> Java was going to be the universal systems language
My heart stopped here for a while [0]. Are there any papers on Java as system language? I'd love to read more - as embedded developer, this really is out of my scope.
They also created SunSPOT before RasperryPI, Arduino were even ideas, where beyond a basic layer written in native code, everything else was Java based.
Also Java is actually used as systems language in some scenarios, just not on your desktop.
When it is compiled AOT to be deployed on bare-metal scenarios such like the SDKs being sold by PTC and Aicas (just two examples, there are other companies)
Even 16 or so years earlier in 1990, Sun played with the idea of putting a PostScript interpreter in the SunOS kernel.
Like NeWS was the Network extensible Window System, so NeFS was the Network extensible File System, or NFS 3.0.
It was actually a great idea, just a wee bit before its time, and very poorly named and positioned!
For example: If you want to make a copy of a file on the server, you can send a PostScript program that runs in the kernel and copies the file locally on the server in the kernel with ZERO context switches, instead of sending it over the net to the client, then back from the client to the server. Even if you rsh'ed the user command "cp" on the server, it would still incur context switching, but if your copy loop was running in the kernel then it didn't need to switch in and out and in and out for every block it copied.
There are more examples of why it's a great idea in the paper.
This comparison of NeWS to AJAX also applies NeFS, which is like kernel NeWS with file operations instead of a graphics library -- it also saves you lots of user/kernel context switches even if you're not doing any networking:
>NeWS was architecturally similar to what is now called AJAX, except that NeWS coherently:
>- used PostScript code instead of JavaScript for programming.
>- used PostScript graphics instead of DHTML and CSS for rendering.
>- used PostScript data instead of XML and JSON for data representation.
It didn't go over very well because the unenlightened philistines of the time couldn't get their head around an API to the file system that wasn't compatible with creat open close read write and ioctl.
Network Extensible File System Protocol Specification
1.0 Introduction
The Network Extensible File System protocol (NeFS) provides transparent remote access to shared
file systems over networks. The NeFS protocol is designed to be machine, operating system,
network architecture, and transport protocol independent. This document is the draft specification
for the protocol. It will remain in draft form during a period of public review. Italicized comments
in the document are intended to present the rationale behind elements of the design and to raise
questions where there are doubts. Comments and suggestions on this draft specification are most
welcome.
[...]
Example: Copy a File
Make a copy of file (foo) called (bar). Both files exist in the same directory dfh. The request
starts by looking up the filehandle for the file to be copied and creates a filehandle for the copy.
The loop operator executes a procedure that copies the file using 1K reads and writes. It
maintains a running count of the number of bytes yet to be copied.
% Copy a file
%
dfh (foo) lookup /foofh exch def % get filehandle for (foo)
dfh (bar) create /barfh exch def % create filehandle for (bar)
/bytes foofh getattr /fsize get def % get size of (foo) so we know how much to copy
/offset 0 def % initialize offset for (bar)
{
/data foofh offset 1024 read def % read up to 1K from (foo)
barfh offset data write % write up to 1K to (bar)
/bytes bytes 1024 sub def % decrement byte count by 1024
bytes 0 le { exit } if % if it’s < 0 then we’re done
/offset offset 1024 add def % increment offset by 1024
}
loop
barfh getattr 1 encodereply sendreply % return the attributes of the new file to client.
From: brent@terra.Sun.COM (Brent Callaghan)
Newsgroups: comp.protocols.nfs
Subject: NeFS Protocol Spec Available
Keywords: NFS version 3
Date: 13 Feb 90 01:57:31 GMT
NeFS is not NFS. It started out as an NFS protocol rev
(NFS version 3) but its protocol is a radical departure
from the NFS's remote procedure call model. In order
to avoid confusion with NFS we're calling it NeFS for
now - Network Extensible File System (the similarity of
the name to a window system protocol is entirely intentional).
A draft spec for this new protocol is available via anonymous
FTP from titan.rice.edu (128.42.1.30) as
/public/nefs.doc.ps
The file is ~250K of PostScript. It prints 52 pages.
The spec is not available in any other format.
Comments, suggestions, flames etc are welcomed. Direct them
to "nfs3@sun.COM".
Thanks
Made in New Zealand --> Brent Callaghan @ Sun Microsystems
uucp: sun!bcallaghan
phone: (415) 336 1051
From: mo@messy.bellcore.com (Michael O'Dell)
Newsgroups: comp.protocols.nfs
Subject: RE: NeFS protocol
Date: 23 May 90 11:57:34 GMT
Organization: Center for Chaotic Repeatabilty
Dave Clark, Internet Architect, just gave a talk here at Bellcore and
he was lobbying for exactly the kind of approach being proposed by the
new NeFS protocol - don't send packets, send programs!
I do recommend you read the NeFS document and think about it hard
before you jump to any conclusions. The proposed model is novel, and
goes a long way toward moving us to "action at a distance" instead of
"remoting local operations." This turns out to be vitally important if
networks are to scale with latency, since, as Dave Clark so eloquently
showed, for large networks (ie, country-sized), as bandwidth goes to
infinity latency goes to 30milliseconds, and you can't do anything
about that, because you can't change the speed of light. So, to do
very well in the face of that, you must avoid round-trip delays like
the plague. Sending a program to the server can save many round-trips
for many operations.
Anyway, it is interesting reading. Particularly in light of Dave
Clark's talk.
-Mike
Although I don't keep them bookmarked, I looked into my collection of real-time or embedded GC's to find these that you might feel inspired by or see as potentially useful. :)
My heart stopped here for a while [0]. Are there any papers on Java as system language? I'd love to read more - as embedded developer, this really is out of my scope.
[0]: don't worry it does it 60 times per minute