February 1998
- OT: Following in the footsteps of JCL Alex Oren
- OT: Following in the footsteps of JCL Nathan Yospe
- OT: Following in the footsteps of JCL Richard Woolcock
- OT: Following in the footsteps of JCL Chris Gray
- OT: Following in the footsteps of JCL coder@ibm.net
- OT: Following in the footsteps of JCL Marc Eyrignoux
- Ada? Andrew C.M. McClintock
- Monthly FAQ posting Koster, Raph
- Monthly FAQ posting Adam Wiggins
- Monthly FAQ posting Ling
- Monthly FAQ Posting Ling
- Monthly FAQ Posting Ling
- Monthly FAQ Posting Ling
- Monthly FAQ Posting Chris Gray
- Monthly FAQ Posting Ling
- Monthly FAQ Posting J C Lawrence
- Monthly FAQ Posting J C Lawrence
- Monthly FAQ Posting Alex Oren
- Monthly FAQ Posting Greg Miller
- Monthly FAQ Posting s001gmu@nova.wright.edu
- Monthly FAQ Posting Ling
- Monthly FAQ Posting Ling
- Monthly FAQ Posting Ling
- Monthly FAQ Posting Ling
- Monthly FAQ Posting Ling
- Monthly FAQ Posting Ling
- Monthly FAQ Posting Ling
- Monthly FAQ Posting Ling
- Monthly FAQ Posting Ling
- Monthly FAQ Posting Ling Lo
- Monthly FAQ Posting Koster, Raph
- Monthly FAQ Posting Ling Lo
- Monthly FAQ Posting Greg Miller
- Monthly FAQ Posting Marian Griffith
- Monthly FAQ Posting Greg Miller
- Monthly FAQ Posting Ling Lo
- Databases Shawn Halpenny
- OT: This is a test coder@ibm.net
- OT: This is a test Alex Oren
- Clients and things [Was: OT: This is a test] Matt Chatterley
- Clients and things [Was: OT: This is a test] coder@ibm.net
- Clients and things [Was: OT: This is a test] Matt Chatterley
- MUD Development Digest Dr. Cat
- DBs and Events Greg Munt
- DBs and Events Nathan Yospe
- DBs and Events Greg Munt
- DBs and Events Nathan Yospe
- DBs and Events Felix A. Croes
- DBs and Events Jon A. Lambert
- DBs and Events coder@ibm.net
- DBs and Events s001gmu@nova.wright.edu
- DBs and Events Jon A. Lambert
- DBs and Events coder@ibm.net
- (subject missing) Ben Greear
- META: Unsubscribed users dur to bounces coder@ibm.net
- META: Unsubscribed users dur to bounces Adam Wiggins
- Source Code Release Greg Munt
- Source Code Release Ben Greear
- Source Code Release Greg Munt
- Source Code Release Ben Greear
- Source Code Release Greg Munt
- Source Code Release Richard Woolcock
- Source Code Release Ben Greear
- Source Code Release Chris Gray
- Source Code Release Greg Munt
- Source Code Release coder@ibm.net
- Source Code Release Richard Woolcock
- Source Code Release Stephen Zepp
- Source Code Release Jon A. Lambert
- Source Code Release Greg Munt
- Source Code Release Jon A. Lambert
- Source Code Release Greg Munt
- Source Code Release Travis Casey
- Source Code Release Jon A. Lambert
- Source Code Release Jon A. Lambert
- [RESEARCH]MUD articles archive (fwd) Greg Munt
- Socket programming (Was: The impact of the web on muds) Jon Leonard
- Socket programming (was: The impact of the web on muds) Vadim Tkachenko
- Socket programming (was: The impact of the web on muds) Richard Woolcock
- byte-code anyone? Chris Gray
- byte-code anyone? Jon Leonard
- byte-code anyone? Chris Gray
[Jon Leonard:]
:I've been implementing something similar in the MUD I'm writing, but I
:realized fairly early on that I could get even better speedups by compiling
:all the way to machine code instead of just to bytecode. (What JIT runtimes
:do for Java)
I thought about that. It's still a possibility, but I probably won't need
it. I would do direct code generation within my system, rather than go via
an external compiler. I would have to *really* want it, however, since doing
it that way is inherently non-portable. Since most of the things that a
MUD scenario does (string operations, DB access, NL parsing, dynamic
calls, etc.) are fairly expensive, most MUD code would see little benefit
from going to native code. The particular code I'm interested in would,
but its hard to justify the effort and non-portability just for that.
:My recommendations would be more complete if I were done, but here's the
:advice I'm giving myself:
:
:1) Test the virtual machine carefully starting early on, so fewer bugs need
: to be laboriously traced by single-stepping an interpreter.
Hmm. I'd planned on testing by fire. My byte-code machine is going to be
quite low level, so visual inspection is feasible. Also, it would be extra
work to create an 'assembler' for it.
:2) Design so that no matter how perverse the byte codes you get fed are,
: you don't crash or violate security assumptions. Going from an interpreted
: language to byte codes or machine code makes demonstrating correctness
: much harder.
