int = IOCompletion(func, arg )
Set a callback that will be used for handling asynchronous I/O operations.
CommentsIf you call this multiple times, the previous callback will be discarded.
A reference to the callback and args are held until EXTENSION_CONTROL_BLOCK::DoneWithSession is called. If the callback function fails, DoneWithSession(HSE_STATUS_ERROR) will automatically be called and no further callbacks for the ECB will be made.