function returns the error status for the asynchronous I/O request
with control block pointed to by
This function returns
if the request has not been
if the request was canceled.
It returns 0 if the request completed successfully.
Otherwise an error value is returned, the same value that would have
been stored in the
variable in case of a synchronous
On error, the error value is returned.
does not point at a control block for an asynchronous I/O request
of which the return status (see
has not been retrieved yet.