Microsoft Specific
Perform an atomic exchange operation, which copies the address passed in as the second argument to the first and returns the original address of the first.
void * _InterlockedExchangePointer(
void * volatile * Target,
void * Value
);
void * _InterlockedExchangePointer_acq(
void * volatile * Target,
void * Value
);
Parameters
[in, out] Target
Pointer to the pointer to the value to exchange. The function sets the value to Value and returns its previous value.[in] Value
Value to be exchanged with the value pointed to by Target.
Return Value
The function returns the initial value pointed to by Target.
Requirements
Intrinsic |
Architecture |
|---|---|
_InterlockedExchangePointer |
IPF, x64 |
_InterlockedExchangePointer_acq |
IPF |
Note On the x86 architecture, _InterlockedExchangePointer is a macro that calls _InterlockedExchange.
Header file <intrin.h>
Remarks
On a 64-bit system, the parameters are 64 bits and must be aligned on 64-bit boundaries; otherwise, the function fails. On a 32-bit system, the parameters are 32 bits and must be aligned on 32-bit boundaries.
Use _InterlockedExchangePointer_acq if you need acquire semantics, such as at the beginning of 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.