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This function performs an atomic addition of an increment value to an Addend variable. The function prevents more than one thread from using the same variable simultaneously.

LONG InterlockedExchangeAdd(
  LPLONG Addend,
  LONG Increment


[in, out] Pointer to the number that will have the Increment number added to it.


[in] Specifies the number to be added to the variable pointed to by the Addend parameter.

Initial value of the variable pointed to by the Addend parameter.

The InterlockedExchangeAdd, InterlockedCompareExchange, InterlockedDecrement, InterlockedExchange, and InterlockedIncrement functions 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 InterlockedExchangeAdd function performs an atomic addition of the Increment value to the value pointed to by Addend. The result is stored in the address specified by Addend. The initial value of the variable pointed to by Addend is returned as the function value.

The variables for InterlockedExchangeAdd must be aligned on a 32-bit boundary.

Windows Embedded CEWindows CE .NET 4.0 and later
Windows MobileWindows Mobile Version 5.0 and later

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