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Re: What for Break Key No Work?

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Andrew Haley wrote:
>>>   disk GET  ['] foo CATCH  disk RELEASE  throw
>> 
>> Good to know that you now see it as good practice, too.
> 
> I don't quite understand this remark.  What else would you do?  If FOO
> can throw while holding a lock then you have to do this.  The problem
> with asynchronous interrupts is that any word can throw, so every
> caller has to be aware of that.

That's why Gforth's pthread-based multitasker has a C-SECTION word, which 
takes an xt and a lock, and does essentially both those things.

: c-section ( xt addr -- )
    \G implement a critical section that will unlock the semaphore
    \G even in case there's an exception within.
    { sema } try sema lock execute 0 restore sema unlock endtry throw ;

You better do that anyways, because if you make a mistake, it will throw, 
too.  The problem with this approach and standard Forth is that if you ctrl-
C between catch and the successful unlock, you'll get thrown out.  That's 
why Gforth has try/restore/endtry, here the restore part is performed before 
unwinding the exception handler, so any ctrl-C between restore and entry 
will jump to the restore label again.  As the exception frame is on the 
return stack, I put the semaphore address on the locals stack to avoid 
conflicts.

> I wonder if we're really talking about different things.  I'm trying
> to think about how asynchronous interrupts might be made robust, so
> that a reliable system could safely use them.  But maybe it's just too
> much trouble: better not to allow them at all or reserve them for a
> programmer convenience facility and accept that the system (and your
> program) might be toast after being interrupted.

From my experience, it doesn't make sense to have ctrl-C interrupt a 
background threads.  Therefore, I simply block all asynchronous exceptions 
on all background threads - the one single foreground thread will receive 
them.  If your background thread gets stuck, you still can get to an 
interactive command line and kill those background tasks.

-- 
Bernd Paysan
"If you want it done right, you have to do it yourself"
http://bernd-paysan.de/

