InterlockedExchange64 function (winnt.h)

Sets a 64-bit variable to the specified value as an atomic operation.

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

To operate on a 32-bit variable, use the InterlockedExchange function.

LONG64 InterlockedExchange64(
  [in, out] LONG64 volatile *Target,
  [in]      LONG64          Value
);

[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.

The function returns the initial value of the Target parameter.

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 _InterlockedExchange64.

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 InterlockedExchangeAcquire64 instead.

Interlocked Variable Access

InterlockedCompareExchange

InterlockedExchange

InterlockedExchange16

InterlockedExchange16Acquire

InterlockedExchange16NoFence

InterlockedExchange8

InterlockedExchangeAcquire

InterlockedExchangeAcquire64

InterlockedExchangeAdd

InterlockedExchangeNoFence

InterlockedExchangeNoFence64

InterlockedExchangePointer

InterlockedExchangePointerAcquire

InterlockedExchangePointerNoFence

InterlockedExchangeSubtract

Synchronization Functions