gmane.lisp.scheme.scheme48

Re: Reinitializer failing to run

Taylor R Campbell — 2013-04-30T19:03:19

   Date: Tue, 30 Apr 2013 18:30:51 +0000
   From: Taylor R Campbell <campbell< at >mumble.net>

      Date: Tue, 30 Apr 2013 10:39:32 -0700
      From: Will Noble <will< at >cow9.org>

      However, in this case a ton of signals-related procedures in the POSIX
      module would need this treatment. I think Mike would want to use some other
      solution.

   Would they really?  I think only WAIT-FOR-CHILD-PROCESS and
   FIND-NEXT-SIGNAL rely on it.

FORK, too, I suppose, or anything that could create child processes,
so that we don't end up with zombies and nothing to reap them.

Re: Reinitializer failing to run

Taylor R Campbell — 2013-04-30T18:32:51

   Date: Tue, 30 Apr 2013 10:08:02 -0700
   From: Will Noble <will< at >cow9.org>

   Of course, it would be great if we don't get any unneeded reinitializers (or
   code to reload unneeded share objects) in images. 

The dynamic externals reloading mechanism currently doesn't use
reinitializers because it has to run before lots of them.  What if
each reinitializer had a list of those reinitializers that it depends
on, so that anything relying on dynamic externals would have to list
the dynamic externals renitializer?  If nothing depends on dynamic
externals then the dynamic externals reinitializer could be GC'd and
wouldn't have to run.

Re: Reinitializer failing to run

Taylor R Campbell — 2013-04-30T18:30:51

   Date: Tue, 30 Apr 2013 10:39:32 -0700
   From: Will Noble <will< at >cow9.org>

   However, in this case a ton of signals-related procedures in the POSIX
   module would need this treatment. I think Mike would want to use some other
   solution.

Would they really?  I think only WAIT-FOR-CHILD-PROCESS and
FIND-NEXT-SIGNAL rely on it.

Re: Reinitializer failing to run

Will Noble — 2013-04-30T17:39:32

Thanks for the quick reply. No-op is a good trick to remember. I was just
thinking that if I did

(define (wait-for-child-process pid)
  signals-reinitializer
  ...)

the variable reference might get removed.

However, in this case a ton of signals-related procedures in the POSIX
module would need this treatment. I think Mike would want to use some other
solution.

Best,
Will

Re: Reinitializer failing to run

Will Noble — 2013-04-30T17:08:02

What I meant was that by changing the mechanism of reinitializers, we could
forget about the transitive closure of the resumer procedure and simply
include every reinitializer. I can think of a couple of reasons for doing
things this way.

For one thing, we already reload dynamically loaded libraries when resuming
from a resumer procedure-type dumped image. In this case, posix.so has
already polluted the image without the benefit of having signals work,
because of the missing reinitializer.

Second, the signal handler reinitializer doesn't do anything heavy. It only
arranges for the system to pick up on signals. To receive those signals the
user has to use the provided functions. Otherwise they would observe not
observe any effects.

Of course, it would be great if we don't get any unneeded reinitializers (or
code to reload unneeded share objects) in images. I think for that we would
need to have procedures refer to their containing packages, and have
packages refer to package-specific reinitializers.

Best

Re: Reinitializer failing to run

Michael Sperber — 2013-04-30T13:40:05

Will Noble <will< at >cow9.org> writes:


Hmmm.  It seems the problem is not so much the mechanism but that there
is no path from `date' to the reinitializer for the signal handlers.
Otherwise, it'd be likely that reinitializers would pollute images
dumped with a resumer procedure.  Having said that, I'll have to think a
bit more about how to create such a path.

Re: Reinitializer failing to run

Taylor R Campbell — 2013-04-29T14:42:43

   Date: Mon, 29 Apr 2013 07:10:14 -0700
   From: Will Noble <will< at >cow9.org>

   It seems to me that we should be able to expect reinitializers to run. I'm
   not sure what the best solution here is. We could use a separate
   second-stage initialization thunk list to implement reinitializers, instead
   of the current method (relying on record resumers). Or maybe there is a
   natural way of ensuring that reinitializers are always reachable. If we find
   an acceptable solution I'd be happy to code it up.

If you want to guarantee that the reinitializer has been included in
the image in some code you want to run, you can pass it to the NO-OP
procedure (from the BIG-UTIL structure, if I recall correctly) in that
code.  E.g., you might do this at the start of WAIT-FOR-CHILD-PROCESS:

(define (wait-for-child-process pid)
  (no-op sigchld-reinitializer)
  ...mess with pid...)

Reinitializer failing to run

Will Noble — 2013-04-29T14:10:14

Hi all,

I'm having a problem with reinitializers. The macro DEFINE-REINITIALIZER
defines a record variable, which might or might not be reachable from a
resumer function. When it is not, the reinitialization routine doesn't make
it into the saved heap image.

Take this example:
    (cond ((fork) => wait-for-child-process)
          (else (exec "date"))))
; no values returned
Writing good.image
Writing bad.image

Resuming good.image and calling DATE works as expected, but running the VM
with bad.image hangs it because the reinitializer from the posix-process
module that installs signal handlers doesn't run, causing the system to
ignore SIGCHLD signals.

Using ADD-INITIALIZTION-THUNK! instead of a reinitializer doesn't work
because when the thunk runs posix.so would not yet have been loaded back in.

