EAThread/include/eathread/x86/eathread_atomic_x86.h

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

#if defined(EA_PRAGMA_ONCE_SUPPORTED)
	#pragma once // Some compilers (e.g. VC++) benefit significantly from using this. We've measured 3-4% build speed improvements in apps as a result.
#endif

/////////////////////////////////////////////////////////////////////////////
// Defines functionality for threadsafe primitive operations.
/////////////////////////////////////////////////////////////////////////////


#ifndef EATHREAD_X86_EATHREAD_ATOMIC_X86_H
#define EATHREAD_X86_EATHREAD_ATOMIC_X86_H


#include <EABase/eabase.h>
#include <stddef.h>
#include <eathread/internal/eathread_atomic_standalone.h>

// 4146: unary minus operator applied to unsigned type, result still unsigned
// 4339: use of undefined type detected in CLR meta-data
EA_DISABLE_VC_WARNING(4146 4339)

// This is required for Windows Phone (ARM) because we are temporarily not using
// CPP11 style atomics and we are depending on the MSVC intrinics.
#if defined(EA_PROCESSOR_X86) || defined(EA_PROCESSOR_ARM)
	#define EA_THREAD_ATOMIC_IMPLEMENTED

	namespace EA
	{
		namespace Thread
		{
			/// class AtomicInt
			/// Actual implementation may vary per platform. May require certain alignments, sizes, 
			/// and declaration specifications per platform.
			template <class T>
			class AtomicInt
			{
			public:
				typedef AtomicInt<T> ThisType;
				typedef T            ValueType;

				/// AtomicInt
				/// Empty constructor. Intentionally leaves mValue in an unspecified state.
				/// This is done so that an AtomicInt acts like a standard built-in integer.
				/// Problem: C/C++ has two ways to initialize a built-in type x: x and x(),
				///          and they have different semantics, as the first does nothing but 
				///          the second initializes x to zero. C++ does not provide a means 
				///          to tell which of tell which of these two ways a C++ class instance
				///          initialized. Thus we probably can't easily argue that this constructor 
				///          should do nothing vs. initialize the variable to 0. It's probably
				///          safer for us to make it initialize to 0, and it wouldn't break 
				///          users to do so, though it would add a tiny runtime cost.
				AtomicInt()
					{}

				AtomicInt(ValueType n) : mValue(0) // Initialize mValue because otherwise SetValue may read it before it's initialized. 
					{ SetValue(n); }

				AtomicInt(const ThisType& x)
					: mValue(x.GetValue()) {}

				AtomicInt& operator=(const ThisType& x)
					{ mValue = x.GetValue(); return *this; }

				ValueType GetValue() const
					{ return mValue; }

				ValueType GetValueRaw() const
					{ return mValue; }

				ValueType SetValue(ValueType n);
				bool      SetValueConditional(ValueType n, ValueType condition);
				ValueType Increment();
				ValueType Decrement();
				ValueType Add(ValueType n);

				// operators
				inline            operator const ValueType() const { return GetValue(); }
				inline ValueType  operator =(ValueType n)          {        SetValue(n); return n; }
				inline ValueType  operator+=(ValueType n)          { return Add(n);}
				inline ValueType  operator-=(ValueType n)          { return Add(-n);}
				inline ValueType  operator++()                     { return Increment();}
				inline ValueType  operator++(int)                  { return Increment() - 1;}
				inline ValueType  operator--()                     { return Decrement(); }
				inline ValueType  operator--(int)                  { return Decrement() + 1;}

			protected:
				volatile ValueType mValue;
			};

			#if defined(EA_PLATFORM_MICROSOFT) && defined(EA_COMPILER_MSVC)

				// 32 bit versions
				template<> inline
				AtomicInt<int32_t>::ValueType AtomicInt<int32_t>::SetValue(ValueType n)
					{ return (ValueType)InterlockedExchangeImp((long*)&mValue, (long)n); } // Even though we shouldn't need to use InterlockedExchange on x86, the intrinsic x86 InterlockedExchange is at least as fast as C code we would otherwise put here.

