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 InterlockedIncrement Function

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InterlockedIncrement Function

Increments (increases by one) the value of the specified 32-bit variable as an atomic operation.

To operate on 64-bit values, use the InterlockedIncrement64 function.

Syntax

C++
LONG __cdecl InterlockedIncrement(
  __inout  LONG volatile *Addend
);

Parameters

Addend [in, out]

A pointer to the variable to be incremented.

Return Value

The function returns the resulting incremented value.

Remarks

The variable pointed to by the Addend parameter must be aligned on a 32-bit boundary; otherwise, this function will behave unpredictably on multiprocessor x86 systems and any non-x86 systems. See _aligned_malloc.

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 _InterlockedIncrement.

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

Intel IPF:  For performance-critical applications, use InterlockedIncrementAcquire or InterlockedIncrementRelease instead.

Requirements

Minimum supported clientWindows 2000 Professional
Minimum supported serverWindows 2000 Server
HeaderWinbase.h (include Windows.h)
LibraryKernel32.lib
DLLKernel32.dll

See Also

Interlocked Variable Access
InterlockedIncrement64
InterlockedIncrementAcquire
InterlockedIncrementRelease
Synchronization Functions

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Build date: 7/2/2009

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