On Sat, Jan 14, 2012 at 5:35 AM, Eric Niebler <eric@boostpro.com> wrote:

On 1/12/2012 6:29 AM, Ovanes Markarian wrote:
> Hello *,

I prefer Eric, but hey. ;-)

I thought someone else could answer the question as well... So it was not a special question for you ;) Because I know, that you spend considerable amount of time to maintain all your libs, so asking you directly to answer the post is a bit unpolite IMO ;) But many thanks for that answer.

Yep, I know the problem. I'm sorry to say that it's by design -- or
rather, that it's a known limitation of the way regex impls are
ref-counted and would be very hard to fix, if it can be fixed at all. At
least it's documented, but you'd have to read the docs very carefully.
See here:

http://www.boost.org/doc/libs/1_48_0/doc/html/xpressive/user_s_guide.html#boost_xpressive.user_s_guide.tips_n_tricks.create_grammars_on_a_single_thread

You're nesting regex objects; i.e., building a grammar. When you are
building a grammar, both the outer *and* inner regex objects are
modified. What is happening is that the sregex object (presumably) held
by parser_ is being mutated simultaneously from several threads. That's bad.

That link tells you that you need to build your grammars on a single
thread. I would create this regex once the same place where you build
the regex returned by parser_->delimiter(). Then use that regex instead
of constructing it at local scope over and over.

HTH,

Yes, this is what I did by using Nifty Counter, even static initialization was not enough in my context, since there was some logger thread in a huge fw which did "bad things" when main was left and cause the application crash at exit.

Many thanks for your great answer and verification of my assumption.

Ovanes