AuroraRuntime/Source/IO/Loop/LSLocalSemaphore.cpp

238 lines
5.2 KiB
C++

/***
Copyright (C) 2023 J Reece Wilson (a/k/a "Reece"). All rights reserved.
File: LSLocalSemaphore.cpp
Date: 2023-10-21
Author: Reece
***/
#include <RuntimeInternal.hpp>
#include "LSLocalSemaphore.hpp"
#include <Source/Threading/Primitives/SMTYield.hpp>
namespace Aurora::IO::Loop
{
LSLocalSemaphore::LSLocalSemaphore()
{
}
LSLocalSemaphore::~LSLocalSemaphore()
{
}
bool LSLocalSemaphore::TryInit(AuUInt32 initialCount)
{
if (!LSSemaphore::TryInit(initialCount))
{
return false;
}
this->uAtomicSemaphore = initialCount;
this->uAtomicKernelSemaphore = initialCount;
return true;
}
bool LSLocalSemaphore::OnTrigger(AuUInt handle)
{
auto bRet = this->TryTakeNoSpin();
bool bTriggerLater = !bRet;
while (true)
{
auto uOld = this->uAtomicKernelSemaphore;
if (uOld == 0)
{
break;
}
if (AuAtomicCompareExchange(&this->uAtomicKernelSemaphore, uOld - 1, uOld) == uOld)
{
auto uCount = AuAtomicLoad(&this->uAtomicSemaphore);
if (uOld - 1 == 0)
{
if (uCount)
{
AuAtomicAdd(&this->uAtomicKernelSemaphore, uCount);
LSSemaphore::AddMany(uCount);
}
else
{
(void)LSSemaphore::OnTrigger(0);
bTriggerLater = false;
}
}
else if (uOld || !bRet)
{
(void)LSSemaphore::OnTrigger(0);
bTriggerLater = false;
}
break;
}
}
#if 0
if (bTriggerLater)
{
(void)LSSemaphore::OnTrigger(0);
}
#endif
return bRet;
}
bool LSLocalSemaphore::AddOne()
{
auto uNext = AuAtomicAdd(&this->uAtomicSemaphore, 1u);
if (AuAtomicLoad(&this->uAtomicKernelSemaphore) >= uNext)
{
return true;
}
AuAtomicAdd(&this->uAtomicKernelSemaphore, 1u);
LSSemaphore::AddOne();
return true;
}
bool LSLocalSemaphore::AddMany(AuUInt32 uCount)
{
auto uNext = AuAtomicAdd(&this->uAtomicSemaphore, 1u);
if (AuAtomicLoad(&this->uAtomicKernelSemaphore) >= uNext)
{
return true;
}
AuAtomicAdd(&this->uAtomicKernelSemaphore, uCount);
LSSemaphore::AddMany(uCount);
return true;
}
bool LSLocalSemaphore::IsSignaled()
{
return this->TryTake();
}
bool LSLocalSemaphore::IsSignaledNoSpinIfUserland()
{
return this->TryTakeNoSpin();
}
bool LSLocalSemaphore::WaitOn(AuUInt32 timeout)
{
return this->TryTakeWaitMS(timeout);
}
ELoopSource LSLocalSemaphore::GetType()
{
return ELoopSource::eSourceFastSemaphore;
}
bool LSLocalSemaphore::TryTakeNoSpin()
{
AuUInt32 uOld {};
while ((uOld = this->uAtomicSemaphore))
{
if (AuAtomicCompareExchange(&this->uAtomicSemaphore, uOld - 1, uOld) == uOld)
{
return true;
}
}
return false;
}
bool LSLocalSemaphore::TryTakeSpin()
{
return Threading::Primitives::DoTryIf([&]
{
return this->TryTakeNoSpin();
});
}
bool LSLocalSemaphore::TryTake()
{
return this->TryTakeSpin();
}
bool LSLocalSemaphore::TryTakeWaitMS(AuUInt32 timeout)
{
auto uEndTime = timeout ?
AuTime::SteadyClockNS() + AuMSToNS<AuUInt64>(timeout) :
0;
if (this->TryTakeSpin())
{
return true;
}
while (!this->TryTakeNoSpin())
{
if (!timeout)
{
if (LSSemaphore::WaitOn(0))
{
return true;
}
}
else
{
auto uStartTime = Time::SteadyClockNS();
if (uStartTime >= uEndTime)
{
return false;
}
auto uDeltaMs = AuNSToMS<AuInt64>(uEndTime - uStartTime);
if (uDeltaMs &&
LSSemaphore::WaitOn(uDeltaMs))
{
return true;
}
else if (!uDeltaMs)
{
if (this->TryTakeSpin())
{
return true;
}
}
}
}
return true;
}
void LSLocalSemaphore::OnPresleep()
{
}
void LSLocalSemaphore::OnFinishSleep()
{
}
AUKN_SYM AuSPtr<ILSSemaphore> NewLSSemaphore(AuUInt32 initialCount)
{
auto pMutex = AuMakeShared<LSLocalSemaphore>();
if (!pMutex)
{
SysPushErrorGeneric();
return {};
}
if (!pMutex->TryInit(initialCount))
{
SysPushErrorNested();
return {};
}
return pMutex;
}
}