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What for Break Key No Work? Jason Damisch <jasondamisch@yahoo.com> - 2014-07-22 14:44 -0700
  Re: What for Break Key No Work? Roger Levy <roger.levy@gmail.com> - 2014-07-22 14:50 -0700
    Re: What for Break Key No Work? Jason Damisch <jasondamisch@yahoo.com> - 2014-07-22 15:04 -0700
      Re: What for Break Key No Work? Jason Damisch <jasondamisch@yahoo.com> - 2014-07-22 16:03 -0700
      Re: What for Break Key No Work? BruceMcF <agila61@netscape.net> - 2014-07-22 18:34 -0700
        Re: What for Break Key No Work? Jason Damisch <jasondamisch@yahoo.com> - 2014-07-22 19:32 -0700
          Re: What for Break Key No Work? Spam@ControlQ.com - 2014-07-22 22:43 -0400
            Re: What for Break Key No Work? Jason Damisch <jasondamisch@yahoo.com> - 2014-07-23 09:57 -0700
              Re: What for Break Key No Work? "Elizabeth D. Rather" <erather@forth.com> - 2014-07-23 07:12 -1000
                Re: What for Break Key No Work? Jason Damisch <jasondamisch@yahoo.com> - 2014-07-23 10:15 -0700
          Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-22 22:44 -0400
            Re: What for Break Key No Work? Jason Damisch <jasondamisch@yahoo.com> - 2014-07-23 09:58 -0700
              Re: What for Break Key No Work? "Elizabeth D. Rather" <erather@forth.com> - 2014-07-23 21:28 -1000
          Re: What for Break Key No Work? BruceMcF <agila61@netscape.net> - 2014-07-23 13:12 -0700
            Re: What for Break Key No Work? Jason Damisch <jasondamisch@yahoo.com> - 2014-07-23 14:52 -0700
              Re: What for Break Key No Work? Mark Wills <markwills1970@gmail.com> - 2014-07-24 01:54 -0700
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-24 07:54 -0400
                Re: What for Break Key No Work? Mark Wills <markwills1970@gmail.com> - 2014-07-24 06:49 -0700
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-24 10:39 -0400
                Re: What for Break Key No Work? bruce.mcfarling@gmail.com - 2014-07-24 08:52 -0700
                Re: What for Break Key No Work? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-07-24 13:07 -0500
                Re: What for Break Key No Work? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-25 10:50 +0000
                Re: What for Break Key No Work? Bernd Paysan <bernd.paysan@gmx.de> - 2014-07-25 14:38 +0200
                Re: What for Break Key No Work? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-25 17:07 +0000
                Re: What for Break Key No Work? Bernd Paysan <bernd.paysan@gmx.de> - 2014-07-26 00:36 +0200
                Re: What for Break Key No Work? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-27 13:47 +0000
                Re: What for Break Key No Work? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-07-25 09:21 -0500
                Re: What for Break Key No Work? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-25 17:10 +0000
                Re: What for Break Key No Work? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-07-26 04:38 -0500
                Re: What for Break Key No Work? Bernd Paysan <bernd.paysan@gmx.de> - 2014-07-26 15:56 +0200
                Re: What for Break Key No Work? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-27 13:27 +0000
                Re: What for Break Key No Work? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-07-27 09:36 -0500
                Re: What for Break Key No Work? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-28 11:38 +0000
                Re: What for Break Key No Work? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-07-28 10:42 -0500
                Re: What for Break Key No Work? "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-07-25 16:56 -0400
                Re: What for Break Key No Work? "Elizabeth D. Rather" <erather@forth.com> - 2014-07-26 09:33 +0000
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-24 19:40 -0400
                Re: What for Break Key No Work? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-07-25 00:00 +0000
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-24 22:17 -0400
                Re: What for Break Key No Work? bruce.mcfarling@gmail.com - 2014-07-25 06:54 -0700
                Re: What for Break Key No Work? "Elizabeth D. Rather" <erather@forth.com> - 2014-07-25 13:13 -0400
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-25 13:24 -0400
                Re: What for Break Key No Work? bruce.mcfarling@gmail.com - 2014-07-25 14:37 -0700
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-25 19:01 -0400
                Re: What for Break Key No Work? bruce.mcfarling@gmail.com - 2014-07-25 16:20 -0700
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-25 22:02 -0400
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-25 22:17 -0400
                Re: What for Break Key No Work? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-07-26 09:09 +0000
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-26 05:36 -0400
                Re: What for Break Key No Work? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-07-26 04:41 -0500
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-26 22:50 -0400
                Re: What for Break Key No Work? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-07-27 02:49 -0500
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-27 15:08 -0400
                Re: What for Break Key No Work? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-07-27 14:11 -0500
                Re: What for Break Key No Work? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-28 12:00 +0000
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-28 10:41 -0400
                Re: What for Break Key No Work? Bernd Paysan <bernd.paysan@gmx.de> - 2014-07-27 14:31 +0200
                Re: What for Break Key No Work? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-27 13:08 +0000
                Re: What for Break Key No Work? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-07-27 19:37 +0000
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-27 16:35 -0400
                Re: What for Break Key No Work? "Elizabeth D. Rather" <erather@forth.com> - 2014-07-27 22:24 +0000
                Re: What for Break Key No Work? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-07-28 13:14 +0000
                Re: What for Break Key No Work? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-07-28 03:41 -0500
                Re: What for Break Key No Work? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-28 12:09 +0000
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-28 10:48 -0400
                Re: What for Break Key No Work? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-28 15:29 +0000
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-28 14:30 -0400
                Re: What for Break Key No Work? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-29 08:12 +0000
                Re: What for Break Key No Work? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-07-28 13:10 +0000
                Re: What for Break Key No Work? bruce.mcfarling@gmail.com - 2014-07-27 11:33 -0700
                Re: What for Break Key No Work? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-28 11:55 +0000
                Re: What for Break Key No Work? "Alex McDonald" <blog@rivadpm.com> - 2014-07-28 14:03 +0100
                Re: What for Break Key No Work? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-27 13:02 +0000
                Re: What for Break Key No Work? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-07-26 08:57 +0000
                Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-26 05:05 -0400
                Re: What for Break Key No Work? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-07-26 09:20 +0000
            Re: What for Break Key No Work? "Alex McDonald" <blog@rivadpm.com> - 2014-07-23 23:48 +0100
            Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-24 04:53 -0400
              Re: What for Break Key No Work? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-24 10:59 +0000
                Re: What for Break Key No Work? mhx@iae.nl - 2014-07-24 04:23 -0700
          Re: What for Break Key No Work? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-07-24 19:28 +0000
            Re: What for Break Key No Work? "Elizabeth D. Rather" <erather@forth.com> - 2014-07-24 13:01 -1000
              Re: What for Break Key No Work? Roelf Toxopeus <rt4all@notthis.hetnet.nl> - 2014-07-25 10:13 +0200
      Re: What for Break Key No Work? "Elizabeth D. Rather" <erather@forth.com> - 2014-07-22 17:11 -1000
        Re: What for Break Key No Work? Jason Damisch <jasondamisch@yahoo.com> - 2014-07-23 09:59 -0700
  Re: What for Break Key No Work? David Schultz <abuse@127.0.0.1> - 2014-07-22 17:47 -0500
    Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-22 19:12 -0400
      Re: What for Break Key No Work? Jason Damisch <jasondamisch@yahoo.com> - 2014-07-22 16:21 -0700
        Re: What for Break Key No Work? rickman <gnuarm@gmail.com> - 2014-07-22 22:51 -0400
  Re: What for Break Key No Work? Matthias Trute <matthias.trute@gmail.com> - 2014-07-23 02:18 -0700
  Re: What for Break Key No Work? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-23 13:21 +0000
    Re: What for Break Key No Work? Jason Damisch <jasondamisch@yahoo.com> - 2014-07-23 10:02 -0700
    Re: What for Break Key No Work? Bernd Paysan <bernd.paysan@gmx.de> - 2014-07-24 04:10 +0200
  Re: What for Break Key No Work? mhx@iae.nl - 2014-07-23 13:45 -0700
  Re: What for Break Key No Work? BruceMcF <agila61@netscape.net> - 2014-07-23 16:37 -0700
  Re: What for Break Key No Work? "Clyde W. Phillips Jr." <cwpjr02@gmail.com> - 2014-07-30 16:13 -0700
  Re: What for Break Key No Work? francois.ganza@wanadoo.fr - 2014-07-30 22:55 -0700

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