Re: [RFA] JVMTI Stack Tracing

[Andrew Haley <aph at redhat dot com>]

David Daney writes:
 > Andrew Haley wrote:
 > > Kyle Galloway writes:
 > >
 > > Aha!  That makes sense, thanks.  You didn't say that, so I was very
 > > confused.
 > >
 > > As far as I know, you're right.  There doesn't seem to be any way to
 > > use gcc's unwinder machinery to trace the stack of anything othe than
 > > the current thread.
 > >   
 > It shouldn't be too difficult though.  All the unwinder does is load up 
 > a framestate structure with values taken from the current thread and run 
 > its state machine. 

No, it's not as easy as that.  The unwinder data is not always valid:
we only emit unwinder information at places where we believe an
exception might be thrown.  A thread that has been pre-empted might
not have unwinder data for the current PC.

Andrew.