info-vax (07/24/82)
>From Samuelson@SANDIA Fri Jul 23 20:23:09 1982
You are correct, you cannot delete a mailbox until all processes which
have a channel to the mailbox close that channel (ie: it will be marked
for deletion, making it look like a temporary mailbox, the it will go
away when the last process closes the channel).
If you want to know if the reader/creator of the mailbox is still around
we have found that the best way is not to let senders keep the mailbox
open all the time, but to re-open it each time they want to send to it.
That is extra overhead, but it avoids the problem of not knowing if
the creator is alive or dead.
- Sam -
-------info-vax (07/24/82)
>From MADLER@MIT-ML Fri Jul 23 20:59:24 1982
According to the VMS documentation, when the image that creates a mailbox
deassigns the mailbox channel, the mailbox is deleted. It has been my
experience that the mailbox remains until all processes which have
assigned a channel (for write) to the mailbox have closed their channels.
How can a process tell that the creator of the mailbox is gone (without
an exit handler and a special, predefined message?) I checked the
io status byte, and the returned values look the same when a mailbox
is not being read but is still opened by the creator and when the mailbox
has been deassigned by the creator.
Please reply to me, I am not on the list.
-Michael