				template<> inline
				AtomicInt<uint32_t>::ValueType AtomicInt<uint32_t>::SetValue(ValueType n)
					{ return (ValueType)InterlockedExchangeImp((long*)&mValue, (long)n); } // Even though we shouldn't need to use InterlockedExchange on x86, the intrinsic x86 InterlockedExchange is at least as fast as C code we would otherwise put here.

				template<> inline
				bool AtomicInt<int32_t>::SetValueConditional(ValueType n, ValueType condition)
					{ return ((ValueType)InterlockedCompareExchangeImp((long*)&mValue, (long)n, (long)condition) == condition); }

				template<> inline
				bool AtomicInt<uint32_t>::SetValueConditional(ValueType n, ValueType condition)
					{ return ((ValueType)InterlockedCompareExchangeImp((long*)&mValue, (long)n, (long)condition) == condition); }

				template<> inline
				AtomicInt<int32_t>::ValueType AtomicInt<int32_t>::Increment()
					{ return (ValueType)InterlockedIncrementImp((long*)&mValue); }

				template<> inline
				AtomicInt<uint32_t>::ValueType AtomicInt<uint32_t>::Increment()
					{ return (ValueType)InterlockedIncrementImp((long*)&mValue); }

				template<> inline
				AtomicInt<int32_t>::ValueType AtomicInt<int32_t>::Decrement()
					{ return (ValueType)InterlockedDecrementImp((long*)&mValue); }

				template<> inline
				AtomicInt<uint32_t>::ValueType AtomicInt<uint32_t>::Decrement()
					{ return (ValueType)InterlockedDecrementImp((long*)&mValue); }

				template<> inline
				AtomicInt<int32_t>::ValueType AtomicInt<int32_t>::Add(ValueType n)
					{ return ((ValueType)InterlockedExchangeAddImp((long*)&mValue, (long)n) + n); }

				template<> inline
				AtomicInt<uint32_t>::ValueType AtomicInt<uint32_t>::Add(ValueType n)
					{ return ((ValueType)InterlockedExchangeAddImp((long*)&mValue, (long)n) + n); }



				// 64 bit versions
				template<> inline
				AtomicInt<int64_t>::ValueType AtomicInt<int64_t>::GetValue() const{
					int64_t condition, nNewValue;
					do{
						nNewValue = condition = mValue; // Todo: This function has a problem unless the assignment of mValue to condition is atomic.
					} while(!InterlockedSetIfEqual(const_cast<int64_t*>(&mValue), nNewValue, condition));
					return nNewValue;
				}

				template<> inline
				AtomicInt<uint64_t>::ValueType AtomicInt<uint64_t>::GetValue() const{
					uint64_t condition, nNewValue;
					do{
						nNewValue = condition = mValue; // Todo: This function has a problem unless the assignment of mValue to condition is atomic.
					} while(!InterlockedSetIfEqual(const_cast<uint64_t*>(&mValue), nNewValue, condition));
					return nNewValue;
				}

				template<> inline
				AtomicInt<int64_t>::ValueType AtomicInt<int64_t>::SetValue(ValueType n){
					int64_t condition;
					do{
						condition = mValue;
					} while(!InterlockedSetIfEqual(&mValue, n, condition));
					return condition;
				}

				template<> inline
				AtomicInt<uint64_t>::ValueType AtomicInt<uint64_t>::SetValue(ValueType n){
					uint64_t condition;
					do{
						condition = mValue;
					} while(!InterlockedSetIfEqual(&mValue, n, condition));
					return condition;
				}

				template<> inline
				bool AtomicInt<int64_t>::SetValueConditional(ValueType n, ValueType condition){
					return InterlockedSetIfEqual(&mValue, n, condition);
				}

