;
AuAtomicAdd(&this->writersPending_, 1);
if (!this->GetConditionWriter().WaitForSignal(timeout))
{
@ -383,7 +402,7 @@ namespace Aurora::Threading::Primitives
}
}
this->bElevaterPending_ = false;
AuAtomicSub(&this->writersPending_, 1);
this->reentrantWriteLockHandle_ = GetThreadCookie();
this->state_ = -1;
return true;

5
Source/Threading/Primitives/AuRWLock.hpp
View File

@ -93,10 +93,7 @@ namespace Aurora::Threading::Primitives
#endif
ThreadCookie_t reentrantWriteLockHandle_ {};
volatile AuInt32 state_ {};
AuInt32 writersPending_ : 31 {};
AuInt32 bElevaterPending_ : 1 {};
//bool bElevaterPending_{};
//bool reentrantWriteLock_ {true};
AuInt32 writersPending_ {};
public:
cstatic const AuUInt8 kOffsetOfRead = AuOffsetOf(&RWLockImpl::read_);