Re: Exception propagation in C

From	jgk@panix.com (Joe keane)
Newsgroups	comp.lang.c, alt.os.development
Subject	Re: Exception propagation in C
Date	2012-01-03 21:25 +0000
Organization	Public Access Networks Corp.
Message-ID	<jdvrnt$bu0$1@reader1.panix.com> (permalink)
References	<99fbedd4-b37f-4ced-8759-4ba9656259dc@m7g2000vbc.googlegroups.com>

Cross-posted to 2 groups.

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In article <99fbedd4-b37f-4ced-8759-4ba9656259dc@m7g2000vbc.googlegroups.com>,
James Harris  <james.harris.1@googlemail.com> wrote:
>* Option 3. The function detecting an exception creates an exception
>object and sets an exception type in a thread-specific variable. Any
>calling functions, after each call (or group of calls) test that
>variable. If non-zero they jump to a local exception handler if there
>is one or jump to a return from the current function if not. This does
>involve a test and branch for each call but that is very fast (fusible
>and single cycle) and it avoids the need for exception handling
>context to be pushed and popped. It would also preserve the branch
>prediction of calls and returns.

I'm baffled as to why one would do that.

It's like using a global variable to pass information between a function
and a function it calls or the reverse.  Then you realize that it
doesn't work for multi-threaded and make it more complicated.

It still doesn't work when you get an exception, then the cleanup code
itself gets an exception.  [Of course, in some cases you just throw up
your hands and call abort(), but this often can be handled.]  Presumably
the callers want the -first- error code but you overwrote it.

If the stack works [or registers] why not use that?

