Applies to: desktop apps | Metro style apps
Decrements (decreases by one) the value of the specified 32-bit variable as an atomic operation.
To operate on 64-bit values, use the InterlockedDecrement64 function.
Syntax
LONG __cdecl InterlockedDecrement( __inout LONG volatile *Addend );
Parameters
- Addend [in, out]
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A pointer to the variable to be decremented.
Return value
The function returns the resulting decremented 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 _InterlockedDecrement.
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 InterlockedDecrementAcquire or InterlockedDecrementRelease instead.
Requirements
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Minimum supported client | Windows XP |
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Minimum supported server | Windows Server 2003 |
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See also
- Interlocked Variable Access
- InterlockedDecrement64
- InterlockedDecrementAcquire
- InterlockedDecrementRelease
- Synchronization Functions
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Build date: 3/7/2012