[Info-vax] yet another sys$qiow question

[JF Mezei]

On 15-08-21 09:41, Johnny Billquist wrote:

> Uh? It's a completely valid and not poor practice to check the iosb 
> before the operation completes. And the IOSB is defined as being set to 
> zero by the initiation of the I/O.


Pardon my ignorance here, but what purpose is served by checking the
IOSB before the IO completes ?

Is this some performance thing to check IOSB for non-zero value instead
of checking if event-flag has been set ?


I've always done either QIOW, or QIO with AST or QIO with event flag. I
personally really like the AST model.