It seems to me that we should be able to expect reinitializers to run. I'm
not sure what the best solution here is. We could use a separate
second-stage initialization thunk list to implement reinitializers, inst

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Michael Sperber — 2013-03-10T13:25:20

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Re: Map doesn't work with n lists

Michael Sperber — 2013-03-03T14:52:36

Cinolt <cinolt.yk< at >gmail.com> writes:


I don't know exactly what you're looking at, but Scheme 48, in all
versions I've had running, says something like this:

Welcome to Scheme 48 1.9 (made by sperber on 2013-02-14)
See http://s48.org/ for more information.
Please report bugs to scheme-48-bugs< at >s48.org.
Get more information at http://www.s48.org/.
Type ,? (comma question-mark) for help.
(2 4 6)

Map doesn't work with n lists

Cinolt — 2013-03-02T14:24:29

R5RS specifies that map work with an arbitrary amount of lists, "(map proc
list1 list2 ...)" however I get an error when I try to evaluate:

(map + '(1 2 3) '(1 2 3))

assertion-violation: wrong number of arguments [tail-call]
                     (#{procedure 8517 map} '(#{procedure 110 +} (1 2 3) (1 2 3)))

testing 3

Jonathan Rees — 2013-02-25T21:20:22

Testing mail server configuration. No action is required on your part.

Best
Jonathan

Re: Scheme 48 1.9 available

Roderic Morris — 2013-01-27T15:28:41

This is awesome Mike, thanks for the release! 


On Friday, January 25, 2013 at 2:14 AM, Michael Sperber wrote:


I'll be looking into making a release in the next few weeks. Not having an officially packaged s48 1.9 was our biggest blocker for distribution. 

-Roderic

Re: Scheme 48 1.9 available

Michael Sperber — 2013-01-25T07:14:36

gavino_learning <visphatesjava< at >gmail.com> writes:


I believe the scsh people have already been working on the basis of of
the development code that has been released as 1.9, but don't know the
exact status.


I already ported some of it, mainly what's needed for ftpd to run.  Help
with completing the port would be appreciated:

http://www.s48.org/cgi-bin/hgwebdir.cgi/sunet/


It just means steering Scheme 48 more towards practical applications.
The next big concrete step is R6RS support.

Re: Scheme 48 1.9 available

gavino_learning — 2013-01-23T20:48:14

awesome!
will scsh follow?
sunet?

You mentioned a new direction? What will it be?

Re: Scheme 48 1.9 available

Marcus Crestani — 2013-01-23T12:47:22

JR> The name of the command ought to be:
JR> ,show-known-structures (or more precisely
JR> ,show-structures-in-config-package , which I assume is what it does).

Thanks for catching this, we are going to fix this.

Re: Scheme 48 1.9 available

Michael Sperber — 2013-01-22T19:19:40

Jonathan Rees <jar< at >mumble.net> writes:


It's an Eclipse plugin for Scheme 48:

http://www.s48.org/sdt/

Re: Scheme 48 1.9 available

Jonathan Rees — 2013-01-22T18:14:21

On Jan 22, 2013, at 12:28 PM, Michael Sperber wrote:


Probably too late to change now, but ,show-known-packages lists structures, not packages. Packages in scheme 48 are almost always anonymous - the package/structure distinction is an important part of the design. The name of the command ought to be: ,show-known-structures (or more precisely ,show-structures-in-config-package , which I assume is what it does).

(Yes, there are many commands with names of the form ,xxx-package that take structure names, but they only take structure names as an expedient, because there is usually no way to name a package.  The meaning is usually: operate on the package that underlies the designated structure.)

Sorry I missed this on my earlier review; I neglected to read the new features list. If it's too late to change the command name, perhaps its documentation can at least be corrected in some future release.

Just curious, what is SDT and why is it playing with the command processor? I found no google hits for "SDT (Ma

Scheme 48 1.9 available

Michael Sperber — 2013-01-22T17:28:26

Version 1.9 of the Scheme 48 system is now available from the Scheme 48
home page:

http://www.s48.org/

Scheme 48 is a based on byte-code interpreter and comes with a module
system, an extensive set of libraries, an interactive command-line-based
development environment and a manual in various formats. Scheme 48 runs
on most Unix/Linux systems, as well as Windows NT, 2000, XP, and Vista,
and is fully R5RS-conformant.

The 1.9 release has been a long time in the making, and is a substantial
feature release, with help from many contributors.  See the attached
release notes for details.

This release marks a change in direction (actually two
changes) for Scheme 48:

As most regular users of the system know, the system was originally
developed by Richard Kelsey and Jonathan Rees.  I have handled the
releases of Scheme 48 since version 1.1, with the help of Martin
Gasbichler, Marcus Crestani and many other volunteers.  We have tried to
make the system more oriented towards practical uses, and thus moved
away fr

Re: Scheme 48 1.9 release candidate #1

Jonathan Rees — 2012-12-31T17:33:23

On Dec 30, 2012, at 11:40 AM, Michael Sperber wrote:


Compiled and ran tests on a 2008 SUSE Linux, all ok.
Compiled (with ./configure CFLAGS="-O0") and ran tests on Lion, all ok.
Without -O0 on Lion compilation and execution were excruciatingly slow, as you reported.
Haven't tested it with my own programs yet.
Jonathan

Re: Scheme 48 1.9 release candidate #1

Marcus Crestani — 2012-12-30T17:41:20

MS> I'd appreciate if people could give this a whirl.  I'm especially
MS> interested in reports Mac OS X Mountain Lion and Windows 8.

Mountain Lion's LLVM/Clang still has the bug you've mentioned.  I work
around it by turning off the compiler's optimization ("-O0"), e.g.

  ./configure CFLAGS="-O0"

Other than that, the release candidate works fine.