				template<> inline
				bool AtomicInt<uint64_t>::SetValueConditional(ValueType n, ValueType condition){
					return InterlockedSetIfEqual(&mValue, n, condition);
				}

				template<> inline
				AtomicInt<int64_t>::ValueType AtomicInt<int64_t>::Increment(){
					int64_t condition, nNewValue;
					do{
						condition = mValue;
						nNewValue = condition + 1;
					} while(!InterlockedSetIfEqual(&mValue, nNewValue, condition));
					return nNewValue;
				}

				template<> inline
				AtomicInt<uint64_t>::ValueType AtomicInt<uint64_t>::Increment(){
					uint64_t condition, nNewValue;
					do{
						condition = mValue;
						nNewValue = condition + 1;
					} while(!InterlockedSetIfEqual(&mValue, nNewValue, condition));
					return nNewValue;
				}

				template<> inline
				AtomicInt<int64_t>::ValueType AtomicInt<int64_t>::Decrement(){
					int64_t condition, nNewValue;
					do{
						condition = mValue;
						nNewValue = condition - 1;
					} while(!InterlockedSetIfEqual(&mValue, nNewValue, condition));
					return nNewValue;
				}

				template<> inline
				AtomicInt<uint64_t>::ValueType AtomicInt<uint64_t>::Decrement(){
					uint64_t condition, nNewValue;
					do{
						condition = mValue;
						nNewValue = condition - 1;
					} while(!InterlockedSetIfEqual(&mValue, nNewValue, condition));
					return nNewValue;
				}

				template<> inline
				AtomicInt<int64_t>::ValueType AtomicInt<int64_t>::Add(ValueType n){
					int64_t condition, nNewValue;
					do{
						condition = mValue;
						nNewValue = condition + n;
					} while(!InterlockedSetIfEqual(&mValue, nNewValue, condition));
					return nNewValue;
				}

				template<> inline
				AtomicInt<uint64_t>::ValueType AtomicInt<uint64_t>::Add(ValueType n){
					uint64_t condition, nNewValue;
					do{
						condition = mValue;
						nNewValue = condition + n;
					} while(!InterlockedSetIfEqual(&mValue, nNewValue, condition));
					return nNewValue;
				}


			#elif defined(EA_COMPILER_GNUC) || defined (EA_COMPILER_CLANG)

				// Recent versions of GCC have atomic primitives built into the compiler and standard library.
				#if defined (EA_COMPILER_CLANG) || defined(EA_PLATFORM_APPLE) || (defined(EA_COMPILER_GNUC) && EA_COMPILER_VERSION >= 4003) // GCC 4.3 or later

					template <> inline
					AtomicInt<int32_t>::ValueType AtomicInt<int32_t>::GetValue() const
						{ return __sync_add_and_fetch(const_cast<ValueType*>(&mValue), 0); }

					template <> inline
					AtomicInt<uint32_t>::ValueType AtomicInt<uint32_t>::GetValue() const
						{ return __sync_add_and_fetch(const_cast<ValueType*>(&mValue), 0); }

					template <> inline
					AtomicInt<int32_t>::ValueType AtomicInt<int32_t>::SetValue(ValueType n)
						{ __sync_synchronize(); return __sync_lock_test_and_set(&mValue, n); }

					template <> inline
					AtomicInt<uint32_t>::ValueType AtomicInt<uint32_t>::SetValue(ValueType n)
						{ __sync_synchronize(); return __sync_lock_test_and_set(&mValue, n); }

					template <> inline
					bool AtomicInt<int32_t>::SetValueConditional(ValueType n, ValueType condition)
						{ return (__sync_val_compare_and_swap(&mValue, condition, n) == condition); }

					template <> inline
					bool AtomicInt<uint32_t>::SetValueConditional(ValueType n, ValueType condition)
						{ return (__sync_val_compare_and_swap(&mValue, condition, n) == condition); }

