Re: [PATCH] Enable multi process debugging for AIX

[Ulrich Weigand <Ulrich.Weigand@de.ibm.com>]

Aditya Kamath1 <Aditya.Kamath1@ibm.com> wrote:

>>Is there any other way of figuring out what the parent process of
>>the new child is?  Maybe you should just do that when you get the
>>child event.
>
>I fully did not get the above suggestion " Maybe you should just do that when you get the
>child event ". Kindly let me know what you are trying to tell me in this context. 

The last iteration of you patch simply has a list of "pending parent"
and "pending child" PIDs.  If you get a fork event for the child, and
there is *any* parent PID in the "pending" list, you automatically
assume that this is the parent of *this* child.

I'm concerned that this may not always be true.  For example, if you
are already debugging multiple processes, and *two* of those fork at
the same time, you'll be getting four ptrace events in GDB - two
events for the two parent processes, and two events for the two new
child processes.  If this happens, you'll need to verify which child
is actually associated with *which* parent.

As you note, on other platforms this relationship is reported as part
of the ptrace event directly, and this is apparently not the case on
AIX.  However, the OS of course still knows what the parent process
of each of the child processes is - so I guess there should be *some*
way to find this out from within GDB.  (E.g. in Linux you could get
at that information by reading some /proc files.)

Bye,
Ulrich