Traces: fs -> tid

[Dmitry Timoshkov]

"Francois Gouget" <fgouget at free.fr> wrote:

>    I noticed that fs was replaced by tid in relay (and snoop & co too
> now). I propose a slightly different version based on the following
> premises:
> 
>  * when suspecting a threading problem it could be nice to tag each
> trace with the id of the thread that emits it
> 
>  * when there's no thread issue, then fs and tid are unnecessary and
> only clutter the traces by making lines longer and harder to read
> 
>  * I find that lines are more readable if the thread id comes first as
> it's always the same length and doesn't mess up the alignment of the
> other fields
> 
>    So this patch adds a debug channel called 'tid' which activates
> printing the tid as the first field of all traces. Actually, it might
> make sense to merge 'tid' with the 'thread' debug channel.

The point was to be able to easy track down problems in multiprocess/multithreaded
environment with just +relay trace. You never know, what surprise you will see
analysing the traces from the news group. Besides that, at least I always start
searching for the problem with +relay trace: it would be too late to add +tid
(or whatever) to notice, that the actual problem is related to process/thread
interaction.

Regarding too long lines: it is not the actual problem (doesn't it?). I would
complain about too large files with the trace logs :-)