					template <> inline
					AtomicInt<int32_t>::ValueType AtomicInt<int32_t>::Increment()
						{ return __sync_add_and_fetch(&mValue, 1); }

					template <> inline
					AtomicInt<uint32_t>::ValueType AtomicInt<uint32_t>::Increment()
						{ return __sync_add_and_fetch(&mValue, 1); }

					template <> inline
					AtomicInt<int32_t>::ValueType AtomicInt<int32_t>::Decrement()
						{ return __sync_sub_and_fetch(&mValue, 1); }

					template <> inline
					AtomicInt<uint32_t>::ValueType AtomicInt<uint32_t>::Decrement()
						{ return __sync_sub_and_fetch(&mValue, 1); }

					template <> inline
					AtomicInt<int32_t>::ValueType AtomicInt<int32_t>::Add(ValueType n)
						{ return __sync_add_and_fetch(&mValue, n); }

					template <> inline
					AtomicInt<uint32_t>::ValueType AtomicInt<uint32_t>::Add(ValueType n)
						{ return __sync_add_and_fetch(&mValue, n); }



					template <> inline
					AtomicInt<int64_t>::ValueType AtomicInt<int64_t>::GetValue() const
						{ return __sync_add_and_fetch(const_cast<ValueType*>(&mValue), 0); }

					template <> inline
					AtomicInt<uint64_t>::ValueType AtomicInt<uint64_t>::GetValue() const
						{ return __sync_add_and_fetch(const_cast<ValueType*>(&mValue), 0); }

					template <> inline
					AtomicInt<int64_t>::ValueType AtomicInt<int64_t>::SetValue(ValueType n)
						{ __sync_synchronize(); return __sync_lock_test_and_set(&mValue, n); }

					template <> inline
					AtomicInt<uint64_t>::ValueType AtomicInt<uint64_t>::SetValue(ValueType n)
						{ __sync_synchronize(); return __sync_lock_test_and_set(&mValue, n); }

					template <> inline
					bool AtomicInt<int64_t>::SetValueConditional(ValueType n, ValueType condition)
						{ return (__sync_val_compare_and_swap(&mValue, condition, n) == condition); }

					template <> inline
					bool AtomicInt<uint64_t>::SetValueConditional(ValueType n, ValueType condition)
						{ return (__sync_val_compare_and_swap(&mValue, condition, n) == condition); }

					template <> inline
					AtomicInt<int64_t>::ValueType AtomicInt<int64_t>::Increment()
						{ return __sync_add_and_fetch(&mValue, 1); }

					template <> inline
					AtomicInt<uint64_t>::ValueType AtomicInt<uint64_t>::Increment()
						{ return __sync_add_and_fetch(&mValue, 1); }

					template <> inline
					AtomicInt<int64_t>::ValueType AtomicInt<int64_t>::Decrement()
						{ return __sync_sub_and_fetch(&mValue, 1); }

					template <> inline
					AtomicInt<uint64_t>::ValueType AtomicInt<uint64_t>::Decrement()
						{ return __sync_sub_and_fetch(&mValue, 1); }

					template <> inline
					AtomicInt<int64_t>::ValueType AtomicInt<int64_t>::Add(ValueType n)
						{ return __sync_add_and_fetch(&mValue, n); }

					template <> inline
					AtomicInt<uint64_t>::ValueType AtomicInt<uint64_t>::Add(ValueType n)
						{ return __sync_add_and_fetch(&mValue, n); }

				#else

					// If the above intrinsics aren't used...
					#ifndef InterlockedCompareExchangeImp
					namespace
					{
						int32_t InterlockedExchange(volatile int32_t* m, int32_t n)
						{
							int32_t result;

							__asm__ __volatile__ (
								"xchgl %%eax, (%2)" // The xchg instruction does an implicit lock instruction.
								: "=a" (result)     // outputs
								: "a" (n), "q" (m)  // inputs
								: "memory"          // clobbered
								);

							return result;
						}

						int32_t InterlockedCompareExchange(volatile int32_t* m, int32_t n, int32_t condition)
						{
							int32_t result;

