[9fans] Ephase question.

["Roman V. Shaposhnick" <vugluskr@unicorn.math.spbu.ru>]

Hi everybody,

digging inside 4th edition gave me some very unexpected results
in terms of file access semantics in user space. But let me show
a scenario first:

first-user$ cat > /shared-directory/file
blah-blah-blah

second-user$ rm /shared-directory/file

[first user after hitting <CR> ]
"phase error -- directory entry not allocated"

I was a little bit shocked at first, mainly because I've got so used to
UNIX semantics of "once you get it -- it's yours", that I've been taking
it for granted in Plan9 as well.

Suddenly I can't remember how 3nd and 2nd editions behaved.

Before now I was under the impression that regular unopened fids are mostly
used for reference counting and once you grab a fid nobody can kill the
actual object it refers to, but 4th edition proved me wrong. Even though
I still can't understand why it behaves this way. Could somebody explain
the rationale behind that to me, please ? And I'm really curios now about
what obligations server is supposed to have when it accepts a new fid from
a client for a given object.

Thanks,
Roman.