[Info-vax] QIO Writes to a mailbox

[Roy Omond]

On 09/11/2011 13:44, Steve Bainbridge cast these words into stone:

> [...big snip ...]
>
> Depending upon who you believe QIOs may or may not copy the data
> buffer before it returns - several people have said that mailboxes use
> buffered IO and the buffer is copied before it returns from the QIO.
> Everyone seems to agree that this is implementation specific and you
> can't rely upon it always being the case.

Hi Steve, I've kept quiet in this thread ;-)

You know you have access to the VMS source listings, don't you ?

Ask Costas or Simon to fish out the source listing for the mailbox
driver and see for yourself how the data buffer is handled by the
driver.  I wouldn't say it's "implementation specific" - that would
seem to imply that there are differences between "implementations"
of VMS.