Re: Automating Qemu and GDB together

[R. Diez]

> [...]
> Sure - for our test script it's not a problem because it gracefully
> handles a failed connection which can occur for a number of other
> mundane reasons.

Could you point me to such a script?

I guess this is not script "tests/guest-debug/run-test.py", because I did not 
see such a logic there.


> TCP will attempt to connect to a port for some seconds before timing
> out if nothing is listening.

That is not true: if there is no listening TCP socket, you get a "connection 
refused" straight away.

Sometimes, a firewall will just drop the packets instead. That is often the case with servers on the Internet that are worried about hackers doing 
port scans. But in a local host, or in a LAN, that is not normally the case.


> Why not just script GDB to attempt to re-connect if it failed the first
> time?

That is easier said than done. 8-) GDB may or may not have been compiled with Python, which is not normally the case when building cross-compilation 
toolchains. In any case, I do not know Python yet (I remained in Perl). And GDB's default simple scripting language does not handle errors very well.


> > Do you know what happens if QEMU is waiting for the first GDB
> > connection, and that socket connection does nothing but connect and
> > disconnect? Will QEMU then start the emulator?
>
> Yes.

That is unfortunate. I would have hoped it would have waited at least for some 
GDB protocol handshake.

Regards,
  rdiez