Thread

Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2011-12-29 09:52 -0800
  Re: Exception propagation in C jacob navia <jacob@spamsink.net> - 2011-12-29 19:40 +0100
    Re: Exception propagation in C BGB <cr88192@hotmail.com> - 2011-12-29 14:03 -0600
  Re: Exception propagation in C BGB <cr88192@hotmail.com> - 2011-12-29 13:07 -0600
    Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2011-12-30 13:38 -0800
      Re: Exception propagation in C BGB <cr88192@hotmail.com> - 2011-12-30 20:24 -0600
        Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2012-01-03 02:19 -0800
          Re: Exception propagation in C BGB <cr88192@hotmail.com> - 2012-01-03 14:04 -0600
            Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2012-01-04 04:26 -0800
              Re: Exception propagation in C BGB <cr88192@hotmail.com> - 2012-01-06 14:05 -0600
                Re: Exception propagation in C jacob navia <jacob@spamsink.net> - 2012-01-06 23:54 +0100
                Re: Exception propagation in C "Ed Coran" <sysdev@new.net> - 2012-01-06 22:24 -0600
                Re: Exception propagation in C jacob navia <jacob@spamsink.net> - 2012-01-07 09:15 +0100
                Re: Exception propagation in C "Ed Coran" <sysdev@new.net> - 2012-01-08 23:45 -0600
                Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2012-01-08 12:52 -0800
                Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2012-01-08 14:20 -0800
                Re: Exception propagation in C jacob navia <jacob@spamsink.net> - 2012-01-09 00:19 +0100
                Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2012-01-08 21:12 -0800
                Re: Exception propagation in C Scott Wood <scott@buserror.net> - 2012-01-08 23:41 -0600
                Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2012-01-09 11:00 -0800
                Re: Exception propagation in C Scott Wood <scott@buserror.net> - 2012-01-10 00:42 -0600
                Re: Exception propagation in C jgk@panix.com (Joe keane) - 2012-01-11 07:40 +0000
                Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2012-01-11 12:59 -0800
                Re: Exception propagation in C "Ed Coran" <sysdev@new.net> - 2012-01-09 00:05 -0600
                Re: Exception propagation in C Ian Collins <ian-news@hotmail.com> - 2012-01-09 20:40 +1300
                Re: Exception propagation in C "Ed Coran" <sysdev@new.net> - 2012-01-09 04:53 -0600
                Re: Exception propagation in C 88888 Dihedral <dihedral88888@googlemail.com> - 2012-01-09 05:49 -0800
                Re: Exception propagation in C Scott Wood <scott@buserror.net> - 2012-01-08 17:29 -0600
                Re: Exception propagation in C jacob navia <jacob@spamsink.net> - 2012-01-09 00:37 +0100
                Re: Exception propagation in C Nomen Nescio <nobody@dizum.com> - 2012-01-09 11:36 +0100
                Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2012-01-09 11:08 -0800
          Re: Exception propagation in C Scott Wood <scott@buserror.net> - 2012-01-05 01:25 -0600
            Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2012-01-05 09:18 -0800
      Re: Exception propagation in C "s_dubrovich@yahoo.com" <s_dubrovich@yahoo.com> - 2011-12-30 21:20 -0800
        Re: Exception propagation in C "Rod Pemberton" <do_not_have@noavailemail.cmm> - 2011-12-31 06:19 -0500
        Re: Exception propagation in C Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-01-01 10:32 -0800
      Re: Exception propagation in C "Rod Pemberton" <do_not_have@noavailemail.cmm> - 2011-12-31 05:53 -0500
        Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2012-01-01 16:30 -0800
          Re: Exception propagation in C "Rod Pemberton" <do_not_have@noavailemail.cmm> - 2012-01-02 01:50 -0500
            Re: Exception propagation in C Scott Wood <scott@buserror.net> - 2012-01-02 02:03 -0600
              Re: Exception propagation in C "Rod Pemberton" <do_not_have@noavailemail.cmm> - 2012-01-02 15:59 -0500
                Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2012-01-03 04:12 -0800
                Re: Exception propagation in C Scott Wood <scott@buserror.net> - 2012-01-04 23:53 -0600
                Re: Exception propagation in C "Rod Pemberton" <do_not_have@noavailemail.cmm> - 2012-01-05 06:45 -0500
            Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2012-01-03 04:16 -0800
              Re: Exception propagation in C Keith Thompson <kst-u@mib.org> - 2012-01-03 11:50 -0800
      Re: Exception propagation in C Jens Gustedt <jens.gustedt@loria.fr> - 2011-12-31 13:40 +0100
        Re: Exception propagation in C BGB <cr88192@hotmail.com> - 2011-12-31 10:40 -0600
          Re: Exception propagation in C Jens Gustedt <jens.gustedt@loria.fr> - 2012-01-02 16:49 +0100
            Re: Exception propagation in C BGB <cr88192@hotmail.com> - 2012-01-02 13:02 -0600
              Re: Exception propagation in C Dr Nick <3-nospam@temporary-address.org.uk> - 2012-01-02 19:53 +0000
                Re: Exception propagation in C ImpalerCore <jadill33@gmail.com> - 2012-01-02 13:10 -0800
              Re: Exception propagation in C ImpalerCore <jadill33@gmail.com> - 2012-01-02 12:58 -0800
              Re: Exception propagation in C Jens Gustedt <jens.gustedt@loria.fr> - 2012-01-04 18:01 +0100
                Re: Exception propagation in C BGB <cr88192@hotmail.com> - 2012-01-06 14:38 -0600
                Re: Exception propagation in C "Rod Pemberton" <do_not_have@noavailemail.cmm> - 2012-01-06 21:40 -0500
  Re: Exception propagation in C Kaz Kylheku <kaz@kylheku.com> - 2011-12-29 21:02 +0000
    Re: Exception propagation in C jacob navia <jacob@spamsink.net> - 2011-12-30 10:38 +0100
    Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2011-12-30 14:38 -0800
  Re: Exception propagation in C "Rod Pemberton" <do_not_have@noavailemail.cmm> - 2011-12-29 18:37 -0500
  Re: Exception propagation in C "BartC" <bc@freeuk.com> - 2011-12-30 01:07 +0000
    Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2011-12-30 14:07 -0800
  Re: Exception propagation in C Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-12-30 17:53 -0500
    Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2012-01-03 03:56 -0800
  Re: Exception propagation in C jgk@panix.com (Joe keane) - 2012-01-02 09:49 +0000
    Re: Exception propagation in C Kleuske <kleuske@nowhere.net> - 2012-01-02 10:51 +0000
      Re: Exception propagation in C "Rod Pemberton" <do_not_have@noavailemail.cmm> - 2012-01-02 16:01 -0500
        Re: Exception propagation in C Kleuske <kleuske@nowhere.net> - 2012-01-03 11:14 +0000
      Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2012-01-03 03:59 -0800
        Re: Exception propagation in C Kleuske <kleuske@nowhere.net> - 2012-01-03 12:09 +0000
  Re: Exception propagation in C jgk@panix.com (Joe keane) - 2012-01-03 21:25 +0000
    Re: Exception propagation in C James Harris <james.harris.1@googlemail.com> - 2012-02-15 14:24 -0800
      Re: Exception propagation in C jgk@panix.com (Joe keane) - 2012-02-17 22:38 +0000

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