This function atomically exchanges a pair of 32-bit values.
At a Glance
| Header file: | Winbase.h |
| Windows CE versions: | 1.0 and later |
Syntax
LONG InterlockedExchange( LPLONG Target, LONG Value );
Parameters
Target
[in] Pointer to the LONG value to exchange. The function sets this LONG value to Value, and returns its prior value.
Value
[in] Specifies a new value for the LONG value pointed to by Target.
Return Values
The prior value of the LONG value pointed to by Target indicates success.
Remarks
The functions InterlockedExchange, InterlockedCompareExchange, InterlockedDecrement, 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 Target parameter must be aligned on a 32-bit boundary; otherwise, this function will fail on multiprocessor x86 systems.
See Also