_InterlockedExchange Intrinsic Functions
Microsoft Specific
Provide compiler intrinsic support for the Win32 Platform SDK InterlockedExchange function.
long _InterlockedExchange(
long * Target,
long Value
);
long _InterlockedExchange_acq(
long * Target,
long Value
);
__int64 _InterlockedExchange64(
__int64 * Target,
__int64 Value
);
__int64 _InterlockedExchange64_acq(
__int64 * Target,
__int64 Value
);
Parameters
- [in, out] Target
Pointer to the value to be exchanged. The function sets this variable to Value and returns its prior value.
- [in] Value
Value to be exchanged with the value pointed to by Target.
Return Value
Returns the initial value pointed to by Target.
Requirements
| Intrinsic | Architecture |
|---|---|
_InterlockedExchange |
x86, IPF, x64 |
_InterlockedExchange_acq |
IPF |
_InterlockedExchange64 |
IPF, x64 |
_InterlockedExchange64_acq |
IPF |
Header file <intrin.h>
Remarks
There are several variations on _InterlockedExchange that vary based on the data types they involve and whether processor-specific acquire or release semantics is used.
While the _InterlockedExchange function operates on 32-bit integer values, _InterlockedExchange64 operates on 64-bit integer values.
The _InterlockedExchange_acq and _InterlockedExchange64_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.
Example
For a sample of how to use _InterlockedExchange, see _InterlockedDecrement.