InterlockedExchangePointer

InterlockedExchangePointer atomically exchanges a pair of addresses.

Syntax

Copy

PVOID InterlockedExchangePointer(
    [in, out]  PVOID volatile *Target,
    [in]       PVOID           Value
);

Parameters

[in, out] Target

A pointer to the value to be exchanged. The function sets this variable to Value and returns its prior value.

[in] Value

The value to be exchanged with the value pointed to by Target.

Return Value

The function returns the initial value of the Target parameter.

Remarks

This function copies the address passed as the second parameter to the first and returns the original address of the first.

On a 64-bit system, the parameters are 64 bits and the Target parameter must be aligned on 64-bit boundaries; otherwise, the function will behave unpredictably.

The interlocked functions provide a simple mechanism for synchronizing access to a variable shared by multiple threads. This function is atomic concerning calls to other interlocked functions.

This function is implemented using a compiler intrinsic where possible. For more information, see the winbase.h header file and _InterlockedExchangePointer.

This function generates a full memory barrier (or fence) to ensure that memory operations are completed properly.

Requirements

Minimum supported version	Header
wRTOS 1.0 SDK	windows.h