This is the mail archive of the
gdb-patches@sources.redhat.com
mailing list for the GDB project.
Re: threads and target-function-calls
Andrew Cagney wrote:
>
> > Michael Snyder wrote:
> >
> >>
> >> Andrew Cagney wrote:
> >
> >> >
> >
> >> > > Hey folks,
> >> > >
> >> > > Did you know that (at least on x86 linux), if you have a multi-thread
> >> > > program and you execute a target function call, all the threads get to
> >> > > run? Doesn't that seem like a bad thing? Wouldn't we really rather
> >> > > only run the thread that is executing the target function call?
> >
> >> >
> >> > Ha! That's just the start. Doing nested inferior function calls on
> >> > alternative threads scrables the dummy frame cache:
> >> > http://sources.redhat.com/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gdb&pr=468
> >
> >>
> >> But... that's just sick. ;-(
> >> Wait -- you can't do that. It isn't meaningful to change threads
> >> and then continue/whatever. It assumes gdb has more control over
> >> scheduling than it actually has.
> >
> >
> > Oh, I think I misunderstood. You have in mind this:
> > (gdb) print foo()
> > [switching thread to xyz]
> > Breakpoint 2 in foo ()
> > (gdb) print bar()
> >
> > not this:
> > (gdb) print foo ()
> > breakpoint 2 in foo()
> > (gdb) thread xyz
> > (gdb) print bar()
> >
> > right?
>
> Either.
OK, well, the second should not be a concern, because
prepare_to_proceed is supposed to switch us back to the
event thread before we resume.