_InterlockedExchangeAdd Intrinsic Functions

Microsoft Specific

Provide compiler intrinsic support for the Win32 Windows SDK _InterlockedExchangeAdd Intrinsic Functions function.

long _InterlockedExchangeAdd(
   long volatile * Addend,
   long Value
);
long _InterlockedExchangeAdd_acq(
   long volatile * Addend,
   long Value
);
long _InterlockedExchangeAdd_rel(
   long volatile * Addend,
   long Value
);
__int64 _InterlockedExchangeAdd64(
   __int64 volatile * Addend,
   __int64 Value
);
__int64 _InterlockedExchangeAdd64_acq(
   __int64 volatile * Addend,
   __int64 Value
);
__int64 _InterlockedExchangeAdd64_rel(
   __int64 volatile * Addend,
   __int64 Value
);

Parameters

• [in, out] Addend
  The value to be added to; replaced by the result of the addition.

• [in] Value
  The value to add.

Return Value

The return value is the initial value of the variable pointed to by the Addend parameter.

Requirements

Header file <intrin.h>

Remarks

There are several variations on _InterlockedExchangeAdd that vary based on the data types they involve and whether processor-specific acquire or release semantics is used.

While the _InterlockedExchangeAdd function operates on 32-bit integer values, _InterlockedExchangeAdd64 operates on 64-bit integer values.

The _InterlockedExchangeAdd_acq and _InterlockedExchangeAdd64_acq intrinsic functions are the same as the corresponding functions without the _acq suffix except that the operation is performed with acquire semantics, which is useful when entering a critical section.

There is no version of this function that uses release semantics.

In Visual C++ 2005, these functions behave as read-write memory barriers. For more information, see _ReadWriteBarrier.

These routines are only available as intrinsics. Thus, they are intrinsic whether or not /Oi or #pragma intrinsic is used. It is not possible to use #pragma function on these intrinsics.

Example

For a sample of how to use _InterlockedExchangeAdd, see _InterlockedDecrement.

See Also

Reference

Compiler Intrinsics

C++ Keywords

Conflicts with the x86 Compiler