That would slow the system down too much. I've found, for example, that
even having a 'default' in the byte-code case statement adds noticeable
overhead. I have made a simple disassembler that lets me see the byte-
code for functions. Since the only source of byte-code will be the simple
compiler, my current view is that checking the byte-code is not needed.
There will be some processing required to set it up for execution (linking
to other bytecode), but I think that's about it.
You have reminded me that I forgot about my security model in this,
however. I might just punt by deciding that any function that changes
the security settings from that of its caller will not be compiled. I
have the luxury of falling back on the full parse tree interpreter.
Why does going from an interpreted language make things harder? In my case,
it makes things a lot easier. I already have correct parse trees for the
code, and can just traverse them to emit the code. My language is strongly
typed, so I don't have any of those nasty issues to worry about. The one
non-strongly typed construct (call of action retrieved as a value, rather
than by name), can be handled, or, I might just disallow compilation of
routines that do that. I can do that, since I still have the original
parse tree interpreter.
:3) Pick carefully what the simple primitives are. Missing a vital one
: can cost lots of performance, but too many bloats your
: interpreter/compiler/security model.
Agreed. I've been fiddling as I go along. I expect I'll end up with around
100 opcodes (considerably less than Java has).
:4) Don't expect to be done soon. A compiler can be a lot of work.
Ah, but most of it is already done. I expect to be running some simple
byte-code today. I haven't even specified all of the byte-codes yet, but
doing things incrementally lets me cycle the design with little cost. As
long as I have enough for at least function entry and exit, I can run things.
Oh yes, AmigaOS has the 'load' and 'unload' calls, so the scheme of
compiling via an external compiler could be made to work. The big issue
would be resolution of references to the already-loaded code. You'd have
to do that with a jump vector passed to the loaded code. (I did that on
a game system on CP/M, and I also use it in my current AmigaMUD system.)
--
Chris Gray cg@ami-cg.GraySage.Edmonton.AB.CA - byte-code anyone? Jon Leonard
- byte-code anyone? Chris Gray
- byte-code anyone? Chris Gray
- user-centered design (was Clients) Mike Sellers
- OT: Linux g++ Greg Munt
- OT: Linux g++ Ben Greear
- OT: Linux g++ coder@ibm.net
- OT: Linux g++ Shawn Halpenny
- OT: Linux g++ Chris Gray
- OT: Clients Vadim Tkachenko
- OT: Clients Adam Wiggins
- OT: Clients coder@ibm.net
- META: OS wars coder@ibm.net
- META: OS wars Mike Sellers
- Clients Stephen Zepp
- Moore's Law sucks (was: 3D graphics) Brandon J. Rickman
- Moore's Law sucks (was: 3D graphics) Adam Wiggins
- Moore's Law sucks (was: 3D graphics) Chris Gray
- Moore's Law sucks (was: 3D graphics) coder@ibm.net
- Moore's Law sucks (was: 3D graphics) Brandon J. Rickman
- Moore's Law sucks (was: 3D graphics) Mike Sellers
- Moore's Law sucks (was: 3D graphics) Chris Gray
- Moore's Law sucks (was: 3D graphics) Ben Greear
- Moore's Law sucks (was: 3D graphics) Ling
- Moore's Law sucks (was: 3D graphics) Brandon J. Rickman
- Moore's Law sucks (was: 3D graphics) coder@ibm.net
- Moore's Law sucks (was: 3D graphics) Alex Oren
- Version Control (was: DBs and Events) Vadim Tkachenko
- Version Control (was: DBs and Events) coder@ibm.net
- Version Control (was: DBs and Events) Vadim Tkachenko
- Version Control (was: DBs and Events) coder@ibm.net
- Version Control (was: DBs and Events) coder@ibm.net
- Version Control (was: DBs and Events) Jon A. Lambert
- Version Control (was: DBs and Events) s001gmu@nova.wright.edu
- Version Control (was: DBs and Events) Raph & Kristen Koster
- Version Control (was: DBs and Events) coder@ibm.net
- Version Control (was: DBs and Events) Felix A. Croes
- Net protocols for MUDing (was: Moore's Law sucks) Jon Leonard
- Net protocols for MUDing (was: Moore's Law sucks) coder@ibm.net
- Net protocols for MUDing (was: Moore's Law sucks) s001gmu@nova.wright.edu
- Net protocols for MUDing (was: Moore's Law sucks) Vadim Tkachenko
- Net protocols for MUDing (was: Moore's Law sucks) Chris Gray
- Net protocols for MUDing (was: Moore's Law sucks) Caliban Tiresias Darklock
- Net protocols for MUDing (was: Moore's Law sucks) J C Lawrence
