InterlockedDecrement - Win32 Programmer's Reference (win32.hlp)

Win32 Programmer's Reference

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Windows NT
Yes
Win95
Yes
Win32s
No
Import Library
kernel32.lib
Header File
winbase.h
Unicode
No
Platform Notes
None

InterlockedDecrement

The InterlockedDecrement function both decrements (decreases by one) the value of the specified 32-bit variable and checks the resulting value. The function prevents more than one thread from using the same variable simultaneously.

LONG InterlockedDecrement(

LPLONG lpAddend	// address of the variable to decrement
);

Parameters
lpAddend

Points to the 32-bit variable to decrement.

Return Values
If the result of the decrement is zero, the return value is zero.

If the result of the decrement is less than zero, the return value is less than zero. If the result of the decrement is greater than zero, the return value is greater than zero. A nonzero return value may not be equal to the result of the decrement.

Remarks
The functions InterlockedDecrement, InterlockedCompareExchange, InterlockedExchange, InterlockedExchangeAdd, and InterlockedIncrement provide a simple mechanism for synchronizing access to a variable that is shared by multiple threads. The threads of different processes can use this mechanism if the variable is in shared memory.

The variable pointed to by the lpAddend parameter must be aligned on a 32-bit boundary; otherwise, this function will fail on multiprocessor x86 systems.

See Also
InterlockedCompareExchange, InterlockedExchange, InterlockedExchangeAdd, InterlockedIncrement

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