Expedited I/O Functions

I/O functions containing the “Ex” suffix are expedited I/O functions. Expedited I/O functions directly access the memory containing the input address space or the output address space, bypassing the normal API execution processing. This improves the performance, which may be important when many I/O functions are called in a short period of time, or when the response of the I/O function must be as fast as possible.

Because the normal API execution processing is bypassed, expedited I/O functions cannot be executed from the API Buffer. For more information, see API Functions with Special Properties.