							__asm__ __volatile__(
								"lock; cmpxchgl %3, (%1) \n"        // Test *m against EAX, if same, then *m = n
								: "=a" (result), "=q" (m)           // outputs
								: "a" (condition), "q" (n), "1" (m) // inputs
								: "memory"                          // clobbered
								);

							return result;
						}

						#define InterlockedExchangeImp        InterlockedExchange
						#define InterlockedCompareExchangeImp InterlockedCompareExchange
					}
					#endif

					// 32 bit versions
					template<> inline
					AtomicInt<int32_t>::ValueType AtomicInt<int32_t>::SetValue(ValueType n)
						{ return (ValueType)InterlockedExchangeImp(&mValue, n); }

					template<> inline
					AtomicInt<uint32_t>::ValueType AtomicInt<uint32_t>::SetValue(ValueType n)
						{ return (ValueType)InterlockedExchangeImp((int32_t*)&mValue, n); }

					template<> inline
					bool AtomicInt<int32_t>::SetValueConditional(ValueType n, ValueType condition)
						{ return ((ValueType)InterlockedCompareExchangeImp(&mValue, n, condition) == condition); }

					template<> inline
					bool AtomicInt<uint32_t>::SetValueConditional(ValueType n, ValueType condition)
						{ return ((ValueType)InterlockedCompareExchangeImp((int32_t*)&mValue, n, condition) == condition); }

					template<> inline
					AtomicInt<int32_t>::ValueType AtomicInt<int32_t>::Increment()
					{
						int32_t result;

						__asm__ __volatile__ ("lock; xaddl %0, %1"
											: "=r" (result), "=m" (mValue)
											: "0" (1), "m" (mValue)
											: "memory"
											);
						return result + 1;
					}

					template<> inline
					AtomicInt<uint32_t>::ValueType AtomicInt<uint32_t>::Increment()
					{
						int32_t result;

						__asm__ __volatile__ ("lock; xaddl %0, %1"
											: "=r" (result), "=m" (mValue)
											: "0" (1), "m" (mValue)
											: "memory"
											);
						return result + 1;
					}

					template<> inline
					AtomicInt<int32_t>::ValueType AtomicInt<int32_t>::Decrement()
					{
						int32_t result;

						__asm__ __volatile__ ("lock; xaddl %0, %1"
											: "=r" (result), "=m" (mValue)
											: "0" (-1), "m" (mValue)
											: "memory"
											);
						return result - 1;
					}

					template<> inline
					AtomicInt<uint32_t>::ValueType AtomicInt<uint32_t>::Decrement()
					{
						uint32_t result;

						__asm__ __volatile__ ("lock; xaddl %0, %1"
											: "=r" (result), "=m" (mValue)
											: "0" (-1), "m" (mValue)
											: "memory"
											);
						return result - 1;
					}

					template<> inline
					AtomicInt<int32_t>::ValueType AtomicInt<int32_t>::Add(ValueType n)
					{
						int32_t result;

						__asm__ __volatile__ ("lock; xaddl %0, %1"
											: "=r" (result), "=m" (mValue)
											: "0" (n), "m" (mValue)
											: "memory"
											);
						return result + n;
					}

					template<> inline
					AtomicInt<uint32_t>::ValueType AtomicInt<uint32_t>::Add(ValueType n)
					{
						uint32_t result;

						__asm__ __volatile__ ("lock; xaddl %0, %1"
											: "=r" (result), "=m" (mValue)
											: "0" (n), "m" (mValue)
											: "memory"
											);
						return result + n;
					}



					// 64 bit versions

					inline bool
					InterlockedSetIfEqual(volatile int64_t* dest, int64_t newValue, int64_t condition)
					{
						int64_t oldValue;

