{
   libunwind causes spurious report
   Memcheck:Param
   msync(start)
   ...
   obj:/usr/lib64/libunwind.so.*
   ...
   fun:_ULx86_64_step
   ...
}

{
   boost unlocks before signalling cond var
   Helgrind:Misc
   ...
   fun:pthread_cond_signal@*
   fun:maybe_unlock_and_signal_one<boost::asio::detail::scoped_lock<boost::asio::detail::posix_mutex> >
   ...
}