Re: threads and target-function-calls

[Michael Snyder <msnyder at redhat dot com>]

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?