- Net protocols for MUDing (was: Moore's Law sucks) J C Lawrence
- Net protocols for MUDing (was: Moore's Law sucks) Adam Wiggins
- Net protocols for MUDing (was: Moore's Law sucks) Chris Gray
- Net protocols for MUDing (was: Moore's Law sucks) Vadim Tkachenko
- Net protocols for MUDing (was: Moore's Law sucks) Chris Gray
- Net protocols for MUDing (was: Moore's Law sucks) Vadim Tkachenko
- Net protocols for MUDing (was: Moore's Law sucks) Chris Gray
- Net protocols for MUDing (was: Moore's Law sucks) Adam Wiggins
- Net protocols for MUDing (was: Moore's Law sucks) Chris Gray
- Net protocols for MUDing (was: Moore's Law sucks) J C Lawrence
- Net protocols for MUDing (was: Moore's Law sucks) Chris Gray
- Net protocols for MUDing (was: Moore's Law sucks) Adam Wiggins
- Net protocols for MUDing (was: Moore's Law sucks) Ben Greear
- Net protocols for MUDing (was: Moore's Law sucks) Adam Wiggins
- Net protocols for MUDing (was: Moore's Law sucks) s001gmu@nova.wright.edu
- Net protocols for MUDing (was: Moore's Law sucks) Jon A. Lambert
- Net protocols for MUDing (was: Moore's Law sucks) J C Lawrence
- VEIL (was: Clients) Brandon Gillespie
- LDMs (large dynamic maps) was Unique items Mike Sellers
- Describing the environment Stephen Zepp
- Describing the environment Richard Woolcock
- Back on the list Niklas Elmqvist
- Back on the list Chris Gray
- Back on the list coder@ibm.net
- Unique items The Eternal City
- Unique items coder@ibm.net
- Position sorting Adam Wiggins
- Position sorting coder@ibm.net
- Unique items coder@ibm.net
- Unique items Nathan F Yospe
- BOOK: Myer's Silverlock coder@ibm.net
- BOOK: Myer's Silverlock Chris Gray
- BOOK: Myer's Silverlock Adam Wiggins
- Dynamic Loading of Modules (was: Back on the list) Niklas Elmqvist
- Dynamic Loading of Modules (was: Back on the list) Vadim Tkachenko
- Dynamic Loading of Modules (was: Back on the list) J C Lawrence
- Dynamic Loading of Modules (was: Back on the list Jon A. Lambert
- Net protocols for MUDing s001gmu@nova.wright.edu
- Net protocols for MUDing Stephen Zepp
- Net protocols for MUDing Chris Gray
- Net protocols for MUDing Adam Wiggins
- Net protocols for MUDing J C Lawrence
- Net protocols for MUDing Shawn Halpenny
- Net protocols for MUDing J C Lawrence
- Net protocols for MUDing Chris Gray
- Dynamic Loading of Modules Niklas Elmqvist
- Senses (was: The MLI Project) s001gmu@nova.wright.edu
- bar-time (was The MLI Project) Mike Sellers
- 3D engines for MUDs (was: The MLI Project) Niklas Elmqvist
- 3D engines for MUDs (was: The MLI Project) J C Lawrence
- 3D engines for MUDs (was: The MLI Project) Michael Hohensee
- 3D engines for MUDs (was: The MLI Project) Miroslav Silovic
- 3D engines for MUDs (was: The MLI Project) Michael Hohensee
- Why not compile java into object code? Ben Greear
- Why not compile java into object code? Cynbe ru Taren
- Why not compile java into object code? Caliban Tiresias Darklock
- Why not compile java into object code? Nathan F Yospe
- Why not compile java into object code? Niklas Elmqvist
- Why not compile java into object code? Ben Greear
- Why not compile java into object code? Jon A. Lambert
- Why not compile java into object code? Travis Casey
- Why not compile java into object code? Chris Gray
- Tutorial: Comments on Hand-crafting a compiler Jon A. Lambert
- Tutorial: Let's build a Compiler! - Part I: Introduction Jon A. Lambert
- Tutorial: Let's build a Compiler! - Part II: Expression Parsing Jon A. Lambert
- Tutorial: Let's build a Compiler! - Part I: Introductio Chris Gray
- Tutorial: Let's build a Compiler! - Part I: Introductio s001gmu@nova.wright.edu
- Tutorial: Let's build a Compiler! - Part I: Introductio coder@ibm.net
- MUD Development Digest Dr. Cat
- MUD Development Digest Koster, Raph
- MUD Development Digest Mike Sellers
- Tutorial: Let's build a Compiler! - Part III: More Expressions Jon A. Lambert
- Tutorial: Let's build a Compiler! - Part IV: Interpreters Jon A. Lambert
- Tutorial: Let's build a Compiler! - Part V: Control Constructs Jon A. Lambert
- Tutorial: Let's build a Compiler! - Part VI: Boolean Expressions Jon A. Lambert
- Tutorial: Let's build a Compiler! - Comments Jon A. Lambert
- Tutorial: Let's build a Compiler! - Part VII: Lexical Scanning Jon A. Lambert
- Tutorial: Let's build a Compiler! - Part VIII: A Little Philosophy Jon A. Lambert
- Tutorial: Let's build a Compiler! - Part IX: A Top View Jon A. Lambert
- Tutorial: Let's build a Compiler! - Part X: Introducing TINY Jon A. Lambert
- Compilers: Toy available for ftp Chris Gray