EAThread/source/eathread_storage.cpp

///////////////////////////////////////////////////////////////////////////////
// Copyright (c) Electronic Arts Inc. All rights reserved.
///////////////////////////////////////////////////////////////////////////////

#include <eathread/eathread_storage.h>
#include <eathread/eathread.h>

EA_DISABLE_VC_WARNING(4574)
#include <new>
EA_RESTORE_VC_WARNING()

#if defined(EA_PLATFORM_SONY)
	#include <kernel.h>

	EA::Thread::ThreadLocalStorage::ThreadLocalStorage()
		: mTLSData()
	{
		// To consider: Support the specification of a destructor instead of just passing NULL.
		mTLSData.mResult = scePthreadKeyCreate(&mTLSData.mKey, NULL);
		EAT_ASSERT(mTLSData.mResult == 0);
	}


	EA::Thread::ThreadLocalStorage::~ThreadLocalStorage()
	{
		if(mTLSData.mResult == 0)
			scePthreadKeyDelete(mTLSData.mKey);
	}


	void* EA::Thread::ThreadLocalStorage::GetValue()
	{
		return scePthreadGetspecific(mTLSData.mKey);
	}


	bool EA::Thread::ThreadLocalStorage::SetValue(const void* pData)
	{
		if(scePthreadSetspecific(mTLSData.mKey, pData) == 0)
			return true;
		return false;
	}



#elif (defined(EA_PLATFORM_UNIX) || EA_POSIX_THREADS_AVAILABLE) && !defined(CS_UNDEFINED_STRING)
	#if defined(EA_PLATFORM_UNIX)
		#include <unistd.h>
	#elif defined(EA_PLATFORM_WINDOWS)
		EA_DISABLE_ALL_VC_WARNINGS()
		#include <Windows.h>
		EA_RESTORE_ALL_VC_WARNINGS()
	#endif

	EA::Thread::ThreadLocalStorage::ThreadLocalStorage()
		: mTLSData()
	{
		// To consider: Support the specification of a destructor instead of just passing NULL.
		mTLSData.mResult = pthread_key_create(&mTLSData.mKey, NULL);
		EAT_ASSERT(mTLSData.mResult == 0);
	}


	EA::Thread::ThreadLocalStorage::~ThreadLocalStorage()
	{
		if(mTLSData.mResult == 0)
			pthread_key_delete(mTLSData.mKey);
	}


	void* EA::Thread::ThreadLocalStorage::GetValue()
	{
		return pthread_getspecific(mTLSData.mKey);
	}


	bool EA::Thread::ThreadLocalStorage::SetValue(const void* pData)
	{
		if(pthread_setspecific(mTLSData.mKey, pData) == 0)
			return true;
		return false;
	}



#elif defined(EA_PLATFORM_MICROSOFT) && !defined(EA_PLATFORM_WINDOWS_PHONE) && !(defined(EA_PLATFORM_WINDOWS) && !EA_WINAPI_FAMILY_PARTITION(EA_WINAPI_PARTITION_DESKTOP)) 
		EA_DISABLE_ALL_VC_WARNINGS()
		#include <Windows.h>
		EA_RESTORE_ALL_VC_WARNINGS()

	EA::Thread::ThreadLocalStorage::ThreadLocalStorage()
		: mTLSData(TlsAlloc())
	{
		EAT_ASSERT(mTLSData != TLS_OUT_OF_INDEXES);
	}


	EA::Thread::ThreadLocalStorage::~ThreadLocalStorage()
	{
		if(mTLSData != TLS_OUT_OF_INDEXES)
			TlsFree(mTLSData);
	}


	void* EA::Thread::ThreadLocalStorage::GetValue()
	{
		return TlsGetValue(mTLSData);
	}


	bool EA::Thread::ThreadLocalStorage::SetValue(const void* pData)
	{
		if(TlsSetValue(mTLSData, (void*)pData))
			return true;
		return false;
	}

