InterlockedExchange function

Sets a 32-bit variable to the specified value as an atomic operation.

To operate on a pointer variable, use the InterlockedExchangePointer function.

To operate on a 16-bit variable, use the InterlockedExchange16 function.

To operate on a 64-bit variable, use the InterlockedExchange64 function.

Syntax

unsigned InterlockedExchange(
  _Interlocked_operand_ unsigned *Target,
  unsigned                       Value
);

Parameters

Target

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

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

The interlocked functions provide a simple mechanism for synchronizing access to a variable that is shared by multiple threads. This function is atomic with respect to 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 _InterlockedExchange.

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

Itanium-based systems:  For performance-critical applications, use InterlockedExchangeAcquire instead.

Note  This function is supported on Windows RT-based systems.
 

Requirements

   
Windows version Windows XP [desktop apps UWP apps] Windows Server 2003 [desktop apps UWP apps]
Target Platform Windows
Header winbase.h (include Windows.h)
Library Kernel32.lib
DLL Kernel32.dll

See Also

Interlocked Variable Access

InterlockedCompareExchange

InterlockedExchange

InterlockedExchange16

InterlockedExchange16Acquire

InterlockedExchange16NoFence

InterlockedExchange64

InterlockedExchange8

InterlockedExchangeAcquire

InterlockedExchangeAcquire64

InterlockedExchangeAdd

InterlockedExchangeAdd64

InterlockedExchangeAddAcquire

InterlockedExchangeAddAcquire64

InterlockedExchangeAddNoFence

InterlockedExchangeAddNoFence64

InterlockedExchangeAddRelease

InterlockedExchangeAddRelease64

InterlockedExchangeNoFence

InterlockedExchangeNoFence64

InterlockedExchangePointer

InterlockedExchangePointerAcquire

InterlockedExchangePointerNoFence

InterlockedExchangeSubtract

Synchronization Functions