[ltt-dev] UST communication library

[david.goulet@polymtl.ca (David Goulet)]

Hi everyone,

We are in the process of moving out the UST control library out to lttng-tools
(thus soon deprecating ustctl and usttrace from the UST git tree). However,
there is a common part which is the communication library (libustcomm) where
every command to the tracer and responses are done through a Unix socket using
that specific libs (that contains key functions to pack/unpack data).

So the problem is where this lib should go? Here are the possibilities I've
discussed with Mathieu:

1) Keep libustcomm in UST and linking it in lttng-tools. Cons : direct
dependency! ... not good

2) Move libustcomm in lttng-tools and linking it with UST. Cons: direct
dependency! ... not good

3) Keep libustcomm in UST and dlopen() functions in lttng-tools. For that, we
will need an exported header that contains the symbols. So again... getting some
sort of dependency! (header in UST or git tree)... not good

4) Copy & Paste technique into both trees. REALLY NOT GOOD!

5) Making it a standalone library. So, new git tree, new package and getting it
dependent on lttng-tools and UST.

It seems that the fifth option should be the best idea...

Please any thoughts on that?

Cheers
David