Aucbvax.3178
fa.unix-wizards
utzoo!decvax!ucbvax!unix-wizards
Wed Sep 16 13:33:34 1981
signals and events
>From cbosg!ewl@Berkeley Wed Sep 16 13:27:53 1981
I am looking at the possibility of adding Events to UNIX and
changing parts of the Signal mechanism. Events could be
defined for use between user processes (perhaps they would be
similar to VMS events) or between a user and the system kernel,
to indicate things like "you just received 20 characters on
line 7" or "a child just died" or "your write completed, you
may reuse the buffer", etc. It is not clear whether this can
be done in a way that is upward compatible with current systems,
nor what events should be allowed and how events could be defined
dynamically. If events existed, which should be available and
how should they be implemented? Should they be asynchronous,
like Signals, or should they be deliberately waited for and
perhaps have a general "an event occurred" signal?
Signals could (should?) be changed to allow them to be temporarily
ignored and queued while masked and made so that none slip through
the cracks due to races when reenabling. Perhaps something similar
to UCB 4.1BSD sigsys(2) (or to one of the others that have been
proposed) should be implemented as a (BTL) standard?
Many people have mumbled something about wanting a different kind
of signals or having user/kernel events or messages. My task is
to see if people realy want it and if it would be worth it to
make rather fundamental changes to the nature of (BTL) UNIX.
For BTL folks, I have an even more long-winded MF version of this news
item. However, I am interested in the opinions of all UNIX followers,
both BTL and outsiders. I may be reached at:
Bill Leggett cbosg!ewl csvax.ewl@berkeley
Bell Laboratories 6200 E Broad St., Columbus OH 43213
(614)-868-4464
There is, of course, no guarantee that any changes will be made nor
that any options I might develop would become available in standard
UNIX from BTL. The current thinking is that signals should not be
changed and events not added. However, my long-term goal is to
produce aids for those designing real-time cooperating process
systems, so any thoughts about signals, events, language features,
IPC mechanisms, etc., will be appreciated, even though non-BTLers
may see no changes to standard (BTL) UNIX for quite a while.
-----------------------------------------------------------------
gopher://quux.org/ conversion by John Goerzen <
[email protected]>
of
http://communication.ucsd.edu/A-News/
This Usenet Oldnews Archive
article may be copied and distributed freely, provided:
1. There is no money collected for the text(s) of the articles.
2. The following notice remains appended to each copy:
The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996
Bruce Jones, Henry Spencer, David Wiseman.
