IoBufferMask Enumeration | 
Specifies whether the operation should be performed on the I/O read buffer, the write buffer, or both buffers.
enum IoBufferMask
Member name  | Description  | |
|---|---|---|
IoReadBuffer  | I/O read buffer.  | |
IoWriteBuffer  | I/O write buffer.  | |
IoReadAndWriteBuffers  | Both the I/O read and write buffers.  |