InterlockedExchangeAdd
[New
- Windows NT]
The InterlockExchangeAdd
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 (
|
PLONG Addend, |
// pointer
to the addend |
|
LONG Increment |
//
increment value |
|
); |
|
Parameters
Addend
Specifies the
address of the number that will have the Increment number added to it.
Increment
Specifies the
number to be added to the variable pointed to by the Addend parameter.
Return Values
The return
value is the initial value of the Addend parameter.
Remarks
The functions
InterlockedExchangeAdd, InterlockedCompareExchange, InterlockedDecrement, InterlockedExchange, 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 InterlockedExchangeAdd
function performs an atomic addition of the Increment value to the Addend
value. The result is stored in the address specified by Addend. The
initial value of Addend is returned as the function value.
The variables
for InterlockedExchangeAdd must be aligned on a 32-bit boundary;
otherwise, this function will fail on multiprocessor x86 systems.
See Also