[PATCH 1/2] gdb: introduce 'all_non_exited_process_targets' and 'switch_to_target_no_thread'

[Aktemur, Tankut Baris]

On Wednesday, May 13, 2020 12:29 AM, Christian Biesinger wrote:
> On Sun, May 3, 2020 at 10:37 AM Tankut Baris Aktemur via Gdb-patches
> <gdb-patches@sourceware.org> wrote:
> > @@ -83,3 +84,27 @@ process_stratum_target::has_execution (inferior *inf)
> >       through hoops.  */
> >    return inf->pid != 0;
> >  }
> > +
> > +/* See process-stratum-target.h.  */
> > +
> > +std::set<process_stratum_target *>
> > +all_non_exited_process_targets ()
> > +{
> > +  std::set<process_stratum_target *> targets;
> > +  for (inferior *inf : all_non_exited_inferiors ())
> > +    targets.insert (inf->process_target ());
> > +
> > +  return targets;
> 
> Instead of creating a new set, it seems like it would be a lot more
> efficient to just wrap the all_non_exited_inferiors() iterator and
> return it->process_target(). What do you think?

But the inferiors may share targets and this would not eliminate duplicates from
appearing, would it?  We would still need a mechanism to remember the previously
returned process targets and skip duplicates, I think.

A remark about the code above is that the order of elements when iterating the set
is not necessarily the same order we would get when iterating inferiors (i.e. the
order of insertion into the set).  I don't think this matters, though.  And as long
as a new target is not added to or removed from the debug session, the order obtained
from each call to all_non_exited_process_targets is consistent.

-Baris


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