#elif (!EA_THREADS_AVAILABLE || defined(EA_PLATFORM_CONSOLE)) && !defined(CS_UNDEFINED_STRING)

	#include <string.h>

	#if !EA_THREADS_AVAILABLE
		#define OSEnableInterrupts()
		#define OSDisableInterrupts()
	#else
		#error Need to define EnableInterrupts/DisableInterrupts for the given platform.
	#endif


	EAThreadLocalStorageData::ThreadToDataPair* EAThreadLocalStorageData::GetTLSEntry(bool bCreateIfNotFound)
	{
		const int                  kArraySize = (sizeof(mDataArray) / sizeof(mDataArray[0]));
		ThreadToDataPair*          pCurrent, *pEnd;

		EA::Thread::ThreadUniqueId nCurrentThreadID;
		EAThreadGetUniqueId(nCurrentThreadID);

		// The code below is likely to execute very quickly and never transfers 
		// execution outside the function, so we can very briefly disable interrupts
		// for the period needed to do the logic below.
		OSDisableInterrupts();

		// We make the assumption that there are likely to be less than 10 threads most of 
		// the time. Thus, instead of maintaining a sorted array and do a binary search 
		// within that array, we do a linear search. An improvement would be to make the 
		// array be sorted if it goes above some preset size, such as 20.
		for(pCurrent = mDataArray, pEnd = mDataArray + mDataArrayCount; pCurrent < pEnd; ++pCurrent)
		{
			if(pCurrent->mThreadID == nCurrentThreadID)
			{
				OSEnableInterrupts();
				return pCurrent;
			}
		}

		if((pCurrent >= pEnd) && ((mDataArrayCount + 1) < kArraySize) && bCreateIfNotFound) // If we didn't find it above and there is more room and we should create if not found...
		{
			pCurrent = mDataArray + mDataArrayCount++;
			pCurrent->mThreadID = nCurrentThreadID;
		}
		else
			pCurrent = NULL;

		OSEnableInterrupts();

		return pCurrent;
	}


	EA::Thread::ThreadLocalStorage::ThreadLocalStorage()
	{
		memset(mTLSData.mDataArray, 0, sizeof(mTLSData.mDataArray));
		mTLSData.mDataArrayCount = 0;
	}


	EA::Thread::ThreadLocalStorage::~ThreadLocalStorage()
	{
		// Nothing to do.
	}


	void* EA::Thread::ThreadLocalStorage::GetValue()
	{
		EAThreadLocalStorageData::ThreadToDataPair* const pTDP = mTLSData.GetTLSEntry(false);
		if(pTDP)
			return (void*)pTDP->mpData;
		return NULL;
	}


	bool EA::Thread::ThreadLocalStorage::SetValue(const void* pData)
	{
		if(pData == NULL)
		{  // We remove it from the container so that the container can have room for others.
			EAThreadLocalStorageData::ThreadToDataPair* pTDP = mTLSData.GetTLSEntry(false);

			if(pTDP)
			{
				OSDisableInterrupts(); // Briefly disable interrupts for the duration of the logic below.
				const EAThreadLocalStorageData::ThreadToDataPair* const pTDPEnd = mTLSData.mDataArray + mTLSData.mDataArrayCount;
				while(++pTDP <= pTDPEnd)    // What we do here is move all the other values downward. This is an O(n) operation, 
					pTDP[-1] = pTDP[0];     // but the number of unique threads usinug us is likely to be pretty small.
				mTLSData.mDataArrayCount = (int)(pTDPEnd - mTLSData.mDataArray - 1);
				OSEnableInterrupts();
			}
			return true;
		}

		EAThreadLocalStorageData::ThreadToDataPair* const pTDP = mTLSData.GetTLSEntry(true);
		if(pTDP)
			pTDP->mpData = pData;
		return (pTDP != NULL);
	}

#else

	// Use reference std::map implementation.
	EA_DISABLE_VC_WARNING(4574)
	#include <map>
	EA_RESTORE_VC_WARNING()