						__asm __volatile ("lock; cmpxchg8b %1"
										 : "=A" (oldValue), "=m" (*dest)
										 : "b" (((int32_t) newValue) & 0xffffffff),
										   "c" ((int32_t)(newValue >> 32)),
										   "m" (*dest), "a" (((int32_t) condition) & 0xffffffff),
										   "d" ((int32_t)(condition >> 32)));

						return oldValue == condition;

						// Reference non-thread-safe implementation:
						// if(*dest == condition)
						// {
						//     *dest = newValue
						//     return true;
						// }
						// return false;
					}

					inline bool
					InterlockedSetIfEqual(volatile uint64_t* dest, uint64_t newValue, uint64_t condition)
					{
						uint64_t oldValue;

						__asm __volatile ("lock; cmpxchg8b %1"
										 : "=A" (oldValue), "=m" (*dest)
										 : "b" (((uint32_t) newValue) & 0xffffffff),
										   "c" ((uint32_t)(newValue >> 32)),
										   "m" (*dest), "a" (((uint32_t) condition) & 0xffffffff),
										   "d" ((uint32_t)(condition >> 32)));

						return oldValue == condition;

						// Reference non-thread-safe implementation:
						// if(*dest == condition)
						// {
						//     *dest = newValue
						//     return true;
						// }
						// return false;
					}

					template<> inline
					AtomicInt<int64_t>::ValueType AtomicInt<int64_t>::GetValue() const{
						int64_t condition, nNewValue;
						do{
							nNewValue = condition = mValue; // Todo: This function has a problem unless the assignment of mValue to condition is atomic.
						} while(!InterlockedSetIfEqual(const_cast<int64_t*>(&mValue), nNewValue, condition));
						return nNewValue;
					}

					template<> inline
					AtomicInt<uint64_t>::ValueType AtomicInt<uint64_t>::GetValue() const{
						uint64_t condition, nNewValue;
						do{
							nNewValue = condition = mValue; // Todo: This function has a problem unless the assignment of mValue to condition is atomic.
						} while(!InterlockedSetIfEqual(const_cast<uint64_t*>(&mValue), nNewValue, condition));
						return nNewValue;
					}

					template<> inline
					AtomicInt<int64_t>::ValueType AtomicInt<int64_t>::SetValue(ValueType n){
						int64_t condition;
						do{
							condition = mValue;
						} while(!InterlockedSetIfEqual(&mValue, n, condition));
						return condition;
					}

					template<> inline
					AtomicInt<uint64_t>::ValueType AtomicInt<uint64_t>::SetValue(ValueType n){
						uint64_t condition;
						do{
							condition = mValue;
						} while(!InterlockedSetIfEqual(&mValue, n, condition));
						return condition;
					}

					template<> inline
					bool AtomicInt<int64_t>::SetValueConditional(ValueType n, ValueType condition){
						return InterlockedSetIfEqual(&mValue, n, condition);
					}

					template<> inline
					bool AtomicInt<uint64_t>::SetValueConditional(ValueType n, ValueType condition){
						return InterlockedSetIfEqual(&mValue, n, condition);
					}

					template<> inline
					AtomicInt<int64_t>::ValueType AtomicInt<int64_t>::Increment(){
						int64_t condition, nNewValue;
						do{
							condition = mValue;
							nNewValue = condition + 1;
						} while(!InterlockedSetIfEqual(&mValue, nNewValue, condition));
						return nNewValue;
					}

					template<> inline
					AtomicInt<uint64_t>::ValueType AtomicInt<uint64_t>::Increment(){
						uint64_t condition, nNewValue;
						do{
							condition = mValue;
							nNewValue = condition + 1;
						} while(!InterlockedSetIfEqual(&mValue, nNewValue, condition));
						return nNewValue;
					}

