Re: RFC: Two small remote protocol extensions

[Daniel Jacobowitz <drow at mvista dot com>]

On Wed, Sep 17, 2003 at 12:19:35PM -0400, Andrew Cagney wrote:
> 
> >Well, Ht is effectively a new letter - H is only defined for c and g.
> >We could explicitly state that, or look for a new letter.  I recommend
> >a multi-letter sequence, the extra bytes don't matter and we don't have
> >all that many letters.
> 
> Definitly a multi-letter sequence, but a new letter :-)
> 
> >To summarize, here's what we seem to have now natively:
> >  - Single step one thread, all others stopped.
> >  - Single step one thread, all others continued.
> >  - Signal one thread, all others stopped.
> >  - Signal one thread, all others continued.
> >  - Continue all threads.
> >
> >Here's what I think would be useful, though:
> >  - Per thread, specify stopped/singlestepped/signal/continue.
> >
> >Some of the combinations aren't useful; singlestepping multiple threads
> >for instance is not usually useful.  Well, I suppose it could be.
> 
> Who are we to argue :-)

Heh.

> >But specific signals to multiple threads at the same time (well, same
> >time is really kind of approximate without better native interfaces...)
> >- now that's useful in debugging race conditions.
> >
> >So, do you agree?  If so, here's just one possible way to implement it. 
> >I left it as Ht because I'm too lazy to go find another letter.  This
> >doesn't include step out of range because I'm not sure how that should
> >look (what was the problem with step out of range anyway?  That caused
> >it to get disabled? - and its current syntax is not in the manual).
> 
> It wasn't thread friendly, wasn't documented, it wasn't consistent with 
> the other continuation packets (it had two replies).

OK.  I think there's room to add it to something like this, so I'm not
gonna fret about it for now.

> >  Ht 'TID' 'DISPOSITION' [';' 'TID' 'DISPOSITION']... [';' 'DISPOSITION']
> >
> >'TID' should be a numeric thread ID, to affect one thread.
> >
> >'DISPOSITION' can be:
> >  's'
> >  'c'
> >  'C' 'SIGNAL'
> 
> I hope TID is decimal :-)

Heh, 'c', right.  Any objection to using decimal thread IDs, or would
you rather have 'TID' : 'DISPOSITION' ; ... ?

> >A final 'DISPOSITION' is applied to all threads not explicitly listed.
> >
> >Note that this Ht is a continue packet, not a select-thread packet.  So
> >Ht is not a good choice.
> 
> Yep.

How about, um, "vCont"?

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer