Re: [Boost-users] [Boost.Graph] Profiling using the graph library

From: Doug Gregor (dgregor_at_[hidden])
Date: 2007-06-27 14:06:33

On Jun 27, 2007, at 1:51 PM, Ewgenij Sokolovski wrote:

> Hello, I use the boost graph library (Version 1.33.1 of Boost) for  
> my programming task. I wanted to profile my program with gprof. I  
> compilated the source code with the -pg option and linked it also  
> with that option. Now I'm examining the output file of gprof. Some  
> functions of boost graph library are not explicitly listed there  
> althogh I use them. These functions are:
>
> vertices()
> add_edge()
>
> What I see instead are some complicated functions. I have copied  
> them here from my gprof-Output. But where are vertices() and  
> add_edge()? Or are they meant by these complicated functions.

Profiling the BGL can be a scary exercise, as you've found... let's  
see if we can identify what these are:

> 1) std::pair<std::vector<boost::detail::sei_<unsigned long,  
> std::_List_iterator<boost::list_edge<unsigned long,  
> boost::property<boost::edge_bundle_t, float, boost::no_property> >  
> >, boost::property<boost::edge_bundle_t, float, boost::no_property>  
> >, std::allocator<boost::detail::sei_<unsigned long,  
> std::_List_iterator<boost::list_edge<unsigned long,  
> boost::property<boost::edge_bundle_t, float, boost::no_property> >  
> >, boost::property<boost::edge_bundle_t, float, boost::no_property>  
> > > >::iterator, bool>  
> boost::graph_detail::push<std::vector<boost::detail::sei_<unsigned  
> long, std::_List_iterator<boost::list_edge<unsigned long,  
> boost::property<boost::edge_bundle_t, float, boost::no_property> >  
> >, boost::property<boost::edge_bundle_t, float, boost::no_property>  
> >, std::allocator<boost::detail::sei_<unsigned long,  
> std::_List_iterator<boost::list_edge<unsigned long,  
> boost::property<boost::edge_bundle_t, float, boost::no_property> >  
> >, boost::property<boost::edge_bundle_t, float, boost::no_property>  
> > > >, boost::detail::sei_<unsigned long,  
> std::_List_iterator<boost::list_edge<unsigned long,  
> boost::property<boost::edge_bundle_t, float, boost::no_property> >  
> >, boost::property<boost::edge_bundle_t, float, boost::no_property>  
> > >(std::vector<boost::detail::sei_<unsigned long,  
> std::_List_iterator<boost::list_edge<unsigned long,  
> boost::property<boost::edge_bundle_t, float, boost::no_property> >  
> >, boost::property<boost::edge_bundle_t, float, boost::no_property>  
> >, std::allocator<boost::detail::sei_<unsigned long,  
> std::_List_iterator<boost::list_edge<unsigned long,  
> boost::property<boost::edge_bundle_t, float, boost::no_property> >  
> >, boost::property<boost::edge_bundle_t, float, boost::no_property>  
> > > >&, boost::detail::sei_<unsigned long,  
> std::_List_iterator<boost::list_edge<unsigned long,  
> boost::property<boost::edge_bundle_t, float, boost::no_property> >  
> >, boost::property<boost::edge_bundle_t, float, boost::no_property>  
> > const&)

The is one of the routines called by add_edge, named  
boost::graph_detail::push, which adds an element to a container.

> 2)  
> boost::detail::postfix_increment_result<boost::counting_iterator<unsig 
> ned long, boost::use_default, boost::use_default>, unsigned long,  
> unsigned long const&, boost::random_access_traversal_tag>::type  
> boost::operator++<boost::counting_iterator<unsigned long,  
> boost::use_default, boost::use_default>, unsigned long,  
> boost::random_access_traversal_tag, unsigned long const&, long> 
> (boost::iterator_facade<boost::counting_iterator<unsigned long,  
> boost::use_default, boost::use_default>, unsigned long,  
> boost::random_access_traversal_tag, unsigned long const&, long>&, int)

This is the increment operator for the vertex_iterator type. I expect  
that this is just noise, because this routine would normally just  
inline to a single call to the increment operator for unsigned longs.

   - Doug