[Info-vax] yet another sys$qiow question

[David Froble]

JF Mezei wrote:
> On 15-08-12 22:28, David Froble wrote:
> 
>> I find timer ASTs to be rather trivial ...
> 
> 
> But when a timer AST is triggered, you still need code to check if the
> actioal IO completed, if not, then $CANCEL it with some flag indicating
> it timed out (so the code that executes when the IO completion AST is
> triggered knows the IO was timed out but still process whatever was in
> the buffer.

A timer AST is just to stop the waiting.  You can still choose to attempt to 
process any available data.

That said, the manner in which I usually use a timer AST with a sync read is to 
decide that the task didn't complete in time, and therefore is considered to be 
discarded.

But, as usual, it depends on what you're trying to do ....