Re: [9fans] AFS-client for Plan9 - ?

["Douglas A. Gwyn" <gwyn@arl.army.mil>]

rog@vitanuova.com wrote:
> however, it's worth remembering, that in the Unix i remember at any
> rate, _exit() is not always invoked on program exit.  it isn't invoked
> if the program dies from a signal, for instance.

Right; upon abnormal termination (what POSIX terms "termination
with actions" as I recall), the application process has lost
control, so only the kernel clean-up actions can be performed
(which include closing open FDs, as others have remarked).

> i've always presumed that the final close of fds is done when their
> refcount drops to zero, i.e.  when the exited process's file table is
> cleared up by the kernel.

It depends on the kernel (there might be process-owned locks to
release, for example), but that's the roght general idea.
Closing a "file" decrements its in-use count and only when that
count goes to zero is the "real" close function performed, e.g.
device driver drops READY etc.

> so the actual _?exit() system calls are not that crucial to the issue
> of file closing under AFS. stdio is a different matter, of course.

Yes, sorry if I digressed.