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Re: Multi-packet gdb server request/response - problem?
- From: Philippe Waroquiers <philippe dot waroquiers at skynet dot be>
- To: Ivo Raisr <ivosh at ivosh dot net>
- Cc: gdb at sourceware dot org
- Date: Tue, 10 Dec 2013 22:46:13 +0100
- Subject: Re: Multi-packet gdb server request/response - problem?
- Authentication-results: sourceware.org; auth=none
- References: <CANXv6=u1BjBdJJDNtF=j=djNJVoNHo45gL4JZruzDYsaSqEU6Q at mail dot gmail dot com>
On Tue, 2013-12-10 at 13:22 +0100, Ivo Raisr wrote:
> My questions are:
> - Is multi-packet request/response supported by gdb?
> - In other words, is that gdb's behaviour intentional?
> - If yes, then why it cannot handle multi-packet response?
> - If no, then is that a bug?
Valgrind gdbserver implements (only) the all-stop mode.
To my knowledge, with that mode, the principle is that GDB should
send one command (such as "s" step), and then should wait for the reply.
So, having an "s" packet directly followed by an "m" packet
looks strange to me (at least, I never saw this).
Does this also happen with the gdbserver included in the GDB
(be sure GDB is in all stop mode :
When using the Valgrind gdbserver, does the problem also happens
if you first instruct GDB to keep the "ack mode" ?
i.e. first use
set remote noack-packet 0
target remote | vgdb
In that mode, GDB and Valgrind gdbserver will continue
to have each packet acknowledged using a +.
NB: when GDB is set in non stop mode and connected to the Valgrind
gdbserver, it reports that the remote stub does not support
non stop mode, but still continues (and that does not work properly
I am wondering why the choice between all-stop and non-stop is
then not automatically "auto choosed/probed" by GDB ?