[Info-vax] QIO Writes to a mailbox

[JF Mezei]

VAXman- @SendSpamHere.ORG wrote:

> Specify the IOSB, check it and assume nothing!  Then, the code should
> work.

No. Looking at the IOSB won't make the code work and the problem
disappear. You will just notice a bad retrun code should there be one.

However, the writing process may be working fine and it may be the
reading process which dicards a message by mistake.

While it is not kosher for the writng process do to a $QIO without
waiting for completion and checking the IOSB to at least report a
problem in a log, this may not be the cause of the problem. It just
allows the problem to go undetected by the writing process IF the
problem is with the writing process.

Note that if the writing process excepts an answer from the other
process, there may be a wait statement there (waiting for the answer)
which does imply that the writing process will wait for the $QIO to
complete before issuing the next one.