					template<> inline
					AtomicInt<int64_t>::ValueType AtomicInt<int64_t>::Decrement(){
						int64_t condition, nNewValue;
						do{
							condition = mValue;
							nNewValue = condition - 1;
						} while(!InterlockedSetIfEqual(&mValue, nNewValue, condition));
						return nNewValue;
					}

					template<> inline
					AtomicInt<uint64_t>::ValueType AtomicInt<uint64_t>::Decrement(){
						uint64_t condition, nNewValue;
						do{
							condition = mValue;
							nNewValue = condition - 1;
						} while(!InterlockedSetIfEqual(&mValue, nNewValue, condition));
						return nNewValue;
					}

					template<> inline
					AtomicInt<int64_t>::ValueType AtomicInt<int64_t>::Add(ValueType n){
						int64_t condition, nNewValue;
						do{
							condition = mValue;
							nNewValue = condition + n;
						} while(!InterlockedSetIfEqual(&mValue, nNewValue, condition));
						return nNewValue;
					}

					template<> inline
					AtomicInt<uint64_t>::ValueType AtomicInt<uint64_t>::Add(ValueType n){
						uint64_t condition, nNewValue;
						do{
							condition = mValue;
							nNewValue = condition + n;
						} while(!InterlockedSetIfEqual(&mValue, nNewValue, condition));
						return nNewValue;
					}

				#endif

			#elif defined(EA_COMPILER_INTEL) || defined(EA_COMPILER_MSVC) || defined(EA_COMPILER_BORLAND)

				// This is won't compile when ValueType is 64 bits.

				template<class T> inline 
				typename AtomicInt<T>::ValueType AtomicInt<T>::SetValue(ValueType n)
				{
					__asm{
						mov  ecx, this                 // mValue is expected to be at offset zero of this.
						mov  eax, n 
						xchg eax, dword ptr [ecx]      // The xchg instruction does an implicit lock instruction.
					}
				}

				template<class T> inline 
				bool AtomicInt<T>::SetValueConditional(ValueType n, ValueType condition)
				{
					__asm{
						mov  ecx, this                       // mValue is expected to be at offset zero of this.
						mov  edx, n 
						mov  eax, condition
						lock cmpxchg dword ptr [ecx], edx    // Compares mValue to condition. If equal, z flag is set and n is copied into mValue.
						jz    condition_met
						xor  eax, eax
						jmp  end
						condition_met:
						mov  eax, 1
						end:
					}
				}

				template<class T>  inline 
				bool typename AtomicInt<T>::ValueType AtomicInt<T>::Increment()
				{
					__asm{
						mov  ecx, this                 // mValue is expected to be at offset zero of this.
						mov  eax, 1 
						lock xadd dword ptr [ecx], eax // Sum goes into [ecx], old mValue goes into eax.
						inc  eax                       // Increment eax because the return value is the new value.
					}
				}

				template<class T>  inline 
				bool typename AtomicInt<T>::ValueType AtomicInt<T>::Decrement()
				{
					__asm{
						mov  ecx, this                 // mValue is expected to be at offset zero of this.
						mov  eax, 0xffffffff
						lock xadd dword ptr [ecx], eax // Sum goes into [ecx], old mValue goes into eax.
						dec  eax                       // Increment eax because the return value is the new value.
					}
				}

				template<class T>  inline 
				bool typename AtomicInt<T>::ValueType AtomicInt<T>::Add(ValueType n)
				{
					__asm{
						mov  ecx, this                 // mValue is expected to be at offset zero of this.
						mov  eax, n 
						lock xadd dword ptr [ecx], eax // Sum goes into [ecx], old mValue goes into eax.
						add  eax, n
					}
				}


			#else
				// Compiler not currently supported.

			#endif

		} // namespace Thread

	} // namespace EA


#endif // EA_PROCESSOR_X86

EA_RESTORE_VC_WARNING()

#endif // EATHREAD_X86_EATHREAD_ATOMIC_X86_H