InterlockedExchangePointer function (wdm.h)
The InterlockedExchangePointer routine performs an atomic operation that sets a pointer to a new value.
Syntax
PVOID InterlockedExchangePointer(
[in, out] PVOID volatile *Target,
[in, optional] PVOID Value
);
Parameters
[in, out] Target
A pointer to a PVOID value. The routine sets (*Target) to Value.
[in, optional] Value
Specifies the PVOID value to set (*Target) to.
Return value
InterlockedExchangePointer returns the original value of the pointer at *Target (that is, the value of this pointer at entry to the routine).
Remarks
InterlockedExchangePointer provides a fast, atomic way to synchronize updating a pointer variable that is shared by multiple threads.
InterlockedExchangePointer is designed for speed and, typically, is implemented inline by a compiler. InterlockedExchangePointer is atomic only with respect to other InterlockedXxx calls. It does not use a spin lock and can be safely used on pageable data.
The Target parameter should be aligned on either a 32-bit or 64-bit boundary, depending on the system type, for better performance.
A call to InterlockedExchangePointer is atomic only with respect to other InterlockedXxx calls.
Interlocked operations cannot be used on non-cached memory.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Available starting with Windows 2000. |
| Target Platform | Desktop |
| Header | wdm.h (include Wdm.h, Ntddk.h, Ntifs.h, Miniport.h) |
| IRQL | Any level |