	#include <eathread/eathread_futex.h>

	void** EAThreadLocalStorageData::GetTLSEntry(bool bCreateIfNotFound)
	{
		EA::Thread::ThreadUniqueId nThreadID;
		EAThreadGetUniqueId(nThreadID);

		EA::Thread::AutoFutex autoFutex(mFutex);

		if(bCreateIfNotFound) // We expect this to be true most of the time.
		{
			// Create as needed
			if (mThreadToDataMap == NULL)
			{
				mThreadToDataMap = new std::map<EA::Thread::ThreadUniqueId, const void*>;
			}

			return (void**)(char*)&((*mThreadToDataMap)[nThreadID]); // Dereferencing a std::map value by index inserts the value if it is not present.
		}

		if (mThreadToDataMap == NULL)
		{
			return NULL;
		}
		
		std::map<EA::Thread::ThreadUniqueId, const void*>::iterator it(mThreadToDataMap->find(nThreadID));
		if(it != mThreadToDataMap->end())
		{
			std::map<EA::Thread::ThreadUniqueId, const void*>::value_type& value = *it;
			return (void**)(char*)&value.second;
		}
		return NULL;
	}


	EA::Thread::ThreadLocalStorage::ThreadLocalStorage()
	{
	}


	EA::Thread::ThreadLocalStorage::~ThreadLocalStorage()
	{
		// Nothing to do.
	}


	void* EA::Thread::ThreadLocalStorage::GetValue()
	{
		void** const ppData = mTLSData.GetTLSEntry(false);
		if(ppData)
			return *ppData;
		return NULL;
	}


	bool EA::Thread::ThreadLocalStorage::SetValue(const void* pData)
	{
		if(pData == NULL)
		{
			ThreadUniqueId nThreadID;
			EAThreadGetUniqueId(nThreadID);

			EA::Thread::AutoFutex autoFutex(mTLSData.mFutex);
			
			if (mTLSData.mThreadToDataMap)
			{
				std::map<EA::Thread::ThreadUniqueId, const void*>::iterator it(mTLSData.mThreadToDataMap->find(nThreadID));
				if(it != mTLSData.mThreadToDataMap->end())
					mTLSData.mThreadToDataMap->erase(it);
			}
			return true;
		}

		void** const ppData = mTLSData.GetTLSEntry(true);
		if(ppData)
			*ppData = (void*)pData;
		return (*ppData != NULL);
	}

#endif


namespace EA
{
	namespace Thread
	{
		extern Allocator* gpAllocator;
	}
}


EA::Thread::ThreadLocalStorage* EA::Thread::ThreadLocalStorageFactory::CreateThreadLocalStorage()
{
	if(gpAllocator)
		return new(gpAllocator->Alloc(sizeof(EA::Thread::ThreadLocalStorage))) EA::Thread::ThreadLocalStorage;
	else
		return new EA::Thread::ThreadLocalStorage;
}

void EA::Thread::ThreadLocalStorageFactory::DestroyThreadLocalStorage(EA::Thread::ThreadLocalStorage* pThreadLocalStorage)
{
	if(gpAllocator)
	{
		pThreadLocalStorage->~ThreadLocalStorage();
		gpAllocator->Free(pThreadLocalStorage);
	}
	else
		delete pThreadLocalStorage;
}

size_t EA::Thread::ThreadLocalStorageFactory::GetThreadLocalStorageSize()
{
	return sizeof(EA::Thread::ThreadLocalStorage);
}

EA::Thread::ThreadLocalStorage* EA::Thread::ThreadLocalStorageFactory::ConstructThreadLocalStorage(void* pMemory)
{
	return new(pMemory) EA::Thread::ThreadLocalStorage;
}

void EA::Thread::ThreadLocalStorageFactory::DestructThreadLocalStorage(EA::Thread::ThreadLocalStorage* pThreadLocalStorage)
{
	pThreadLocalStorage->~ThreadLocalStorage();
}


#undef OSEnableInterrupts   
#undef OSDisableInterrupts