[Info-vax] Mailbox driver analysis regarding greater than 65535 messages in mailbox

[Hein RMS van den Heuvel]

On Tuesday, December 1, 2020 at 12:42:31 PM UTC-5, Marc Van Dyck wrote:
> Hein RMS van den Heuvel submitted this idea :
> > But still 
> > they can keep writing and reading peaking above 64K messages only getting a 
> > non-success status when the mailbox is empty.:
:
> No. If you look at the test I described in my original copy, you can 
> write any number of messages you want, but you can't read them all 
> back. The next time that the message count 16 bits field gets back to 
> zero, the read operation returns an "end of file" status and the 
> messages still remaining in the mailbox become inaccessible. 

I just saw that in the original topic "Large mailboxes" - which got badly off-track as usual  - thanks for testing!

So I have to revise my suggestion. too bad.
If it is broken as is then it is better to return an error when a send is attempted with  UCB$W_MSGCNT being 65535.
I still maintain that it might be enough to promote the UCB count field to an aligned longword and let the reports be incorrect for the time being.
Of course it is better to fix it all, if fixed at all.

Cheers,
Hein.